/// <summary>
/// Asynchronously wait for the Chromium widget window to be created for the given ChromiumWebBrowser,
/// and when created hook into its Windows message loop.
/// </summary>
/// <param name="browser">The browser to intercept Windows messages for.</param>
/// <param name="forwardAction">This action will be called whenever a Windows message is received.</param>
internal static void SetupLoop(ChromiumWebBrowser browser, Action <Message> forwardAction)
{
Task.Factory.StartNew(() =>
{
try
{
bool foundWidget = false;
while (!foundWidget)
{
browser.Invoke((Action)(() =>
{
IntPtr chromeWidgetHostHandle;
if (ChromeWidgetHandleFinder.TryFindHandle(browser, out chromeWidgetHostHandle))
{
foundWidget = true;
new ChromeWidgetMessageInterceptor(browser, chromeWidgetHostHandle, forwardAction);
}
else
{
// Chrome hasn't yet set up its message-loop window.
Thread.Sleep(10);
}
}));
}
}
catch
{
// Errors are likely to occur if browser is disposed, and no good way to check from another thread
}
});
}
/// <summary>
/// Chrome's message-loop Window isn't created synchronously, so this may not find it.
/// If so, you need to wait and try again later.
/// </summary>
public static bool TryFindHandle(ChromiumWebBrowser browser, out IntPtr chromeWidgetHostHandle)
{
var browserHandle = browser.Handle;
var windowHandleInfo = new ChromeWidgetHandleFinder(browserHandle);
const string chromeWidgetHostClassName = "Chrome_RenderWidgetHostHWND";
chromeWidgetHostHandle = windowHandleInfo.FindDescendantByClassName(chromeWidgetHostClassName);
return(chromeWidgetHostHandle != IntPtr.Zero);
}
/// <summary>
/// The ChromiumWebBrowserControl does not fire MouseEnter/Move/Leave events, because Chromium handles these.
/// This method provides a demo of hooking the Chrome_RenderWidgetHostHWND handle to receive low level messages.
/// You can likely hook other window messages using this technique, drag/drog etc
/// </summary>
private void SetupMessageInterceptor()
{
if (messageInterceptor != null)
{
messageInterceptor.ReleaseHandle();
messageInterceptor = null;
}
Task.Run(async() =>
{
try
{
while (true)
{
IntPtr chromeWidgetHostHandle;
if (ChromeWidgetHandleFinder.TryFindHandle(browserHandle, out chromeWidgetHostHandle))
{
messageInterceptor = new ChromeWidgetMessageInterceptor((Control)Browser, chromeWidgetHostHandle, message =>
{
const int WM_MOUSEACTIVATE = 0x0021;
const int WM_NCLBUTTONDOWN = 0x00A1;
const int WM_DESTROY = 0x0002;
// Render process switch happened, need to find the new handle
if (message.Msg == WM_DESTROY)
{
SetupMessageInterceptor();
return;
}
if (message.Msg == WM_MOUSEACTIVATE)
{
// The default processing of WM_MOUSEACTIVATE results in MA_NOACTIVATE,
// and the subsequent mouse click is eaten by Chrome.
// This means any .NET ToolStrip or ContextMenuStrip does not get closed.
// By posting a WM_NCLBUTTONDOWN message to a harmless co-ordinate of the
// top-level window, we rely on the ToolStripManager's message handling
// to close any open dropdowns:
// http://referencesource.microsoft.com/#System.Windows.Forms/winforms/Managed/System/WinForms/ToolStripManager.cs,1249
var topLevelWindowHandle = message.WParam;
PostMessage(topLevelWindowHandle, WM_NCLBUTTONDOWN, IntPtr.Zero, IntPtr.Zero);
}
//Forward mouse button down message to browser control
//else if(message.Msg == WM_LBUTTONDOWN)
//{
// PostMessage(browserHandle, WM_LBUTTONDOWN, message.WParam, message.LParam);
//}
// The ChromiumWebBrowserControl does not fire MouseEnter/Move/Leave events, because Chromium handles these.
// However we can hook into Chromium's messaging window to receive the events.
//
//const int WM_MOUSEMOVE = 0x0200;
//const int WM_MOUSELEAVE = 0x02A3;
//
//switch (message.Msg) {
// case WM_MOUSEMOVE:
// Console.WriteLine("WM_MOUSEMOVE");
// break;
// case WM_MOUSELEAVE:
// Console.WriteLine("WM_MOUSELEAVE");
// break;
//}
});
break;
}
else
{
// Chrome hasn't yet set up its message-loop window.
await Task.Delay(10);
}
}
}
catch
{
// Errors are likely to occur if browser is disposed, and no good way to check from another thread
}
});
}
private void OnIsBrowserInitializedChanged(object sender, IsBrowserInitializedChangedEventArgs args)
{
if (args.IsBrowserInitialized)
{
//Get the underlying browser host wrapper
var browserHost = Browser.GetBrowser().GetHost();
var requestContext = browserHost.RequestContext;
string errorMessage;
// Browser must be initialized before getting/setting preferences
var success = requestContext.SetPreference("enable_do_not_track", true, out errorMessage);
if (!success)
{
this.InvokeOnUiThreadIfRequired(() => MessageBox.Show("Unable to set preference enable_do_not_track errorMessage: " + errorMessage));
}
//Example of disable spellchecking
//success = requestContext.SetPreference("browser.enable_spellchecking", false, out errorMessage);
var preferences = requestContext.GetAllPreferences(true);
var doNotTrack = (bool)preferences["enable_do_not_track"];
//Use this to check that settings preferences are working in your code
//success = requestContext.SetPreference("webkit.webprefs.minimum_font_size", 24, out errorMessage);
//If we're using CefSetting.MultiThreadedMessageLoop (the default) then to hook the message pump,
// which running in a different thread we have to use a NativeWindow
if (multiThreadedMessageLoopEnabled)
{
Task.Run(() =>
{
try
{
while (true)
{
IntPtr chromeWidgetHostHandle;
if (ChromeWidgetHandleFinder.TryFindHandle(browserHandle, out chromeWidgetHostHandle))
{
messageInterceptor = new ChromeWidgetMessageInterceptor((Control)Browser, chromeWidgetHostHandle, message =>
{
const int WM_MOUSEACTIVATE = 0x0021;
const int WM_NCLBUTTONDOWN = 0x00A1;
const int WM_LBUTTONDOWN = 0x0201;
if (message.Msg == WM_MOUSEACTIVATE)
{
// The default processing of WM_MOUSEACTIVATE results in MA_NOACTIVATE,
// and the subsequent mouse click is eaten by Chrome.
// This means any .NET ToolStrip or ContextMenuStrip does not get closed.
// By posting a WM_NCLBUTTONDOWN message to a harmless co-ordinate of the
// top-level window, we rely on the ToolStripManager's message handling
// to close any open dropdowns:
// http://referencesource.microsoft.com/#System.Windows.Forms/winforms/Managed/System/WinForms/ToolStripManager.cs,1249
var topLevelWindowHandle = message.WParam;
PostMessage(topLevelWindowHandle, WM_NCLBUTTONDOWN, IntPtr.Zero, IntPtr.Zero);
}
//Forward mouse button down message to browser control
//else if(message.Msg == WM_LBUTTONDOWN)
//{
// PostMessage(browserHandle, WM_LBUTTONDOWN, message.WParam, message.LParam);
//}
// The ChromiumWebBrowserControl does not fire MouseEnter/Move/Leave events, because Chromium handles these.
// However we can hook into Chromium's messaging window to receive the events.
//
//const int WM_MOUSEMOVE = 0x0200;
//const int WM_MOUSELEAVE = 0x02A3;
//
//switch (message.Msg) {
// case WM_MOUSEMOVE:
// Console.WriteLine("WM_MOUSEMOVE");
// break;
// case WM_MOUSELEAVE:
// Console.WriteLine("WM_MOUSELEAVE");
// break;
//}
});
break;
}
else
{
// Chrome hasn't yet set up its message-loop window.
Thread.Sleep(10);
}
}
}
catch
{
// Errors are likely to occur if browser is disposed, and no good way to check from another thread
}
});
}
}
}
/// <summary>
/// Chrome's message-loop Window isn't created synchronously, so this may not find it.
/// If so, you need to wait and try again later.
/// </summary>
public static bool TryFindHandle(ChromiumWebBrowser browser, out IntPtr chromeWidgetHostHandle)
{
var browserHandle = browser.Handle;
var windowHandleInfo = new ChromeWidgetHandleFinder(browserHandle);
const string chromeWidgetHostClassName = "Chrome_RenderWidgetHostHWND";
chromeWidgetHostHandle = windowHandleInfo.FindDescendantByClassName(chromeWidgetHostClassName);
return chromeWidgetHostHandle != IntPtr.Zero;
}