Make File-Picker modal on Linux

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
index 32092cffdf11e018a8929855812b8fe0e7204b82..5e9abb3a667aab398a656d0417711f96dee99c66 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc
@@ -32,6 +32,7 @@
 #include "ui/events/devices/x11/device_list_cache_x11.h"
 #include "ui/events/devices/x11/touch_factory_x11.h"
 #include "ui/events/event_utils.h"
+#include "ui/events/null_event_targeter.h"
 #include "ui/events/platform/platform_event_source.h"
 #include "ui/events/platform/x11/x11_event_source.h"
 #include "ui/gfx/display.h"
@@ -153,6 +154,21 @@ std::vector<::Window> GetParentsList(XDisplay* xdisplay, ::Window window) {
 
 }  // namespace
 
+DesktopWindowTreeHostX11::ScopedHandle::ScopedHandle(const base::Closure&
+    destroy_callback)
+    : destroy_callback_(destroy_callback) {
+}
+
+void DesktopWindowTreeHostX11::ScopedHandle::CancelCallback() {
+  if (!destroy_callback_.is_null())
+    destroy_callback_.Reset();
+}
+
+DesktopWindowTreeHostX11::ScopedHandle::~ScopedHandle() {
+  if (!destroy_callback_.is_null())
+    destroy_callback_.Run();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopWindowTreeHostX11, public:
 
@@ -177,6 +193,8 @@ DesktopWindowTreeHostX11::DesktopWindowTreeHostX11(
       custom_window_shape_(false),
       urgency_hint_set_(false),
       activatable_(true),
+      modal_dialog_xid_(0),
+      scoped_handle_(NULL),
       close_widget_factory_(this) {
 }
 
@@ -338,6 +356,12 @@ void DesktopWindowTreeHostX11::Close() {
   // TODO(erg): Might need to do additional hiding tasks here.
   delayed_resize_task_.Cancel();
 
+  // We should cancel the callback function when trying to close
+  // the host window while opening the file-picker, which allows
+  // to invalidate weak pointers of |close_widget_factory_|.
+  if (targeter_for_modal_)
+    scoped_handle_->CancelCallback();

[joone, 2016/04/21 20:45:45]

I added CancelCallback method to fix the problem that the file-picker is not
closed when trying to close the host window while opening the file-picker. The
reason is that |close_widget_factory_| has weak pointers at this situation so
the CloseNow callback cannot be called.

[sadrul, 2016/05/11 05:27:47]

I am not sure I understand this well. What happens if we don't do this
CancelCallback()?

[joone, 2016/05/11 19:18:05]

This file-pick is still opened after closing the host window. Then, the instance
of the host window is still alive after closing the file-picker. 

[sadrul, 2016/05/11 19:20:36]

If this host-window is closed, then that would invalidate the weak-ptr to this
DWTHX11 object, and the callback would not be run when the file-dialog is
closed.
?? Not sure what this means.

+
   if (!close_widget_factory_.HasWeakPtrs()) {
     // And we delay the close so that if we are called from an ATL callback,
     // we don't destroy the window before the callback returned (as the caller
@@ -1527,7 +1551,8 @@ void DesktopWindowTreeHostX11::DispatchTouchEvent(ui::TouchEvent* event) {
 }
 
 void DesktopWindowTreeHostX11::DispatchKeyEvent(ui::KeyEvent* event) {
-  GetInputMethod()->DispatchKeyEvent(event);
+  if (native_widget_delegate_->AsWidget()->IsActive())
+    GetInputMethod()->DispatchKeyEvent(event);
 }
 
 void DesktopWindowTreeHostX11::ConvertEventToDifferentHost(
@@ -2022,6 +2047,32 @@ gfx::Rect DesktopWindowTreeHostX11::ToPixelRect(
   return gfx::ToEnclosingRect(rect_in_pixels);
 }
 
+XID DesktopWindowTreeHostX11::GetModalDialog() {
+  return modal_dialog_xid_;
+}
+
+std::unique_ptr<DesktopWindowTreeHostX11::ScopedHandle>
+    DesktopWindowTreeHostX11::DisableEventListening(XID dialog) {
+  DCHECK(dialog);
+  DCHECK(!modal_dialog_xid_);
+  modal_dialog_xid_ = dialog;
+  // ScopedWindowTargeter is used to temporarily replace the event-targeter
+  // with NullEventTargeter to make |dialog| modal.
+  targeter_for_modal_.reset(new aura::ScopedWindowTargeter(window(),
+      std::unique_ptr<ui::EventTargeter>(new ui::NullEventTargeter)));
+
+  scoped_handle_ = new DesktopWindowTreeHostX11::ScopedHandle(
+      base::Bind(&DesktopWindowTreeHostX11::EnableEventListening,
+      close_widget_factory_.GetWeakPtr()));
+  return base::WrapUnique(scoped_handle_);
+}
+
+void DesktopWindowTreeHostX11::EnableEventListening() {
+  DCHECK(modal_dialog_xid_);
+  modal_dialog_xid_ = 0;
+  targeter_for_modal_.reset();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DesktopWindowTreeHost, public: