spice client: sticky Alt activation when holding an Alt key: bug #505912.

Additional changes that were required for the feature:
    1) focusing on the pointed window in full screen mode
    2) In X11 - handling events that occur during keyboard ungrabbing
    3) In X11 - handling Leave/Enter Notify events that occur during keyboard grabbing/ungrabbing
    4) In X11 - fix for focus events that are handled in the wrong order (happens when
       focus events occur during grabbing the keyboard)
    5) In X11 - ignoring key release events during key holding
    6) In Windows - synchronizing keyboard release events that occured during a modal loop

1 files changed, 19 insertions, 6 deletions

diff --git a/client/screen.cpp b/client/screen.cpp
index 8b7ee289..bbc76e75 100644
--- a/client/screen.cpp
+++ b/client/screen.cpp
@@ -93,11 +93,13 @@ RedScreen::RedScreen(Application& owner, int id, const std::wstring& name, int w
     _window.set_menu(*menu);
     AutoRef<Icon> icon(Platform::load_icon(RED_ICON_RES_ID));
     _window.set_icon(*icon);
+    _window.start_key_interception();
 }
 
 RedScreen::~RedScreen()
 {
     bool captured = is_captured();
+    _window.stop_key_interception();
     relase_inputs();
     destroy_composit_area();
     _owner.deactivate_interval_timer(*_update_timer);
@@ -435,9 +437,6 @@ void RedScreen::capture_inputs()
         reset_mouse_pos();
         _window.cupture_mouse();
     }
-#ifndef NO_KEY_GRAB
-    _window.start_key_interception();
-#endif
     _captured = true;
 }
 
@@ -446,9 +445,6 @@ void RedScreen::relase_inputs()
     if (!_captured) {
         return;
     }
-#ifndef NO_KEY_GRAB
-    _window.stop_key_interception();
-#endif
     _captured = false;
     _window.release_mouse();
     if (_owner.get_mouse_mode() == RED_MOUSE_MODE_SERVER) {
@@ -576,6 +572,11 @@ void RedScreen::on_pointer_enter()
     if (!_frame_area) {
         _pointer_location = POINTER_IN_ACTIVE_AREA;
         update_active_cursor();
+        if (_full_screen) {
+            /* allowing enterance to key interception mode without
+               requiring the user to press the window */
+            activate();
+        }
     }
 }
 
@@ -584,6 +585,18 @@ void RedScreen::on_pointer_leave()
     _pointer_location = POINTER_OUTSIDE_WINDOW;
 }
 
+void RedScreen::on_start_key_interception()
+{
+    _key_interception = true;
+    _owner.on_start_screen_key_interception(this);
+}
+
+void RedScreen::on_stop_key_interception()
+{
+    _key_interception = false;
+    _owner.on_stop_screen_key_interception(this);
+}
+
 void RedScreen::enter_modal_loop()
 {
     _forec_update_timer++;