Code:
/ DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / MS / Internal / documents / HostedElements.cs / 1 / HostedElements.cs
//---------------------------------------------------------------------------- // // Copyright (C) Microsoft Corporation. All rights reserved. // // File: HostedElements.cs // // Enumerator class for returning descendants of TextBlock and FlowDocumentPage // // History: // 01/17/2005 : [....] - created. // //--------------------------------------------------------------------------- using System.Collections; using MS.Internal.Documents; using System.Collections.Generic; using System.Collections.ObjectModel; using System; using System.Diagnostics; #pragma warning disable 1634, 1691 // suppressing PreSharp warnings namespace System.Windows.Documents { ////// Enumerator class for implementation of IContentHost on TextBlock and FlowDocumentPage. /// Used to iterate through descendants of the content host /// internal class HostedElements : IEnumerator{ //------------------------------------------------------------------- // // Constructors // //------------------------------------------------------------------- #region Constructors internal HostedElements(ReadOnlyCollection textSegments) { _textSegments = textSegments; _currentPosition = null; _currentTextSegment = 0; } #endregion Constructors //-------------------------------------------------------------------- // // IDisposable Methods // //------------------------------------------------------------------- #region IDisposable Methods void IDisposable.Dispose() { _textSegments = null; } #endregion IDisposable Methods //-------------------------------------------------------------------- // // Private Methods // //-------------------------------------------------------------------- #region Private Methods public bool MoveNext() { // If _textSegments has been disposed, throw exception if (_textSegments == null) { throw new ObjectDisposedException("HostedElements"); } if (_textSegments.Count == 0) return false; // Verify that current position matches with current text segment, and set it if it's null. if (_currentPosition == null) { // We should be at the start Debug.Assert(_currentTextSegment == 0); // Type check that we can create _currentPosition here if (_textSegments[0].Start is TextPointer) { _currentPosition = new TextPointer(_textSegments[0].Start as TextPointer); } else { // We cannot search, return false _currentPosition = null; return false; } } else if (_currentTextSegment < _textSegments.Count) { // We have not yet reached the end of the container. Assert that our position matches with // our current text segment Debug.Assert(((ITextPointer)_currentPosition).CompareTo(_textSegments[_currentTextSegment].Start) >= 0 && ((ITextPointer)_currentPosition).CompareTo(_textSegments[_currentTextSegment].End) < 0); // This means that we are in the middle of content, so the previous search would have returned // something. We want to now move beyond that position _currentPosition.MoveToNextContextPosition(LogicalDirection.Forward); } // Search strarting from the position in the current segment while (_currentTextSegment < _textSegments.Count) { Debug.Assert(((ITextPointer)_currentPosition).CompareTo(_textSegments[_currentTextSegment].Start) >= 0); while (((ITextPointer)_currentPosition).CompareTo(_textSegments[_currentTextSegment].End) < 0) { if (_currentPosition.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.ElementStart || _currentPosition.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.EmbeddedElement) { return true; } else { _currentPosition.MoveToNextContextPosition(LogicalDirection.Forward); } } // We have reached the end of a segement. Update counters _currentTextSegment++; if (_currentTextSegment < _textSegments.Count) { // Move to the next segment if (_textSegments[_currentTextSegment].Start is TextPointer) { _currentPosition = new TextPointer(_textSegments[_currentTextSegment].Start as TextPointer); } else { // This state is invalid, set to null and return false _currentPosition = null; return false; } } } // We have reached the end without finding an element. Return false. return false; } #endregion Private Methods //------------------------------------------------------------------- // // Private Properties // //-------------------------------------------------------------------- #region Private Properties object IEnumerator.Current { get { return this.Current; } } void IEnumerator.Reset() { throw new NotImplementedException(); } public IInputElement Current { get { // Disable PRESharp warning 6503: "Property get methods should not throw exceptions". // HostedElements must throw exception if Current property is incorrectly accessed if (_textSegments == null) { // Collection was modified #pragma warning suppress 6503 // IEnumerator.Current is documented to throw this exception throw new InvalidOperationException(SR.Get(SRID.EnumeratorCollectionDisposed)); } if (_currentPosition == null) { // Enumerator not started. Call MoveNext to see if we can move ahead #pragma warning suppress 6503 // IEnumerator.Current is documented to throw this exception throw new InvalidOperationException(SR.Get(SRID.EnumeratorNotStarted)); } IInputElement currentElement = null; switch (_currentPosition.GetPointerContext(LogicalDirection.Forward)) { case TextPointerContext.ElementStart: Debug.Assert(_currentPosition.GetAdjacentElementFromOuterPosition(LogicalDirection.Forward) is IInputElement); currentElement = _currentPosition.GetAdjacentElementFromOuterPosition(LogicalDirection.Forward); break; case TextPointerContext.EmbeddedElement: Debug.Assert(_currentPosition.GetAdjacentElement(LogicalDirection.Forward) is IInputElement); currentElement = (IInputElement)_currentPosition.GetAdjacentElement(LogicalDirection.Forward); break; default: // Throw exception because this function should only be called after MoveNext, and not // if MoveNext returns false Debug.Assert(false, "Invalid state in HostedElements.cs"); break; } return currentElement; } } #endregion Private Properties //------------------------------------------------------------------- // // Private Fields // //------------------------------------------------------------------- #region Private Fields ReadOnlyCollection _textSegments; TextPointer _currentPosition; int _currentTextSegment; #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
- ProviderConnectionPoint.cs
- ellipse.cs
- PasswordDeriveBytes.cs
- Int32Collection.cs
- WriteStateInfoBase.cs
- SqlDataSourceFilteringEventArgs.cs
- TableLayoutRowStyleCollection.cs
- EventMappingSettings.cs
- AuthorizationRule.cs
- ExtenderProviderService.cs
- PromptEventArgs.cs
- MouseOverProperty.cs
- RewritingValidator.cs
- InputGestureCollection.cs
- XmlILIndex.cs
- MsmqAppDomainProtocolHandler.cs
- Material.cs
- HttpPostedFileBase.cs
- PagePropertiesChangingEventArgs.cs
- Opcode.cs
- MorphHelper.cs
- ServiceThrottlingBehavior.cs
- FormsAuthenticationEventArgs.cs
- SQLBytesStorage.cs
- PixelFormat.cs
- ObjectStateEntryDbUpdatableDataRecord.cs
- DiscoveryMessageProperty.cs
- ByteStreamBufferedMessageData.cs
- Geometry3D.cs
- ProcessHostConfigUtils.cs
- KeyInstance.cs
- WebPartUserCapability.cs
- OutputCacheProviderCollection.cs
- AspNetCacheProfileAttribute.cs
- hresults.cs
- RangeValueProviderWrapper.cs
- BindingValueChangedEventArgs.cs
- MulticastDelegate.cs
- FirstMatchCodeGroup.cs
- XmlWhitespace.cs
- Command.cs
- StandardMenuStripVerb.cs
- RelationalExpressions.cs
- TitleStyle.cs
- IPAddress.cs
- CodeTypeConstructor.cs
- Model3DCollection.cs
- PlainXmlSerializer.cs
- PersonalizationProvider.cs
- NodeFunctions.cs
- OleDbCommandBuilder.cs
- OleServicesContext.cs
- SmiRequestExecutor.cs
- MembershipUser.cs
- HMACSHA256.cs
- HotCommands.cs
- ServiceProviders.cs
- BrowserCapabilitiesFactory.cs
- XmlAttributeCollection.cs
- CroppedBitmap.cs
- TimeEnumHelper.cs
- ObjectView.cs
- CompositeKey.cs
- SqlInternalConnectionTds.cs
- SwitchElementsCollection.cs
- NavigationProperty.cs
- GridViewUpdateEventArgs.cs
- ScriptingAuthenticationServiceSection.cs
- SqlConnection.cs
- WindowsFormsDesignerOptionService.cs
- AstTree.cs
- StoreAnnotationsMap.cs
- BooleanFacetDescriptionElement.cs
- SingleQueryOperator.cs
- Cursor.cs
- TypeInitializationException.cs
- FusionWrap.cs
- DbDataReader.cs
- _SafeNetHandles.cs
- BamlCollectionHolder.cs
- LinkClickEvent.cs
- PerfService.cs
- PriorityBindingExpression.cs
- Main.cs
- SessionPageStatePersister.cs
- FilterQueryOptionExpression.cs
- ElementsClipboardData.cs
- ObjectNotFoundException.cs
- RectAnimationUsingKeyFrames.cs
- PenThreadWorker.cs
- ForwardPositionQuery.cs
- TextComposition.cs
- IgnoreDeviceFilterElementCollection.cs
- FilterableData.cs
- EventBindingService.cs
- TableSectionStyle.cs
- SqlBinder.cs
- ThicknessAnimationUsingKeyFrames.cs
- SiteMembershipCondition.cs
- WorkflowRuntime.cs