Hide the browser actions gripper when it's not in use.

chrome/browser/gtk/browser_actions_toolbar_gtk.cc

 // Copyright (c) 2010 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/gtk/browser_actions_toolbar_gtk.h"
 
 #include <vector>
 
 #include "base/i18n/rtl.h"
 #include "chrome/browser/browser.h"
@@ skipping 332 matching lines @@
       model_(NULL),
       hbox_(gtk_hbox_new(FALSE, 0)),
       button_hbox_(gtk_chrome_shrinkable_hbox_new(TRUE, FALSE, kButtonPadding)),
       overflow_button_(browser->profile()),
       separator_(theme_provider_->CreateToolbarSeparator()),
       drag_button_(NULL),
       drop_index_(-1),
       resize_animation_(this),
       desired_width_(0),
       start_width_(0),
+      draw_gripper_(false),
       method_factory_(this) {
   ExtensionsService* extension_service = profile_->GetExtensionsService();
   // The |extension_service| can be NULL in Incognito.
   if (!extension_service)
     return;
 
   GtkWidget* gripper = gtk_button_new();
   GTK_WIDGET_UNSET_FLAGS(gripper, GTK_CAN_FOCUS);
   gtk_widget_add_events(gripper, GDK_POINTER_MOTION_MASK);
   signals_.Connect(gripper, "motion-notify-event",
@@ skipping 383 matching lines @@
       -event->x :
       event->x - widget->allocation.width;
   gint new_width = button_hbox_->allocation.width - distance_dragged;
   SetButtonHBoxWidth(new_width);
 
   return FALSE;
 }
 
 gboolean BrowserActionsToolbarGtk::OnGripperExpose(GtkWidget* gripper,
                                                    GdkEventExpose* expose) {
+  if (!draw_gripper_)
+    return TRUE;
+
   cairo_t* cr = gdk_cairo_create(GDK_DRAWABLE(expose->window));
 
   CairoCachedSurface* surface = theme_provider_->GetSurfaceNamed(
       IDR_RESIZE_GRIPPER, gripper);
   gfx::Point center = gfx::Rect(gripper->allocation).CenterPoint();
   center.Offset(-surface->Width() / 2, -surface->Height() / 2);
   surface->SetSource(cr, center.x(), center.y());
   gdk_cairo_rectangle(cr, &expose->area);
   cairo_fill(cr);
 
   cairo_destroy(cr);
 
   return TRUE;
 }
 
 // These three signal handlers (EnterNotify, LeaveNotify, and ButtonRelease)
 // are used to give the gripper the resize cursor. Since it doesn't have its
 // own window, we have to set the cursor whenever the pointer moves into the
 // button or leaves the button, and be sure to leave it on when the user is
 // dragging.
 gboolean BrowserActionsToolbarGtk::OnGripperEnterNotify(
     GtkWidget* gripper, GdkEventCrossing* event) {
   gdk_window_set_cursor(gripper->window,
                         gtk_util::GetCursor(GDK_SB_H_DOUBLE_ARROW));
+  draw_gripper_ = true;

[sky, 2010/07/01 16:40:14]

How come you don't queue_draw here and @ 793?

[Evan Stade, 2010/07/01 17:35:08]

GtkButtons already queue_draw when the mouse enters/leaves (because the hover
state changes, and hence drawing may change). Thus we don't need to call
queue_draw, although it probably wouldn't hurt either.

+
   return FALSE;
 }
 
 gboolean BrowserActionsToolbarGtk::OnGripperLeaveNotify(
     GtkWidget* gripper, GdkEventCrossing* event) {
-  if (!(event->state & GDK_BUTTON1_MASK))
+  if (!(event->state & GDK_BUTTON1_MASK)) {
     gdk_window_set_cursor(gripper->window, NULL);
+    draw_gripper_ = false;
+  }
+
   return FALSE;
 }
 
 gboolean BrowserActionsToolbarGtk::OnGripperButtonRelease(
     GtkWidget* gripper, GdkEventButton* event) {
   gfx::Rect gripper_rect(0, 0,
                          gripper->allocation.width, gripper->allocation.height);
   gfx::Point release_point(event->x, event->y);
-  if (!gripper_rect.Contains(release_point))
+  if (!gripper_rect.Contains(release_point)) {
     gdk_window_set_cursor(gripper->window, NULL);
+    draw_gripper_ = false;
+    gtk_widget_queue_draw(gripper);
+  }
 
   // After the user resizes the toolbar, we want to smartly resize it to be
   // the perfect size to fit the buttons.
   int visible_icon_count =
       gtk_chrome_shrinkable_hbox_get_visible_child_count(
           GTK_CHROME_SHRINKABLE_HBOX(button_hbox_.get()));
   AnimateToShowNIcons(visible_icon_count);
   model_->SetVisibleIconCount(visible_icon_count);
 
   return FALSE;
@@ skipping 68 matching lines @@
   }
 
   it->second.get()->GetContextMenu()->PopupAsContext(event->time);
   return TRUE;
 }
 
 void BrowserActionsToolbarGtk::OnButtonShowOrHide(GtkWidget* sender) {
   if (!resize_animation_.is_animating())
     UpdateChevronVisibility();
 }