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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//
// Description: Text editing service for controls.
//
namespace System.Windows.Documents
{
using MS.Internal;
using MS.Internal.Interop;
using System.Globalization;
using System.Threading;
using System.ComponentModel;
using System.Text;
using System.Collections; // ArrayList
using System.Runtime.InteropServices;
using System.Windows.Threading;
using System.Windows.Input;
using System.Windows.Controls; // ScrollChangedEventArgs
using System.Windows.Controls.Primitives; // CharacterCasing, TextBoxBase
using System.Windows.Media;
using System.Windows.Markup;
using System.Security;
using System.Windows.Interop;
using MS.Utility;
using MS.Win32;
using MS.Internal.Documents;
using MS.Internal.Commands; // CommandHelpers
/// <summary>
/// Subcomponent of TextEditor class - Support for Typing
/// </summary>
internal static class TextEditorTyping
{
//------------------------------------------------------
//
// Class Internal Methods
//
//------------------------------------------------------
#region Class Internal Methods
/// <summary>
/// Registes all handlers needed for text editing control functioning.
/// </summary>
/// <param name="controlType">
/// A type of control for which typing component is registered
/// </param>
/// <param name="registerEventListeners">
/// If registerEventListeners is false, caller is responsible for calling OnXXXEvent methods on TextEditor from
/// UIElement and FrameworkElement virtual overrides (piggy backing on the
/// UIElement/FrameworkElement class listeners). If true, TextEditor will register
/// its own class listener for events it needs.
///
/// This method will always register private command listeners.
/// </param>
internal static void _RegisterClassHandlers(Type controlType, bool registerEventListeners)
{
if (registerEventListeners)
{
EventManager.RegisterClassHandler(controlType, Keyboard.PreviewKeyDownEvent, new KeyEventHandler(OnPreviewKeyDown));
EventManager.RegisterClassHandler(controlType, Keyboard.KeyDownEvent, new KeyEventHandler(OnKeyDown));
EventManager.RegisterClassHandler(controlType, Keyboard.KeyUpEvent, new KeyEventHandler(OnKeyUp));
EventManager.RegisterClassHandler(controlType, TextCompositionManager.TextInputEvent, new TextCompositionEventHandler(OnTextInput));
}
var onEnterBreak = new ExecutedRoutedEventHandler(OnEnterBreak);
var onSpace = new ExecutedRoutedEventHandler(OnSpace);
var onQueryStatusNYI = new CanExecuteRoutedEventHandler(OnQueryStatusNYI);
var onQueryStatusEnterBreak = new CanExecuteRoutedEventHandler(OnQueryStatusEnterBreak);
EventManager.RegisterClassHandler(controlType, Mouse.MouseMoveEvent, new MouseEventHandler(OnMouseMove), true /* handledEventsToo */);
EventManager.RegisterClassHandler(controlType, Mouse.MouseLeaveEvent, new MouseEventHandler(OnMouseLeave), true /* handledEventsToo */);
CommandHelpers.RegisterCommandHandler(controlType, ApplicationCommands.CorrectionList , new ExecutedRoutedEventHandler(OnCorrectionList) , new CanExecuteRoutedEventHandler(OnQueryStatusCorrectionList) , nameof(SR.KeyCorrectionList), nameof(SR.KeyCorrectionListDisplayString) );
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.ToggleInsert , new ExecutedRoutedEventHandler(OnToggleInsert) , onQueryStatusNYI , KeyGesture.CreateFromResourceStrings(KeyToggleInsert, nameof(SR.KeyToggleInsertDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.Delete , new ExecutedRoutedEventHandler(OnDelete) , onQueryStatusNYI , KeyGesture.CreateFromResourceStrings(KeyDelete, nameof(SR.KeyDeleteDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.DeleteNextWord , new ExecutedRoutedEventHandler(OnDeleteNextWord) , onQueryStatusNYI , KeyGesture.CreateFromResourceStrings(KeyDeleteNextWord, nameof(SR.KeyDeleteNextWordDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.DeletePreviousWord , new ExecutedRoutedEventHandler(OnDeletePreviousWord) , onQueryStatusNYI , KeyGesture.CreateFromResourceStrings(KeyDeletePreviousWord, nameof(SR.KeyDeletePreviousWordDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.EnterParagraphBreak , onEnterBreak , onQueryStatusEnterBreak , KeyGesture.CreateFromResourceStrings(KeyEnterParagraphBreak, nameof(SR.KeyEnterParagraphBreakDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.EnterLineBreak , onEnterBreak , onQueryStatusEnterBreak , KeyGesture.CreateFromResourceStrings(KeyEnterLineBreak, nameof(SR.KeyEnterLineBreakDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.TabForward , new ExecutedRoutedEventHandler(OnTabForward) , new CanExecuteRoutedEventHandler(OnQueryStatusTabForward) , KeyGesture.CreateFromResourceStrings(KeyTabForward, nameof(SR.KeyTabForwardDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.TabBackward , new ExecutedRoutedEventHandler(OnTabBackward) , new CanExecuteRoutedEventHandler(OnQueryStatusTabBackward) , KeyGesture.CreateFromResourceStrings(KeyTabBackward, nameof(SR.KeyTabBackwardDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.Space , onSpace , onQueryStatusNYI , KeyGesture.CreateFromResourceStrings(KeySpace, nameof(SR.KeySpaceDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.ShiftSpace , onSpace , onQueryStatusNYI , KeyGesture.CreateFromResourceStrings(KeyShiftSpace, nameof(SR.KeyShiftSpaceDisplayString) ));
CommandHelpers.RegisterCommandHandler(controlType, EditingCommands.Backspace , new ExecutedRoutedEventHandler(OnBackspace) , onQueryStatusNYI , KeyGesture.CreateFromResourceStrings(KeyBackspace, SR.KeyBackspaceDisplayString), KeyGesture.CreateFromResourceStrings(KeyShiftBackspace, SR.KeyShiftBackspaceDisplayString) );
}
/// <summary>
/// Add the input language changed event handler and save it
/// into UIContext data slot.
/// </summary>
internal static void _AddInputLanguageChangedEventHandler(TextEditor This)
{
TextEditorThreadLocalStore threadLocalStore;
Invariant.Assert(This._dispatcher == null);
This._dispatcher = Dispatcher.CurrentDispatcher;
Invariant.Assert(This._dispatcher != null);
threadLocalStore = TextEditor._ThreadLocalStore;
// Only add the input language changed event handler once that safe per UIContext
if (threadLocalStore.InputLanguageChangeEventHandlerCount == 0)
{
// Add input changed event handler into InputLanguageManager
InputLanguageManager.Current.InputLanguageChanged += new InputLanguageEventHandler(OnInputLanguageChanged);
// Add the dispatcher shutdown finished event handler to remove InputLanguageChangedEventHandler
// before dispose the dispatcher.
Dispatcher.CurrentDispatcher.ShutdownFinished += new EventHandler(OnDispatcherShutdownFinished);
}
threadLocalStore.InputLanguageChangeEventHandlerCount++;
}
/// <summary>
/// Remove the input language changed event handler from UIContext data slot.
/// </summary>
internal static void _RemoveInputLanguageChangedEventHandler(TextEditor This)
{
TextEditorThreadLocalStore threadLocalStore;
threadLocalStore = TextEditor._ThreadLocalStore;
// Decrease the input language changed event handler reference count
threadLocalStore.InputLanguageChangeEventHandlerCount--;
// Remove the input language changed event handler when nobody reference it
if (threadLocalStore.InputLanguageChangeEventHandlerCount == 0)
{
// Remove InputLanguageEventHandler
InputLanguageManager.Current.InputLanguageChanged -= new InputLanguageEventHandler(OnInputLanguageChanged);
// Remove the dispatcher shutdown finished event handler
Dispatcher.CurrentDispatcher.ShutdownFinished -= new EventHandler(OnDispatcherShutdownFinished);
}
}
/// <summary>
/// Discards previous typing undo unit, to prevent
/// from merging it with the subsequent typing.
/// </summary>
internal static void _BreakTypingSequence(TextEditor This)
{
// Discard typing undo unit
This._typingUndoUnit = null;
}
// Handles any pending input events.
internal static void _FlushPendingInputItems(TextEditor This)
{
TextEditorThreadLocalStore threadLocalStore;
if (This.TextView != null)
{
This.TextView.ThrottleBackgroundTasksForUserInput();
}
threadLocalStore = TextEditor._ThreadLocalStore;
if (threadLocalStore.PendingInputItems != null)
{
try
{
for (int i = 0; i < threadLocalStore.PendingInputItems.Count; i++)
{
((InputItem)threadLocalStore.PendingInputItems[i]).Do();
// After the first dequeue, clear the bit that tracks if
// any events are handled after ctl+shift (change flow direction keyboard hotkey).
threadLocalStore.PureControlShift = false;
}
}
finally
{
threadLocalStore.PendingInputItems.Clear();
}
}
// Clear the bit that tracks if any events are handled after
// ctl+shift (change flow direction keyboard hotkey) one last
// time, in case the queue was empty.
//
// Because we only call this method in preparation for handling
// a Command, we want this bit cleared.
threadLocalStore.PureControlShift = false;
}
// Un-hides the mouse cursor.
internal static void _ShowCursor()
{
if (TextEditor._ThreadLocalStore.HideCursor)
{
TextEditor._ThreadLocalStore.HideCursor = false;
SafeNativeMethods.ShowCursor(true);
}
}
// ................................................................
//
// Event Handlers
//
// ................................................................
/// <summary>
/// Removes selected content in a RichTextBox when an IME is jump-starting a composition
/// over existing content.
/// </summary>
/// <remarks>
/// This is a work around for a messy situation we get into when a composition starts
/// over a non-empty selection in the RichTextBox (eg, a user selects some content and
/// then starts typing with an IME).
///
/// In general, code in TextStore.cs tracks IME composition events with character offsets
/// and often restores and then "plays back" the changes. If the character offsets of the
/// original and played back composition events do not match exactly, the editor enters
/// an inconsistent state and crashes or worse.
///
/// There is code in TextStore.OnStartComposition that attempts to ensure character offsets
/// always match in the case where an IME starts a non-empty composition. Comments in the
/// method have details.
///
/// However, that code only handles the case where the selection is empty (a caret/single
/// insertion point). It will in fact cause problems if the composition is non-empty
/// because the initial selection was non-empty. In that case, the code in
/// TextStore.OnStartComposition attempts to convert
/// elements like LineBreak that are normally invisible to the IME but round-trip as text
/// like "\r\n". This confuses the before/after playback state because character counts
/// do not match.
///
/// The code here is a work around -- if we detect a composition start request with a non-empty
/// selection, we preemtively remove the selected content before the IME has a chance to do
/// so. We can't do that work later because once the IME has started a composition no
/// reentrant edits are allowed.
///
/// Modifying the document from PreviewKeyDown is not ideal. A better long term solution
/// is to change the way we expose the document to the IME so that reentrancy is not an
/// issue. However, we don't have time left in dev10 to do that work. This solution is
/// a compromise that avoids serious crashes while typing over selected text with IMEs.
/// </remarks>
internal static void OnPreviewKeyDown(object sender, KeyEventArgs e)
{
if (e.Key != Key.ImeProcessed)
{
return;
}
RichTextBox richTextBox = sender as RichTextBox;
if (richTextBox == null)
{
return;
}
TextEditor This = richTextBox.TextEditor;
if (This == null || !This._IsEnabled || This.IsReadOnly || !This._IsSourceInScope(e.OriginalSource))
{
return;
}
// Ignore repeated events generated when the key is hold down for long time
if (e.IsRepeat)
{
return;
}
if (This.TextStore == null ||
This.TextStore.IsComposing)
{
return;
}
if (richTextBox.Selection.IsEmpty)
{
return;
}
This.SetText(This.Selection, String.Empty, InputLanguageManager.Current.CurrentInputLanguage);
// NB: we do not handle the event. We want the IME to handle it.
}
// KeyDownEvent handler - needed for handling FlowDirection commands on KeyUp
internal static void OnKeyDown(object sender, KeyEventArgs e)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || (This.IsReadOnly && !This.IsReadOnlyCaretVisible) || !This._IsSourceInScope(e.OriginalSource))
{
return;
}
// Ignore repeated events generated when the key is hold down for long time
if (e.IsRepeat)
{
return;
}
// If UiScope has a ToolTip and it is open, any keyboard/mouse activity should close the tooltip.
This.CloseToolTip();
TextEditorThreadLocalStore threadLocalStore = TextEditor._ThreadLocalStore;
// Clear a flag indicating that Shift key was pressed without any following key
// This flag is necessary for KeyUp(RightShift/LeftShift) processing.
threadLocalStore.PureControlShift = false;
// Shift+Ctrl combination must be executed only when it's "pure" -
// no mouse dragging/movement, no other key downs involved in a gesture.
if (This.TextView != null && !This.UiScope.IsMouseCaptured)
{
if ((e.Key == Key.RightShift || e.Key == Key.LeftShift) && //
(e.KeyboardDevice.Modifiers & ModifierKeys.Control) != 0 && (e.KeyboardDevice.Modifiers & ModifierKeys.Alt) == 0)
{
threadLocalStore.PureControlShift = true; // will be cleared by any other key down
}
else if ((e.Key == Key.RightCtrl || e.Key == Key.LeftCtrl) && //
(e.KeyboardDevice.Modifiers & ModifierKeys.Shift) != 0 && (e.KeyboardDevice.Modifiers & ModifierKeys.Alt) == 0)
{
threadLocalStore.PureControlShift = true; // will be cleared by any other key down
}
else if (e.Key == Key.RightCtrl || e.Key == Key.LeftCtrl)
{
UpdateHyperlinkCursor(This);
}
}
}
// Handler for KeyUp events
internal static void OnKeyUp(object sender, KeyEventArgs e)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || (This.IsReadOnly && !This.IsReadOnlyCaretVisible) || !This._IsSourceInScope(e.OriginalSource))
{
return;
}
// Delegate the work to specific handlers.
switch (e.Key)
{
case Key.RightShift:
case Key.LeftShift:
if (TextEditor._ThreadLocalStore.PureControlShift && (e.KeyboardDevice.Modifiers & ModifierKeys.Alt) == 0)
{
TextEditorTyping.ScheduleInput(This, new KeyUpInputItem(This, e.Key, e.KeyboardDevice.Modifiers));
}
break;
case Key.LeftCtrl:
case Key.RightCtrl:
UpdateHyperlinkCursor(This);
break;
}
}
// TextInputEvent handler.
internal static void OnTextInput(object sender, TextCompositionEventArgs e)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly || !This._IsSourceInScope(e.OriginalSource))
{
return;
}
FrameworkTextComposition composition = e.TextComposition as FrameworkTextComposition;
// Ignore any event with an empty Text property.
// The public TextCompositionEventArgs ctor allows null Text values.
// Also it's possible to have non-null ControlText or AltText with String.Empty Text values.
if (composition == null &&
(e.Text == null || e.Text.Length == 0))
{
return;
}
// Consider event handled
e.Handled = true;
if (This.TextView != null)
{
This.TextView.ThrottleBackgroundTasksForUserInput();
}
// If this event is our Cicero TextStore composition, we always handles through ITextStore::SetText.
if (composition != null)
{
if (composition.Owner == This.TextStore)
{
This.TextStore.UpdateCompositionText(composition);
}
else if (composition.Owner == This.ImmComposition)
{
This.ImmComposition.UpdateCompositionText(composition);
}
}
else
{
// Input text (with springload formatting if any)
// We'll delay the event handling, batching it up with other
// input if layout is too slow to keep up with the input stream.
KeyboardDevice keyboard = e.Device as KeyboardDevice;
TextEditorTyping.ScheduleInput(This, new TextInputItem(This, e.Text, /*isInsertKeyToggled:*/keyboard != null ? keyboard.IsKeyToggled(Key.Insert) : false));
}
}
#endregion Class Internal Methods
//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
#region Private Methods
// ................................................................
//
// Command Handlers
//
// ................................................................
/// <summary>
/// CorrectionList command QueryStatus handler
/// </summary>
private static void OnQueryStatusCorrectionList(object target, CanExecuteRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(target);
if (This == null)
{
return;
}
if (This.TextStore != null)
{
// Don't do actual reconversion, it just checks if the current selection is reconvertable.
args.CanExecute = This.TextStore.QueryRangeOrReconvertSelection( /*fDoReconvert:*/ false);
}
else
{
// If there is no textstore, this command is not enabled.
args.CanExecute = false;
}
}
/// <summary>
/// CorrectionList command event handler.
/// </summary>
private static void OnCorrectionList(object target, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(target);
if (This == null)
{
return;
}
if (This.TextStore != null)
{
This.TextStore.QueryRangeOrReconvertSelection( /*fDoReconvert:*/ true);
}
}
/// <summary>
/// ToggleInsert command handler
/// </summary>
private static void OnToggleInsert(object target, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(target);
if (This == null || !This._IsEnabled || This.IsReadOnly)
{
return;
}
This._OvertypeMode = !This._OvertypeMode;
// Use Cicero's transitory extension for OverTyping.
if (TextServicesLoader.ServicesInstalled && (This.TextStore != null))
{
TextServicesHost tsfHost = TextServicesHost.Current;
if (tsfHost != null)
{
if (This._OvertypeMode)
{
IInputElement element = target as IInputElement;
if (element != null)
{
PresentationSource.AddSourceChangedHandler(element, OnSourceChanged);
}
TextServicesHost.StartTransitoryExtension(This.TextStore);
}
else
{
IInputElement element = target as IInputElement;
if (element != null)
{
PresentationSource.RemoveSourceChangedHandler(element, OnSourceChanged);
}
TextServicesHost.StopTransitoryExtension(This.TextStore);
}
}
}
}
// This should only be invoked on a text control in Overtype mode being tracked for presentation source
// changes. Connecting or disconnecting from a window fires this notification.
private static void OnSourceChanged(object sender, SourceChangedEventArgs args)
{
OnToggleInsert(sender, null);
}
// ...........................................................................
//
// Delete Characters
//
// ...........................................................................
private static void OnDelete(object sender, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly || !This._IsSourceInScope(args.Source))
{
return;
}
TextEditorTyping._FlushPendingInputItems(This);
// Note, that Delete and Backspace keys behave differently.
((TextSelection)This.Selection).ClearSpringloadFormatting();
// Forget previously suggested horizontal position
TextEditorSelection._ClearSuggestedX(This);
using (This.Selection.DeclareChangeBlock())
{
ITextPointer position = This.Selection.End;
if (This.Selection.IsEmpty)
{
ITextPointer deletePosition = position.GetNextInsertionPosition(LogicalDirection.Forward);
if (deletePosition == null)
{
// Nothing to delete.
return;
}
if (TextPointerBase.IsAtRowEnd(deletePosition))
{
// Backspace and delete are a no-op at row end positions.
return;
}
if (position is TextPointer && !IsAtListItemStart(deletePosition) &&
HandleDeleteWhenStructuralBoundaryIsCrossed(This, (TextPointer)position, (TextPointer)deletePosition))
{
// We are crossing structural boundary and
// selection was updated in HandleDeleteWhenStructuralBoundaryIsCrossed.
return;
}
// Selection is empty, extend selection forward to delete the following char.
This.Selection.ExtendToNextInsertionPosition(LogicalDirection.Forward);
}
// Delete selected text.
This.Selection.Text = String.Empty;
}
}
private static void OnBackspace(object sender, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly || !This._IsSourceInScope(args.Source))
{
return;
}
TextEditorTyping._FlushPendingInputItems(This);
// Forget previously suggested horizontal position.
TextEditorSelection._ClearSuggestedX(This);
using (This.Selection.DeclareChangeBlock())
{
ITextPointer position = This.Selection.Start;
// Note that this is different than the previous insertion position in backward direction,
// in case of combining characters and surrogates.
ITextPointer backspacePosition = null;
// In case when selection is empty we will need to expand
// it backward. Check first whether we are crossing
// any structural boundary - to disable the operation
// in such case.
if (This.Selection.IsEmpty)
{
// Identify a case for special actions in the beginning of paragraphs or list items
if (This.AcceptsRichContent && IsAtListItemStart(position))
{
// Remove a bullet from this list item.
// Note that doing anything more aggressive like unindenting
// would make backspace very inconvenient for merging two same-level list items.
TextRangeEditLists.ConvertListItemsToParagraphs((TextRange)This.Selection);
}
else if (This.AcceptsRichContent &&
(IsAtListItemChildStart(position, false /* emptyChildOnly */) || IsAtIndentedParagraphOrBlockUIContainerStart(This.Selection.Start)))
{
// Unindent the list by one level.
TextEditorLists.DecreaseIndentation(This);
}
else
{
// Find a preceding position.
ITextPointer deletePosition = position.GetNextInsertionPosition(LogicalDirection.Backward);
if (deletePosition == null)
{
// Nothing to delete.
((TextSelection)This.Selection).ClearSpringloadFormatting();
return;
}
if (TextPointerBase.IsAtRowEnd(deletePosition))
{
// Backspace and delete are a no-op at row end positions.
((TextSelection)This.Selection).ClearSpringloadFormatting();
return;
}
if (position is TextPointer &&
HandleDeleteWhenStructuralBoundaryIsCrossed(This, (TextPointer)position, (TextPointer)deletePosition))
{
// We are crossing structural boundary and
// selection was updated in HandleDeleteWhenStructuralBoundaryIsCrossed.
return;
}
// Normalize the current position backward.
position = position.GetFrozenPointer(LogicalDirection.Backward);
// If TextView is valid, we can get the backspace position from TextView and then
// delete the content from the backspace position to the current position.
// Otherwise, we move the selection to the previous insertion position then delete.
if (This.TextView != null &&
position.HasValidLayout &&
position.GetPointerContext(LogicalDirection.Backward) == TextPointerContext.Text)
{
// Get the backspace caret unit position from TextView that support surrogate
// and all internal characters
backspacePosition = This.TextView.GetBackspaceCaretUnitPosition(position);
Invariant.Assert(backspacePosition != null);
// bug 1733868
// backspacePosition should always be less than position.
// But backspacing before '\n' (no preceding '\r') exposes
// this bug.
if (backspacePosition.CompareTo(position) == 0)
{
// As of 6/30/2006 we're too close to ship to fix
// this bug cleanly. Ideally, we would stop referencing
// the position at the end-of-line (which mil text does not
// consider a valid position), and instead reference the start
// of the next line (flipping the original position's gravity).
//
// As a work-around, take the previous insertion position,
// ignoring glyph level backspace positions.
//
This.Selection.ExtendToNextInsertionPosition(LogicalDirection.Backward);
backspacePosition = null;
}
// If there is no text preceding the backspacePosition, extend to the next
// insertion position to make sure we cleanup any empty Inlines left
// after the delete. We don't want a non-empty selection if there is
// bordering text, because we might normalize outside of a run of combining
// marks otherwise.
else if (backspacePosition.GetPointerContext(LogicalDirection.Backward) != TextPointerContext.Text)
{
This.Selection.Select(This.Selection.End, backspacePosition);
backspacePosition = null;
}
}
else
{
// Selection is empty, extend it backward to include the preceeding char.
This.Selection.ExtendToNextInsertionPosition(LogicalDirection.Backward);
}
}
}
// Save current formatting properties for springload formatting before backspace
// Note, that Delete and Backspace keys behave differently: it's by design.
if (This.AcceptsRichContent)
{
((TextSelection)This.Selection).ClearSpringloadFormatting();
((TextSelection)This.Selection).SpringloadCurrentFormatting();
}
// If backspace position is available from TextView, we can delete it directly
// without the normalization. Because we already normalized the backspace position.
if (backspacePosition != null)
{
Invariant.Assert(backspacePosition.CompareTo(position) < 0);
// Delete the content from the backspace to the current position
backspacePosition.DeleteContentToPosition(position);
}
else
{
// Delete selected text
This.Selection.Text = String.Empty;
position = This.Selection.Start;
}
// Set the caret position with the Backward direction,
// because we want to appear close to previous character.
// However, we do not allow to stop at end of line.
// We alow to stop next to space - to be consistent with typing behavior.
This.Selection.SetCaretToPosition(position, LogicalDirection.Backward, /*allowStopAtLineEnd:*/false, /*allowStopNearSpace:*/true);
}
}
// Helper for OnDelete/OnBackspace, handles special case scenarios for delete when table or BlockUIContainer boundaries are crossed.
// Returns true if passed positions were in this category and appropriate editing action was taken for handling delete operation.
// Otherwise, returns false.
private static bool HandleDeleteWhenStructuralBoundaryIsCrossed(TextEditor This, TextPointer position, TextPointer deletePosition)
{
if (!TextRangeEditTables.IsTableStructureCrossed(position, deletePosition) &&
!IsBlockUIContainerBoundaryCrossed(position, deletePosition) &&
!TextPointerBase.IsAtRowEnd(position))
{
return false;
}
LogicalDirection directionOfDelete = position.CompareTo(deletePosition) < 0 ? LogicalDirection.Forward : LogicalDirection.Backward;
Block paragraphOrBlockUIContainerToDelete = position.ParagraphOrBlockUIContainer;
// Check if an empty paragraph or BlockUIContainer needs to be deleted.
if (paragraphOrBlockUIContainerToDelete != null)
{
if (directionOfDelete == LogicalDirection.Forward)
{
// We check for next/previous block here, to avoid deletion of an empty paragraph when a list/table boundary is crossed.
// Note however, we dont treat sections as structural boundaries. So this check does not let us delete a last empty
// paragraph in a section. Investigate the section case more...
if (paragraphOrBlockUIContainerToDelete.NextBlock != null &&
paragraphOrBlockUIContainerToDelete is Paragraph && Paragraph.HasNoTextContent((Paragraph)paragraphOrBlockUIContainerToDelete) || // empty paragraph
paragraphOrBlockUIContainerToDelete is BlockUIContainer && paragraphOrBlockUIContainerToDelete.IsEmpty) // empty BlockUIContainer
{
paragraphOrBlockUIContainerToDelete.RepositionWithContent(null);
}
}
else
{
if (paragraphOrBlockUIContainerToDelete.PreviousBlock != null &&
paragraphOrBlockUIContainerToDelete is Paragraph && Paragraph.HasNoTextContent((Paragraph)paragraphOrBlockUIContainerToDelete) || // empty paragraph
paragraphOrBlockUIContainerToDelete is BlockUIContainer && paragraphOrBlockUIContainerToDelete.IsEmpty) // empty BlockUIContainer
{
paragraphOrBlockUIContainerToDelete.RepositionWithContent(null);
}
}
}
// Set caret position.
This.Selection.SetCaretToPosition(deletePosition, directionOfDelete, /*allowStopAtLineEnd:*/false, /*allowStopNearSpace:*/true);
if (directionOfDelete == LogicalDirection.Backward)
{
// Clear springload formatting in case of backspace
((TextSelection)This.Selection).ClearSpringloadFormatting();
}
return true;
}
// Tests if the position is at the beginning of indented paragraph -
// to allow Backspace to decrease indentation
private static bool IsAtIndentedParagraphOrBlockUIContainerStart(ITextPointer position)
{
if ((position is TextPointer) && TextPointerBase.IsAtParagraphOrBlockUIContainerStart(position))
{
Block paragraphOrBlockUIContainer = ((TextPointer)position).ParagraphOrBlockUIContainer;
if (paragraphOrBlockUIContainer != null)
{
FlowDirection flowDirection = paragraphOrBlockUIContainer.FlowDirection;
Thickness margin = paragraphOrBlockUIContainer.Margin;
return
flowDirection == FlowDirection.LeftToRight && margin.Left > 0 ||
flowDirection == FlowDirection.RightToLeft && margin.Right > 0 ||
(paragraphOrBlockUIContainer is Paragraph && ((Paragraph)paragraphOrBlockUIContainer).TextIndent > 0);
}
}
return false;
}
// Tests if the position is at the beginning of some list item -
// to allow Backspace to delete the bullet.
private static bool IsAtListItemStart(ITextPointer position)
{
// Check for empty ListItem case
if (typeof(ListItem).IsAssignableFrom(position.ParentType) &&
position.GetPointerContext(LogicalDirection.Backward) == TextPointerContext.ElementStart &&
position.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.ElementEnd)
{
return true;
}
while (position.GetPointerContext(LogicalDirection.Backward) == TextPointerContext.ElementStart)
{
Type parentType = position.ParentType;
if (TextSchema.IsBlock(parentType))
{
if (TextSchema.IsParagraphOrBlockUIContainer(parentType))
{
position = position.GetNextContextPosition(LogicalDirection.Backward);
if (position.GetPointerContext(LogicalDirection.Backward) == TextPointerContext.ElementStart &&
typeof(ListItem).IsAssignableFrom(position.ParentType))
{
return true;
}
}
return false;
}
position = position.GetNextContextPosition(LogicalDirection.Backward);
}
return false;
}
// Tests if a position is at the start of a Block
// within a ListItem.
//
// position must be normalized at an insertion point.
private static bool IsAtListItemChildStart(ITextPointer position, bool emptyChildOnly)
{
if (position.GetPointerContext(LogicalDirection.Backward) != TextPointerContext.ElementStart)
{
return false;
}
if (emptyChildOnly &&
position.GetPointerContext(LogicalDirection.Forward) != TextPointerContext.ElementEnd)
{
return false;
}
ITextPointer navigator = position.CreatePointer();
// Cross inline opening tags.
while (navigator.GetPointerContext(LogicalDirection.Backward) == TextPointerContext.ElementStart &&
typeof(Inline).IsAssignableFrom(navigator.ParentType))
{
navigator.MoveToElementEdge(ElementEdge.BeforeStart);
}
// Check if navigator is at the start of a block.
if (!(navigator.GetPointerContext(LogicalDirection.Backward) == TextPointerContext.ElementStart &&
TextSchema.IsParagraphOrBlockUIContainer(navigator.ParentType)))
{
return false;
}
// Move just past the block.
navigator.MoveToElementEdge(ElementEdge.BeforeStart);
return typeof(ListItem).IsAssignableFrom(navigator.ParentType);
}
// Tests if position1 and position2 cross a BlockUIContainer boundary.
private static bool IsBlockUIContainerBoundaryCrossed(TextPointer position1, TextPointer position2)
{
return
(position1.Parent is BlockUIContainer || position2.Parent is BlockUIContainer) &&
position1.Parent != position2.Parent;
}
// ...........................................................................
//
// Delete Words
//
// ...........................................................................
private static void OnDeleteNextWord(object sender, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly)
{
return;
}
if (This.Selection.IsTableCellRange)
{
return;
}
TextEditorTyping._FlushPendingInputItems(This);
ITextPointer wordBoundary = This.Selection.End.CreatePointer();
// When selection is not empty the command deletes selected content
// without extending it to the word bopundary. For empty selection
// the command deletes a content from caret position to
// nearest word boundary in a given direction
if (This.Selection.IsEmpty)
{
TextPointerBase.MoveToNextWordBoundary(wordBoundary, LogicalDirection.Forward);
}
if (TextRangeEditTables.IsTableStructureCrossed(This.Selection.Start, wordBoundary))
{
return;
}
ITextRange textRange = new TextRange(This.Selection.Start, wordBoundary);
// When a range is TableCellRange we do not want to make deletions
if (textRange.IsTableCellRange)
{
return;
}
if (!textRange.IsEmpty)
{
using (This.Selection.DeclareChangeBlock())
{
// Note asymetry with Backspace: we do not load springload formatting here
if (This.AcceptsRichContent)
{
((TextSelection)This.Selection).ClearSpringloadFormatting();
}
This.Selection.Select(textRange.Start, textRange.End);
// Delete selected text
This.Selection.Text = String.Empty;
}
}
}
private static void OnDeletePreviousWord(object sender, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly)
{
return;
}
if (This.Selection.IsTableCellRange)
{
// Add code for clearing table cell range contents
return;
}
TextEditorTyping._FlushPendingInputItems(This);
ITextPointer wordBoundary = This.Selection.Start.CreatePointer();
// When selection is not empty the command deletes selected content
// without extending it to the word bopundary. For empty selection
// the command deletes a content from caret position to
// nearest word boundary in a given direction
if (This.Selection.IsEmpty)
{
TextPointerBase.MoveToNextWordBoundary(wordBoundary, LogicalDirection.Backward);
}
// When the movement to word boundary crosses table structure, ignore the command
if (TextRangeEditTables.IsTableStructureCrossed(wordBoundary, This.Selection.Start))
{
return;
}
// Build a range from a start of a word preceding start of selection, ending at the end of whole selection
// This range is supposed to be deleted by the operation.
ITextRange textRange = new TextRange(wordBoundary, This.Selection.End);
// When a range is TableCellRange we do not want to make deletions
if (textRange.IsTableCellRange)
{
return;
}
if (!textRange.IsEmpty)
{
using (This.Selection.DeclareChangeBlock())
{
// Note asymetry with Backspace: we DO load springload formatting here
if (This.AcceptsRichContent)
{
((TextSelection)This.Selection).ClearSpringloadFormatting();
This.Selection.Select(textRange.Start, textRange.End);
((TextSelection)This.Selection).SpringloadCurrentFormatting();
}
else
{
This.Selection.Select(textRange.Start, textRange.End);
}
// Delete selected text
This.Selection.Text = String.Empty;
}
}
}
// ...........................................................................
//
// Enter Breaks
//
// ...........................................................................
/// <summary>
/// EnterParagraphBreak/EnterLineBreak command QueryStatus handler
/// </summary>
private static void OnQueryStatusEnterBreak(object sender, CanExecuteRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly)
{
args.ContinueRouting = true;
return;
}
if (This.Selection.IsTableCellRange || !This.AcceptsReturn)
{
args.ContinueRouting = true;
return;
}
args.CanExecute = true;
}
// EnterParagraphBreak/EnterLineBreak command handler
private static void OnEnterBreak(object sender, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly)
{
return;
}
if (This.Selection.IsTableCellRange || !This.AcceptsReturn || !This.UiScope.IsKeyboardFocused)
{
return;
}
TextEditorTyping._FlushPendingInputItems(This);
// We do not merge Enter typing with other typing - for better undo structuring
using (This.Selection.DeclareChangeBlock())
{
// Flag to indicate if selection was changed. It may be unaffected in following cases:
// 1. In plain text case, Environment.NewLine can not fit in MaxLength
// 2. In rich text case, we cannot split a hyperlink ancestor to insert a paragraph break
bool wasSelectionChanged;
if (This.AcceptsRichContent && This.Selection.Start is TextPointer)
{
// Paragraph insertion for the case of rich text
wasSelectionChanged = HandleEnterBreakForRichText(This, args.Command);
}
else
{
// Newline insertion for plain text
wasSelectionChanged = HandleEnterBreakForPlainText(This);
}
// Update caret and clear SuggestedX only when selection has changed.
if (wasSelectionChanged)
{
// Position the caret.
This.Selection.SetCaretToPosition(This.Selection.End, LogicalDirection.Forward, /*allowStopAtLineEnd:*/false, /*allowStopNearSpace:*/false);
// Forget previously suggested horizontal position
TextEditorSelection._ClearSuggestedX(This);
}
}
}
// Helper for OnEnterBreak for rich text case
private static bool HandleEnterBreakForRichText(TextEditor This, ICommand command)
{
bool wasSelectionChanged = true;
// Save current inline settings to continue on the next paragraph
((TextSelection)This.Selection).SpringloadCurrentFormatting();
if (!This.Selection.IsEmpty)
{
// Delete selected content
This.Selection.Text = String.Empty;
}
if (HandleEnterBreakWhenStructuralBoundaryIsCrossed(This, command))
{
// We are crossing structural boundary and
// selection was updated if HandleEnterBreakWhenStructuralBoundaryIsCrossed returned true
}
else
{
TextPointer newEnd = ((TextSelection)This.Selection).End;
if (command == EditingCommands.EnterParagraphBreak)
{
if (newEnd.HasNonMergeableInlineAncestor && !TextPointerBase.IsPositionAtNonMergeableInlineBoundary(newEnd))
{
// Selection end is in the middle of a hyperlink element, enter is a no-op.
wasSelectionChanged = false;
}
else
{
newEnd = TextRangeEdit.InsertParagraphBreak(newEnd, /*moveIntoSecondParagraph*/true);
}
}
else if (command == EditingCommands.EnterLineBreak)
{
newEnd = newEnd.InsertLineBreak();
}
if (wasSelectionChanged)
{
This.Selection.Select(newEnd, newEnd);
}
}
return wasSelectionChanged;
}
// Helper for OnEnterBreak for plain text case
private static bool HandleEnterBreakForPlainText(TextEditor This)
{
bool wasSelectionChanged = true;
// Filter Environment.NewLine based on TextBox.MaxLength
string filteredText = This._FilterText(Environment.NewLine, This.Selection);
if (filteredText != String.Empty)
{
This.Selection.Text = Environment.NewLine;
}
else
{
// Do not update selection if Environment.NewLine can not fit in.
wasSelectionChanged = false;
}
return wasSelectionChanged;
}
// Helper for rich text OnEnterBreak case, handles special cases when a
// structural boundary such as listitem, table, blockuicontainer is crossed.
private static bool HandleEnterBreakWhenStructuralBoundaryIsCrossed(TextEditor This, ICommand command)
{
Invariant.Assert(This.Selection.Start is TextPointer);
TextPointer position = (TextPointer)This.Selection.Start;
bool structuralBoundaryIsCrossed = true;
if (TextPointerBase.IsAtRowEnd(position))
{
// For both ParagraphBreak and LineBreak commands, insert a new row after the current one
TextRange range = ((TextSelection)This.Selection).InsertRows(+1);
This.Selection.SetCaretToPosition(range.Start, LogicalDirection.Forward, /*allowStopAtLineEnd:*/false, /*allowStopNearSpace:*/false);
}
else if (This.Selection.IsEmpty &&
(TextPointerBase.IsInEmptyListItem(position) || IsAtListItemChildStart(position, true /* emptyChildOnly */)) &&
command == EditingCommands.EnterParagraphBreak)
{
// Unindent the list by one level.
TextEditorLists.DecreaseIndentation(This);
}
else if (TextPointerBase.IsBeforeFirstTable(position) ||
TextPointerBase.IsAtBlockUIContainerStart(position))
{
// Calling EnsureInsertionPosition has the effect of inserting a paragraph BEFORE the table or BlockUIContainer/Table.
// In this case, we do not want to move selection end to the paragraph just created.
TextRangeEditTables.EnsureInsertionPosition(position);
}
else if (TextPointerBase.IsAtBlockUIContainerEnd(position))
{
// Calling EnsureInsertionPosition has the effect of inserting a paragraph AFTER the BlockUIContainer.
// Update selection end to position in the following paragraph.
TextPointer newEnd = TextRangeEditTables.EnsureInsertionPosition(position);
This.Selection.Select(newEnd, newEnd);
}
else
{
structuralBoundaryIsCrossed = false;
}
return structuralBoundaryIsCrossed;
}
// ...........................................................................
//
// Flow Direction
//
// ...........................................................................
/// <summary>
/// LeftToRightFlowDirection command event handler.
/// </summary>
private static void OnFlowDirectionCommand(TextEditor This, Key key)
{
// Detect appropriateness of FlowDirection command
using (This.Selection.DeclareChangeBlock())
{
if (key == Key.LeftShift)
{
if (This.AcceptsRichContent && (This.Selection is TextSelection))
{
// NOTE: We do not call OnApplyProperty to avoid recursion for FlushPendingInput
((TextSelection)This.Selection).ApplyPropertyValue(FlowDocument.FlowDirectionProperty, FlowDirection.LeftToRight, /*applyToParagraphs*/true);
}
else
{
Invariant.Assert(This.UiScope != null);
UIElementPropertyUndoUnit.Add(This.TextContainer, This.UiScope, FrameworkElement.FlowDirectionProperty, FlowDirection.LeftToRight);
This.UiScope.SetValue(FrameworkElement.FlowDirectionProperty, FlowDirection.LeftToRight);
}
}
else
{
Invariant.Assert(key == Key.RightShift);
if (This.AcceptsRichContent && (This.Selection is TextSelection))
{
// NOTE: We do not call OnApplyProperty to avoid recursion for FlushPendingInput
((TextSelection)This.Selection).ApplyPropertyValue(FlowDocument.FlowDirectionProperty, FlowDirection.RightToLeft, /*applyToParagraphs*/true);
}
else
{
Invariant.Assert(This.UiScope != null);
UIElementPropertyUndoUnit.Add(This.TextContainer, This.UiScope, FrameworkElement.FlowDirectionProperty, FlowDirection.RightToLeft);
This.UiScope.SetValue(FrameworkElement.FlowDirectionProperty, FlowDirection.RightToLeft);
}
}
((TextSelection)This.Selection).UpdateCaretState(CaretScrollMethod.Simple);
}
}
// ...........................................................................
//
// In some controls, Space and Shift+Space keys are mapped to
// scroll down and scroll up commands respectively.
// In TextEditor, we handle them as text input.
// Using the command system allows controls to override the existing default behavior.
// ...........................................................................
// Space, Shift+Space handler
private static void OnSpace(object sender, ExecutedRoutedEventArgs e)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly || !This._IsSourceInScope(e.OriginalSource))
{
return;
}
// If this event is our Cicero TextStore composition, we always handles through ITextStore::SetText.
if (This.TextStore != null && This.TextStore.IsComposing)
{
return;
}
if (This.ImmComposition != null && This.ImmComposition.IsComposition)
{
return;
}
// Consider event handled
e.Handled = true;
if (This.TextView != null)
{
This.TextView.ThrottleBackgroundTasksForUserInput();
}
ScheduleInput(This, new TextInputItem(This, " ", /*isInsertKeyToggled:*/!This._OvertypeMode));
}
// ...........................................................................
//
// Tab and Back-Tab
//
// ...........................................................................
/// <summary>
/// ForwardTabStop command QueryStatus handler
/// </summary>
private static void OnQueryStatusTabForward(object sender, CanExecuteRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This != null && This.AcceptsTab)
{
args.CanExecute = true;
}
else
{
args.ContinueRouting = true;
}
}
/// <summary>
/// BackwardTabStop command QueryStatus handler
/// </summary>
private static void OnQueryStatusTabBackward(object sender, CanExecuteRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This != null && This.AcceptsTab)
{
args.CanExecute = true;
}
else
{
args.ContinueRouting = true;
}
}
// Tab handler.
private static void OnTabForward(object sender, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly || !This.UiScope.IsKeyboardFocused)
{
return;
}
TextEditorTyping._FlushPendingInputItems(This);
if (HandleTabInTables(This, LogicalDirection.Forward))
{
// All done on table level.
return;
}
if (This.AcceptsRichContent && (!This.Selection.IsEmpty || TextPointerBase.IsAtParagraphOrBlockUIContainerStart(This.Selection.Start)) &&
EditingCommands.IncreaseIndentation.CanExecute(null, (IInputElement)sender))
{
// In RichTextBox Tab/Shift+Tab keys work as paragraph/list indentation
EditingCommands.IncreaseIndentation.Execute(null, (IInputElement)sender);
}
else
{
// In plain text we treat tab as a characters always
DoTextInput(This, "\t", /*isInsertKeyToggled:*/!This._OvertypeMode, /*acceptControlCharacters:*/true);
}
}
// Shift+Tab handler.
private static void OnTabBackward(object sender, ExecutedRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(sender);
if (This == null || !This._IsEnabled || This.IsReadOnly || !This.UiScope.IsKeyboardFocused)
{
return;
}
// Implement paragraph decrease level command
TextEditorTyping._FlushPendingInputItems(This);
if (HandleTabInTables(This, LogicalDirection.Backward))
{
// All done on table level.
return;
}
if (This.AcceptsRichContent && (!This.Selection.IsEmpty || TextPointerBase.IsAtParagraphOrBlockUIContainerStart(This.Selection.Start)) &&
EditingCommands.DecreaseIndentation.CanExecute(null, (IInputElement)sender))
{
// In RichTextBox Tab/Shift+Tab keys work as paragraph/list indentation
EditingCommands.DecreaseIndentation.Execute(null, (IInputElement)sender);
}
else
{
// In plain text we treat tab as a characters always
DoTextInput(This, "\t", /*isInsertKeyToggled:*/!This._OvertypeMode, /*acceptControlCharacters:*/true);
}
}
// Command handler for Tab and ShiftTab - moves caret between table cells
// if the selection is within a table. Otherwise does nothing and returns false.
private static bool HandleTabInTables(TextEditor This, LogicalDirection direction)
{
if (!This.AcceptsRichContent)
{
return false;
}
if (This.Selection.IsTableCellRange)
{
// When table cell range is selected, Tab simply collapses
// a selection to a content of a first cell
This.Selection.SetCaretToPosition(This.Selection.Start, LogicalDirection.Backward, /*allowStopAtLineEnd:*/false, /*allowStopNearSpace:*/false);
return true;
}
if (This.Selection.IsEmpty && TextPointerBase.IsAtRowEnd(This.Selection.End))
{
// From the end of row we go to the first cell of a next row
TableCell cell = null;
TableRow row = ((TextPointer)This.Selection.End).Parent as TableRow;
Invariant.Assert(row != null);
TableRowGroup body = row.RowGroup;
int rowIndex = body.Rows.IndexOf(row);
if (direction == LogicalDirection.Forward)
{
if (rowIndex + 1 < body.Rows.Count)
{
cell = body.Rows[rowIndex + 1].Cells[0];
}
}
else
{
if (rowIndex > 0)
{
cell = body.Rows[rowIndex - 1].Cells[body.Rows[rowIndex - 1].Cells.Count - 1];
}
}
if (cell != null)
{
This.Selection.Select(cell.ContentStart, cell.ContentEnd);
}
return true;
}
// Check if selection is within a table
TextElement parent = ((TextPointer)This.Selection.Start).Parent as TextElement;
while (parent != null && !(parent is TableCell))
{
parent = parent.Parent as TextElement;
}
if (parent is TableCell)
{
TableCell cell = (TableCell)parent;
TableRow row = cell.Row;
TableRowGroup body = row.RowGroup;
int cellIndex = row.Cells.IndexOf(cell);
int rowIndex = body.Rows.IndexOf(row);
if (direction == LogicalDirection.Forward)
{
if (cellIndex + 1 < row.Cells.Count)
{
cell = row.Cells[cellIndex + 1];
}
else if (rowIndex + 1 < body.Rows.Count)
{
cell = body.Rows[rowIndex + 1].Cells[0];
}
else
{
// Add code for inserting new table row - at the end of a table
}
}
else
{
if (cellIndex > 0)
{
cell = row.Cells[cellIndex - 1];
}
else if (rowIndex > 0)
{
cell = body.Rows[rowIndex - 1].Cells[body.Rows[rowIndex - 1].Cells.Count - 1];
}
else
{
// Add code for inserting new table row - at the end of a table
}
}
Invariant.Assert(cell != null);
This.Selection.Select(cell.ContentStart, cell.ContentEnd);
return true;
}
return false;
}
// ......................................................
//
// Handling Text Input
//
// ......................................................
/// <summary>
/// This is a single method used to insert user input characters.
/// It takes care of typing undo, springload formatting, overtype mode etc.
/// </summary>
/// <param name="This"></param>
/// <param name="textData">
/// Text to insert.
/// </param>
/// <param name="isInsertKeyToggled">
/// Reflects a state of Insert key at the moment of textData input.
/// </param>
/// <param name="acceptControlCharacters">
/// True indicates that control characters like '\t' or '\r' etc. can be inserted.
/// False means that all control characters are filtered out.
/// </param>
private static void DoTextInput(TextEditor This, string textData, bool isInsertKeyToggled, bool acceptControlCharacters)
{
// Hide the mouse cursor on user input.
HideCursor(This);
// Remove control characters. Note that this is not included into _FilterText,
// because we want such kind of filtering only for real input,
// not for copy/paste.
if (!acceptControlCharacters)
{
for (int i = 0; i < textData.Length; i++)
{
if (Char.IsControl(textData[i]))
{
textData = textData.Remove(i--, 1); // decrement i to compensate for character removal
}
}
}
string filteredText = This._FilterText(textData, This.Selection);
if (filteredText.Length == 0)
{
return;
}
TextEditorTyping.OpenTypingUndoUnit(This);
UndoCloseAction closeAction = UndoCloseAction.Rollback;
try
{
using (This.Selection.DeclareChangeBlock())
{
This.Selection.ApplyTypingHeuristics(This.AllowOvertype && This._OvertypeMode && filteredText != "\t");
This.SetSelectedText(filteredText, InputLanguageManager.Current.CurrentInputLanguage);
// Create caret position normalized backward to keep formatting of a character just typed
ITextPointer caretPosition = This.Selection.End.CreatePointer(LogicalDirection.Backward);
// Set selection at the end of input content
This.Selection.SetCaretToPosition(caretPosition, LogicalDirection.Backward, /*allowStopAtLineEnd:*/true, /*allowStopNearSpace:*/true);
// Note: Using explicit backward orientation we keep formatting with
// a previous character during typing.
closeAction = UndoCloseAction.Commit;
}
}
finally
{
TextEditorTyping.CloseTypingUndoUnit(This, closeAction);
}
}
// Takes state originating with a KeyDownEvent or TextInputEvent and
// schedules it for eventual handling.
//
// Normally we delay handling until a Background priority event fires.
// This has the effect of batching multiple input events when
// layout cannot keep up with the input stream.
//
// However, if any mouse events are pending, we handle the event
// immediately, since otherwise we risk the possibility of handling
// the events out of order.
private static void ScheduleInput(TextEditor This, InputItem item)
{
if (!This.AcceptsRichContent || IsMouseInputPending(This))
{
// We have to do the work now, or we'll get out of synch.
TextEditorTyping._FlushPendingInputItems(This);
item.Do();
}
else
{
TextEditorThreadLocalStore threadLocalStore;
threadLocalStore = TextEditor._ThreadLocalStore;
if (threadLocalStore.PendingInputItems == null)
{
threadLocalStore.PendingInputItems = new ArrayList(1);
Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Background, new DispatcherOperationCallback(BackgroundInputCallback), This);
}
threadLocalStore.PendingInputItems.Add(item);
}
}
// Returns true if any mouse input event is currently waiting in the
// win32 message queue for processing.
// Avalon doesn't keep a separate queue for input events. Instead
// it interleaves work items with the win32 input queue.
private static bool IsMouseInputPending(TextEditor This)
{
bool mouseInputPending = false;
IWin32Window win32Window = PresentationSource.CriticalFromVisual(This.UiScope) as IWin32Window;
if (win32Window != null)
{
IntPtr hwnd = IntPtr.Zero;
hwnd = win32Window.Handle;
if (hwnd != (IntPtr)0)
{
System.Windows.Interop.MSG message = new System.Windows.Interop.MSG();
mouseInputPending = UnsafeNativeMethods.PeekMessage(ref message, new HandleRef(null, hwnd), WindowMessage.WM_MOUSEFIRST, WindowMessage.WM_MOUSELAST, NativeMethods.PM_NOREMOVE);
}
}
return mouseInputPending;
}
// Background priority callback used to process keystrokes.
private static object BackgroundInputCallback(object This)
{
TextEditorThreadLocalStore threadLocalStore = TextEditor._ThreadLocalStore;
Invariant.Assert(This is TextEditor);
Invariant.Assert(threadLocalStore.PendingInputItems != null);
try
{
TextEditorTyping._FlushPendingInputItems((TextEditor)This);
}
finally
{
threadLocalStore.PendingInputItems = null;
}
return null;
}
/// <summary>
/// Callback for shutdown finished dispatcher. Before shutdown dispatcher, we should clean
/// InputLanguageChangedEventHandler.
/// </summary>
private static void OnDispatcherShutdownFinished(object sender, EventArgs args)
{
// Remove the dispatcher shutdown finished event handler
Dispatcher.CurrentDispatcher.ShutdownFinished -= new EventHandler(OnDispatcherShutdownFinished);
// Remove the input language changed event handler
InputLanguageManager.Current.InputLanguageChanged -= new InputLanguageEventHandler(OnInputLanguageChanged);
TextEditorThreadLocalStore threadLocalStore = TextEditor._ThreadLocalStore;
// Clear InputLanguageChangeEventHandler count
threadLocalStore.InputLanguageChangeEventHandlerCount = 0;
}
// InputLanguageChanged handler.
private static void OnInputLanguageChanged(object sender, InputLanguageEventArgs e)
{
TextSelection.OnInputLanguageChanged(e.NewLanguage);
}
// Base class for keyboard/text input items.
// Individual keystroke/text events are batched and handled together
// when layout cannot keep up with the input stream.
private abstract class InputItem
{
// Ctor.
internal InputItem(TextEditor textEditor)
{
_textEditor = textEditor;
}
// Handles the input event.
internal abstract void Do();
// The TextEditor instance on which this input item applies.
TextEditor _textEditor;
protected TextEditor TextEditor
{
get
{
return _textEditor;
}
}
}
// Holds state originating from a single TextInputEvent.
private class TextInputItem : InputItem
{
// Ctor.
internal TextInputItem(TextEditor textEditor, string text, bool isInsertKeyToggled)
: base (textEditor)
{
_text = text;
_isInsertKeyToggled = isInsertKeyToggled;
}
// Inserts event content into the document.
internal override void Do()
{
if (TextEditor.UiScope == null)
{
// We dont want to process the input item if the editor has already been detached from its UiScope.
return;
}
DoTextInput(TextEditor, _text, _isInsertKeyToggled, /*acceptControlCharacters:*/false);
}
// Text to input.
private readonly string _text;
private readonly bool _isInsertKeyToggled;
}
// Holds state originating from a single KeyDownEvent.
private class KeyUpInputItem : InputItem
{
// Ctor.
internal KeyUpInputItem(TextEditor textEditor, Key key, ModifierKeys modifiers)
: base(textEditor)
{
_key = key;
_modifiers = modifiers;
}
// Fires the command associated with a keystroke.
internal override void Do()
{
if (TextEditor.UiScope == null)
{
// We dont want to process the input item if the editor has already been detached from its UiScope.
return;
}
// Delegate the work to specific handlers.
switch (_key)
{
case Key.RightShift:
// Only support RTL flow direction in case of having the installed
// bidi input language.
if (TextSelection.IsBidiInputLanguageInstalled() == true)
{
TextEditorTyping.OnFlowDirectionCommand(TextEditor, _key);
}
break;
case Key.LeftShift:
TextEditorTyping.OnFlowDirectionCommand(TextEditor, _key);
break;
default:
Invariant.Assert(false, "Unexpected key value!");
break;
}
}
// Key associated with the original event.
private readonly Key _key;
// Modifier state when the original event fired.
private readonly ModifierKeys _modifiers;
}
// ----------------------------------------------------------
//
// Merge Typing Undo Units
//
// ----------------------------------------------------------
#region Merge Typing Undo Units
/// <summary>
/// The helper for typing undo unit merging.
/// Supposed to be called in the beginning of typing block -
/// before making any changes.
/// Assumes that CloseTypingUndoUnit method will be called
/// after the change is completed.
/// </summary>
private static void OpenTypingUndoUnit(TextEditor This)
{
UndoManager undoManager = This._GetUndoManager();
if (undoManager != null && undoManager.IsEnabled)
{
if (This._typingUndoUnit != null && undoManager.LastUnit == This._typingUndoUnit && !This._typingUndoUnit.Locked)
{
undoManager.Reopen(This._typingUndoUnit);
}
else
{
This._typingUndoUnit = new TextParentUndoUnit(This.Selection);
undoManager.Open(This._typingUndoUnit);
}
}
}
/// <summary>
/// The helper for typing undo unit megring.
/// Supposed to be called at the end of typing block -
/// after all changes are done.
/// Assumes that OpenTypingUndoUnit method was called
/// in the beginning of this sequence.
/// </summary>
private static void CloseTypingUndoUnit(TextEditor This, UndoCloseAction closeAction)
{
UndoManager undoManager = This._GetUndoManager();
if (undoManager != null && undoManager.IsEnabled)
{
if (This._typingUndoUnit != null && undoManager.LastUnit == This._typingUndoUnit && !This._typingUndoUnit.Locked)
{
if (This._typingUndoUnit is TextParentUndoUnit)
{
((TextParentUndoUnit)This._typingUndoUnit).RecordRedoSelectionState();
}
undoManager.Close(This._typingUndoUnit, closeAction);
}
}
else
{
This._typingUndoUnit = null;
}
}
/// <summary>
/// StartInputCorrection command QueryStatus handler
/// </summary>
private static void OnQueryStatusNYI(object target, CanExecuteRoutedEventArgs args)
{
TextEditor This = TextEditor._GetTextEditor(target);
if (This == null)
{
return;
}
args.CanExecute = true;
}
#endregion Merge Typing Undo Units
// MouseMoveEvent listener.
private static void OnMouseMove(object sender, MouseEventArgs e)
{
// Un-vanish the cursor on any mouse move.
_ShowCursor();
}
// MouseMoveEvent listener.
// We only need this event because of the edge case where
// moving the mouse from the outermost pixel of the UiScope to
// another UIElement's real estate doesn't raise a MouseMoveEvent.
private static void OnMouseLeave(object sender, MouseEventArgs e)
{
// Un-vanish the cursor on any mouse leave.
_ShowCursor();
}
// Hides the mouse cursor when the user starts typing.
private static void HideCursor(TextEditor This)
{
if (!TextEditor._ThreadLocalStore.HideCursor &&
SystemParameters.MouseVanish &&
This.UiScope.IsMouseOver)
{
TextEditor._ThreadLocalStore.HideCursor = true;
SafeNativeMethods.ShowCursor(false);
}
}
// When the mouse cursor is over a Hyperlink, force a cursor update
// to display the "hand" cursor appropriately.
private static void UpdateHyperlinkCursor(TextEditor This)
{
if (This.UiScope is RichTextBox && This.TextView != null && This.TextView.IsValid)
{
TextPointer pointer = (TextPointer)This.TextView.GetTextPositionFromPoint(Mouse.GetPosition(This.TextView.RenderScope), false);
if (pointer != null &&
pointer.Parent is TextElement &&
TextSchema.HasHyperlinkAncestor((TextElement)pointer.Parent))
{
Mouse.UpdateCursor();
}
}
}
#endregion Private Methods
private const string KeyBackspace = "Backspace";
private const string KeyDelete = "Delete";
private const string KeyDeleteNextWord = "Ctrl+Delete";
private const string KeyDeletePreviousWord = "Ctrl+Backspace";
private const string KeyEnterLineBreak = "Shift+Enter";
private const string KeyEnterParagraphBreak = "Enter";
private const string KeyShiftBackspace = "Shift+Backspace";
private const string KeyShiftSpace = "Shift+Space";
private const string KeySpace = "Space";
private const string KeyTabBackward = "Shift+Tab";
private const string KeyTabForward = "Tab";
private const string KeyToggleInsert = "Insert";
}
}
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