private void InitRichTextBoxRuntime()
{
if (IsInitialized)
{
throw new InvalidOperationException("The underlying RichTextBox has already been initialized.");
}
if (!IsHandleCreated)
{
base.CreateHandle();
}
// We can't pass our actual handle property to another thread, so we make a copy and pass that.
if (_thisHandle == IntPtr.Zero)
{
_thisHandle = Handle;
}
// Note: a task gets closed automatically on regular shutdown, whereas a thread needs explicit cleanup
// or Environment.Exit(). Tasks seem to work just as well and are easier to use, so I'm using a task
// for now.
if (_asyncTask == null)
{
_asyncTask = new Task(() =>
{
// The RichTextBox is *created* on this thread, which is what allows it to be async, but we
// *declared* it on the main thread, which means we can still reference it, as long as we do
// it through an Invoke() or BeginInvoke().
// TODO: We shouldn't be setting ReadOnly here, but just for testing purposes
_richTextBoxInternal = new RichTextBox_CH {
ReadOnly = true, BackColor = SystemColors.Window
};
// And the same sort of setup with the ApplicationContext, just in case we want to call into
// it too
_asyncRTBAppContext = new RTB_AppContext(this, _richTextBoxInternal, _waitHandle);
// This starts a second message loop, which is what we want: the RichTextBox will have its
// own UI thread
Application.Run(_asyncRTBAppContext);
});
_asyncTask.Start();
// We have to use signaling because we're not waiting for the task to finish, but only for the
// ApplicationContext's constructor to finish. And besides, Application.Run() means the task will
// never finish anyway.
_waitHandle.WaitOne();
// This is why we need to pass our handle and run CreateHandle() on the RichTextBox (see below);
// this is what puts the RichTextBox inside our main UI (while still keeping it asynchronous)
_richTextBoxInternal.Invoke(RTB_DockToUI, true);
// "Set Dock to DockStyle.Fill" as it were
_richTextBoxInternal.BeginInvoke(new Action(() => _richTextBoxInternal.Location = new Point(0, 0)));
SetRichTextBoxSizeToFill();
}
IsInitialized = true;
}
private void InitRichTextBoxDesignTime()
{
if (IsInitialized)
{
throw new InvalidOperationException("The underlying RichTextBox has already been initialized.");
}
_richTextBoxInternal = new RichTextBox_CH();
Controls.Add(_richTextBoxInternal);
_richTextBoxInternal.Dock = DockStyle.Fill;
IsInitialized = true;
}
internal RTB_AppContext(RichTextBoxAsync owner, RichTextBox_CH richTextBox, AutoResetEvent waitHandle)
{
_owner = owner;
_richTextBox = richTextBox;
_richTextBox.KeyDown += _richTextBox_KeyDown;
_richTextBox.MouseDown += _richTextBox_MouseDown;
// CreateHandle() is not exposed, so to get at it we have to subclass RichTextBox and expose it
// ourselves. We could call CreateControl() which is exposed, but that will only work if the
// control is visible, and we don't want to have to set it to visible right off the bat.
if (!_richTextBox.IsHandleCreated)
{
_richTextBox.CreateHandle();
}
// Notify the main thread that we're done initializing
waitHandle.Set();
}