src/chrome/browser/ui/gtk/throbber_gtk.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/gtk/throbber_gtk.h"
   6
   7 #include "base/logging.h"
   8 #include "chrome/browser/chrome_notification_types.h"
   9 #include "chrome/browser/ui/gtk/gtk_theme_service.h"
  10 #include "content/public/browser/notification_source.h"
  11 #include "grit/ui_resources.h"
  12 #include "ui/gfx/animation/tween.h"
  13 #include "ui/gfx/image/cairo_cached_surface.h"
  14
  15 namespace {
  16
  17 // The length of a single cycle of the animation in milliseconds.
  18 const int kThrobberDurationMs = 750;
  19
  20 }  // namespace
  21
  22 ThrobberGtk::ThrobberGtk(GtkThemeService* theme_service)
  23     : theme_service_(theme_service),
  24       animation_(this),
  25       num_frames_(0) {
  26   DCHECK(theme_service_);
  27   Init();
  28 }
  29
  30 ThrobberGtk::~ThrobberGtk() {
  31   widget_.Destroy();
  32 }
  33
  34 void ThrobberGtk::Start() {
  35   animation_.Show();
  36 }
  37
  38 void ThrobberGtk::Stop() {
  39   animation_.Reset();
  40 }
  41
  42 void ThrobberGtk::AnimationEnded(const gfx::Animation* animation) {
  43   animation_.Reset();
  44   animation_.Show();
  45 }
  46
  47 void ThrobberGtk::AnimationProgressed(const gfx::Animation* animation) {
  48   gtk_widget_queue_draw(widget_.get());
  49 }
  50
  51 void ThrobberGtk::Observe(int type,
  52                           const content::NotificationSource& source,
  53                           const content::NotificationDetails& details) {
  54   DCHECK_EQ(chrome::NOTIFICATION_BROWSER_THEME_CHANGED, type);
  55   LoadFrames();
  56   gtk_widget_queue_draw(widget_.get());
  57 }
  58
  59 gboolean ThrobberGtk::OnExpose(GtkWidget* widget, GdkEventExpose* expose) {
  60   cairo_t* cairo_context =
  61       gdk_cairo_create(GDK_DRAWABLE(gtk_widget_get_window(widget)));
  62   GtkAllocation allocation;
  63   gtk_widget_get_allocation(widget, &allocation);
  64   cairo_translate(cairo_context, allocation.x, allocation.y);
  65
  66   gfx::CairoCachedSurface* cairo_frames = frames_.ToCairo();
  67   const int frame =
  68       static_cast<int>(animation_.GetCurrentValue() * (num_frames_ - 1));
  69   const int image_size = cairo_frames->Height();
  70   const int image_offset = frame * image_size;
  71
  72   cairo_frames->SetSource(cairo_context, widget, -image_offset, 0);
  73   cairo_rectangle(cairo_context, 0, 0, image_size, image_size);
  74   cairo_fill(cairo_context);
  75   cairo_destroy(cairo_context);
  76
  77   return TRUE;
  78 }
  79
  80 void ThrobberGtk::Init() {
  81   animation_.SetSlideDuration(kThrobberDurationMs);
  82   animation_.SetTweenType(gfx::Tween::LINEAR);
  83   widget_.Own(gtk_image_new());
  84   gtk_widget_set_can_focus(widget_.get(), FALSE);
  85   g_signal_connect(widget_.get(), "expose-event", G_CALLBACK(OnExposeThunk),
  86                    this);
  87
  88   theme_service_->InitThemesFor(this);
  89   registrar_.Add(this, chrome::NOTIFICATION_BROWSER_THEME_CHANGED,
  90                  content::Source<ThemeService>(theme_service_));
  91 }
  92
  93 void ThrobberGtk::LoadFrames() {
  94   frames_ = theme_service_->GetImageNamed(IDR_THROBBER);
  95   DCHECK(!frames_.IsEmpty());
  96   const int width = frames_.ToCairo()->Width();
  97   const int height = frames_.ToCairo()->Height();
  98   DCHECK_EQ(0, width % height);
  99   num_frames_ = width / height;
 100
 101   gtk_widget_set_size_request(widget_.get(), height, height);
 102 }