// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Input;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.AvalonEdit.Editing;
using ICSharpCode.AvalonEdit.Utils;
namespace ICSharpCode.AvalonEdit.Snippets
{
/// <summary>
/// Represents the context of a snippet insertion.
/// </summary>
public class InsertionContext : IWeakEventListener
{
enum Status
{
Insertion,
RaisingInsertionCompleted,
Interactive,
RaisingDeactivated,
Deactivated
}
Status currentStatus = Status.Insertion;
/// <summary>
/// Creates a new InsertionContext instance.
/// </summary>
public InsertionContext(TextArea textArea, int insertionPosition)
{
if (textArea == null)
throw new ArgumentNullException("textArea");
this.TextArea = textArea;
this.Document = textArea.Document;
this.SelectedText = textArea.Selection.GetText();
this.InsertionPosition = insertionPosition;
this.startPosition = insertionPosition;
DocumentLine startLine = this.Document.GetLineByOffset(insertionPosition);
ISegment indentation = TextUtilities.GetWhitespaceAfter(this.Document, startLine.Offset);
this.Indentation = Document.GetText(indentation.Offset, Math.Min(indentation.EndOffset, insertionPosition) - indentation.Offset);
this.Tab = textArea.Options.IndentationString;
this.LineTerminator = TextUtilities.GetNewLineFromDocument(this.Document, startLine.LineNumber);
}
/// <summary>
/// Gets the text area.
/// </summary>
public TextArea TextArea { get; private set; }
/// <summary>
/// Gets the text document.
/// </summary>
public TextDocument Document { get; private set; }
/// <summary>
/// Gets the text that was selected before the insertion of the snippet.
/// </summary>
public string SelectedText { get; private set; }
/// <summary>
/// Gets the indentation at the insertion position.
/// </summary>
public string Indentation { get; private set; }
/// <summary>
/// Gets the indentation string for a single indentation level.
/// </summary>
public string Tab { get; private set; }
/// <summary>
/// Gets the line terminator at the insertion position.
/// </summary>
public string LineTerminator { get; private set; }
/// <summary>
/// Gets/Sets the insertion position.
/// </summary>
public int InsertionPosition { get; set; }
readonly int startPosition;
AnchorSegment wholeSnippetAnchor;
bool deactivateIfSnippetEmpty;
/// <summary>
/// Gets the start position of the snippet insertion.
/// </summary>
public int StartPosition {
get {
if (wholeSnippetAnchor != null)
return wholeSnippetAnchor.Offset;
else
return startPosition;
}
}
/// <summary>
/// Inserts text at the insertion position and advances the insertion position.
/// This method will add the current indentation to every line in <paramref name="text"/> and will
/// replace newlines with the expected newline for the document.
/// </summary>
public void InsertText(string text)
{
if (text == null)
throw new ArgumentNullException("text");
if (currentStatus != Status.Insertion)
throw new InvalidOperationException();
text = text.Replace("\t", this.Tab);
using (this.Document.RunUpdate()) {
int textOffset = 0;
SimpleSegment segment;
while ((segment = NewLineFinder.NextNewLine(text, textOffset)) != SimpleSegment.Invalid) {
string insertString = text.Substring(textOffset, segment.Offset - textOffset)
+ this.LineTerminator + this.Indentation;
this.Document.Insert(InsertionPosition, insertString);
this.InsertionPosition += insertString.Length;
textOffset = segment.EndOffset;
}
string remainingInsertString = text.Substring(textOffset);
this.Document.Insert(InsertionPosition, remainingInsertString);
this.InsertionPosition += remainingInsertString.Length;
}
}
Dictionary<SnippetElement, IActiveElement> elementMap = new Dictionary<SnippetElement, IActiveElement>();
List<IActiveElement> registeredElements = new List<IActiveElement>();
/// <summary>
/// Registers an active element. Elements should be registered during insertion and will be called back
/// when insertion has completed.
/// </summary>
/// <param name="owner">The snippet element that created the active element.</param>
/// <param name="element">The active element.</param>
public void RegisterActiveElement(SnippetElement owner, IActiveElement element)
{
if (owner == null)
throw new ArgumentNullException("owner");
if (element == null)
throw new ArgumentNullException("element");
if (currentStatus != Status.Insertion)
throw new InvalidOperationException();
elementMap.Add(owner, element);
registeredElements.Add(element);
}
/// <summary>
/// Returns the active element belonging to the specified snippet element, or null if no such active element is found.
/// </summary>
public IActiveElement GetActiveElement(SnippetElement owner)
{
if (owner == null)
throw new ArgumentNullException("owner");
IActiveElement element;
if (elementMap.TryGetValue(owner, out element))
return element;
else
return null;
}
/// <summary>
/// Gets the list of active elements.
/// </summary>
public IEnumerable<IActiveElement> ActiveElements {
get { return registeredElements; }
}
/// <summary>
/// Calls the <see cref="IActiveElement.OnInsertionCompleted"/> method on all registered active elements
/// and raises the <see cref="InsertionCompleted"/> event.
/// </summary>
/// <param name="e">The EventArgs to use</param>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1030:UseEventsWhereAppropriate",
Justification="There is an event and this method is raising it.")]
public void RaiseInsertionCompleted(EventArgs e)
{
if (currentStatus != Status.Insertion)
throw new InvalidOperationException();
if (e == null)
e = EventArgs.Empty;
currentStatus = Status.RaisingInsertionCompleted;
int endPosition = this.InsertionPosition;
this.wholeSnippetAnchor = new AnchorSegment(Document, startPosition, endPosition - startPosition);
TextDocumentWeakEventManager.UpdateFinished.AddListener(Document, this);
deactivateIfSnippetEmpty = (endPosition != startPosition);
foreach (IActiveElement element in registeredElements) {
element.OnInsertionCompleted();
}
if (InsertionCompleted != null)
InsertionCompleted(this, e);
currentStatus = Status.Interactive;
if (registeredElements.Count == 0) {
// deactivate immediately if there are no interactive elements
Deactivate(new SnippetEventArgs(DeactivateReason.NoActiveElements));
} else {
myInputHandler = new SnippetInputHandler(this);
// disable existing snippet input handlers - there can be only 1 active snippet
foreach (TextAreaStackedInputHandler h in TextArea.StackedInputHandlers) {
if (h is SnippetInputHandler)
TextArea.PopStackedInputHandler(h);
}
TextArea.PushStackedInputHandler(myInputHandler);
}
}
SnippetInputHandler myInputHandler;
/// <summary>
/// Occurs when the all snippet elements have been inserted.
/// </summary>
public event EventHandler InsertionCompleted;
/// <summary>
/// Calls the <see cref="IActiveElement.Deactivate"/> method on all registered active elements.
/// </summary>
/// <param name="e">The EventArgs to use</param>
public void Deactivate(SnippetEventArgs e)
{
if (currentStatus == Status.Deactivated || currentStatus == Status.RaisingDeactivated)
return;
if (currentStatus != Status.Interactive)
throw new InvalidOperationException("Cannot call Deactivate() until RaiseInsertionCompleted() has finished.");
if (e == null)
e = new SnippetEventArgs(DeactivateReason.Unknown);
TextDocumentWeakEventManager.UpdateFinished.RemoveListener(Document, this);
currentStatus = Status.RaisingDeactivated;
TextArea.PopStackedInputHandler(myInputHandler);
foreach (IActiveElement element in registeredElements) {
element.Deactivate(e);
}
if (Deactivated != null)
Deactivated(this, e);
currentStatus = Status.Deactivated;
}
/// <summary>
/// Occurs when the interactive mode is deactivated.
/// </summary>
public event EventHandler<SnippetEventArgs> Deactivated;
bool IWeakEventListener.ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
{
return ReceiveWeakEvent(managerType, sender, e);
}
/// <inheritdoc cref="IWeakEventListener.ReceiveWeakEvent"/>
protected virtual bool ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
{
if (managerType == typeof(TextDocumentWeakEventManager.UpdateFinished)) {
// Deactivate if snippet is deleted. This is necessary for correctly leaving interactive
// mode if Undo is pressed after a snippet insertion.
if (wholeSnippetAnchor.Length == 0 && deactivateIfSnippetEmpty)
Deactivate(new SnippetEventArgs(DeactivateReason.Deleted));
return true;
}
return false;
}
}
}