Home | History | Annotate | Download | only in caption_buttons 
      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
    189