WPF - Add Experimental LifeSpanHandler capable of hosting popups using TabControl/ContentControl

[amaitland]

Add LifeSpanHandler implementation capable of hosting popups as Tabs/Controls

• Similar to Doc - Clarify LifeSpanHandler.OnBeforePopup return true behaviour #3847
• Based on https://github.com/cefsharp/CefSharp/blob/master/CefSharp.Wpf.Example/Handlers/ExperimentalLifespanHandler.cs

There are still some CEF bugs that mean this is still classed as experimental. One such issue was reported at #3847 (comment)

It's important to remember that only bugs in CefSharp can be fixed directly in this repository, CEF has it's own issue tracker at https://bitbucket.org/chromiumembedded/cef

• Update Wiki
• Further testing

Example:

// Open popup (browser) in a new WPF Window
// Can be used to host in TabControl/ContentControl/etc
browser.LifeSpanHandler = CefSharp.Wpf.Experimental.LifeSpanHandler
	.Create()
	.OnPopupCreated((ctrl, targetUrl, targetFrameName, windowInfo) =>
	{
		var windowX = (windowInfo.X == int.MinValue) ? double.NaN : windowInfo.X;
		var windowY = (windowInfo.Y == int.MinValue) ? double.NaN : windowInfo.Y;
		var windowWidth = (windowInfo.Width == int.MinValue) ? double.NaN : windowInfo.Width;
		var windowHeight = (windowInfo.Height == int.MinValue) ? double.NaN : windowInfo.Height;
		var popup = new System.Windows.Window
		{
			Left = windowX,
			Top = windowY,
			Width = windowWidth,
			Height = windowHeight,
			Content = ctrl,
			Owner = Window.GetWindow(browser),
			Title = targetFrameName
		};
		popup.Closed += (o, e) =>
		{
			var w = o as System.Windows.Window;
			if (w != null && w.Content is IWebBrowser)
			{
				(w.Content as IWebBrowser)?.Dispose();
				w.Content = null;
			}
		};
	})
	.OnPopupBrowserCreated((ctrl, browser) =>
	{
		ctrl.Dispatcher.Invoke(() =>
		{
			var owner = System.Windows.Window.GetWindow(ctrl);
			if (owner != null && owner.Content == ctrl)
			{
				owner.Show();
			}
		});
	})
	.OnPopupDestroyed((ctrl, popupBrowser) =>
	{
		//If browser is disposed then we don't need to remove the tab
		if (!ctrl.IsDisposed)
		{
			var owner = System.Windows.Window.GetWindow(ctrl);
			if (owner != null && owner.Content == ctrl)
			{
				owner.Close();
			}
		}
	}).Build();

[amaitland]

The delegates have been renamed to add a LifeSpanHandler prefix.

This will be included in M107