using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using DigitalRune.Windows.TextEditor.Document;
using DigitalRune.Windows.TextEditor.Utilities;
namespace DigitalRune.Windows.TextEditor
{
/// <summary>
/// Performs the clipboard actions (cut, copy, paste, ...) for a text area.
/// </summary>
internal class TextAreaClipboardHandler
{
private const string LineSelectedType = "MSDEVLineSelect"; // This is the type VS 2003 and 2005 use for flagging a whole line copy
private readonly TextArea _textArea;
/// <summary>
/// Gets a value indicating whether Cut is enabled.
/// </summary>
/// <value><see langword="true"/> if Cut is enabled; otherwise, .
public bool EnableCut
{
get { return _textArea.EnableCutOrPaste; }
}
/// <summary>
/// Gets a value indicating whether Copy is enabled.
/// </summary>
/// <value><see langword="true"/> if copy is enabled; otherwise, .
public bool EnableCopy
{
get { return true; }
}
/// <summary>
/// Checks whether the clipboard contains text.
/// </summary>
/// <returns>
/// <see langword="true"/> if the clipboard contains text; otherwise <see langword="false"/>.
/// </returns>
public delegate bool ClipboardContainsTextDelegate();
/// <summary>
/// Is called when <see cref="EnablePaste"/> is queried and checks whether the clipboards
/// contains text. If this property is <see langword="null"/> (the default value), the text editor uses
/// <see cref="Clipboard.ContainsText()"/>.
/// </summary>
/// <remarks>
/// This property is useful if you want to prevent the default <see cref="Clipboard.ContainsText()"/>
/// behaviour that waits for the clipboard to be available - the clipboard might never become
/// available if it is owned by a process that is paused by the debugger.
/// </remarks>
public static ClipboardContainsTextDelegate GetClipboardContainsText;
/// <summary>
/// Gets a value indicating whether Paste is enabled (i.e. something is in the clipboard).
/// </summary>
/// <value><see langword="true"/> if Paste is enabled; otherwise, .
public bool EnablePaste
{
get
{
if (!_textArea.EnableCutOrPaste)
return false;
ClipboardContainsTextDelegate d = GetClipboardContainsText;
if (d != null)
{
return d();
}
try
{
return Clipboard.ContainsText();
}
catch (ExternalException)
{
return false;
}
}
}
/// <summary>
/// Gets a value indicating whether 'delete' is enabled.
/// </summary>
/// <value><see langword="true"/> if 'delete' is enabled; otherwise, .
public bool EnableDelete
{
get { return _textArea.SelectionManager.HasSomethingSelected && !_textArea.SelectionManager.SelectionIsReadonly; }
}
/// <summary>
/// Gets a value indicating whether 'select all' is enabled.
/// </summary>
/// <value><see langword="true"/> if 'select all' is enabled; otherwise, .
public bool EnableSelectAll
{
get { return true; }
}
/// <summary>
/// Occurs when a text is copied into the clipboard.
/// </summary>
public event EventHandler<CopyTextEventArgs> CopyText;
/// <summary>
/// Initializes a new instance of the <see cref="TextAreaClipboardHandler"/> class.
/// </summary>
/// <param name="textArea">The text area.</param>
public TextAreaClipboardHandler(TextArea textArea)
{
_textArea = textArea;
textArea.SelectionManager.SelectionChanged += DocumentSelectionChanged;
}
void DocumentSelectionChanged(object sender, EventArgs e)
{
_textArea.MotherTextEditorControl.NotifySelectionChanged();
}
bool CopyTextToClipboard(string stringToCopy, bool asLine)
{
if (stringToCopy.Length > 0)
{
DataObject dataObject = new DataObject();
dataObject.SetData(DataFormats.UnicodeText, true, stringToCopy);
if (asLine)
{
MemoryStream lineSelected = new MemoryStream(1);
lineSelected.WriteByte(1);
dataObject.SetData(LineSelectedType, false, lineSelected);
}
// Default has no highlighting, therefore we don't need RTF output
if (_textArea.Document.HighlightingStrategy.Name != "Default")
{
dataObject.SetData(DataFormats.Rtf, RtfWriter.GenerateRtf(_textArea));
}
OnCopyText(new CopyTextEventArgs(stringToCopy));
SafeSetClipboard(dataObject);
return true;
}
else
{
return false;
}
}
[ThreadStatic]
private static int _safeSetClipboardDataVersion;
static void SafeSetClipboard(object dataObject)
{
// Work around ExternalException bug. (SD2-426)
// Best reproducible inside Virtual PC.
int version = unchecked(++_safeSetClipboardDataVersion);
try
{
Clipboard.SetDataObject(dataObject, true);
}
catch (ExternalException)
{
Timer timer = new Timer();
timer.Interval = 100;
timer.Tick += delegate
{
timer.Stop();
timer.Dispose();
if (_safeSetClipboardDataVersion == version)
{
try
{
Clipboard.SetDataObject(dataObject, true, 10, 50);
}
catch (ExternalException) { }
}
};
timer.Start();
}
}
bool CopyTextToClipboard(string stringToCopy)
{
return CopyTextToClipboard(stringToCopy, false);
}
/// <summary>
/// Cuts the selected text and puts it in the clipboard.
/// </summary>
public void Cut()
{
if (_textArea.SelectionManager.HasSomethingSelected)
{
if (CopyTextToClipboard(_textArea.SelectionManager.SelectedText))
{
if (_textArea.SelectionManager.SelectionIsReadonly)
return;
// Remove text
_textArea.BeginUpdate();
_textArea.Caret.Position = _textArea.SelectionManager.Selections[0].StartPosition;
_textArea.SelectionManager.RemoveSelectedText();
_textArea.EndUpdate();
}
}
else if (_textArea.Document.TextEditorProperties.CutCopyWholeLine)
{
// No text was selected, select and cut the entire line
int curLineNr = _textArea.Document.GetLineNumberForOffset(_textArea.Caret.Offset);
LineSegment lineWhereCaretIs = _textArea.Document.GetLineSegment(curLineNr);
string caretLineText = _textArea.Document.GetText(lineWhereCaretIs.Offset, lineWhereCaretIs.TotalLength);
_textArea.SelectionManager.SetSelection(_textArea.Document.OffsetToPosition(lineWhereCaretIs.Offset), _textArea.Document.OffsetToPosition(lineWhereCaretIs.Offset + lineWhereCaretIs.TotalLength));
if (CopyTextToClipboard(caretLineText, true))
{
if (_textArea.SelectionManager.SelectionIsReadonly)
return;
// remove line
_textArea.BeginUpdate();
_textArea.Caret.Position = _textArea.Document.OffsetToPosition(lineWhereCaretIs.Offset);
_textArea.SelectionManager.RemoveSelectedText();
_textArea.Document.RequestUpdate(new TextAreaUpdate(TextAreaUpdateType.PositionToEnd, new TextLocation(0, curLineNr)));
_textArea.EndUpdate();
}
}
}
/// <summary>
/// Copies the selected text into the clipboard.
/// </summary>
public void Copy()
{
if (!CopyTextToClipboard(_textArea.SelectionManager.SelectedText) && _textArea.Document.TextEditorProperties.CutCopyWholeLine)
{
// No text was selected, select the entire line, copy it, and then deselect
int curLineNr = _textArea.Document.GetLineNumberForOffset(_textArea.Caret.Offset);
LineSegment lineWhereCaretIs = _textArea.Document.GetLineSegment(curLineNr);
string caretLineText = _textArea.Document.GetText(lineWhereCaretIs.Offset, lineWhereCaretIs.TotalLength);
CopyTextToClipboard(caretLineText, true);
}
}
/// <summary>
/// Pastes the content of the clipboard into the document.
/// </summary>
public void Paste()
{
if (!_textArea.EnableCutOrPaste)
return;
// Clipboard.GetDataObject may throw an exception...
for (int i = 0; ; i++)
{
try
{
IDataObject data = Clipboard.GetDataObject();
if (data == null)
return;
bool fullLine = data.GetDataPresent(LineSelectedType);
if (data.GetDataPresent(DataFormats.UnicodeText))
{
string text = (string) data.GetData(DataFormats.UnicodeText);
if (text.Length > 0)
{
_textArea.Document.UndoStack.StartUndoGroup();
try
{
if (_textArea.SelectionManager.HasSomethingSelected)
{
_textArea.Caret.Position = _textArea.SelectionManager.Selections[0].StartPosition;
_textArea.SelectionManager.RemoveSelectedText();
}
if (fullLine)
{
int col = _textArea.Caret.Column;
_textArea.Caret.Column = 0;
if (!_textArea.IsReadOnly(_textArea.Caret.Offset))
_textArea.InsertString(text);
_textArea.Caret.Column = col;
}
else
{
// _textArea.EnableCutOrPaste already checked readonly for this case
_textArea.InsertString(text);
}
}
finally
{
_textArea.Document.UndoStack.EndUndoGroup();
}
}
}
return;
}
catch (ExternalException)
{
// GetDataObject does not provide RetryTimes parameter
if (i > 5) throw;
}
}
}
/// <summary>
/// Deletes the currently selected text.
/// </summary>
public void Delete()
{
new Actions.Delete().Execute(_textArea);
}
/// <summary>
/// Selects the entire document.
/// </summary>
public void SelectAll()
{
new Actions.SelectWholeDocument().Execute(_textArea);
}
/// <summary>
/// Raises the <see cref="CopyText"/> event.
/// </summary>
/// <param name="e">The <see cref="CopyTextEventArgs"/> instance containing the event data.
protected virtual void OnCopyText(CopyTextEventArgs e)
{
if (CopyText != null)
CopyText(this, e);
}
}
/// <summary>
/// Event arguments for <see cref="TextAreaClipboardHandler.CopyText"/> event.
/// </summary>
internal class CopyTextEventArgs : EventArgs
{
private readonly string _text;
/// <summary>
/// Gets the text.
/// </summary>
/// <value>The text.</value>
public string Text
{
get { return _text; }
}
/// <summary>
/// Initializes a new instance of the <see cref="CopyTextEventArgs"/> class.
/// </summary>
/// <param name="text">The text.</param>
public CopyTextEventArgs(string text)
{
_text = text;
}
}
}
