Bug 1026803 part 4 - Convert GTK native event times to timestamps; r=karlt

This patch adds a helper class to widgets/gtk/nsWindow.cpp similar to the one in
widgets/windows/nsWindow.cpp and uses it to convert native event times to
mozilla::TimeStamp objects on events returned by this class.

This is similar to the operations performed for Windows native event times that
were added in bug 77992.

widget/gtk/mozgtk/mozgtk.c

@@ -122,6 +122,7 @@ STUB(gdk_x11_display_get_user_time)
 STUB(gdk_x11_display_get_xdisplay)
 STUB(gdk_x11_get_default_root_xwindow)
 STUB(gdk_x11_get_default_xdisplay)
+STUB(gdk_x11_get_server_time)
 STUB(gdk_x11_get_xatom_by_name)
 STUB(gdk_x11_lookup_xdisplay)
 STUB(gdk_x11_screen_get_xscreen)

widget/gtk/nsWindow.cpp

@@ -22,6 +22,7 @@
 #include "nsDragService.h"
 #include "nsIWidgetListener.h"
 #include "nsIScreenManager.h"
+#include "SystemTimeConverter.h"
 
 #include "nsGtkKeyUtils.h"
 #include "nsGtkCursors.h"
@@ -261,6 +262,28 @@ static nsresult    initialize_prefs        (void);
 static guint32 sLastUserInputTime = GDK_CURRENT_TIME;
 static guint32 sRetryGrabTime;
 
+static SystemTimeConverter<guint32>&
+TimeConverter() {
+    static SystemTimeConverter<guint32> sTimeConverterSingleton;
+    return sTimeConverterSingleton;
+}
+
+namespace mozilla {
+
+class MOZ_STACK_CLASS CurrentX11TimeGetter
+{
+public:
+    CurrentX11TimeGetter(GdkWindow* aWindow) : mWindow(aWindow) { }
+    guint32 operator() () {
+        return gdk_x11_get_server_time(mWindow);
+    }
+
+private:
+    GdkWindow* mWindow;
+};
+
+} // namespace mozilla
+
 static NS_DEFINE_IID(kCDragServiceCID,  NS_DRAGSERVICE_CID);
 
 // The window from which the focus manager asks us to dispatch key events.
@@ -2376,6 +2399,7 @@ nsWindow::OnEnterNotifyEvent(GdkEventCrossing *aEvent)
     event.refPoint.y = nscoord(aEvent->y);
 
     event.time = aEvent->time;
+    event.timeStamp = GetEventTimeStamp(aEvent->time);
 
     LOG(("OnEnterNotify: %p\n", (void *)this));
 
@@ -2417,6 +2441,7 @@ nsWindow::OnLeaveNotifyEvent(GdkEventCrossing *aEvent)
     event.refPoint.y = nscoord(aEvent->y);
 
     event.time = aEvent->time;
+    event.timeStamp = GetEventTimeStamp(aEvent->time);
 
     event.exit = is_top_level_mouse_exit(mGdkWindow, aEvent)
         ? WidgetMouseEvent::eTopLevel : WidgetMouseEvent::eChild;
@@ -2477,6 +2502,7 @@ nsWindow::OnMotionNotifyEvent(GdkEventMotion *aEvent)
         modifierState = xevent.xmotion.state;
 
         event.time = xevent.xmotion.time;
+        event.timeStamp = GetEventTimeStamp(xevent.xmotion.time);
 #else
         event.refPoint.x = nscoord(aEvent->x);
         event.refPoint.y = nscoord(aEvent->y);
@@ -2484,6 +2510,7 @@ nsWindow::OnMotionNotifyEvent(GdkEventMotion *aEvent)
         modifierState = aEvent->state;
 
         event.time = aEvent->time;
+        event.timeStamp = GetEventTimeStamp(aEvent->time);
 #endif /* MOZ_X11 */
     }
     else {
@@ -2500,6 +2527,7 @@ nsWindow::OnMotionNotifyEvent(GdkEventMotion *aEvent)
         modifierState = aEvent->state;
 
         event.time = aEvent->time;
+        event.timeStamp = GetEventTimeStamp(aEvent->time);
     }
 
     KeymapWrapper::InitInputEvent(event, modifierState);
@@ -2596,6 +2624,7 @@ nsWindow::InitButtonEvent(WidgetMouseEvent& aEvent,
     KeymapWrapper::InitInputEvent(aEvent, modifierState);
 
     aEvent.time = aGdkEvent->time;
+    aEvent.timeStamp = GetEventTimeStamp(aGdkEvent->time);
 
     switch (aGdkEvent->type) {
     case GDK_2BUTTON_PRESS:
@@ -2855,6 +2884,24 @@ nsWindow::DispatchKeyDownEvent(GdkEventKey *aEvent, bool *aCancelled)
     return true;
 }
 
+TimeStamp
+nsWindow::GetEventTimeStamp(guint32 aEventTime)
+{
+    if (MOZ_UNLIKELY(!mGdkWindow)) {
+        // nsWindow has been Destroy()ed.
+        return TimeStamp::Now();
+    }
+    if (aEventTime == 0) {
+        // Some X11 and GDK events may be received with a time of 0 to indicate
+        // that they are synthetic events. Some input method editors do this.
+        // In this case too, just return the current timestamp.
+        return TimeStamp::Now();
+    }
+    CurrentX11TimeGetter getCurrentTime = CurrentX11TimeGetter(mGdkWindow);
+    return TimeConverter().GetTimeStampFromSystemTime(aEventTime,
+                                                      getCurrentTime);
+}
+
 gboolean
 nsWindow::OnKeyPressEvent(GdkEventKey *aEvent)
 {
@@ -2958,6 +3005,7 @@ nsWindow::OnKeyPressEvent(GdkEventKey *aEvent)
 
         contextMenuEvent.refPoint = LayoutDeviceIntPoint(0, 0);
         contextMenuEvent.time = aEvent->time;
+        contextMenuEvent.timeStamp = GetEventTimeStamp(aEvent->time);
         contextMenuEvent.clickCount = 1;
         KeymapWrapper::InitInputEvent(contextMenuEvent, aEvent->state);
         status = DispatchInputEvent(&contextMenuEvent);
@@ -2978,6 +3026,7 @@ nsWindow::OnKeyPressEvent(GdkEventKey *aEvent)
             textString[2] = 0;
             compositionChangeEvent.mData = textString;
             compositionChangeEvent.time = event.time;
+            compositionChangeEvent.timeStamp = GetEventTimeStamp(aEvent->time);
             DispatchEvent(&compositionChangeEvent, status);
         }
     }
@@ -3084,6 +3133,7 @@ nsWindow::OnScrollEvent(GdkEventScroll *aEvent)
     KeymapWrapper::InitInputEvent(wheelEvent, aEvent->state);
 
     wheelEvent.time = aEvent->time;
+    wheelEvent.timeStamp = GetEventTimeStamp(aEvent->time);
 
     DispatchAPZAwareEvent(&wheelEvent);
 }
@@ -3228,6 +3278,7 @@ nsWindow::DispatchDragEvent(uint32_t aMsg, const nsIntPoint& aRefPoint,
 
     event.refPoint = LayoutDeviceIntPoint::FromUntyped(aRefPoint);
     event.time = aTime;
+    event.timeStamp = GetEventTimeStamp(aTime);
 
     DispatchInputEvent(&event);
 }

widget/gtk/nsWindow.h

@@ -67,6 +67,10 @@ class nsPluginNativeWindowGtk;
 class nsShmImage;
 #endif
 
+namespace mozilla {
+class TimeStamp;
+}
+
 class nsWindow : public nsBaseWidget
 {
 public:
@@ -263,6 +267,7 @@ public:
     // otherwise, FALSE.
     bool               DispatchKeyDownEvent(GdkEventKey *aEvent,
                                             bool *aIsCancelled);
+    mozilla::TimeStamp GetEventTimeStamp(guint32 aEventTime);
 
     NS_IMETHOD_(void) SetInputContext(const InputContext& aContext,
                                       const InputContextAction& aAction) override;