Code:
/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / Orcas / NetFXw7 / wpf / src / Framework / System / Windows / Documents / UIElementPropertyUndoUnit.cs / 1 / UIElementPropertyUndoUnit.cs
//---------------------------------------------------------------------------- // // File: UIElementPropertyUndoUnit.cs // // Description: Undo unit for property sets on UIElement. // It is created for: // 1. FlowDirectionProperty sets on a TextEditor's UI scope element. // 2. HorizontalAlignmentProperty sets on UIElement child of BlockUIContainer. // // History: // 01/13/2006 : pjoshi - Branched from FlowDirectionUndoUnit.cs // //--------------------------------------------------------------------------- using System; using System.Windows; using MS.Internal; using MS.Internal.Documents; namespace System.Windows.Documents { // 1. Undo unit for FlowDirectionProperty sets on a TextEditor's UI scope element. // // The TextEditor lets users configure the FlowDirection of text dynamically // even when running on TextBoxes (TextEditor.AcceptsRichContent == false). // In this case, there's no TextElement to hang property values on, so we must // resort to assigning values directly to the TextEditor's UiScope, which is // not covered by the TextContainer's undo infrastructure. // // This class encapsulates an undo unit used to track FlowDirection changes on // plain text documents. // // 2. Undo unit for HorizontalAlignmentProperty sets on UIElement child of BlockUIContainer. // // When applying TextAlignment property to BlockUIContainer elements in rich text documents, // text alignment must be translated into HorizontalAlignment of its child UIElement. // We must assign this property value directly to the embedded UIElement. // Since TextEditor's undo mechanism for property changes on TextElements in the tree relies // on the OnPropertyChanged event listener, it is unable to track this property change. // Also, it is infeasible to have a OnPropertyChanged listener for all UIElements. // So we resort to explicitly adding this special undo unit in such situation. // internal class UIElementPropertyUndoUnit : IUndoUnit { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors // Create a new undo unit instance. private UIElementPropertyUndoUnit(UIElement uiElement, DependencyProperty property, object oldValue) { _uiElement = uiElement; _property = property; _oldValue = oldValue; } #endregion Constructors //------------------------------------------------------ // // Public Methods // //----------------------------------------------------- #region Public Methods // Called by the undo manager. Restores tree state to its condition // when the unit was created. public void Do() { if (_oldValue != DependencyProperty.UnsetValue) { _uiElement.SetValue(_property, _oldValue); } else { _uiElement.ClearValue(_property); } } // Called by the undo manager. public bool Merge(IUndoUnit unit) { Invariant.Assert(unit != null); return false; } #endregion Public Methods //------------------------------------------------------ // // Internal Methods // //------------------------------------------------------ #region Internal Methods // Note that following strongly typed overloads of Add are meant to restrict the usage of UIElementPropertyUndoUnit // for tracking changes to only a limited set of properties of UIElements. // In general, it is not safe to keep a reference to the original property value, however for enum types, it is safe to do so. // Add a new UIElementPropertyUndoUnit to the undo stack for HorizontalAlignment property. internal static void Add(ITextContainer textContainer, UIElement uiElement, DependencyProperty property, HorizontalAlignment newValue) { AddPrivate(textContainer, uiElement, property, newValue); } // Add a new UIElementPropertyUndoUnit to the undo stack for FlowDirection property. internal static void Add(ITextContainer textContainer, UIElement uiElement, DependencyProperty property, FlowDirection newValue) { AddPrivate(textContainer, uiElement, property, newValue); } #endregion Internal Methods //----------------------------------------------------- // // Privte Methods // //------------------------------------------------------ #region Private Methods // Private helper that adds a new UIElementPropertyUndoUnit to the undo stack. private static void AddPrivate(ITextContainer textContainer, UIElement uiElement, DependencyProperty property, object newValue) { UndoManager undoManager = TextTreeUndo.GetOrClearUndoManager(textContainer); if (undoManager == null) { return; } object currentValue = uiElement.ReadLocalValue(property); if (currentValue is Expression) { // Can't undo when old value is an expression, so clear the stack. undoManager.Clear(); return; } if (currentValue.Equals(newValue)) { // No property change. return; } undoManager.Add(new UIElementPropertyUndoUnit(uiElement, property, currentValue)); } #endregion Private Methods //----------------------------------------------------- // // Private Fields // //----------------------------------------------------- #region Private Fields // UIElement associated with this undo unit. private readonly UIElement _uiElement; // DependencyProperty of the UIElement associated with this undo unit. private readonly DependencyProperty _property; // Original property value. private readonly object _oldValue; #endregion Private Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved. //---------------------------------------------------------------------------- // // File: UIElementPropertyUndoUnit.cs // // Description: Undo unit for property sets on UIElement. // It is created for: // 1. FlowDirectionProperty sets on a TextEditor's UI scope element. // 2. HorizontalAlignmentProperty sets on UIElement child of BlockUIContainer. // // History: // 01/13/2006 : pjoshi - Branched from FlowDirectionUndoUnit.cs // //--------------------------------------------------------------------------- using System; using System.Windows; using MS.Internal; using MS.Internal.Documents; namespace System.Windows.Documents { // 1. Undo unit for FlowDirectionProperty sets on a TextEditor's UI scope element. // // The TextEditor lets users configure the FlowDirection of text dynamically // even when running on TextBoxes (TextEditor.AcceptsRichContent == false). // In this case, there's no TextElement to hang property values on, so we must // resort to assigning values directly to the TextEditor's UiScope, which is // not covered by the TextContainer's undo infrastructure. // // This class encapsulates an undo unit used to track FlowDirection changes on // plain text documents. // // 2. Undo unit for HorizontalAlignmentProperty sets on UIElement child of BlockUIContainer. // // When applying TextAlignment property to BlockUIContainer elements in rich text documents, // text alignment must be translated into HorizontalAlignment of its child UIElement. // We must assign this property value directly to the embedded UIElement. // Since TextEditor's undo mechanism for property changes on TextElements in the tree relies // on the OnPropertyChanged event listener, it is unable to track this property change. // Also, it is infeasible to have a OnPropertyChanged listener for all UIElements. // So we resort to explicitly adding this special undo unit in such situation. // internal class UIElementPropertyUndoUnit : IUndoUnit { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors // Create a new undo unit instance. private UIElementPropertyUndoUnit(UIElement uiElement, DependencyProperty property, object oldValue) { _uiElement = uiElement; _property = property; _oldValue = oldValue; } #endregion Constructors //------------------------------------------------------ // // Public Methods // //----------------------------------------------------- #region Public Methods // Called by the undo manager. Restores tree state to its condition // when the unit was created. public void Do() { if (_oldValue != DependencyProperty.UnsetValue) { _uiElement.SetValue(_property, _oldValue); } else { _uiElement.ClearValue(_property); } } // Called by the undo manager. public bool Merge(IUndoUnit unit) { Invariant.Assert(unit != null); return false; } #endregion Public Methods //------------------------------------------------------ // // Internal Methods // //------------------------------------------------------ #region Internal Methods // Note that following strongly typed overloads of Add are meant to restrict the usage of UIElementPropertyUndoUnit // for tracking changes to only a limited set of properties of UIElements. // In general, it is not safe to keep a reference to the original property value, however for enum types, it is safe to do so. // Add a new UIElementPropertyUndoUnit to the undo stack for HorizontalAlignment property. internal static void Add(ITextContainer textContainer, UIElement uiElement, DependencyProperty property, HorizontalAlignment newValue) { AddPrivate(textContainer, uiElement, property, newValue); } // Add a new UIElementPropertyUndoUnit to the undo stack for FlowDirection property. internal static void Add(ITextContainer textContainer, UIElement uiElement, DependencyProperty property, FlowDirection newValue) { AddPrivate(textContainer, uiElement, property, newValue); } #endregion Internal Methods //----------------------------------------------------- // // Privte Methods // //------------------------------------------------------ #region Private Methods // Private helper that adds a new UIElementPropertyUndoUnit to the undo stack. private static void AddPrivate(ITextContainer textContainer, UIElement uiElement, DependencyProperty property, object newValue) { UndoManager undoManager = TextTreeUndo.GetOrClearUndoManager(textContainer); if (undoManager == null) { return; } object currentValue = uiElement.ReadLocalValue(property); if (currentValue is Expression) { // Can't undo when old value is an expression, so clear the stack. undoManager.Clear(); return; } if (currentValue.Equals(newValue)) { // No property change. return; } undoManager.Add(new UIElementPropertyUndoUnit(uiElement, property, currentValue)); } #endregion Private Methods //----------------------------------------------------- // // Private Fields // //----------------------------------------------------- #region Private Fields // UIElement associated with this undo unit. private readonly UIElement _uiElement; // DependencyProperty of the UIElement associated with this undo unit. private readonly DependencyProperty _property; // Original property value. private readonly object _oldValue; #endregion Private Fields } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.
Link Menu
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
- RelatedCurrencyManager.cs
- XmlILConstructAnalyzer.cs
- MissingMemberException.cs
- NumberFormatInfo.cs
- InvokeMethodActivity.cs
- WebPartDescription.cs
- TdsEnums.cs
- FieldAccessException.cs
- SyntaxCheck.cs
- MimeImporter.cs
- HttpListenerContext.cs
- TextProperties.cs
- CredentialCache.cs
- OpCodes.cs
- AssertSection.cs
- SequentialOutput.cs
- PermissionSet.cs
- TemplatingOptionsDialog.cs
- SchemaTableColumn.cs
- DbParameterCollection.cs
- DeploymentExceptionMapper.cs
- ServiceDescriptions.cs
- PointValueSerializer.cs
- PrintingPermissionAttribute.cs
- MarshalByValueComponent.cs
- References.cs
- MatrixKeyFrameCollection.cs
- TraceSwitch.cs
- Viewport2DVisual3D.cs
- Roles.cs
- DataSourceXmlTextReader.cs
- TargetException.cs
- MD5.cs
- FactoryId.cs
- DataGridTableStyleMappingNameEditor.cs
- SafeEventLogReadHandle.cs
- NameSpaceExtractor.cs
- ReferencedCollectionType.cs
- BaseProcessProtocolHandler.cs
- DesignerSerializationOptionsAttribute.cs
- filewebrequest.cs
- AuthorizationSection.cs
- HandlerBase.cs
- MemoryRecordBuffer.cs
- httpserverutility.cs
- GridViewUpdatedEventArgs.cs
- ClientEventManager.cs
- SchemaMapping.cs
- CollectionView.cs
- DataSourceNameHandler.cs
- Track.cs
- PriorityBindingExpression.cs
- FormViewRow.cs
- XamlStream.cs
- DataSourceCache.cs
- XPathNodeIterator.cs
- ListItemParagraph.cs
- IDReferencePropertyAttribute.cs
- IntranetCredentialPolicy.cs
- ProjectionCamera.cs
- TogglePattern.cs
- WriteFileContext.cs
- DictionaryChange.cs
- WorkflowApplicationAbortedException.cs
- TypedElement.cs
- FontWeights.cs
- TextServicesPropertyRanges.cs
- Resources.Designer.cs
- oledbconnectionstring.cs
- XmlDataSource.cs
- ControlBuilderAttribute.cs
- TPLETWProvider.cs
- ReferenceConverter.cs
- BaseTemplateBuildProvider.cs
- LinearQuaternionKeyFrame.cs
- ExpressionPrinter.cs
- Popup.cs
- AsmxEndpointPickerExtension.cs
- CountAggregationOperator.cs
- AtomContentProperty.cs
- StrokeCollectionDefaultValueFactory.cs
- PrintEvent.cs
- MenuItemCollection.cs
- EventBuilder.cs
- PriorityBinding.cs
- SerializerWriterEventHandlers.cs
- Int16AnimationBase.cs
- FontStretches.cs
- WaveHeader.cs
- StylusPlugInCollection.cs
- SchemaTableColumn.cs
- TableRow.cs
- ExtensionQuery.cs
- XmlTextReader.cs
- BitmapInitialize.cs
- _FtpControlStream.cs
- SchemaMerger.cs
- SafeLibraryHandle.cs
- ApplicationException.cs
- BinarySerializer.cs