Call XSetInputFocus after XRaiseWindow when activating.

ui/views/widget/desktop_aura/x11_desktop_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/widget/desktop_aura/x11_desktop_handler.h"
 
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
 
 #include "base/message_loop/message_loop.h"
@@ skipping 76 matching lines @@
     xclient.xclient.data.l[1] = CurrentTime;
     xclient.xclient.data.l[2] = None;
     xclient.xclient.data.l[3] = 0;
     xclient.xclient.data.l[4] = 0;
 
     XSendEvent(xdisplay_, x_root_window_, False,
                SubstructureRedirectMask | SubstructureNotifyMask,
                &xclient);
   } else {
     XRaiseWindow(xdisplay_, window);
+
+    // XRaiseWindow will not give input focus to the window. We now need to ask
+    // the X server to do that. However, if the window is not viewable this will
+    // produce an error so we have to check that before making the call.
+    XWindowAttributes attributes;
+    XGetWindowAttributes(xdisplay_, window, &attributes);
+    if (attributes.map_state == IsViewable)

[sadrul, 2014/01/15 19:23:50]

Is this only ever called from DesktopWindowTreeHostX11::Activate()? Can we make
sure the window is mapped in there? i.e.:

  if (!window_mapped_)
    Show();
  ...

Would that fix the issue? If it does, then I think this would be better.

[mlamouri (slow - plz ping), 2014/01/15 23:15:18]

The assertion goes away but the test fail with that.

However, we can't do that because it is assumed that ::Activate() should not
show the widget if the widget isn't shown yet.

[sadrul, 2014/01/15 23:18:53]

Shouldn't we return early from DesktopWindowTreeHostX11::Activate() if
!window_mapped_, in that case? What does XRaiseWindow do to a hidden window?

[mlamouri (slow - plz ping), 2014/01/15 23:27:50]

I think that would be reasonable but it would break
DesktopScreenX11Test.GetWindowAtScreenPoint. I believe the reason is that
DesktopScreenX11::GetWindowAtScreenPoint() go trough the windows and check their
bounds. Activating the window must change its position in the list.

If you are fine with me disabling the test, I can put an early return in
::Activate().

[sadrul, 2014/01/15 23:31:35]

The test can be fixed by making sure the widgets created are all Show()n before
trying to activate. The test does expect the windows to be visible, otherwise
trying to get the window at a specific point in the screen doesn't make sense.

+      XSetInputFocus(xdisplay_, window, RevertToParent, CurrentTime);
+
     OnActiveWindowChanged(window);
   }
 }
 
 bool X11DesktopHandler::IsActiveWindow(::Window window) const {
   return window == current_window_;
 }
 
 void X11DesktopHandler::ProcessXEvent(const base::NativeEvent& event) {
   switch (event->type) {
@@ skipping 51 matching lines @@
 
   DesktopWindowTreeHostX11* new_host =
       views::DesktopWindowTreeHostX11::GetHostForXID(xid);
   if (new_host)
     new_host->HandleNativeWidgetActivationChanged(true);
 
   current_window_ = xid;
 }
 
 }  // namespace views