Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Framework / System / Windows / Documents / RangeContentEnumerator.cs / 1305600 / RangeContentEnumerator.cs
#pragma warning disable 1634, 1691 // To enable presharp warning disables (#pragma suppress) below. //---------------------------------------------------------------------------- // //// Copyright (C) Microsoft Corporation. All rights reserved. // // // // Description: IEnumerator for TextRange and TextElement content. // // // History: // 05/27/2003 : [....] - Created // //--------------------------------------------------------------------------- using System; using System.Collections; using MS.Internal; using System.Text; using MS.Utility; using System.Windows.Controls; #pragma warning disable 1634, 1691 // suppressing PreSharp warnings namespace System.Windows.Documents { internal class RangeContentEnumerator : IEnumerator { //----------------------------------------------------- // // Constructors // //----------------------------------------------------- #region Constructors // Creates an enumerator instance. // Null start/end creates an empty enumerator. internal RangeContentEnumerator(TextPointer start, TextPointer end) { Invariant.Assert(start != null && end != null || start == null && end == null, "If start is null end should be null!"); _start = start; _end = end; // Remember what generation the backing store was in when we started, // so we can throw if this enumerator is accessed after content has // changed. if (_start != null) { _generation = _start.TextContainer.Generation; } } #endregion Constructors //------------------------------------------------------ // // Public Methods // //----------------------------------------------------- #region Public Methods ////// Return the current object this enumerator is pointing to. This is /// generally a FrameworkElement, TextElement, an embedded /// object, or Text content. /// public object Current { get { int runLength; int offset; if (_navigator == null) { // Disable presharp 6503: Property get methods should not throw exceptions. // We must throw here -- it's part of the IEnumerator contract. #pragma warning suppress 6503 throw new InvalidOperationException(SR.Get(SRID.EnumeratorNotStarted)); } // Check _currentCache before looking at _navigator. For the // last item in the enumeration, _navigator == _end, but // that's ok, the previous get_Current call (which sets _currentCache // non-null) put it there. if (_currentCache != null) { return _currentCache; } if (_navigator.CompareTo(_end) >= 0) { #pragma warning suppress 6503 // IEnumerator.Current is documented to throw this exception throw new InvalidOperationException(SR.Get(SRID.EnumeratorReachedEnd)); } // Throw if the tree has been modified since this enumerator was created unless a tree walk // by the property system is in progress. For example, changing DataContext on FlowDocument // can invalidate a binding on Run.Text during the inherited property change tree walk, // which in turn can modify the TextContainer. if (_generation != _start.TextContainer.Generation && !IsLogicalChildrenIterationInProgress) { #pragma warning suppress 6503 // IEnumerator.Current is documented to throw this exception throw new InvalidOperationException(SR.Get(SRID.EnumeratorVersionChanged)); } switch (_navigator.GetPointerContext(LogicalDirection.Forward)) { case TextPointerContext.Text: offset = 0; // Merge all successive text runs into a single value. do { runLength = _navigator.GetTextRunLength(LogicalDirection.Forward); EnsureBufferCapacity(offset + runLength); _navigator.GetTextInRun(LogicalDirection.Forward, _buffer, offset, runLength); offset += runLength; _navigator.MoveToNextContextPosition(LogicalDirection.Forward); } while (_navigator.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.Text); _currentCache = new string(_buffer, 0, offset); // _navigator is at next content. break; case TextPointerContext.EmbeddedElement: _currentCache = _navigator.GetAdjacentElement(LogicalDirection.Forward); // Position _navigator at next content. _navigator.MoveToNextContextPosition(LogicalDirection.Forward); break; case TextPointerContext.ElementStart: // Return the element, and advance past its entire content. _navigator.MoveToNextContextPosition(LogicalDirection.Forward); _currentCache = _navigator.Parent; // Position _navigator at next content. _navigator.MoveToElementEdge(ElementEdge.AfterEnd); break; default: Invariant.Assert(false, "Unexpected run type!"); _currentCache = null; // We should never get here. break; } return _currentCache; } } ////// Advance the enumerator to the next object in the range. Return true if content /// was found. /// public bool MoveNext() { // Throw if the tree has been modified since this enumerator was created unless a tree walk // by the property system is in progress. For example, changing DataContext on FlowDocument // can invalidate a binding on Run.Text during the inherited property change tree walk, // which in turn can modify the TextContainer. if (_start != null && _generation != _start.TextContainer.Generation && !IsLogicalChildrenIterationInProgress) { throw new InvalidOperationException(SR.Get(SRID.EnumeratorVersionChanged)); } if (_start == null || _start.CompareTo(_end) == 0) return false; if (_navigator != null && _navigator.CompareTo(_end) >= 0) { return false; } if (_navigator == null) { _navigator = new TextPointer(_start); } else if (_currentCache == null) // If we have a cache, _navigator is already positioned at the next item. { switch (_navigator.GetPointerContext(LogicalDirection.Forward)) { case TextPointerContext.Text: // Skip all successive text runs as a single value. do { _navigator.MoveToNextContextPosition(LogicalDirection.Forward); } while (_navigator.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.Text && _navigator.CompareTo(_end) < 0); break; case TextPointerContext.EmbeddedElement: _navigator.MoveToNextContextPosition(LogicalDirection.Forward); break; case TextPointerContext.ElementStart: // Return the element, and advance past its entire content. _navigator.MoveToNextContextPosition(LogicalDirection.Forward); _navigator.MoveToPosition(((TextElement)_navigator.Parent).ElementEnd); break; default: Invariant.Assert(false, "Unexpected run type!"); break; } } _currentCache = null; return (_navigator.CompareTo(_end) < 0); } ////// Reset the enumerator to the start of the range. /// public void Reset() { // Throw if the tree has been modified since this enumerator was created. if (_start != null && _generation != _start.TextContainer.Generation) { throw new InvalidOperationException(SR.Get(SRID.EnumeratorVersionChanged)); } _navigator = null; } #endregion Public Methods //------------------------------------------------------ // // Public Properties // //------------------------------------------------------ #region Public Properties #endregion Public Properties //----------------------------------------------------- // // Public Events // //------------------------------------------------------ #region Public Events #endregion Public Events //----------------------------------------------------- // // Protected Methods // //----------------------------------------------------- #region Protected Methods #endregion Protected Events //----------------------------------------------------- // // Internal Methods // //------------------------------------------------------ #region Internal Methods #endregion Internal methods //----------------------------------------------------- // // Internal Properties // //------------------------------------------------------ #region Internal Properties #endregion Internal Properties //------------------------------------------------------ // // Internal Events // //----------------------------------------------------- #region Internal Events #endregion Internal Events //------------------------------------------------------ // // Private Methods // //----------------------------------------------------- #region Private Methods private void EnsureBufferCapacity(int size) { char [] newBuffer; if (_buffer == null) { _buffer = new char[size]; } else if (_buffer.Length < size) { newBuffer = new char[Math.Max(2*_buffer.Length, size)]; _buffer.CopyTo(newBuffer, 0); _buffer = newBuffer; } } #endregion Private methods //----------------------------------------------------- // // Private Properties // //----------------------------------------------------- #region Private Properties private bool IsLogicalChildrenIterationInProgress { get { DependencyObject node = _start.Parent; while (node != null) { FrameworkElement fe = node as FrameworkElement; if (fe != null) { if (fe.IsLogicalChildrenIterationInProgress) { return true; } } else { FrameworkContentElement fce = node as FrameworkContentElement; if (fce != null && fce.IsLogicalChildrenIterationInProgress) { return true; } } node = LogicalTreeHelper.GetParent(node); } return false; } } #endregion Private Properties //------------------------------------------------------ // // Private Fields // //----------------------------------------------------- #region Private Fields // Edges of the span to enumerator over. private readonly TextPointer _start; private readonly TextPointer _end; // Backing store generation when this enumerator was created. private readonly uint _generation; // Current position in the enumeration. private TextPointer _navigator; // Calculated content at the current position. private object _currentCache; // Buffer to text content retrieval. private char [] _buffer; #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
- StylusTip.cs
- EmptyCollection.cs
- ReferentialConstraint.cs
- DeviceContext2.cs
- BitSet.cs
- TextElementCollection.cs
- TextParagraphView.cs
- ApplicationContext.cs
- BamlVersionHeader.cs
- ProjectionPathSegment.cs
- Matrix3DStack.cs
- WrapPanel.cs
- CustomError.cs
- TextSelection.cs
- BypassElementCollection.cs
- NavigationEventArgs.cs
- RoutedEventValueSerializer.cs
- WebPartEditorCancelVerb.cs
- ServiceHostFactory.cs
- ObjRef.cs
- Variant.cs
- FigureParagraph.cs
- RawStylusActions.cs
- WorkflowQueuingService.cs
- XmlWrappingWriter.cs
- SchemaCompiler.cs
- SettingsPropertyWrongTypeException.cs
- VSWCFServiceContractGenerator.cs
- ModifiableIteratorCollection.cs
- ReadWriteControlDesigner.cs
- Variable.cs
- DisplayNameAttribute.cs
- WebPartZoneBase.cs
- RecipientInfo.cs
- QueryStringParameter.cs
- precedingsibling.cs
- SchemaObjectWriter.cs
- CompareValidator.cs
- ParseChildrenAsPropertiesAttribute.cs
- SkipStoryboardToFill.cs
- StateBag.cs
- FixedSOMTable.cs
- JavaScriptString.cs
- ProfileBuildProvider.cs
- EventHandlersStore.cs
- DependencyPropertyValueSerializer.cs
- OleStrCAMarshaler.cs
- CodeTypeReferenceSerializer.cs
- CqlLexer.cs
- DataTablePropertyDescriptor.cs
- StatusBar.cs
- StickyNoteHelper.cs
- GlyphTypeface.cs
- DataGridViewRowErrorTextNeededEventArgs.cs
- XmlSchemaAppInfo.cs
- RenderDataDrawingContext.cs
- CategoryGridEntry.cs
- DataRecordInternal.cs
- PageCodeDomTreeGenerator.cs
- SourceFileBuildProvider.cs
- Parser.cs
- ElementUtil.cs
- FontSource.cs
- TrimSurroundingWhitespaceAttribute.cs
- StyleModeStack.cs
- SqlDataSourceView.cs
- SerializationAttributes.cs
- ConfigurationSchemaErrors.cs
- SecurityCriticalDataForSet.cs
- HeaderUtility.cs
- Zone.cs
- KeyValuePair.cs
- LifetimeMonitor.cs
- remotingproxy.cs
- StopStoryboard.cs
- Util.cs
- SecurityTokenSerializer.cs
- ContentTextAutomationPeer.cs
- SerializationHelper.cs
- PassportPrincipal.cs
- HijriCalendar.cs
- ElementMarkupObject.cs
- ActivityExecutorSurrogate.cs
- ImportException.cs
- DrawingGroup.cs
- HMACMD5.cs
- IPCCacheManager.cs
- diagnosticsswitches.cs
- WebPartManager.cs
- SatelliteContractVersionAttribute.cs
- BaseServiceProvider.cs
- XslCompiledTransform.cs
- ScopelessEnumAttribute.cs
- TrackBar.cs
- XmlSchemaSet.cs
- Selector.cs
- ContentHostHelper.cs
- CounterCreationData.cs
- x509utils.cs
- CustomAttribute.cs