b=479995 handle drag-failed signal when available. r=enndeakin sr=roc

dom/interfaces/events/nsIDOMDataTransfer.idl

@@ -252,8 +252,9 @@ interface nsIDOMNSDataTransfer : nsISupports
   nsIVariant mozGetDataAt(in DOMString format, in unsigned long index);
 
   /**
-   * Will be true if the user cancelled the drag (typically by pressing Escape).
-   * This will be false otherwise, including if a drag failed for any other reason.
+   * Will be true when the user has cancelled the drag (typically by pressing
+   * Escape) and when the drag has been cancelled unexpectedly.  This will be
+   * false otherwise, including when the drop has been rejected by its target.
    * This property is only relevant for the dragend event.
    */
   readonly attribute boolean mozUserCancelled;

widget/src/gtk2/nsDragService.cpp

@@ -72,6 +72,15 @@
 // This sets how opaque the drag image is
 #define DRAG_IMAGE_ALPHA_LEVEL 0.5
 
+// These values are copied from GtkDragResult (rather than using GtkDragResult
+// directly) so that this code can be compiled against versions of GTK+ that
+// do not have GtkDragResult.
+// GtkDragResult is available from GTK+ version 2.12.
+enum {
+  MOZ_GTK_DRAG_RESULT_SUCCESS,
+  MOZ_GTK_DRAG_RESULT_NO_TARGET
+};
+
 static PRLogModuleInfo *sDragLm = NULL;
 
 static const char gMimeListType[] = "application/x-moz-internal-item-list";
@@ -83,6 +92,12 @@ invisibleSourceDragEnd(GtkWidget        *aWidget,
                        GdkDragContext   *aContext,
                        gpointer          aData);
 
+static gboolean
+invisibleSourceDragFailed(GtkWidget        *aWidget,
+                          GdkDragContext   *aContext,
+                          gint              aResult,
+                          gpointer          aData);
+
 static void
 invisibleSourceDragDataGet(GtkWidget        *aWidget,
                            GdkDragContext   *aContext,
@@ -110,10 +125,19 @@ nsDragService::nsDragService()
                      G_CALLBACK(invisibleSourceDragDataGet), this);
     g_signal_connect(GTK_OBJECT(mHiddenWidget), "drag_end",
                      G_CALLBACK(invisibleSourceDragEnd), this);
+    // drag-failed is available from GTK+ version 2.12
+    guint dragFailedID = g_signal_lookup("drag-failed",
+                                         G_TYPE_FROM_INSTANCE(mHiddenWidget));
+    if (dragFailedID) {
+        g_signal_connect_closure_by_id(mHiddenWidget, dragFailedID, 0,
+                                       g_cclosure_new(G_CALLBACK(invisibleSourceDragFailed),
+                                                      this, NULL),
+                                       FALSE);
+    }
 
     // set up our logging module
     if (!sDragLm)
-    sDragLm = PR_NewLogModule("nsDragService");
+        sDragLm = PR_NewLogModule("nsDragService");
     PR_LOG(sDragLm, PR_LOG_DEBUG, ("nsDragService::nsDragService"));
     mTargetWidget = 0;
     mTargetDragContext = 0;
@@ -1155,36 +1179,58 @@ nsDragService::GetSourceList(void)
 }
 
 void
-nsDragService::SourceEndDrag(GdkDragContext *aContext)
+nsDragService::SourceEndDragSession(GdkDragContext *aContext,
+                                    gint            aResult)
 {
     // this just releases the list of data items that we provide
     mSourceDataItems = nsnull;
 
     if (!mDoingDrag)
-        return; // EndDragSession() was called on drop
+        return; // EndDragSession() was already called on drop or drag-failed
+
+    gint x, y;
+    GdkDisplay* display = gdk_display_get_default();
+    if (display) {
+      gdk_display_get_pointer(display, NULL, &x, &y, NULL);
+      SetDragEndPoint(nsIntPoint(x, y));
+    }
 
     // Either the drag was aborted or the drop occurred outside the app.
     // The dropEffect of mDataTransfer is not updated for motion outside the
     // app, but is needed for the dragend event, so set it now.
 
-    // aContext->dest_window will be non-NULL only if the drop succeeded .
-    GdkDragAction action =
-        aContext->dest_window ? aContext->action : (GdkDragAction)0;
-
-    // Only one bit of action should be set, but, just in case someone does
-    // something funny, erring away from MOVE, and not recording unusual
-    // action combinations as NONE.
     PRUint32 dropEffect;
-    if (!action)
+
+    if (aResult == MOZ_GTK_DRAG_RESULT_SUCCESS) {
+
+        // With GTK+ versions 2.10.x and prior the drag may have been
+        // cancelled (but no drag-failed signal would have been sent).
+        // aContext->dest_window will be non-NULL only if the drop was sent.
+        GdkDragAction action =
+            aContext->dest_window ? aContext->action : (GdkDragAction)0;
+
+        // Only one bit of action should be set, but, just in case someone
+        // does something funny, erring away from MOVE, and not recording
+        // unusual action combinations as NONE.
+        if (!action)
+            dropEffect = DRAGDROP_ACTION_NONE;
+        else if (action & GDK_ACTION_COPY)
+            dropEffect = DRAGDROP_ACTION_COPY;
+        else if (action & GDK_ACTION_LINK)
+            dropEffect = DRAGDROP_ACTION_LINK;
+        else if (action & GDK_ACTION_MOVE)
+            dropEffect = DRAGDROP_ACTION_MOVE;
+        else
+            dropEffect = DRAGDROP_ACTION_COPY;
+
+    } else {
+
         dropEffect = DRAGDROP_ACTION_NONE;
-    else if (action & GDK_ACTION_COPY)
-        dropEffect = DRAGDROP_ACTION_COPY;
-    else if (action & GDK_ACTION_LINK)
-        dropEffect = DRAGDROP_ACTION_LINK;
-    else if (action & GDK_ACTION_MOVE)
-        dropEffect = DRAGDROP_ACTION_MOVE;
-    else
-        dropEffect = DRAGDROP_ACTION_COPY;
+
+        if (aResult != MOZ_GTK_DRAG_RESULT_NO_TARGET) {
+            mUserCancelled = PR_TRUE;
+        }
+    }
 
     nsCOMPtr<nsIDOMNSDataTransfer> dataTransfer =
         do_QueryInterface(mDataTransfer);
@@ -1386,6 +1432,26 @@ invisibleSourceDragDataGet(GtkWidget        *aWidget,
                                aSelectionData, aInfo, aTime);
 }
 
+/* static */
+gboolean
+invisibleSourceDragFailed(GtkWidget        *aWidget,
+                          GdkDragContext   *aContext,
+                          gint              aResult,
+                          gpointer          aData)
+{
+    PR_LOG(sDragLm, PR_LOG_DEBUG, ("invisibleSourceDragFailed %i", aResult));
+    nsDragService *dragService = (nsDragService *)aData;
+    // End the drag session now (rather than waiting for the drag-end signal)
+    // so that operations performed on dropEffect == none can start immediately
+    // rather than waiting for the drag-failed animation to finish.
+    dragService->SourceEndDragSession(aContext, aResult);
+
+    // We should return TRUE to disable the drag-failed animation iff the
+    // source performed an operation when dropEffect was none, but the handler
+    // of the dragend DOM event doesn't provide this information.
+    return FALSE;
+}
+
 /* static */
 void
 invisibleSourceDragEnd(GtkWidget        *aWidget,
@@ -1395,14 +1461,7 @@ invisibleSourceDragEnd(GtkWidget        *aWidget,
     PR_LOG(sDragLm, PR_LOG_DEBUG, ("invisibleSourceDragEnd"));
     nsDragService *dragService = (nsDragService *)aData;
 
-    gint x, y;
-    GdkDisplay* display = gdk_display_get_default();
-    if (display) {
-      gdk_display_get_pointer(display, NULL, &x, &y, NULL);
-      dragService->SetDragEndPoint(nsIntPoint(x, y));
-    }
-
     // The drag has ended.  Release the hostages!
-    dragService->SourceEndDrag(aContext);
+    dragService->SourceEndDragSession(aContext, MOZ_GTK_DRAG_RESULT_SUCCESS);
 }
 

widget/src/gtk2/nsDragService.h

@@ -98,18 +98,19 @@ public:
 
     NS_IMETHOD TargetSetTimeCallback (nsIDragSessionGTKTimeCB aCallback);
 
-    // This is called when the drag started with the invisible widget
-    // finishes.  It's called from within the drag service code but from
-    // a callback - it needs to be public.
-    void           SourceEndDrag(GdkDragContext *aContext);
+    //  END PUBLIC API
+
+    // These methods are public only so that they can be called from functions
+    // with C calling conventions.  They are called for drags started with the
+    // invisible widget.
+    void           SourceEndDragSession(GdkDragContext *aContext,
+                                        gint            aResult);
     void           SourceDataGet(GtkWidget        *widget,
                                  GdkDragContext   *context,
                                  GtkSelectionData *selection_data,
                                  guint             info,
                                  guint32           aTime);
 
-    //  END PUBLIC API
-
 private:
 
     // target side vars