GTK: when doing a drag from a web page, pass a recent mouse down to gtk_drag_...

chrome/browser/tab_contents/tab_contents_view_gtk.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/tab_contents/tab_contents_view_gtk.h"
 
 #include <gdk/gdk.h>
 #include <gtk/gtk.h>
 
 #include "base/mime_util.h"
@@ skipping 332 matching lines @@
       break;
     }
     default:
       NOTREACHED() << "Got a notification we didn't register for.";
       break;
   }
 }
 
 void TabContentsViewGtk::ShowContextMenu(const ContextMenuParams& params) {
   context_menu_.reset(new RenderViewContextMenuGtk(tab_contents(), params,
-                                                   last_mouse_down_time_));
+                                                   last_mouse_down_.time));
   context_menu_->Init();
   context_menu_->Popup();
 }
 
 // Render view DnD -------------------------------------------------------------
 
 void TabContentsViewGtk::DragEnded() {
   if (tab_contents()->render_view_host())
     tab_contents()->render_view_host()->DragSourceSystemDragEnded();
 }
@@ skipping 21 matching lines @@
   drop_data_.reset(new WebDropData(drop_data));
 
   GtkTargetList* list = GtkDndUtil::GetTargetListFromCodeMask(targets_mask);
   if (targets_mask & GtkDndUtil::X_CHROME_WEBDROP_FILE_CONTENTS) {
     drag_file_mime_type_ = gdk_atom_intern(
         mime_util::GetDataMimeType(drop_data.file_contents).c_str(), FALSE);
     gtk_target_list_add(list, drag_file_mime_type_,
                         0, GtkDndUtil::X_CHROME_WEBDROP_FILE_CONTENTS);
   }
 
-  gtk_drag_begin(GetContentNativeView(), list, GDK_ACTION_COPY, 1, NULL);
+  // If we don't pass an event, GDK won't know what event time to start grabbing
+  // mouse events. Technically it's the mouse motion event and not the mouse
+  // down event that causes the drag, but there's no reliable way to know
+  // *which* motion event initiated the drag, so this will have to do.
+  gtk_drag_begin(GetContentNativeView(), list, GDK_ACTION_COPY,
+                 last_mouse_down_.button,
+                 reinterpret_cast<GdkEvent*>(&last_mouse_down_));
   // The drag adds a ref; let it own the list.
   gtk_target_list_unref(list);
 }
 
 // static
 void TabContentsViewGtk::OnDragDataGet(
     GtkWidget* drag_widget,
     GdkDragContext* context, GtkSelectionData* selection_data,
     guint target_type, guint time, TabContentsViewGtk* view) {
   const int bits_per_byte = 8;
@@ skipping 46 matching lines @@
 }
 
 // -----------------------------------------------------------------------------
 
 void TabContentsViewGtk::InsertIntoContentArea(GtkWidget* widget) {
   gtk_fixed_put(GTK_FIXED(fixed_), widget, 0, 0);
 }
 
 gboolean TabContentsViewGtk::OnMouseDown(GtkWidget* widget,
     GdkEventButton* event, TabContentsViewGtk* view) {
-  view->last_mouse_down_time_ = event->time;
+  view->last_mouse_down_ = *event;
   return FALSE;
 }
 
 gboolean TabContentsViewGtk::OnSizeAllocate(GtkWidget* widget,
                                             GtkAllocation* allocation,
                                             TabContentsViewGtk* view) {
   int width = allocation->width;
   int height = allocation->height;
   // |delegate()| can be NULL here during browser teardown.
   if (view->tab_contents()->delegate())
@@ skipping 56 matching lines @@
     gtk_container_child_set_property(GTK_CONTAINER(floating_container),
                                      widget, "x", &value);
 
     int child_y = std::max(half_view_height - (requisition.height / 2), 0);
     g_value_set_int(&value, child_y);
     gtk_container_child_set_property(GTK_CONTAINER(floating_container),
                                      widget, "y", &value);
     g_value_unset(&value);
   }
 }