First shot at implementing drag&drop for Aura

ui/aura_shell/desktop_event_filter.cc

Index: ui/aura_shell/desktop_event_filter.cc
diff --git a/ui/aura_shell/desktop_event_filter.cc b/ui/aura_shell/desktop_event_filter.cc
index 3d17865b069be2301f74e71ef5d8e3276089f845..4800d046e8f620404837abb338c38337af99898f 100644
--- a/ui/aura_shell/desktop_event_filter.cc
+++ b/ui/aura_shell/desktop_event_filter.cc
@@ -4,6 +4,7 @@
 
 #include "ui/aura_shell/desktop_event_filter.h"
 
+#include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/desktop.h"
 #include "ui/aura/event.h"
 #include "ui/aura/focus_manager.h"
@@ -59,6 +60,28 @@ bool DesktopEventFilter::PreHandleKeyEvent(aura::Window* target,
 
 bool DesktopEventFilter::PreHandleMouseEvent(aura::Window* target,
                                              aura::MouseEvent* event) {
+
+  // Give all events to the drag/drop controller is a drag/drop is in progress.

[Ben Goodger (Google), 2011/11/11 17:26:53]

Move this whole section to a separate function HandleDragEvent() in an anonymous
namespace at the head of this file.

The code here then becomes:

if (HandleDragEvent(target, event))
  return true;

[varunjain, 2011/11/15 19:39:33]

Done.

+  aura::DragDropClient* drag_drop_client =
+      aura::Desktop::GetInstance()->drag_drop_client();
+  if (drag_drop_client && drag_drop_client->IsDragAndDropInProgress()) {
+    switch (event->type()) {
+      case ui::ET_MOUSE_DRAGGED:
+        drag_drop_client->DragUpdate(target, *event);
+        break;
+      case ui::ET_MOUSE_RELEASED:
+        drag_drop_client->Drop(target, *event);
+        break;
+      case ui::ET_MOUSE_EXITED:
+        drag_drop_client->DragCancel();
+        break;
+      default:
+        NOTREACHED();
+        break;
+    }
+    return true;
+  }
+
   switch (event->type()) {
     case ui::ET_MOUSE_PRESSED:
       ActivateIfNecessary(target, event);