ash/frame/caption_buttons/frame_caption_button.cc

   1 // Copyright 2013 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 "ash/frame/caption_buttons/frame_caption_button.h"
   6
   7 #include "ui/base/resource/resource_bundle.h"
   8 #include "ui/gfx/animation/slide_animation.h"
   9 #include "ui/gfx/animation/throb_animation.h"
  10 #include "ui/gfx/canvas.h"
  11
  12 namespace ash {
  13
  14 namespace {
  15
  16 // The duration of the crossfade animation when swapping the button's images.
  17 const int kSwapImagesAnimationDurationMs = 200;
  18
  19 // The duration of the fade out animation of the old icon during a crossfade
  20 // animation as a ratio of |kSwapImagesAnimationDurationMs|.
  21 const float kFadeOutRatio = 0.5f;
  22
  23 // The alpha to draw inactive icons with.
  24 const float kInactiveIconAlpha = 0.2f;
  25
  26 }  // namespace
  27
  28 // static
  29 const char FrameCaptionButton::kViewClassName[] = "FrameCaptionButton";
  30
  31 FrameCaptionButton::FrameCaptionButton(views::ButtonListener* listener,
  32                                        CaptionButtonIcon icon)
  33     : CustomButton(listener),
  34       icon_(icon),
  35       paint_as_active_(false),
  36       alpha_(255),
  37       icon_image_id_(-1),
  38       hovered_background_image_id_(-1),
  39       pressed_background_image_id_(-1),
  40       swap_images_animation_(new gfx::SlideAnimation(this)) {
  41   swap_images_animation_->Reset(1);
  42
  43   // Do not flip the gfx::Canvas passed to the OnPaint() method. The snap left
  44   // and snap right button icons should not be flipped. The other icons are
  45   // horizontally symmetrical.
  46 }
  47
  48 FrameCaptionButton::~FrameCaptionButton() {
  49 }
  50
  51 void FrameCaptionButton::SetImages(CaptionButtonIcon icon,
  52                                    Animate animate,
  53                                    int icon_image_id,
  54                                    int hovered_background_image_id,
  55                                    int pressed_background_image_id) {
  56   // The early return is dependant on |animate| because callers use SetImages()
  57   // with ANIMATE_NO to progress the crossfade animation to the end.
  58   if (icon == icon_ &&
  59       (animate == ANIMATE_YES || !swap_images_animation_->is_animating()) &&
  60       icon_image_id == icon_image_id_ &&
  61       hovered_background_image_id == hovered_background_image_id_ &&
  62       pressed_background_image_id == pressed_background_image_id_) {
  63     return;
  64   }
  65
  66   if (animate == ANIMATE_YES)
  67     crossfade_icon_image_ = icon_image_;
  68
  69   icon_ = icon;
  70   icon_image_id_ = icon_image_id;
  71   hovered_background_image_id_ = hovered_background_image_id;
  72   pressed_background_image_id_ = pressed_background_image_id;
  73
  74   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
  75   icon_image_ = *rb.GetImageSkiaNamed(icon_image_id);
  76   hovered_background_image_ = *rb.GetImageSkiaNamed(
  77       hovered_background_image_id);
  78   pressed_background_image_ = *rb.GetImageSkiaNamed(
  79       pressed_background_image_id);
  80
  81   if (animate == ANIMATE_YES) {
  82     swap_images_animation_->Reset(0);
  83     swap_images_animation_->SetSlideDuration(kSwapImagesAnimationDurationMs);
  84     swap_images_animation_->Show();
  85   } else {
  86     swap_images_animation_->Reset(1);
  87   }
  88   PreferredSizeChanged();
  89   SchedulePaint();
  90 }
  91
  92 bool FrameCaptionButton::IsAnimatingImageSwap() const {
  93   return swap_images_animation_->is_animating();
  94 }
  95
  96 void FrameCaptionButton::SetAlpha(int alpha) {
  97   if (alpha_ != alpha) {
  98     alpha_ = alpha;
  99     SchedulePaint();
 100   }
 101 }
 102
 103 gfx::Size FrameCaptionButton::GetPreferredSize() const {
 104   return hovered_background_image_.isNull() ?
 105       gfx::Size() : hovered_background_image_.size();
 106 }
 107
 108 const char* FrameCaptionButton::GetClassName() const {
 109   return kViewClassName;
 110 }
 111
 112 void FrameCaptionButton::OnPaint(gfx::Canvas* canvas) {
 113   if (hover_animation_->is_animating() || state() == STATE_HOVERED) {
 114     int hovered_background_alpha = hover_animation_->is_animating() ?
 115         hover_animation_->CurrentValueBetween(0, 255) : 255;
 116     SkPaint paint;
 117     paint.setAlpha(hovered_background_alpha);
 118     canvas->DrawImageInt(hovered_background_image_, 0, 0, paint);
 119   } else if (state() == STATE_PRESSED) {
 120     canvas->DrawImageInt(pressed_background_image_, 0, 0);
 121   }
 122
 123   int icon_alpha = swap_images_animation_->CurrentValueBetween(0, 255);
 124   int crossfade_icon_alpha = 0;
 125   if (icon_alpha < static_cast<int>(kFadeOutRatio * 255))
 126      crossfade_icon_alpha = static_cast<int>(255 - icon_alpha / kFadeOutRatio);
 127
 128   if (crossfade_icon_alpha > 0 && !crossfade_icon_image_.isNull()) {
 129     gfx::Canvas icon_canvas(icon_image_.size(), canvas->image_scale(), false);
 130     SkPaint paint;
 131     paint.setAlpha(icon_alpha);
 132     icon_canvas.DrawImageInt(icon_image_, 0, 0, paint);
 133
 134     paint.setAlpha(crossfade_icon_alpha);
 135     paint.setXfermodeMode(SkXfermode::kPlus_Mode);
 136     icon_canvas.DrawImageInt(crossfade_icon_image_, 0, 0, paint);
 137
 138     PaintCentered(canvas, gfx::ImageSkia(icon_canvas.ExtractImageRep()),
 139                   alpha_);
 140   } else {
 141     if (!swap_images_animation_->is_animating())
 142       icon_alpha = alpha_;
 143     PaintCentered(canvas, icon_image_, icon_alpha);
 144   }
 145 }
 146
 147 void FrameCaptionButton::OnGestureEvent(ui::GestureEvent* event) {
 148   // CustomButton does not become pressed when the user drags off and then back
 149   // onto the button. Make FrameCaptionButton pressed in this case because this
 150   // behavior is more consistent with AlternateFrameSizeButton.
 151   if (event->type() == ui::ET_GESTURE_SCROLL_BEGIN ||
 152       event->type() == ui::ET_GESTURE_SCROLL_UPDATE) {
 153     if (HitTestPoint(event->location())) {
 154       SetState(STATE_PRESSED);
 155       RequestFocus();
 156       event->StopPropagation();
 157     } else {
 158       SetState(STATE_NORMAL);
 159     }
 160   } else if (event->type() == ui::ET_GESTURE_SCROLL_END) {
 161     if (HitTestPoint(event->location())) {
 162       SetState(STATE_HOVERED);
 163       NotifyClick(*event);
 164       event->StopPropagation();
 165     }
 166   }
 167   CustomButton::OnGestureEvent(event);
 168 }
 169
 170 void FrameCaptionButton::PaintCentered(gfx::Canvas* canvas,
 171                                        const gfx::ImageSkia& to_center,
 172                                        int alpha) {
 173   if (!paint_as_active_) {
 174     // Paint icons as active when they are hovered over or pressed.
 175     double inactive_alpha = kInactiveIconAlpha;
 176     if (hover_animation_->is_animating()) {
 177       inactive_alpha =
 178           hover_animation_->CurrentValueBetween(inactive_alpha, 1.0f);
 179     } else if (state() == STATE_PRESSED || state() == STATE_HOVERED) {
 180       inactive_alpha = 1.0f;
 181     }
 182     alpha *= inactive_alpha;
 183   }
 184
 185   SkPaint paint;
 186   paint.setAlpha(alpha);
 187   canvas->DrawImageInt(to_center,
 188                        (width() - to_center.width()) / 2,
 189                        (height() - to_center.height()) / 2,
 190                        paint);
 191 }
 192
 193 }  // namespace ash