AutomationPeer editor extension

[sloutsky]

Add extension to text editor that allows to inject automation peer that represents IntelliSense suggestion list and the currently selected suggestion - to allow screen narrators to read the suggestion.

[siegfriedpammer]

Thank you very much for your pull request! The changes are looking good, just a few remarks:

1. Can you please clean up the commits? 3 of the 4 commits in this pull request are not related to the actual change.
2. Can you please rename/remove all references to "IntelliSense"... AvalonEdit uses the word "CodeCompletion", we want to prevent any confusion.

If you don't have time to apply these changes, I can do that for you once we merge this.

I will have to take a closer look and test how Narrator behaves now.

[sloutsky]

I have renamed the property. Now I need to figure how to get rid of the "bad commits"

[siegfriedpammer]

Hmmm, it seems, this change currently does not provide a out-of-the-box solution for users of AvalonEdit. I would have expected Narrator to properly work out-of-the-box with how we currently use/instantiate the CompletionWindow in the sample application:

AvalonEdit/ICSharpCode.AvalonEdit.Sample/Window1.xaml.cs

Lines 124 to 154 in 395ef81

	CompletionWindow completionWindow;
	void textEditor_TextArea_TextEntered(object sender, TextCompositionEventArgs e)
	{
	if (e.Text == ".") {
	// open code completion after the user has pressed dot:
	completionWindow = new CompletionWindow(textEditor.TextArea);
	// provide AvalonEdit with the data:
	IList<ICompletionData> data = completionWindow.CompletionList.CompletionData;
	data.Add(new MyCompletionData("Item1"));
	data.Add(new MyCompletionData("Item2"));
	data.Add(new MyCompletionData("Item3"));
	data.Add(new MyCompletionData("Another item"));
	completionWindow.Show();
	completionWindow.Closed += delegate {
	completionWindow = null;
	};
	}
	}
	void textEditor_TextArea_TextEntering(object sender, TextCompositionEventArgs e)
	{
	if (e.Text.Length > 0 && completionWindow != null) {
	if (!char.IsLetterOrDigit(e.Text[0])) {
	// Whenever a non-letter is typed while the completion window is open,
	// insert the currently selected element.
	completionWindow.CompletionList.RequestInsertion(e);
	}
	}
	// do not set e.Handled=true - we still want to insert the character that was typed
	}

Seems like I will have to dig around to get this to work properly like in VS. Thanks anyway for the starting point.