Fix two issues with Drag-N-Drop in gtk tabstrip:

* Handle drag-leave and drag-failed by hiding or destroying the drag arrow respectively.
* Hide the drop arrow instead of destroying the drop info when we set the drop index to -1.  This compensates for the fact that gtk emits the drag-leave signal before the drag-data-received signal.

BUG=none
TEST=Drag a URL in and out of the tabstrip.  The drop arrow should disappear when the dragged mouse leaves the tabstrip or when the drag fails.
Review URL: http://codereview.chromium.org/149093

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19399 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 37 insertions, 2 deletions

diff --git a/chrome/browser/gtk/tabs/tab_strip_gtk.cc b/chrome/browser/gtk/tabs/tab_strip_gtk.cc
index 4399a3b..d5ec368 100755
--- a/chrome/browser/gtk/tabs/tab_strip_gtk.cc
+++ b/chrome/browser/gtk/tabs/tab_strip_gtk.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/gtk/tabs/tab_strip_gtk.h"
 
+#include <algorithm>
+
 #include "app/gfx/canvas_paint.h"
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
@@ -497,6 +499,10 @@ void TabStripGtk::Init() {
                    G_CALLBACK(OnDragMotion), this);
   g_signal_connect(G_OBJECT(tabstrip_.get()), "drag-drop",
                    G_CALLBACK(OnDragDrop), this);
+  g_signal_connect(G_OBJECT(tabstrip_.get()), "drag-leave",
+                   G_CALLBACK(OnDragLeave), this);
+  g_signal_connect(G_OBJECT(tabstrip_.get()), "drag-failed",
+                   G_CALLBACK(OnDragFailed), this);
   g_signal_connect(G_OBJECT(tabstrip_.get()), "drag-data-received",
                    G_CALLBACK(OnDragDataReceived), this);
 
@@ -1125,7 +1131,7 @@ void TabStripGtk::RemoveMessageLoopObserver() {
 gfx::Rect TabStripGtk::GetDropBounds(int drop_index,
                                      bool drop_before,
                                      bool* is_beneath) {
-  DCHECK(drop_index != -1);
+  DCHECK_NE(drop_index, -1);
   int center_x;
   if (drop_index < GetTabCount()) {
     TabGtk* tab = GetTabAt(drop_index);
@@ -1180,10 +1186,13 @@ void TabStripGtk::UpdateDropIndex(GdkDragContext* context, gint x, gint y) {
 void TabStripGtk::SetDropIndex(int index, bool drop_before) {
   if (index == -1) {
     if (drop_info_.get())
-      drop_info_.reset(NULL);
+      gtk_widget_hide(drop_info_->container);
     return;
   }
 
+  if (drop_info_.get() && !GTK_WIDGET_VISIBLE(drop_info_->container))
+    gtk_widget_show(drop_info_->container);
+
   if (drop_info_.get() && drop_info_->drop_index == index &&
       drop_info_->drop_before == drop_before) {
     return;
@@ -1537,6 +1546,23 @@ gboolean TabStripGtk::OnDragDrop(GtkWidget* widget, GdkDragContext* context,
 }
 
 // static
+gboolean TabStripGtk::OnDragLeave(GtkWidget* widget, GdkDragContext* context,
+                                  guint time, TabStripGtk* tabstrip) {
+  // Hide the drop indicator.
+  tabstrip->SetDropIndex(-1, false);
+  return FALSE;
+}
+
+// static
+gboolean TabStripGtk::OnDragFailed(GtkWidget* widget, GdkDragContext* context,
+                                   GtkDragResult result,
+                                   TabStripGtk* tabstrip) {
+  // Hide the drop indicator.
+  tabstrip->SetDropIndex(-1, false);
+  return FALSE;
+}
+
+// static
 gboolean TabStripGtk::OnDragDataReceived(GtkWidget* widget,
                                          GdkDragContext* context,
                                          gint x, gint y,
diff --git a/chrome/browser/gtk/tabs/tab_strip_gtk.h b/chrome/browser/gtk/tabs/tab_strip_gtk.h
index aa731e8..6cb6ef1 100644
--- a/chrome/browser/gtk/tabs/tab_strip_gtk.h
+++ b/chrome/browser/gtk/tabs/tab_strip_gtk.h
@@ -200,6 +200,15 @@ class TabStripGtk : public TabStripModelObserver,
                              gint x, gint y, guint time,
                              TabStripGtk* tabstrip);
 
+  // drag-leave handler that is signaled when the mouse leaves the tabstrip
+  // during a drag.
+  static gboolean OnDragLeave(GtkWidget* widget, GdkDragContext* context,
+                              guint time, TabStripGtk* tabstrip);
+
+  // drag-failed handler that is signaled when the drag fails or is canceled.
+  static gboolean OnDragFailed(GtkWidget* widget, GdkDragContext* context,
+                               GtkDragResult result, TabStripGtk* tabstrip);
+
   // drag-data-received handler that receives the data assocated with the drag.
   static gboolean OnDragDataReceived(GtkWidget* widget, GdkDragContext* context,
                                      gint x, gint y, GtkSelectionData* data,