Fixed the buglet that caused unwanted bogus drag & drop operations to

start, and added some initial resistance to the drag & drop operation
itself.

svn path=/trunk/; revision=3307

2 files changed, 31 insertions, 4 deletions

diff --git a/shell/ChangeLog b/shell/ChangeLog
index 9f481a3a81..29f9e0e3a1 100644
--- a/shell/ChangeLog
+++ b/shell/ChangeLog
@@ -1,5 +1,17 @@
 2000-05-31  Ettore Perazzoli  <ettore@helixcode.com>
 
+	* e-storage-set-view.c: New constant `DRAG_RESISTANCE'.  New
+	members `button_x', `button_y' in `EStorageSetViewPrivate'.
+	(init): Initialize to zero.
+	(button_press_event): Set.
+	(motion_notify_event): Don't start drag unless the current x/y
+	position is farther than `DRAG_RESISTANCE', in any of the two
+	directions, from the original position of the button click.
+	(button_release_event): Always ungrab the pointer, even if
+	`selected_row_path' is NULL.
+
+2000-05-31  Ettore Perazzoli  <ettore@helixcode.com>
+
 	* evolution-shell-component.c (class_init): Eeek!
 	s/owner_set/owner_unset/.
 
diff --git a/shell/e-storage-set-view.c b/shell/e-storage-set-view.c
index 7aa6f65e5a..3b0aabe044 100644
--- a/shell/e-storage-set-view.c
+++ b/shell/e-storage-set-view.c
@@ -56,11 +56,16 @@ struct _EStorageSetViewPrivate {
 	/* Whether we are currently performing a drag from this view.  */
 	int in_drag : 1;
 
+	/* X/Y position for the last button click.  */
+	int button_x, button_y;
+
 	/* Button used for the drag.  This is initialized in the `button_press_event'
            handler.  */
 	int drag_button;
 };
 
+#define DRAG_RESISTANCE 3
+
 
 enum {
 	FOLDER_SELECTED,
@@ -257,6 +262,8 @@ button_press_event (GtkWidget *widget,
 		return FALSE;
 
 	priv->drag_button = event->button;
+	priv->button_x = event->x;
+	priv->button_y = event->y;
 
 	/* KLUDGE ALERT.  So look at this.  We need to grab the pointer now, to check for
            motion events and maybe start a drag operation.  And GtkCTree seems to do it
@@ -293,6 +300,10 @@ motion_notify_event (GtkWidget *widget,
 	if (priv->in_drag || priv->drag_button == 0)
 		return FALSE;
 
+	if (ABS (event->x - priv->button_x) < DRAG_RESISTANCE
+	    && ABS (event->y - priv->button_y) < DRAG_RESISTANCE)
+		return FALSE;
+
 	priv->in_drag = TRUE;
 	priv->dragged_row_path = priv->selected_row_path;
 
@@ -315,14 +326,16 @@ button_release_event (GtkWidget *widget,
 	storage_set_view = E_STORAGE_SET_VIEW (widget);
 	priv = storage_set_view->priv;
 
-	if (! priv->in_drag && priv->selected_row_path != NULL) {
+	if (! priv->in_drag) {
 		gdk_pointer_ungrab (GDK_CURRENT_TIME);
 		gtk_grab_remove (widget);
 		gdk_flush ();
 
-		gtk_signal_emit (GTK_OBJECT (widget), signals[FOLDER_SELECTED],
-				 priv->selected_row_path);
-		priv->selected_row_path = NULL;
+		if (priv->selected_row_path != NULL) {
+			gtk_signal_emit (GTK_OBJECT (widget), signals[FOLDER_SELECTED],
+					 priv->selected_row_path);
+			priv->selected_row_path = NULL;
+		}
 	}
 
 	priv->selected_row_path_before_click = NULL;
@@ -641,6 +654,8 @@ init (EStorageSetView *storage_set_view)
 	priv->dragged_row_path               = NULL;
 	priv->selected_row_path_before_click = NULL;
 	priv->in_drag                        = FALSE;
+	priv->button_x                       = 0;
+	priv->button_y                       = 0;
 
 	storage_set_view->priv = priv;
 }