#@+leo-ver=5-thin
#@+node:ekr.20031218072017.3655: * @file leoFrame.py
'''
The base classes for all Leo Windows, their body, log and tree panes, key bindings and menus.

These classes should be overridden to create frames for a particular gui.
'''
big_text_buttons = True
    # True: show buttons instead of immediately loading big text.
#@+<< imports >>
#@+node:ekr.20120219194520.10464: ** << imports >> (leoFrame)
import leo.core.leoGlobals as g
import leo.core.leoColorizer as leoColorizer
    # NullColorizer is a subclass of ColorizerMixin
import leo.core.leoMenu as LeoMenu
import leo.core.leoNodes as leoNodes
import time
assert time
#@-<< imports >>
#@+<< About handling events >>
#@+node:ekr.20031218072017.2410: ** << About handling events >>
#@+at Leo must handle events or commands that change the text in the outline
# or body panes. We must ensure that headline and body text corresponds
# to the VNode corresponding to presently selected outline, and vice
# versa. For example, when the user selects a new headline in the
# outline pane, we must ensure that:
# 
# 1) All vnodes have up-to-date information and
# 
# 2) the body pane is loaded with the correct data.
# 
# Early versions of Leo attempted to satisfy these conditions when the user
# switched outline nodes. Such attempts never worked well; there were too many
# special cases. Later versions of Leo use a much more direct approach: every
# keystroke in the body pane updates the presently selected VNode immediately.
# 
# The LeoTree class contains all the event handlers for the tree pane, and the
# LeoBody class contains the event handlers for the body pane. The following
# convenience methods exists:
# 
# - body.updateBody & tree.updateBody:
#     Called by k.masterCommand after any keystroke not handled by k.masterCommand.
#     These are suprising complex.
# 
# - body.bodyChanged & tree.headChanged:
#     Called by commands throughout Leo's core that change the body or headline.
#     These are thin wrappers for updateBody and updateTree.
#@-<< About handling events >>
#@+others
#@+node:ekr.20140907201613.18660: ** API classes
# These classes are for documentation and unit testing.
# They are the base class for no class.
#@+node:ekr.20140904043623.18576: *3* class StatusLineAPI
class StatusLineAPI(object):
    '''The required API for c.frame.statusLine.'''

    def __init__(self, c, parentFrame): pass

    def clear(self): pass

    def disable(self, background=None): pass

    def enable(self, background="white"): pass

    def get(self): return ''

    def isEnabled(self): return False

    def put(self, s, bg=None, fg=None): pass

    def setFocus(self): pass

    def update(self): pass
#@+node:ekr.20140907201613.18663: *3* class TreeAPI
class TreeAPI(object):
    '''The required API for c.frame.tree.'''

    def __init__(self, frame): pass
    # Must be defined in subclasses.

    def drawIcon(self, p): pass

    def editLabel(self, v, selectAll=False, selection=None): pass

    def edit_widget(self, p): return None

    def redraw(self, p=None): pass
    redraw_now = redraw

    def scrollTo(self, p): pass
    # May be defined in subclasses.

    def initAfterLoad(self): pass

    def onHeadChanged(self, p, undoType='Typing', s=None, e=None): pass
    # Hints for optimization. The proper default is c.redraw()

    def redraw_after_contract(self, p): pass

    def redraw_after_expand(self, p): pass

    def redraw_after_head_changed(self): pass

    def redraw_after_icons_changed(self): pass

    def redraw_after_select(self, p=None): pass
    # Must be defined in the LeoTree class...
    # def OnIconDoubleClick (self,p):

    def OnIconCtrlClick(self, p): pass

    def endEditLabel(self): pass

    def getEditTextDict(self, v): return None

    def injectCallbacks(self): pass

    def onHeadlineKey(self, event): pass

    def select(self, p): pass

    def updateHead(self, event, w): pass
#@+node:ekr.20140903025053.18631: *3* class WrapperAPI
class WrapperAPI(object):
    '''A class specifying the wrapper api used throughout Leo's core.'''

    def __init__(self, c): pass

    def appendText(self, s): pass

    def clipboard_append(self, s): pass

    def clipboard_clear(self): pass

    def delete(self, i, j=None): pass

    def deleteTextSelection(self): pass

    def disable(self): pass

    def enable(self, enabled=True): pass

    def flashCharacter(self, i, bg='white', fg='red', flashes=3, delay=75): pass

    def get(self, i, j): return ''

    def getAllText(self): return ''

    def getInsertPoint(self): return 0

    def getSelectedText(self): return ''

    def getSelectionRange(self): return (0, 0)

    def getXScrollPosition(self): return 0

    def getYScrollPosition(self): return 0

    def hasSelection(self): return False

    def insert(self, i, s): pass

    def see(self, i): pass

    def seeInsertPoint(self): pass

    def selectAllText(self, insert=None): pass

    def setAllText(self, s): pass

    def setFocus(self): pass # Required: sets the focus to wrapper.widget.

    def setInsertPoint(self, pos, s=None): pass

    def setSelectionRange(self, i, j, insert=None): pass

    def setXScrollPosition(self, i): pass

    def setYScrollPosition(self, i): pass

    def tag_configure(self, colorName, **keys): pass

    def toPythonIndex(self, index): return 0

    def toPythonIndexRowCol(self, index): return (0, 0, 0)
#@+node:ekr.20140904043623.18552: ** class IconBarAPI
class IconBarAPI(object):
    '''The required API for c.frame.iconBar.'''

    def __init__(self, c, parentFrame): pass

    def add(self, *args, **keys): pass

    def addRow(self, height=None): pass

    def addRowIfNeeded(self): pass

    def addWidget(self, w): pass

    def clear(self): pass

    def createChaptersIcon(self): pass

    def deleteButton(self, w): pass

    def getNewFrame(self): pass

    def setCommandForButton(self, button, command, command_p, controller, gnx, script): pass
#@+node:ekr.20031218072017.3656: ** class LeoBody
class LeoBody(object):
    '''The base class for the body pane in Leo windows.'''
    #@+others
    #@+node:ekr.20031218072017.3657: *3* LeoBody.__init__
    def __init__(self, frame, parentFrame):
        '''Ctor for LeoBody class.'''
        c = frame.c
        frame.body = self
        self.c = c
        self.editorWidgets = {} # keys are pane names, values are text widgets
        self.frame = frame
        self.parentFrame = parentFrame # New in Leo 4.6.
        self.totalNumberOfEditors = 0
        # May be overridden in subclasses...
        self.widget = None # set in LeoQtBody.setWidget.
        self.wrapper = None # set in LeoQtBody.setWidget.
        self.numberOfEditors = 1
        self.pb = None # paned body widget.
        # Must be overridden in subclasses...
        self.colorizer = None
        # Init user settings.
        self.use_chapters = False
            # May be overridden in subclasses.
    #@+node:ekr.20150509034810.1: *3* LeoBody.cmd (decorator)
    def cmd(name):
        '''Command decorator for the c.frame.body class.'''
        # pylint: disable=no-self-argument
        return g.new_cmd_decorator(name, ['c', 'frame', 'body'])
    #@+node:ekr.20031218072017.3677: *3* LeoBody.Coloring
    def forceFullRecolor(self):
        pass

    def getColorizer(self):
        return self.colorizer

    def updateSyntaxColorer(self, p):
        return self.colorizer.updateSyntaxColorer(p.copy())

    def recolor(self, p, **kwargs):
        if 'incremental' in kwargs:
            print('c.recolor: incremental keyword is deprecated', g.callers(1))
        self.c.recolor()

    recolor_now = recolor
    #@+node:ekr.20140903103455.18574: *3* LeoBody.Defined in subclasses
    # Methods of this class call the following methods of subclasses (LeoQtBody)
    # Fail loudly if these methods are not defined.

    def oops(self):
        '''Say that a required method in a subclass is missing.'''
        g.trace("(LeoBody) %s should be overridden in a subclass", g.callers())

    def createEditorFrame(self, w):
        self.oops()

    def createTextWidget(self, parentFrame, p, name):
        self.oops()

    def packEditorLabelWidget(self, w):
        self.oops()

    def onFocusOut(self, obj):
        pass
    #@+node:ekr.20060528100747: *3* LeoBody.Editors
    # This code uses self.pb, a paned body widget, created by tkBody.finishCreate.
    #@+node:ekr.20070424053629: *4* LeoBody.entries
    #@+node:ekr.20060528100747.1: *5* LeoBody.addEditor (overridden)
    def addEditor(self, event=None):
        '''Add another editor to the body pane.'''
        c, p = self.c, self.c.p
        self.totalNumberOfEditors += 1
        self.numberOfEditors += 1
        if self.numberOfEditors == 2:
            # Inject the ivars into the first editor.
            # Bug fix: Leo 4.4.8 rc1: The name of the last editor need not be '1'
            d = self.editorWidgets
            keys = list(d.keys())
            if len(keys) == 1:
                w_old = d.get(keys[0])
                self.updateInjectedIvars(w_old, p)
                self.selectLabel(w_old) # Immediately create the label in the old editor.
            else:
                g.trace('can not happen: unexpected editorWidgets', d)
        name = '%d' % self.totalNumberOfEditors
        pane = self.pb.add(name)
        panes = self.pb.panes()
        minSize = float(1.0 / float(len(panes)))
        # Create the text wrapper.
        f = self.createEditorFrame(pane)
        wrapper = self.createTextWidget(f, name=name, p=p)
        wrapper.delete(0, 'end')
        wrapper.insert('end', p.b)
        wrapper.see(0)
        c.k.completeAllBindingsForWidget(wrapper)
        self.recolorWidget(p, wrapper)
        self.editorWidgets[name] = wrapper
        for pane in panes:
            self.pb.configurepane(pane, size=minSize)
        self.pb.updatelayout()
        c.frame.body.wrapper = wrapper
        # Finish...
        self.updateInjectedIvars(wrapper, p)
        self.selectLabel(wrapper)
        self.selectEditor(wrapper)
        self.updateEditors()
        c.bodyWantsFocus()
    #@+node:ekr.20060528132829: *5* LeoBody.assignPositionToEditor
    def assignPositionToEditor(self, p):
        '''Called *only* from tree.select to select the present body editor.'''
        c = self.c
        w = c.frame.body.widget
        self.updateInjectedIvars(w, p)
        self.selectLabel(w)
    #@+node:ekr.20060528170438: *5* LeoBody.cycleEditorFocus
    @cmd('editor-cycle-focus')
    @cmd('cycle-editor-focus') # There is no LeoQtBody method
    def cycleEditorFocus(self, event=None):
        '''Cycle keyboard focus between the body text editors.'''
        c = self.c
        d = self.editorWidgets
        w = c.frame.body.wrapper
        values = list(d.values())
        # g.printDict(d)
        if len(values) > 1:
            i = values.index(w) + 1
            if i == len(values): i = 0
            w2 = values[i]
            assert(w != w2)
            self.selectEditor(w2)
            c.frame.body.wrapper = w2
    #@+node:ekr.20060528113806: *5* LeoBody.deleteEditor (overridden)
    def deleteEditor(self, event=None):
        '''Delete the presently selected body text editor.'''
        c = self.c
        w = c.frame.body.wapper
        d = self.editorWidgets
        if len(list(d.keys())) == 1: return
        name = w.leo_name
        del d[name]
        self.pb.delete(name)
        panes = self.pb.panes()
        minSize = float(1.0 / float(len(panes)))
        for pane in panes:
            self.pb.configurepane(pane, size=minSize)
        # Select another editor.
        w = list(d.values())[0]
        # c.frame.body.wrapper = w # Don't do this now?
        self.numberOfEditors -= 1
        self.selectEditor(w)
    #@+node:ekr.20070425180705: *5* LeoBody.findEditorForChapter
    def findEditorForChapter(self, chapter, p):
        '''Return an editor to be assigned to chapter.'''
        c = self.c
        d = self.editorWidgets
        values = list(d.values())
        # First, try to match both the chapter and position.
        if p:
            for w in values:
                if (
                    hasattr(w, 'leo_chapter') and w.leo_chapter == chapter and
                    hasattr(w, 'leo_p') and w.leo_p and w.leo_p == p
                ):
                    return w
        # Next, try to match just the chapter.
        for w in values:
            if hasattr(w, 'leo_chapter') and w.leo_chapter == chapter:
                return w
        # As a last resort, return the present editor widget.
        return c.frame.body.wrapper
    #@+node:ekr.20060530210057: *5* LeoBody.select/unselectLabel
    def unselectLabel(self, w):
        self.createChapterIvar(w)
        self.packEditorLabelWidget(w)
        s = self.computeLabel(w)
        if hasattr(w, 'leo_label') and w.leo_label:
            w.leo_label.configure(text=s, bg='LightSteelBlue1')

    def selectLabel(self, w):
        if self.numberOfEditors > 1:
            self.createChapterIvar(w)
            self.packEditorLabelWidget(w)
            s = self.computeLabel(w)
            if hasattr(w, 'leo_label') and w.leo_label:
                w.leo_label.configure(text=s, bg='white')
        elif hasattr(w, 'leo_label') and w.leo_label:
            w.leo_label.pack_forget()
            w.leo_label = None
    #@+node:ekr.20061017083312: *5* LeoBody.selectEditor & helpers
    selectEditorLockout = False

    def selectEditor(self, w):
        '''Select the editor given by w and node w.leo_p.'''
        #  Called whenever wrapper must be selected.
        c = self.c
        if self.selectEditorLockout:
            return
        if w and w == self.c.frame.body.widget:
            if w.leo_p and w.leo_p != c.p:
                c.selectPosition(w.leo_p)
                c.bodyWantsFocus()
            return
        try:
            val = None
            self.selectEditorLockout = True
            val = self.selectEditorHelper(w)
        finally:
            self.selectEditorLockout = False
        return val # Don't put a return in a finally clause.
    #@+node:ekr.20070423102603: *6* LeoBody.selectEditorHelper
    def selectEditorHelper(self, wrapper):
        '''Select the editor whose widget is given.'''
        c = self.c
        if not (hasattr(wrapper, 'leo_p') and wrapper.leo_p):
            g.trace('no wrapper.leo_p')
            return
        self.deactivateActiveEditor(wrapper)
        # The actual switch.
        c.frame.body.wrapper = wrapper
        wrapper.leo_active = True
        self.switchToChapter(wrapper)
        self.selectLabel(wrapper)
        if not self.ensurePositionExists(wrapper):
            g.trace('***** no position editor!')
            return
        p = wrapper.leo_p
        c.redraw(p)
        c.recolor()
        c.bodyWantsFocus()
    #@+node:ekr.20060528131618: *5* LeoBody.updateEditors
    # Called from addEditor and assignPositionToEditor

    def updateEditors(self):
        c = self.c; p = c.p
        d = self.editorWidgets
        if len(list(d.keys())) < 2: return # There is only the main widget.
        for key in d:
            wrapper = d.get(key)
            v = wrapper.leo_v
            if v and v == p.v and wrapper != c.frame.body.wrapper:
                wrapper.delete(0, 'end')
                wrapper.insert('end', p.b)
                self.recolorWidget(p, wrapper)
        c.bodyWantsFocus()
    #@+node:ekr.20070424053629.1: *4* LeoBody.utils
    #@+node:ekr.20070422093128: *5* LeoBody.computeLabel
    def computeLabel(self, w):
        s = w.leo_label_s
        if hasattr(w, 'leo_chapter') and w.leo_chapter:
            s = '%s: %s' % (w.leo_chapter.name, s)
        return s
    #@+node:ekr.20070422094710: *5* LeoBody.createChapterIvar
    def createChapterIvar(self, w):
        c = self.c
        cc = c.chapterController
        if not hasattr(w, 'leo_chapter') or not w.leo_chapter:
            if cc and self.use_chapters:
                w.leo_chapter = cc.getSelectedChapter()
            else:
                w.leo_chapter = None
    #@+node:ekr.20070424084651: *5* LeoBody.ensurePositionExists
    def ensurePositionExists(self, w):
        '''Return True if w.leo_p exists or can be reconstituted.'''
        c = self.c
        if c.positionExists(w.leo_p):
            return True
        else:
            g.trace('***** does not exist', w.leo_name)
            for p2 in c.all_unique_positions():
                if p2.v and p2.v == w.leo_v:
                    w.leo_p = p2.copy()
                    return True
            # This *can* happen when selecting a deleted node.
            w.leo_p = c.p
            return False
    #@+node:ekr.20070424080640: *5* LeoBody.deactivateActiveEditor
    # Not used in Qt.

    def deactivateActiveEditor(self, w):
        '''Inactivate the previously active editor.'''
        d = self.editorWidgets
        # Don't capture ivars here! assignPositionToEditor keeps them up-to-date. (??)
        for key in d:
            w2 = d.get(key)
            if w2 != w and w2.leo_active:
                w2.leo_active = False
                self.unselectLabel(w2)
                return
    #@+node:ekr.20060530204135: *5* LeoBody.recolorWidget (QScintilla only)
    def recolorWidget(self, p, w):
        # Support QScintillaColorizer.colorize.
        c = self.c
        colorizer = c.frame.body.colorizer
        if p and colorizer and hasattr(colorizer, 'colorize'):
            old_wrapper = c.frame.body.wrapper
            c.frame.body.wrapper = w
            try:
                c.frame.body.colorizer.colorize(p)
            finally:
                c.frame.body.wrapper = old_wrapper
    #@+node:ekr.20070424084012: *5* LeoBody.switchToChapter
    def switchToChapter(self, w):
        '''select w.leo_chapter.'''
        c = self.c; cc = c.chapterController
        if hasattr(w, 'leo_chapter') and w.leo_chapter:
            chapter = w.leo_chapter
            name = chapter and chapter.name
            oldChapter = cc.getSelectedChapter()
            if chapter != oldChapter:
                cc.selectChapterByName(name)
                c.bodyWantsFocus()
    #@+node:ekr.20070424092855: *5* LeoBody.updateInjectedIvars
    # Called from addEditor and assignPositionToEditor.

    def updateInjectedIvars(self, w, p):
        '''Inject updated ivars in w, a gui widget.'''
        if not w:
            return
        c = self.c
        cc = c.chapterController
        # Was in ctor.
        use_chapters = c.config.getBool('use_chapters')
        if cc and use_chapters:
            w.leo_chapter = cc.getSelectedChapter()
        else:
            w.leo_chapter = None
        w.leo_p = p.copy()
        w.leo_v = w.leo_p.v
        w.leo_label_s = p.h
    #@+node:ekr.20031218072017.4018: *3* LeoBody.Text
    #@+node:ekr.20031218072017.4030: *4* LeoBody.getInsertLines
    def getInsertLines(self):
        '''
        Return before,after where:

        before is all the lines before the line containing the insert point.
        sel is the line containing the insert point.
        after is all the lines after the line containing the insert point.

        All lines end in a newline, except possibly the last line.
        '''
        body = self
        w = body.wrapper
        s = w.getAllText()
        insert = w.getInsertPoint()
        i, j = g.getLine(s, insert)
        before = s[0: i]
        ins = s[i: j]
        after = s[j:]
        before = g.toUnicode(before)
        ins = g.toUnicode(ins)
        after = g.toUnicode(after)
        return before, ins, after
    #@+node:ekr.20031218072017.4031: *4* LeoBody.getSelectionAreas
    def getSelectionAreas(self):
        '''
        Return before,sel,after where:

        before is the text before the selected text
        (or the text before the insert point if no selection)
        sel is the selected text (or "" if no selection)
        after is the text after the selected text
        (or the text after the insert point if no selection)
        '''
        body = self
        w = body.wrapper
        s = w.getAllText()
        i, j = w.getSelectionRange()
        if i == j: j = i + 1
        before = s[0: i]
        sel = s[i: j]
        after = s[j:]
        before = g.toUnicode(before)
        sel = g.toUnicode(sel)
        after = g.toUnicode(after)
        return before, sel, after
    #@+node:ekr.20031218072017.2377: *4* LeoBody.getSelectionLines
    def getSelectionLines(self):
        '''
        Return before,sel,after where:

        before is the all lines before the selected text
        (or the text before the insert point if no selection)
        sel is the selected text (or "" if no selection)
        after is all lines after the selected text
        (or the text after the insert point if no selection)
        '''
        if g.app.batchMode:
            return '', '', ''
        # At present, called only by c.getBodyLines.
        body = self
        w = body.wrapper
        s = w.getAllText()
        i, j = w.getSelectionRange()
        if i == j:
            i, j = g.getLine(s, i)
        else:
            i, junk = g.getLine(s, i)
            junk, j = g.getLine(s, j)
        before = g.toUnicode(s[0: i])
        sel = g.toUnicode(s[i: j])
        after = g.toUnicode(s[j: len(s)])
        return before, sel, after # 3 strings.
    #@+node:ekr.20031218072017.1329: *4* LeoBody.onBodyChanged
    # This is the only key handler for the body pane.

    def onBodyChanged(self, undoType, oldSel=None, oldText=None, oldYview=None):
        '''Update Leo after the body has been changed.'''
        c = self.c
        body, w = self, self.wrapper
        p = c.p
        insert = w.getInsertPoint()
        ch = '' if insert == 0 else w.get(insert - 1)
        ch = g.toUnicode(ch)
        newText = w.getAllText() # Note: getAllText converts to unicode.
        newSel = w.getSelectionRange()
        if not oldText:
            oldText = p.b; changed = True
        else:
            changed = oldText != newText
        if not changed: return
        c.undoer.setUndoTypingParams(p, undoType,
            oldText=oldText, newText=newText, oldSel=oldSel, newSel=newSel, oldYview=oldYview)
        p.v.setBodyString(newText)
        p.v.insertSpot = w.getInsertPoint()
        #@+<< recolor the body >>
        #@+node:ekr.20051026083733.6: *5* << recolor the body >>
        c.frame.scanForTabWidth(p)
        body.recolor(p)
        if g.app.unitTesting:
            g.app.unitTestDict['colorized'] = True
        #@-<< recolor the body >>
        if not c.changed: c.setChanged(True)
        self.updateEditors()
        p.v.contentModified()
        #@+<< update icons if necessary >>
        #@+node:ekr.20051026083733.7: *5* << update icons if necessary >>
        redraw_flag = False
        # Update dirty bits.
        # p.setDirty() sets all cloned and @file dirty bits.
        if not p.isDirty() and p.setDirty():
            redraw_flag = True
        # Update icons. p.v.iconVal may not exist during unit tests.
        val = p.computeIcon()
        if not hasattr(p.v, "iconVal") or val != p.v.iconVal:
            p.v.iconVal = val
            redraw_flag = True
        if redraw_flag:
            c.redraw_after_icons_changed()
        #@-<< update icons if necessary >>
    #@+node:ekr.20031218072017.4037: *4* LeoBody.setSelectionAreas
    def setSelectionAreas(self, before, sel, after):
        '''
        Replace the body text by before + sel + after and
        set the selection so that the sel text is selected.
        '''
        body = self
        w = body.wrapper
        # 2012/02/05: save/restore Yscroll position.
        pos = w.getYScrollPosition()
        s = w.getAllText()
        before = before or ''
        sel = sel or ''
        after = after or ''
        w.delete(0, len(s))
        w.insert(0, before + sel + after)
        i = len(before)
        j = max(i, len(before) + len(sel) - 1)
        w.setSelectionRange(i, j, insert=j)
        w.setYScrollPosition(pos)
        return i, j
    #@-others
#@+node:ekr.20031218072017.3678: ** class LeoFrame
class LeoFrame(object):
    '''The base class for all Leo windows.'''
    instances = 0
    #@+others
    #@+node:ekr.20031218072017.3679: *3* LeoFrame.__init__ & reloadSettings
    def __init__(self, c, gui):
        self.c = c
        self.gui = gui
        self.iconBarClass = NullIconBarClass
        self.statusLineClass = NullStatusLineClass
        self.title = None # Must be created by subclasses.
        # Objects attached to this frame.
        self.body = None
        self.colorPanel = None
        self.comparePanel = None
        self.findPanel = None
        self.fontPanel = None
        self.iconBar = None
        self.isNullFrame = False
        self.keys = None
        self.log = None
        self.menu = None
        self.miniBufferWidget = None
        self.outerFrame = None
        self.prefsPanel = None
        self.statusLine = g.NullObject() # For unit tests.
        self.tree = None
        self.useMiniBufferWidget = False
        # Gui-independent data
        self.cursorStay = True # May be overridden in subclass.reloadSettings.
        self.componentsDict = {} # Keys are names, values are componentClass instances.
        self.es_newlines = 0 # newline count for this log stream
        self.openDirectory = ""
        self.saved = False # True if ever saved
        self.splitVerticalFlag = True
            # Set by initialRatios later.
        self.startupWindow = False # True if initially opened window
        self.stylesheet = None # The contents of <?xml-stylesheet...?> line.
        self.tab_width = 0 # The tab width in effect in this pane.
    #@+node:ekr.20051009045404: *4* frame.createFirstTreeNode
    def createFirstTreeNode(self):
        f = self; c = f.c
        v = leoNodes.VNode(context=c)
        p = leoNodes.Position(v)
        v.initHeadString("NewHeadline")
        # New in Leo 4.5: p.moveToRoot would be wrong: the node hasn't been linked yet.
        p._linkAsRoot(oldRoot=None)
        # c.setRootPosition() # New in 4.4.2.
    #@+node:ekr.20150509194519.1: *3* LeoFrame.cmd (decorator)
    def cmd(name):
        '''Command decorator for the LeoFrame class.'''
        # pylint: disable=no-self-argument
        return g.new_cmd_decorator(name, ['c', 'frame',])
    #@+node:ekr.20061109125528: *3* LeoFrame.May be defined in subclasses
    #@+node:ekr.20071027150501: *4* LeoFrame.event handlers
    def OnBodyClick(self, event=None):
        pass

    def OnBodyRClick(self, event=None):
        pass
    #@+node:ekr.20031218072017.3688: *4* LeoFrame.getTitle & setTitle
    def getTitle(self):
        return self.title

    def setTitle(self, title):
        self.title = title
    #@+node:ekr.20081005065934.3: *4* LeoFrame.initAfterLoad  & initCompleteHint
    def initAfterLoad(self):
        '''Provide offical hooks for late inits of components of Leo frames.'''
        frame = self
        frame.body.initAfterLoad()
        frame.log.initAfterLoad()
        frame.menu.initAfterLoad()
        # if frame.miniBufferWidget: frame.miniBufferWidget.initAfterLoad()
        frame.tree.initAfterLoad()

    def initCompleteHint(self):
        pass
    #@+node:ekr.20031218072017.3687: *4* LeoFrame.setTabWidth
    def setTabWidth(self, w):
        '''Set the tab width in effect for this frame.'''
        # Subclasses may override this to affect drawing.
        self.tab_width = w
    #@+node:ekr.20061109125528.1: *3* LeoFrame.Must be defined in base class
    #@+node:ekr.20031218072017.3689: *4* LeoFrame.initialRatios
    def initialRatios(self):
        c = self.c
        s = c.config.get("initial_split_orientation", "string")
        verticalFlag = s is None or (s != "h" and s != "horizontal")
        if verticalFlag:
            r = c.config.getRatio("initial_vertical_ratio")
            if r is None or r < 0.0 or r > 1.0: r = 0.5
            r2 = c.config.getRatio("initial_vertical_secondary_ratio")
            if r2 is None or r2 < 0.0 or r2 > 1.0: r2 = 0.8
        else:
            r = c.config.getRatio("initial_horizontal_ratio")
            if r is None or r < 0.0 or r > 1.0: r = 0.3
            r2 = c.config.getRatio("initial_horizontal_secondary_ratio")
            if r2 is None or r2 < 0.0 or r2 > 1.0: r2 = 0.8
        return verticalFlag, r, r2
    #@+node:ekr.20031218072017.3690: *4* LeoFrame.longFileName & shortFileName
    def longFileName(self):
        return self.c.mFileName

    def shortFileName(self):
        return g.shortFileName(self.c.mFileName)
    #@+node:ekr.20031218072017.3691: *4* LeoFrame.oops
    def oops(self):
        g.pr("LeoFrame oops:", g.callers(4), "should be overridden in subclass")
    #@+node:ekr.20031218072017.3692: *4* LeoFrame.promptForSave
    def promptForSave(self):
        '''
        Prompt the user to save changes.
        Return True if the user vetos the quit or save operation.
        '''
        c = self.c
        theType = "quitting?" if g.app.quitting else "closing?"
        # See if we are in quick edit/save mode.
        root = c.rootPosition()
        quick_save = not c.mFileName and not root.next() and root.isAtEditNode()
        if quick_save:
            name = g.shortFileName(root.atEditNodeName())
        else:
            name = c.mFileName if c.mFileName else self.title
        answer = g.app.gui.runAskYesNoCancelDialog(c,
            title="Confirm",
            message='Save changes to %s before %s' % (
                g.splitLongFileName(name), theType))
        if answer == "cancel":
            return True # Veto.
        if answer == "no":
            return False # Don't save and don't veto.
        if not c.mFileName:
            root = c.rootPosition()
            if not root.next() and root.isAtEditNode():
                # There is only a single @edit node in the outline.
                # A hack to allow "quick edit" of non-Leo files.
                # See https://bugs.launchpad.net/leo-editor/+bug/381527
                # Write the @edit node if needed.
                if root.isDirty():
                    c.atFileCommands.writeOneAtEditNode(root,
                        toString=False, force=True)
                return False # Don't save and don't veto.
            else:
                c.mFileName = g.app.gui.runSaveFileDialog(c,
                    initialfile='',
                    title="Save",
                    filetypes=[("Leo files", "*.leo")],
                    defaultextension=".leo")
                c.bringToFront()
        if c.mFileName:
            if g.app.gui.guiName() == 'curses':
                g.pr('Saving: %s' % c.mFileName)
            ok = c.fileCommands.save(c.mFileName)
            return not ok # New in 4.2: Veto if the save did not succeed.
        else:
            return True # Veto.
    #@+node:ekr.20031218072017.1375: *4* LeoFrame.frame.scanForTabWidth
    def scanForTabWidth(self, p):
        '''Return the tab width in effect at p.'''
        c = self.c
        tab_width = c.getTabWidth(p)
        c.frame.setTabWidth(tab_width)
    #@+node:ekr.20061119120006: *4* LeoFrame.Icon area convenience methods
    def addIconButton(self, *args, **keys):
        if self.iconBar: return self.iconBar.add(*args, **keys)
        else: return None

    def addIconRow(self):
        if self.iconBar: return self.iconBar.addRow()

    def addIconWidget(self, w):
        if self.iconBar: return self.iconBar.addWidget(w)

    def clearIconBar(self):
        if self.iconBar: self.iconBar.clear()

    def createIconBar(self):
        c = self.c
        if not self.iconBar:
            self.iconBar = self.iconBarClass(c, self.outerFrame)
        return self.iconBar

    def getIconBar(self):
        if not self.iconBar:
            self.iconBar = self.iconBarClass(self.c, self.outerFrame)
        return self.iconBar

    getIconBarObject = getIconBar

    def getNewIconFrame(self):
        if not self.iconBar:
            self.iconBar = self.iconBarClass(self.c, self.outerFrame)
        return self.iconBar.getNewFrame()

    def hideIconBar(self):
        if self.iconBar: self.iconBar.hide()

    def showIconBar(self):
        if self.iconBar: self.iconBar.show()
    #@+node:ekr.20041223105114.1: *4* LeoFrame.Status line convenience methods
    def createStatusLine(self):
        if not self.statusLine:
            self.statusLine = self.statusLineClass(self.c, self.outerFrame)
        return self.statusLine

    def clearStatusLine(self):
        if self.statusLine: self.statusLine.clear()

    def disableStatusLine(self, background=None):
        if self.statusLine: self.statusLine.disable(background)

    def enableStatusLine(self, background="white"):
        if self.statusLine: self.statusLine.enable(background)

    def getStatusLine(self):
        return self.statusLine

    getStatusObject = getStatusLine

    def putStatusLine(self, s, bg=None, fg=None):
        if self.statusLine: self.statusLine.put(s, bg, fg)

    def setFocusStatusLine(self):
        if self.statusLine: self.statusLine.setFocus()

    def statusLineIsEnabled(self):
        if self.statusLine: return self.statusLine.isEnabled()
        else: return False

    def updateStatusLine(self):
        if self.statusLine: self.statusLine.update()
    #@+node:ekr.20070130115927.4: *4* LeoFrame.Cut/Copy/Paste
    #@+node:ekr.20070130115927.5: *5* LeoFrame.copyText
    @cmd('copy-text')
    def copyText(self, event=None):
        '''Copy the selected text from the widget to the clipboard.'''
        # f = self
        w = event and event.widget
        # wname = c.widget_name(w)
        if not w or not g.isTextWrapper(w):
            return
        # Set the clipboard text.
        i, j = w.getSelectionRange()
        if i == j:
            ins = w.getInsertPoint()
            i, j = g.getLine(w.getAllText(), ins)
        # 2016/03/27: Fix a recent buglet.
        # Don't clear the clipboard if we hit ctrl-c by mistake.
        s = w.get(i,j)
        if s:
            g.app.gui.replaceClipboardWith(s)

    OnCopyFromMenu = copyText
    #@+node:ekr.20070130115927.6: *5* LeoFrame.cutText
    @cmd('cut-text')
    def cutText(self, event=None):
        '''Invoked from the mini-buffer and from shortcuts.'''
        f = self; c = f.c; w = event and event.widget
        if not w or not g.isTextWrapper(w):
            return
        name = c.widget_name(w)
        oldSel = w.getSelectionRange()
        oldText = w.getAllText()
        i, j = w.getSelectionRange()
        # Update the widget and set the clipboard text.
        s = w.get(i, j)
        if i != j:
            w.delete(i, j)
            w.see(i) # 2016/01/19: important
            g.app.gui.replaceClipboardWith(s)
        else:
            ins = w.getInsertPoint()
            i, j = g.getLine(oldText, ins)
            s = w.get(i,j)
            w.delete(i,j)
            w.see(i) # 2016/01/19: important
            g.app.gui.replaceClipboardWith(s)
        if name.startswith('body'):
            c.frame.body.onBodyChanged('Cut', oldSel=oldSel, oldText=oldText)
        elif name.startswith('head'):
            # The headline is not officially changed yet.
            # p.initHeadString(s)
            s = w.getAllText()
            # 2011/11/14: Not used at present.
            # width = f.tree.headWidth(p=None,s=s)
            # w.setWidth(width)
        else: pass

    OnCutFromMenu = cutText
    #@+node:ekr.20070130115927.7: *5* LeoFrame.pasteText
    @cmd('paste-text')
    def pasteText(self, event=None, middleButton=False):
        '''
        Paste the clipboard into a widget.
        If middleButton is True, support x-windows middle-mouse-button easter-egg.
        '''
        c = self.c
        w = event and event.widget
        wname = c.widget_name(w)
        if not w or not g.isTextWrapper(w):
            return
        if self.cursorStay and wname.startswith('body'):
            tCurPosition = w.getInsertPoint()
        i, j = oldSel = w.getSelectionRange()
            # Returns insert point if no selection.
        oldText = w.getAllText()
        if middleButton and c.k.previousSelection is not None:
            start, end = c.k.previousSelection
            s = w.getAllText()
            s = s[start: end]
            c.k.previousSelection = None
        else:
            s = g.app.gui.getTextFromClipboard()
        s = g.toUnicode(s)
        singleLine = wname.startswith('head') or wname.startswith('minibuffer')
        if singleLine:
            # Strip trailing newlines so the truncation doesn't cause confusion.
            while s and s[-1] in ('\n', '\r'):
                s = s[: -1]
        # Save the horizontal scroll position.
        if hasattr(w, 'getXScrollPosition'):
            x_pos = w.getXScrollPosition()
        # Update the widget.
        if i != j:
            w.delete(i, j)
        w.insert(i, s)
        w.see(i + len(s) + 2)
        if wname.startswith('body'):
            if self.cursorStay:
                if tCurPosition == j:
                    offset = len(s)-(j-i)
                else:
                    offset = 0
                newCurPosition = tCurPosition + offset
                w.setSelectionRange(i=newCurPosition, j=newCurPosition)
            c.frame.body.onBodyChanged('Paste', oldSel=oldSel, oldText=oldText)
        elif singleLine:
            s = w.getAllText()
            while s and s[-1] in ('\n', '\r'):
                s = s[: -1]
            # 2011/11/14: headline width methods do nothing at present.
            # if wname.startswith('head'):
                # The headline is not officially changed yet.
                # p.initHeadString(s)
                # width = f.tree.headWidth(p=None,s=s)
                # w.setWidth(width)
        else:
            pass
        # Never scroll horizontally.
        if hasattr(w, 'getXScrollPosition'):
            w.setXScrollPosition(x_pos)

    OnPasteFromMenu = pasteText
    #@+node:ekr.20061016071937: *5* LeoFrame.OnPaste (support middle-button paste)
    def OnPaste(self, event=None):
        return self.pasteText(event=event, middleButton=True)
    #@+node:ekr.20031218072017.3980: *4* LeoFrame.Edit Menu
    #@+node:ekr.20031218072017.3981: *5* LeoFrame.abortEditLabelCommand
    @cmd('abort-edit-headline')
    def abortEditLabelCommand(self, event=None):
        '''End editing of a headline and revert to its previous value.'''
        frame = self; c = frame.c; tree = frame.tree
        p = c.p
        if g.app.batchMode:
            c.notValidInBatchMode("Abort Edit Headline")
            return
        # Revert the headline text.
        # Calling c.setHeadString is required.
        # Otherwise c.redraw would undo the change!
        c.setHeadString(p, tree.revertHeadline)
        c.redraw(p)
    #@+node:ekr.20031218072017.3982: *5* LeoFrame.endEditLabelCommand
    @cmd('end-edit-headline')
    def endEditLabelCommand(self, event=None, p=None):
        '''End editing of a headline and move focus to the body pane.'''
        frame = self
        c = frame.c; k = c.k
        if g.app.batchMode:
            c.notValidInBatchMode("End Edit Headline")
        else:
            w = c.get_focus()
            w_name = g.app.gui.widget_name(w)
            if w_name.startswith('head'):
                c.endEditing()
                c.treeWantsFocus()
            else:
                # c.endEditing()
                c.bodyWantsFocus()
                k.setDefaultInputState()
                # Recolor the *body* text, **not** the headline.
                k.showStateAndMode(w=c.frame.body.wrapper)
    #@+node:ekr.20031218072017.3680: *3* LeoFrame.Must be defined in subclasses
    def bringToFront(self): self.oops()
    def cascade(self, event=None): self.oops()
    def contractBodyPane(self, event=None): self.oops()
    def contractLogPane(self, event=None): self.oops()
    def contractOutlinePane(self, event=None): self.oops()
    def contractPane(self, event=None): self.oops()
    def deiconify(self): self.oops()
    def equalSizedPanes(self, event=None): self.oops()
    def expandBodyPane(self, event=None): self.oops()
    def expandLogPane(self, event=None): self.oops()
    def expandOutlinePane(self, event=None): self.oops()
    def expandPane(self, event=None): self.oops()
    def fullyExpandBodyPane(self, event=None): self.oops()
    def fullyExpandLogPane(self, event=None): self.oops()
    def fullyExpandOutlinePane(self, event=None): self.oops()
    def fullyExpandPane(self, event=None): self.oops()
    def get_window_info(self): self.oops()
    def hideBodyPane(self, event=None): self.oops()
    def hideLogPane(self, event=None): self.oops()
    def hideLogWindow(self, event=None): self.oops()
    def hideOutlinePane(self, event=None): self.oops()
    def hidePane(self, event=None): self.oops()
    def leoHelp(self, event=None): self.oops()
    def lift(self): self.oops()
    def minimizeAll(self, event=None): self.oops()
    def resizePanesToRatio(self, ratio, secondary_ratio): self.oops()
    def resizeToScreen(self, event=None): self.oops()
    def setInitialWindowGeometry(self): self.oops()
    def setTopGeometry(self, w, h, x, y, adjustSize=True): self.oops()
    def toggleActivePane(self, event=None): self.oops()
    def toggleSplitDirection(self, event=None): self.oops()
    #@-others
#@+node:ekr.20031218072017.3694: ** class LeoLog
class LeoLog(object):
    '''The base class for the log pane in Leo windows.'''
    #@+others
    #@+node:ekr.20150509054436.1: *3* LeoLog.Birth
    #@+node:ekr.20031218072017.3695: *4* LeoLog.ctor
    def __init__(self, frame, parentFrame):
        '''Ctor for LeoLog class.'''
        self.frame = frame
        self.c = frame.c if frame else None
        self.enabled = True
        self.newlines = 0
        self.isNull = False
        # Official ivars...
        self.canvasCtrl = None # Set below. Same as self.canvasDict.get(self.tabName)
        self.logCtrl = None # Set below. Same as self.textDict.get(self.tabName)
            # Important: depeding on the log *tab*,
            # logCtrl may be either a wrapper or a widget.
        self.tabName = None # The name of the active tab.
        self.tabFrame = None # Same as self.frameDict.get(self.tabName)
        self.canvasDict = {} # Keys are page names.  Values are Tk.Canvas's.
        self.frameDict = {} # Keys are page names. Values are Tk.Frames.
        self.logNumber = 0 # To create unique name fields for text widgets.
        self.newTabCount = 0 # Number of new tabs created.
        self.textDict = {} # Keys are page names. Values are logCtrl's (text widgets).
    #@+node:ekr.20150509054428.1: *4* LeoLog.cmd (decorator)
    def cmd(name):
        '''Command decorator for the LeoLog class.'''
        # pylint: disable=no-self-argument
        return g.new_cmd_decorator(name, ['c', 'frame', 'log'])
    #@+node:ekr.20070302094848.1: *3* LeoLog.clearTab
    def clearTab(self, tabName, wrap='none'):
        self.selectTab(tabName, wrap=wrap)
        w = self.logCtrl
        if w: w.delete(0, 'end')
    #@+node:ekr.20070302094848.2: *3* LeoLog.createTab
    def createTab(self, tabName, createText=True, widget=None, wrap='none'):
        if createText:
            w = self.createTextWidget(self.tabFrame)
            self.canvasDict[tabName] = None
            self.textDict[tabName] = w
        else:
            self.canvasDict[tabName] = None
            self.textDict[tabName] = None
            self.frameDict[tabName] = tabName # tabFrame
    #@+node:ekr.20140903143741.18550: *3* LeoLog.LeoLog.createTextWidget
    def createTextWidget(self, parentFrame):
        return None
    #@+node:ekr.20070302094848.4: *3* LeoLog.cycleTabFocus
    @cmd('cycle-tab-focus')
    def cycleTabFocus(self, event=None):
        '''Cycle keyboard focus between the tabs in the log pane.'''
        d = self.frameDict # Keys are page names. Values are Tk.Frames.
        w = d.get(self.tabName)
        values = list(d.values())
        if self.numberOfVisibleTabs() > 1:
            i = values.index(w) + 1
            if i == len(values): i = 0
            tabName = list(d.keys())[i]
            self.selectTab(tabName)
            return i
    #@+node:ekr.20070302094848.5: *3* LeoLog.deleteTab
    def deleteTab(self, tabName, force=False):
        c = self.c
        if tabName == 'Log':
            pass
        elif tabName in ('Find', 'Spell') and not force:
            self.selectTab('Log')
        else:
            for d in (self.canvasDict, self.textDict, self.frameDict):
                if tabName in d:
                    del d[tabName]
            self.tabName = None
            self.selectTab('Log')
        c.invalidateFocus()
        c.bodyWantsFocus()
    #@+node:ekr.20140903143741.18549: *3* LeoLog.enable/disable
    def disable(self):
        self.enabled = False

    def enable(self, enabled=True):
        self.enabled = enabled
    #@+node:ekr.20070302094848.7: *3* LeoLog.getSelectedTab
    def getSelectedTab(self):
        return self.tabName
    #@+node:ekr.20070302094848.6: *3* LeoLog.hideTab
    def hideTab(self, tabName):
        self.selectTab('Log')
    #@+node:ekr.20070302094848.8: *3* LeoLog.lower/raiseTab
    def lowerTab(self, tabName):
        self.c.invalidateFocus()
        self.c.bodyWantsFocus()

    def raiseTab(self, tabName):
        self.c.invalidateFocus()
        self.c.bodyWantsFocus()
    #@+node:ekr.20111122080923.10184: *3* LeoLog.orderedTabNames
    def orderedTabNames(self, LeoLog=None):
        return list(self.frameDict.values())
    #@+node:ekr.20070302094848.9: *3* LeoLog.numberOfVisibleTabs
    def numberOfVisibleTabs(self):
        return len([val for val in list(self.frameDict.values()) if val is not None])
    #@+node:ekr.20070302101304: *3* LeoLog.put & putnl
    # All output to the log stream eventually comes here.

    def put(self, s, color=None, tabName='Log', from_redirect=False, nodeLink=None):
        print(s)

    def putnl(self, tabName='Log'):
        pass # print ('')
    #@+node:ekr.20070302094848.10: *3* LeoLog.renameTab
    def renameTab(self, oldName, newName):
        pass
    #@+node:ekr.20070302094848.11: *3* LeoLog.selectTab
    def selectTab(self, tabName, createText=True, widget=None, wrap='none'): # widget unused.
        '''Create the tab if necessary and make it active.'''
        c = self.c
        tabFrame = self.frameDict.get(tabName)
        if not tabFrame:
            self.createTab(tabName, createText=createText)
        # Update the status vars.
        self.tabName = tabName
        self.canvasCtrl = self.canvasDict.get(tabName)
        self.logCtrl = self.textDict.get(tabName)
        self.tabFrame = self.frameDict.get(tabName)
        if 0:
            # Absolutely do not do this here!
            # It is a cause of the 'sticky focus' problem.
            c.widgetWantsFocusNow(self.logCtrl)
        return tabFrame
    #@-others
#@+node:ekr.20031218072017.3704: ** class LeoTree
class LeoTree(object):
    '''The base class for the outline pane in Leo windows.'''
    #@+others
    #@+node:ekr.20031218072017.3705: *3* LeoTree.__init__
    def __init__(self, frame):
        '''Ctor for the LeoTree class.'''
        self.frame = frame
        self.c = frame.c
        self.edit_text_dict = {}
            # New in 3.12: keys vnodes, values are edit_widgets.
            # New in 4.2: keys are vnodes, values are pairs (p,edit widgets).
        # "public" ivars: correspond to setters & getters.
        self.drag_p = None
        self.generation = 0
            # Leo 5.6: low-level vnode methods increment
            # this count whenever the tree changes.
        self.redrawCount = 0 # For traces
        self.revertHeadline = None
        self.use_chapters = False # May be overridden in subclasses.
        # Define these here to keep pylint happy.
        self.canvas = None
    #@+node:ekr.20081005065934.8: *3* LeoTree.May be defined in subclasses
    # These are new in Leo 4.6.

    def initAfterLoad(self):
        '''Do late initialization. Called in g.openWithFileName after a successful load.'''

    # Hints for optimization. The proper default is c.redraw()

    def redraw_after_contract(self, p):
        self.c.redraw()

    def redraw_after_expand(self, p):
        self.c.redraw()

    def redraw_after_head_changed(self):
        self.c.redraw()

    def redraw_after_icons_changed(self):
        self.c.redraw()

    def redraw_after_select(self, p=None):
        self.c.redraw()
    #@+node:ekr.20040803072955.91: *4* LeoTree.onHeadChanged (Used by the leoBridge module)
    # Tricky code: do not change without careful thought and testing.
    # Important: This code *is* used by the leoBridge module.
    # See also, nativeTree.onHeadChanged.

    def onHeadChanged(self, p, undoType='Typing', s=None, e=None): # e used in qt_tree.py.
        '''
        Officially change a headline.
        Set the old undo text to the previous revert point.
        '''
        c = self.c; u = c.undoer
        w = self.edit_widget(p)
        if c.suppressHeadChanged:
            return
        if not w:
            return
        ch = '\n' # New in 4.4: we only report the final keystroke.
        if s is None: s = w.getAllText()
        #@+<< truncate s if it has multiple lines >>
        #@+node:ekr.20040803072955.94: *5* << truncate s if it has multiple lines >>
        # Remove trailing newlines before warning of truncation.
        while s and s[-1] == '\n':
            s = s[: -1]
        # Warn if there are multiple lines.
        i = s.find('\n')
        if i > -1:
            g.warning("truncating headline to one line")
            s = s[: i]
        limit = 1000
        if len(s) > limit:
            g.warning("truncating headline to", limit, "characters")
            s = s[: limit]
        s = g.toUnicode(s or '')
        #@-<< truncate s if it has multiple lines >>
        # Make the change official, but undo to the *old* revert point.
        oldRevert = self.revertHeadline
        changed = s != oldRevert
        self.revertHeadline = s
        p.initHeadString(s)
        if g.doHook("headkey1", c=c, p=p, ch=ch, changed=changed):
            return # The hook claims to have handled the event.
        if changed:
            undoData = u.beforeChangeNodeContents(p, oldHead=oldRevert)
            if not c.changed: c.setChanged(True)
            # New in Leo 4.4.5: we must recolor the body because
            # the headline may contain directives.
            c.frame.scanForTabWidth(p)
            c.frame.body.recolor(p)
            dirtyVnodeList = p.setDirty()
            u.afterChangeNodeContents(p, undoType, undoData,
                dirtyVnodeList=dirtyVnodeList, inHead=True)
        if changed:
            c.redraw_after_head_changed()
            # Fix bug 1280689: don't call the non-existent c.treeEditFocusHelper
        g.doHook("headkey2", c=c, p=p, ch=ch, changed=changed)
    #@+node:ekr.20061109165848: *3* LeoTree.Must be defined in base class
    #@+node:ekr.20040803072955.126: *4* LeoTree.endEditLabel
    def endEditLabel(self):
        '''End editing of a headline and update p.h.'''
        c = self.c; k = c.k; p = c.p
        # Important: this will redraw if necessary.
        self.onHeadChanged(p)
        if 0:
            # Can't call setDefaultUnboundKeyAction here: it might put us in ignore mode!
            k.setDefaultInputState()
            k.showStateAndMode()
        if 0:
            # This interferes with the find command and interferes with focus generally!
            c.bodyWantsFocus()
    #@+node:ekr.20031218072017.3716: *4* LeoTree.getEditTextDict
    def getEditTextDict(self, v):
        # New in 4.2: the default is an empty list.
        return self.edit_text_dict.get(v, [])
    #@+node:ekr.20040803072955.21: *4* LeoTree.injectCallbacks
    def injectCallbacks(self):
        c = self.c
        #@+<< define callbacks to be injected in the position class >>
        #@+node:ekr.20040803072955.22: *5* << define callbacks to be injected in the position class >>
        # **Important:: These VNode methods are entitled to know about gui-level code.
        #@+others
        #@+node:ekr.20040803072955.23: *6* OnHyperLinkControlClick
        def OnHyperLinkControlClick(self, event=None, c=c):
            '''Callback injected into position class.'''
            p = self
            if c and c.exists:
                try:
                    if not g.doHook("hypercclick1", c=c, p=p, event=event):
                        c.selectPosition(p)
                        c.redraw()
                        c.frame.body.wrapper.setInsertPoint(0)
                    g.doHook("hypercclick2", c=c, p=p, event=event)
                except Exception:
                    g.es_event_exception("hypercclick")
        #@+node:ekr.20040803072955.24: *6* OnHyperLinkEnter
        def OnHyperLinkEnter(self, event=None, c=c):
            '''Callback injected into position class.'''
            try:
                p = self
                g.doHook("hyperenter1", c=c, p=p, event=event)
                g.doHook("hyperenter2", c=c, p=p, event=event)
            except Exception:
                g.es_event_exception("hyperenter")
        #@+node:ekr.20040803072955.25: *6* OnHyperLinkLeave
        def OnHyperLinkLeave(self, event=None, c=c):
            '''Callback injected into position class.'''
            try:
                p = self
                g.doHook("hyperleave1", c=c, p=p, event=event)
                g.doHook("hyperleave2", c=c, p=p, event=event)
            except Exception:
                g.es_event_exception("hyperleave")
        #@-others
        #@-<< define callbacks to be injected in the position class >>
        for f in (OnHyperLinkControlClick, OnHyperLinkEnter, OnHyperLinkLeave):
            g.funcToMethod(f, leoNodes.position)
    #@+node:ekr.20040803072955.88: *4* LeoTree.onHeadlineKey
    def onHeadlineKey(self, event):
        '''Handle a key event in a headline.'''
        w = event.widget if event else None
        ch = event.char if event else ''
        # This test prevents flashing in the headline when the control key is held down.
        if ch:
            self.updateHead(event, w)
    #@+node:ekr.20120314064059.9739: *4* LeoTree.OnIconCtrlClick (@url)
    def OnIconCtrlClick(self, p):
        g.openUrl(p)
    #@+node:ekr.20031218072017.2312: *4* LeoTree.OnIconDoubleClick (do nothing)
    def OnIconDoubleClick(self, p):
        pass
    #@+node:ekr.20051026083544.2: *4* LeoTree.updateHead
    def updateHead(self, event, w):
        '''Update a headline from an event.

        The headline officially changes only when editing ends.'''
        k = self.c.k
        ch = event.char if event else ''
        i, j = w.getSelectionRange()
        ins = w.getInsertPoint()
        if i != j:
            ins = i
        if ch in ('\b', 'BackSpace'):
            if i != j:
                w.delete(i, j)
                # Bug fix: 2018/04/19.
                w.setSelectionRange(i, i, insert=i)
            elif i > 0:
                i -= 1
                w.delete(i)
                w.setSelectionRange(i, i, insert=i)
            else:
                w.setSelectionRange(0, 0, insert=0)
        elif ch and ch not in ('\n', '\r'):
            if i != j:
                w.delete(i, j)
            elif k.unboundKeyAction == 'overwrite':
                w.delete(i, i + 1)
            w.insert(ins, ch)
            w.setSelectionRange(ins + 1, ins + 1, insert=ins + 1)
        s = w.getAllText()
        if s.endswith('\n'):
            s = s[: -1]
        # 2011/11/14: Not used at present.
            # w.setWidth(self.headWidth(s=s))
        if ch in ('\n', '\r'):
            self.endEditLabel() # Now calls self.onHeadChanged.
    #@+node:ekr.20031218072017.3706: *3* LeoTree.Must be defined in subclasses
    # Drawing & scrolling.

    def drawIcon(self, p): self.oops()

    def redraw(self, p=None): self.oops()
    redraw_now = redraw

    def scrollTo(self, p): self.oops()

    # Headlines.

    def editLabel(self, p, selectAll=False, selection=None): self.oops()

    def edit_widget(self, p): self.oops()
    #@+node:ekr.20040803072955.128: *3* LeoTree.select & helpers
    tree_select_lockout = False

    def select(self, p):
        '''
        Select a node.
        Never redraws outline, but may change coloring of individual headlines.
        The scroll argument is used by the gui to suppress scrolling while dragging.
        '''
        if g.app.killed or self.tree_select_lockout: # Essential.
            return None
        try:
            c = self.c
            self.tree_select_lockout = True
            self.prev_v = c.p.v
            self.selectHelper(p)
        finally:
            self.tree_select_lockout = False
            if c.enableRedrawFlag:
                p = c.p
                # Don't redraw during unit testing: an important speedup.
                if c.expandAllAncestors(p) and not g.unitTesting:
                    # This can happen when doing goto-next-clone.
                    c.redraw_later()
                        # This *does* happen sometimes.
                else:
                    c.outerUpdate() # Bring the tree up to date.
                    if hasattr(self, 'setItemForCurrentPosition'):
                        # pylint: disable=no-member
                        self.setItemForCurrentPosition()
            else:
                c.requestLaterRedraw = True
    #@+node:ekr.20070423101911: *4* selectHelper (LeoTree) & helpers
    def selectHelper(self, p):
        '''
        A helper function for leoTree.select.
        Do **not** "optimize" this by returning if p==c.p!
        '''
        if not p:
            # This is not an error! We may be changing roots.
            # Do *not* test c.positionExists(p) here!
            return
        c = self.c
        if not c.frame.body.wrapper:
            return # Defensive.
        assert p.v.context == c
            # Selecting a foreign position will not be pretty.
        old_p = c.p
        call_event_handlers = p != old_p
        # Order is important...
        self.unselect_helper(old_p, p)
        self.select_new_node(old_p, p)
        self.change_current_position(old_p, p)
        self.scroll_cursor(p)
        self.set_status_line(p)
        if call_event_handlers:
            g.doHook("select2", c=c, new_p=p, old_p=old_p, new_v=p, old_v=old_p)
            g.doHook("select3", c=c, new_p=p, old_p=old_p, new_v=p, old_v=old_p)
    #@+node:ekr.20140831085423.18637: *5* LeoTree.is_qt_body (not used)
    if 0:

        def is_qt_body(self):
            '''Return True if the body widget is a QTextEdit.'''
            c = self.c
            import leo.plugins.qt_text as qt_text
            w = c.frame.body.wrapper.widget
            val = isinstance(w, qt_text.LeoQTextBrowser)
                # c.frame.body.wrapper.widget is a LeoQTextBrowser.
                # c.frame.body.wrapper is a QTextEditWrapper or QScintillaWrapper.
            return val
    #@+node:ekr.20140829053801.18453: *5* 1. LeoTree.unselect_helper & helper
    def unselect_helper(self, old_p, p):
        '''Unselect the old node, calling the unselect hooks.'''
        c = self.c
        call_event_handlers = p != old_p
        if call_event_handlers:
            unselect = not g.doHook("unselect1", c=c, new_p=p, old_p=old_p, new_v=p, old_v=old_p)
        else:
            unselect = True
        if unselect and old_p != p:
            # Actually unselect the old node.
            self.endEditLabel()
        if call_event_handlers:
            g.doHook("unselect2", c=c, new_p=p, old_p=old_p, new_v=p, old_v=old_p)
    #@+node:ekr.20140829053801.18455: *5* 2. LeoTree.select_new_node & helper
    def select_new_node(self, old_p, p):
        '''Select the new node, part 1.'''
        c = self.c
        call_event_handlers = p != old_p
        if call_event_handlers:
            select = not g.doHook("select1",
                c=c, new_p=p, old_p=old_p,
                new_v=p, old_v=old_p)
        else:
            select = True
        if select:
            self.revertHeadline = p.h
            # Not that expensive
            c.frame.setWrap(p)
            self.set_body_text_after_select(p, old_p)
            c.nodeHistory.update(p)
    #@+node:ekr.20090608081524.6109: *6* LeoTree.set_body_text_after_select
    def set_body_text_after_select(self, p, old_p, force=False):
        '''Set the text after selecting a node.'''
        c = self.c
        w = c.frame.body.wrapper
        s = p.v.b # Guaranteed to be unicode.
        # Part 1: get the old text.
        old_s = w.getAllText()
        if not force and p and p == old_p and s == old_s:
            return
        # Part 2: set the new text. This forces a recolor.
        c.setCurrentPosition(p)
            # Important: do this *before* setting text,
            # so that the colorizer will have the proper c.p.
        w.setAllText(s)
        # This is now done after c.p has been changed.
            # p.restoreCursorAndScroll()
    #@+node:ekr.20140829053801.18458: *5* 3. LeoTree.change_current_position
    def change_current_position(self, old_p, p):
        '''Select the new node, part 2.'''
        c = self.c
        # c.setCurrentPosition(p)
            # This is now done in set_body_text_after_select.
        c.frame.scanForTabWidth(p)
            #GS I believe this should also get into the select1 hook
        use_chapters = c.config.getBool('use_chapters')
        if use_chapters:
            cc = c.chapterController
            theChapter = cc and cc.getSelectedChapter()
            if theChapter:
                theChapter.p = p.copy()
        # Do not call treeFocusHelper here!
            # c.treeFocusHelper()
        c.undoer.onSelect(old_p, p)
    #@+node:ekr.20140829053801.18459: *5* 4. LeoTree.scroll_cursor
    def scroll_cursor(self, p):
        '''Scroll the cursor.'''
        p.restoreCursorAndScroll()
            # Was in setBodyTextAfterSelect
    #@+node:ekr.20140829053801.18460: *5* 5. LeoTree.set_status_line
    def set_status_line(self, p):
        '''Update the status line.'''
        c = self.c
        c.frame.body.assignPositionToEditor(p)
            # New in Leo 4.4.1.
        c.frame.updateStatusLine()
            # New in Leo 4.4.1.
        c.frame.clearStatusLine()
        verbose = getattr(c, 'status_line_unl_mode', '') == 'canonical'
        if p and p.v:
            c.frame.putStatusLine(p.get_UNL(with_proto=verbose, with_index=verbose))
    #@+node:ekr.20031218072017.3718: *3* oops
    def oops(self):
        g.pr("LeoTree oops:", g.callers(4), "should be overridden in subclass")
    #@-others
#@+node:ekr.20070317073627: ** class LeoTreeTab
class LeoTreeTab(object):
    '''A class representing a tabbed outline pane.'''
    #@+others
    #@+node:ekr.20070317073627.1: *3*  ctor (LeoTreeTab)
    def __init__(self, c, chapterController, parentFrame):
        self.c = c
        self.cc = chapterController
        self.nb = None # Created in createControl.
        self.parentFrame = parentFrame
    #@+node:ekr.20070317073755: *3* Must be defined in subclasses
    def createControl(self):
        self.oops()

    def createTab(self, tabName, select=True):
        self.oops()

    def destroyTab(self, tabName):
        self.oops()

    def selectTab(self, tabName):
        self.oops()

    def setTabLabel(self, tabName):
        self.oops()
    #@+node:ekr.20070317083104: *3* oops
    def oops(self):
        g.pr("LeoTreeTree oops:", g.callers(4), "should be overridden in subclass")
    #@-others
#@+node:ekr.20031218072017.2191: ** class NullBody (LeoBody)
class NullBody(LeoBody):
    '''A do-nothing body class.'''
    #@+others
    #@+node:ekr.20031218072017.2192: *3*  NullBody.__init__
    def __init__(self, frame, parentFrame):
        '''Ctor for NullBody class.'''
        LeoBody.__init__(self, frame, parentFrame)
            # Init the base class.
        self.insertPoint = 0
        self.selection = 0, 0
        self.s = "" # The body text
        self.widget = None
        self.wrapper = wrapper = StringTextWrapper(c=self.c, name='body')
        self.editorWidgets['1'] = wrapper
        self.colorizer = NullColorizer(self.c)
    #@+node:ekr.20031218072017.2197: *3* NullBody: LeoBody interface
    # Birth, death...

    def createControl(self, parentFrame, p): pass
    # Editors...

    def addEditor(self, event=None): pass

    def assignPositionToEditor(self, p): pass

    def createEditorFrame(self, w): return None

    def cycleEditorFocus(self, event=None): pass

    def deleteEditor(self, event=None): pass

    def selectEditor(self, w): pass

    def selectLabel(self, w): pass

    def setEditorColors(self, bg, fg): pass

    def unselectLabel(self, w): pass

    def updateEditors(self): pass
    # Events...

    def forceFullRecolor(self): pass

    def scheduleIdleTimeRoutine(self, function, *args, **keys): pass
    # Low-level gui...

    def setFocus(self): pass
    #@-others
#@+node:ekr.20031218072017.2218: ** class NullColorizer (BaseColorizer)
class NullColorizer(leoColorizer.BaseColorizer):
    '''A colorizer class that doesn't color.'''
    
    recolorCount = 0
            
    def colorize(self, p):
        self.recolorCount += 1
            # For #503: Use string/null gui for unit tests
#@+node:ekr.20031218072017.2222: ** class NullFrame (LeoFrame)
class NullFrame(LeoFrame):
    '''A null frame class for tests and batch execution.'''
    #@+others
    #@+node:ekr.20040327105706: *3* NullFrame.ctor
    def __init__(self, c, title, gui):
        '''Ctor for the NullFrame class.'''
        LeoFrame.__init__(self, c, gui)
            # Init the base class.
        assert self.c
        self.wrapper = None
        self.iconBar = NullIconBarClass(self.c, self)
        self.isNullFrame = True
        self.outerFrame = None
        self.ratio = self.secondary_ratio = 0.5
        self.statusLineClass = NullStatusLineClass
        self.title = title
        self.top = None # Always None.
        # Create the component objects.
        self.body = NullBody(frame=self, parentFrame=None)
        self.log = NullLog(frame=self, parentFrame=None)
        self.menu = LeoMenu.NullMenu(frame=self)
        self.tree = NullTree(frame=self)
        # Default window position.
        self.w = 600
        self.h = 500
        self.x = 40
        self.y = 40
    #@+node:ekr.20061109124552: *3* NullFrame.do nothings
    def bringToFront(self): pass
    def cascade(self, event=None): pass
    def contractBodyPane(self, event=None): pass
    def contractLogPane(self, event=None): pass
    def contractOutlinePane(self, event=None): pass
    def contractPane(self, event=None): pass
    def deiconify(self): pass
    def destroySelf(self): pass
    def equalSizedPanes(self, event=None): pass
    def expandBodyPane(self, event=None): pass
    def expandLogPane(self, event=None): pass
    def expandOutlinePane(self, event=None): pass
    def expandPane(self, event=None): pass
    def fullyExpandBodyPane(self, event=None): pass
    def fullyExpandLogPane(self, event=None): pass
    def fullyExpandOutlinePane(self, event=None): pass
    def fullyExpandPane(self, event=None): pass
    def get_window_info(self): return 600, 500, 20, 20
    def hideBodyPane(self, event=None): pass
    def hideLogPane(self, event=None): pass
    def hideLogWindow(self, event=None): pass
    def hideOutlinePane(self, event=None): pass
    def hidePane(self, event=None): pass
    def leoHelp(self, event=None): pass
    def lift(self): pass
    def minimizeAll(self, event=None): pass
    def oops(self): g.trace("NullFrame", g.callers(4))
    def resizePanesToRatio(self, ratio, secondary_ratio): pass
    def resizeToScreen(self, event=None): pass
    def setInitialWindowGeometry(self): pass
    def setTopGeometry(self, w, h, x, y, adjustSize=True): return 0, 0, 0, 0
    def setWrap(self, flag, force=False): pass
    def toggleActivePane(self, event=None): pass
    def toggleSplitDirection(self, event=None): pass
    def update(self): pass
    #@+node:ekr.20171112115045.1: *3* NullFrame.finishCreate
    def finishCreate(self):
        
        # 2017/11/12: For #503: Use string/null gui for unit tests.
        self.createFirstTreeNode()
            # Call the base LeoFrame method.
    #@-others
#@+node:ekr.20070301164543: ** class NullIconBarClass
class NullIconBarClass(object):
    '''A class representing the singleton Icon bar'''
    #@+others
    #@+node:ekr.20070301164543.1: *3*  NullIconBarClass.ctor
    def __init__(self, c, parentFrame):
        '''Ctor for NullIconBarClass.'''
        self.c = c
        self.iconFrame = None
        self.parentFrame = parentFrame
        self.w = g.NullObject()
    #@+node:ekr.20070301165343: *3*  NullIconBarClass.Do nothing
    def addRow(self, height=None): pass

    def addRowIfNeeded(self): pass

    def addWidget(self, w): pass

    def createChaptersIcon(self): pass

    def deleteButton(self, w): pass

    def getNewFrame(self): return None

    def hide(self): pass

    def show(self): pass
    #@+node:ekr.20070301164543.2: *3* NullIconBarClass.add
    def add(self, *args, **keys):
        '''Add a (virtual) button to the (virtual) icon bar.'''
        command = keys.get('command')
        text = keys.get('text')
        try:
            g.app.iconWidgetCount += 1
        except Exception:
            g.app.iconWidgetCount = 1
        n = g.app.iconWidgetCount
        name = 'nullButtonWidget %d' % n
        if not command:

            def commandCallback(name=name):
                g.pr("command for %s" % (name))

            command = commandCallback

        class nullButtonWidget:

            def __init__(self, c, command, name, text):
                self.c = c
                self.command = command
                self.name = name
                self.text = text

            def __repr__(self):
                return self.name

        b = nullButtonWidget(self.c, command, name, text)
        return b
    #@+node:ekr.20140904043623.18574: *3* NullIconBarClass.clear
    def clear(self):
        g.app.iconWidgetCount = 0
        g.app.iconImageRefs = []
    #@+node:ekr.20140904043623.18575: *3* NullIconBarClass.setCommandForButton
    def setCommandForButton(self, button, command, command_p, controller, gnx, script):
        button.command = command
    #@-others
#@+node:ekr.20031218072017.2232: ** class NullLog (LeoLog)
class NullLog(LeoLog):
    '''A do-nothing log class.'''
    #@+others
    #@+node:ekr.20070302095500: *3* Birth
    #@+node:ekr.20041012083237: *4* NullLog.__init__
    def __init__(self, frame=None, parentFrame=None):
        # Init the base class.
        LeoLog.__init__(self, frame, parentFrame)
        self.isNull = True
        self.logNumber = 0
        self.widget = self.createControl(parentFrame)
            # self.logCtrl is now a property of the base LeoLog class.
    #@+node:ekr.20120216123546.10951: *4* finishCreate (NullLog)
    def finishCreate(self):
        pass
    #@+node:ekr.20041012083237.1: *4* createControl
    def createControl(self, parentFrame):
        return self.createTextWidget(parentFrame)
    #@+node:ekr.20070302095121: *4* createTextWidget (NullLog)
    def createTextWidget(self, parentFrame):
        self.logNumber += 1
        c = self.c
        log = StringTextWrapper(c=c, name="log-%d" % self.logNumber)
        return log
    #@+node:ekr.20111119145033.10186: *3* isLogWidget (NullLog)
    def isLogWidget(self, w):
        return False
    #@+node:ekr.20041012083237.2: *3* oops
    def oops(self):
        g.trace("NullLog:", g.callers(4))
    #@+node:ekr.20041012083237.3: *3* put and putnl (NullLog)
    def put(self, s, color=None, tabName='Log', from_redirect=False, nodeLink=None):
        # print('(nullGui) print',repr(s))
        if self.enabled:
            try:
                g.pr(s, newline=False)
            except UnicodeError:
                s = s.encode('ascii', 'replace')
                g.pr(s, newline=False)

    def putnl(self, tabName='Log'):
        if self.enabled:
            g.pr('')
    #@+node:ekr.20060124085830: *3* tabs (NullLog)
    def clearTab(self, tabName, wrap='none'): pass

    def createCanvas(self, tabName): pass

    def createTab(self, tabName, createText=True, widget=None, wrap='none'): pass

    def deleteTab(self, tabName, force=False): pass

    def getSelectedTab(self): return None

    def lowerTab(self, tabName): pass

    def raiseTab(self, tabName): pass

    def renameTab(self, oldName, newName): pass

    def selectTab(self, tabName, createText=True, widget=None, wrap='none'): pass
    #@-others
#@+node:ekr.20070302171509: ** class NullStatusLineClass
class NullStatusLineClass(object):
    '''A do-nothing status line.'''

    def __init__(self, c, parentFrame):
        '''Ctor for NullStatusLine class.'''
        self.c = c
        self.enabled = False
        self.parentFrame = parentFrame
        self.textWidget = StringTextWrapper(c, name='status-line')
        # Set the official ivars.
        c.frame.statusFrame = None
        c.frame.statusLabel = None
        c.frame.statusText = self.textWidget
    #@+others
    #@+node:ekr.20070302171917: *3* NullStatusLineClass.methods
    def disable(self, background=None):
        self.enabled = False
        # self.c.bodyWantsFocus()

    def enable(self, background="white"):
        self.c.widgetWantsFocus(self.textWidget)
        self.enabled = True

    def clear(self):
        self.textWidget.delete(0, 'end')

    def get(self):
        return self.textWidget.getAllText()

    def isEnabled(self):
        return self.enabled

    def put(self, s, bg=None, fg=None):
        self.textWidget.insert('end', s)

    def setFocus(self):
        pass

    def update(self):
        pass
    #@-others
#@+node:ekr.20031218072017.2233: ** class NullTree (LeoTree)
class NullTree(LeoTree):
    '''A do-almost-nothing tree class.'''
    #@+others
    #@+node:ekr.20031218072017.2234: *3*  NullTree.__init__
    def __init__(self, frame):
        '''Ctor for NullTree class.'''
        LeoTree.__init__(self, frame) # Init the base class.
        assert(self.frame)
        self.c = frame.c
        self.editWidgetsDict = {} # Keys are tnodes, values are StringTextWidgets.
        self.font = None
        self.fontName = None
        self.canvas = None
        self.redrawCount = 0
        self.updateCount = 0
    #@+node:ekr.20070228163350.2: *3* NullTree.edit_widget
    def edit_widget(self, p):
        d = self.editWidgetsDict
        if not p or not p.v:
            return None
        w = d.get(p.v)
        if not w:
            d[p.v] = w = StringTextWrapper(
                c=self.c,
                name='head-%d' % (1 + len(list(d.keys()))))
            w.setAllText(p.h)
        return w
    #@+node:ekr.20070228164730: *3* NullTree.editLabel
    def editLabel(self, p, selectAll=False, selection=None):
        '''Start editing p's headline.'''
        self.endEditLabel()
        if p:
            self.revertHeadline = p.h
                # New in 4.4b2: helps undo.
            wrapper = StringTextWrapper(c=self.c, name='head-wrapper')
            e = None
            return e, wrapper
        else:
            return None, None
    #@+node:ekr.20070228173611: *3* NullTree.printWidgets
    def printWidgets(self):
        d = self.editWidgetsDict
        for key in d:
            # keys are vnodes, values are StringTextWidgets.
            w = d.get(key)
            g.pr('w', w, 'v.h:', key.headString, 's:', repr(w.s))
    #@+node:ekr.20070228163350.1: *3* NullTree.Drawing & scrolling
    def drawIcon(self, p):
        pass

    def redraw(self, p=None):
        self.redrawCount += 1
        return p
            # Support for #503: Use string/null gui for unit tests
    redraw_now = redraw

    def redraw_after_contract(self, p):
        self.redraw()

    def redraw_after_expand(self, p):
        self.redraw()

    def redraw_after_head_changed(self): self.redraw()

    def redraw_after_icons_changed(self): self.redraw()

    def redraw_after_select(self, p=None): self.redraw()

    def scrollTo(self, p):
        pass
    #@+node:ekr.20070228160345: *3* NullTree.setHeadline
    def setHeadline(self, p, s):
        '''Set the actual text of the headline widget.

        This is called from the undo/redo logic to change the text before redrawing.'''
        w = self.edit_widget(p)
        if w:
            w.delete(0, 'end')
            if s.endswith('\n') or s.endswith('\r'):
                s = s[: -1]
            w.insert(0, s)
            self.revertHeadline = s
        else:
            g.trace('-' * 20, 'oops')
    #@-others
#@+node:ekr.20070228074228.1: ** class StringTextWrapper
class StringTextWrapper(object):
    '''A class that represents text as a Python string.'''
    #@+others
    #@+node:ekr.20070228074228.2: *3* stw.ctor
    def __init__(self, c, name):
        '''Ctor for the StringTextWrapper class.'''
        self.c = c
        self.name = name
        self.ins = 0
        self.sel = 0, 0
        self.s = ''
        self.supportsHighLevelInterface = True
        self.widget = None # This ivar must exist, and be None.

    def __repr__(self):
        return '<StringTextWrapper: %s %s>' % (id(self), self.name)

    def getName(self):
        '''StringTextWrapper.'''
        return self.name # Essential.
    #@+node:ekr.20140903172510.18578: *3* stw.Clipboard
    def clipboard_clear(self):
        g.app.gui.replaceClipboardWith('')

    def clipboard_append(self, s):
        s1 = g.app.gui.getTextFromClipboard()
        g.app.gui.replaceClipboardWith(s1 + s)
    #@+node:ekr.20140903172510.18579: *3* stw.Do-nothings
    # For StringTextWrapper.

    def flashCharacter(self, i, bg='white', fg='red', flashes=3, delay=75): pass

    def getXScrollPosition(self): return 0

    def getYScrollPosition(self): return 0

    def see(self, i): pass

    def seeInsertPoint(self): pass

    def setFocus(self): pass

    def setStyleClass(self, name): pass

    def setXScrollPosition(self, i): pass

    def setYScrollPosition(self, i): pass

    def tag_configure(self, colorName, **keys): pass
    #@+node:ekr.20140903172510.18591: *3* stw.Text
    #@+node:ekr.20140903172510.18592: *4* stw.appendText
    def appendText(self, s):
        '''StringTextWrapper.'''
        self.s = self.s + s
        self.ins = len(self.s)
        self.sel = self.ins, self.ins
    #@+node:ekr.20140903172510.18593: *4* stw.delete
    def delete(self, i, j=None):
        '''StringTextWrapper.'''
        i = self.toPythonIndex(i)
        if j is None: j = i + 1
        j = self.toPythonIndex(j)
        # This allows subclasses to use this base class method.
        if i > j: i, j = j, i
        s = self.getAllText()
        self.setAllText(s[: i] + s[j:])
        # Bug fix: 2011/11/13: Significant in external tests.
        self.setSelectionRange(i, i, insert=i)
    #@+node:ekr.20140903172510.18594: *4* stw.deleteTextSelection
    def deleteTextSelection(self):
        '''StringTextWrapper.'''
        i, j = self.getSelectionRange()
        self.delete(i, j)
    #@+node:ekr.20140903172510.18595: *4* stw.get
    def get(self, i, j=None):
        '''StringTextWrapper.'''
        i = self.toPythonIndex(i)
        if j is None: j = i + 1
        j = self.toPythonIndex(j)
        s = self.s[i: j]
        return g.toUnicode(s)
    #@+node:ekr.20140903172510.18596: *4* stw.getAllText
    def getAllText(self):
        '''StringTextWrapper.'''
        s = self.s
        return g.toUnicode(s)
    #@+node:ekr.20140903172510.18584: *4* stw.getInsertPoint
    def getInsertPoint(self):
        '''StringTextWrapper.'''
        i = self.ins
        if i is None:
            if self.virtualInsertPoint is None:
                i = 0
            else:
                i = self.virtualInsertPoint
        self.virtualInsertPoint = i
        return i
    #@+node:ekr.20140903172510.18597: *4* stw.getSelectedText
    def getSelectedText(self):
        '''StringTextWrapper.'''
        i, j = self.sel
        s = self.s[i: j]
        return g.toUnicode(s)
    #@+node:ekr.20140903172510.18585: *4* stw.getSelectionRange
    def getSelectionRange(self, sort=True):
        '''Return the selected range of the widget.'''
        sel = self.sel
        if len(sel) == 2 and sel[0] >= 0 and sel[1] >= 0:
            i, j = sel
            if sort and i > j: sel = j, i # Bug fix: 10/5/07
            return sel
        else:
            i = self.ins
            return i, i
    #@+node:ekr.20140903172510.18586: *4* stw.hasSelection
    def hasSelection(self):
        '''StringTextWrapper.'''
        i, j = self.getSelectionRange()
        return i != j
    #@+node:ekr.20140903172510.18598: *4* stw.insert
    def insert(self, i, s):
        '''StringTextWrapper.'''
        i = self.toPythonIndex(i)
        s1 = s
        self.s = self.s[: i] + s1 + self.s[i:]
        i += len(s1)
        self.ins = i
        self.sel = i, i
    #@+node:ekr.20140903172510.18589: *4* stw.selectAllText
    def selectAllText(self, insert=None):
        '''StringTextWrapper.'''
        self.setSelectionRange(0, 'end', insert=insert)
    #@+node:ekr.20140903172510.18600: *4* stw.setAllText
    def setAllText(self, s):
        '''StringTextWrapper.'''
        self.s = s
        i = len(self.s)
        self.ins = i
        self.sel = i, i
    #@+node:ekr.20140903172510.18587: *4* stw.setInsertPoint
    def setInsertPoint(self, pos, s=None):
        '''StringTextWrapper.'''
        self.virtualInsertPoint = i = self.toPythonIndex(pos)
        self.ins = i
        self.sel = i, i
    #@+node:ekr.20070228111853: *4* stw.setSelectionRange
    def setSelectionRange(self, i, j, insert=None):
        '''StringTextWrapper.'''
        i, j = self.toPythonIndex(i), self.toPythonIndex(j)
        self.sel = i, j
        self.ins = j if insert is None else self.toPythonIndex(insert)
    #@+node:ekr.20140903172510.18581: *4* stw.toPythonIndex
    def toPythonIndex(self, index):
        '''StringTextWrapper.'''
        return g.toPythonIndex(self.s, index)
    #@+node:ekr.20140903172510.18582: *4* stw.toPythonIndexRowCol
    def toPythonIndexRowCol(self, index):
        '''StringTextWrapper.'''
        s = self.getAllText()
        i = self.toPythonIndex(index)
        row, col = g.convertPythonIndexToRowCol(s, i)
        return i, row, col
    #@-others
#@-others
#@@language python
#@@tabwidth -4
#@@pagewidth 70
#@-leo
