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