Make File-Picker modal on Linux

ui/views/widget/desktop_aura/x11_desktop_handler.cc

Index: ui/views/widget/desktop_aura/x11_desktop_handler.cc
diff --git a/ui/views/widget/desktop_aura/x11_desktop_handler.cc b/ui/views/widget/desktop_aura/x11_desktop_handler.cc
index b7ca334936c924ce4cfac5ed073e300c0c6779ae..a4f6cb4730232d27d1b328e8451d19243d4479c5 100644
--- a/ui/views/widget/desktop_aura/x11_desktop_handler.cc
+++ b/ui/views/widget/desktop_aura/x11_desktop_handler.cc
@@ -47,7 +47,8 @@ X11DesktopHandler::X11DesktopHandler()
       current_window_(None),
       current_window_active_state_(NOT_ACTIVE),
       atom_cache_(xdisplay_, kAtomsToCache),
-      wm_supports_active_window_(false) {
+      wm_supports_active_window_(false),
+      modal_dialog_xid_(None) {
   if (ui::PlatformEventSource::GetInstance())
     ui::PlatformEventSource::GetInstance()->AddPlatformEventDispatcher(this);
   aura::Env::GetInstance()->AddObserver(this);
@@ -170,6 +171,13 @@ uint32_t X11DesktopHandler::DispatchEvent(const ui::PlatformEvent& event) {
         ::Window window;
         if (ui::GetXIDProperty(x_root_window_, "_NET_ACTIVE_WINDOW", &window) &&
             window) {
+          // Set focus to the modal dialog.
+          if (modal_dialog_xid_) {
+             XSetInputFocus(xdisplay_, modal_dialog_xid_, RevertToParent,
+                 CurrentTime);

[sadrul, 2015/06/30 17:30:56]

Is it necessary to maintain a separate modal_dialog_xid_ here? Can you not query
the DWTHX11 here instead?

[joone, 2015/07/01 03:16:06]

Yes, we can query the DWTHX11.

+             break;
+          }
+
           OnActiveWindowChanged(window, ACTIVE);
         }
       }
@@ -216,8 +224,10 @@ void X11DesktopHandler::OnActiveWindowChanged(::Window xid,
   if (active_state == ACTIVE) {
     DesktopWindowTreeHostX11* new_host =
         views::DesktopWindowTreeHostX11::GetHostForXID(xid);
-    if (new_host)
+    if (new_host) {
       new_host->HandleNativeWidgetActivationChanged(true);
+      modal_dialog_xid_ = new_host->GetModalDialog();

[sadrul, 2015/06/30 17:30:56]

Should you set the input-focus here instead?

[joone, 2015/07/01 03:16:06]

The file dialog doesn't pop-up well when opening two browser windows.

[sadrul, 2015/07/01 03:58:14]

Can you clarify what you mean? It should be OK to have two browser windows, open
a modal dialog for one of them, and then switch between the other browser
window, and this modal+browser window, right? So shouldn't we want to make sure
the other browser window does get deactivated correctly (ie. run the code in
lines 213:218 above to deactivate the other browser window, and then instead of
activating this browser window, set input-focus to the modal dialog)?

[joone, 2015/07/01 21:40:37]

Yes, each window can have its own modal dialog and they(window or window+modal
dialog) can be switched among each other.
Now, it is okay to set the input-focus here. There might have been a mistake to
test this fix.

+    }
   }
 }