ui/app_list/views/image_shadow_animator.cc

   1 // Copyright 2015 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 "ui/app_list/views/image_shadow_animator.h"
   6
   7 #include "ui/gfx/animation/animation_delegate.h"
   8 #include "ui/gfx/animation/slide_animation.h"
   9 #include "ui/gfx/image/image_skia_operations.h"
  10
  11 using gfx::Tween;
  12
  13 namespace {
  14
  15 // Tweens between two ShadowValues.
  16 gfx::ShadowValue LinearShadowValueBetween(double progress,
  17                                           const gfx::ShadowValue& start,
  18                                           const gfx::ShadowValue& end) {
  19   gfx::Vector2d offset(
  20       Tween::LinearIntValueBetween(progress, start.x(), end.x()),
  21       Tween::LinearIntValueBetween(progress, start.y(), end.y()));
  22
  23   // The blur must be clamped to even values in order to avoid offsets being
  24   // incorrect when there are uneven margins.
  25   int blur =
  26       Tween::LinearIntValueBetween(progress, start.blur() / 2, end.blur() / 2) *
  27       2;
  28
  29   return gfx::ShadowValue(
  30       offset, blur,
  31       Tween::ColorValueBetween(progress, start.color(), end.color()));
  32 }
  33
  34 }  // namespace
  35
  36 namespace app_list {
  37
  38 ImageShadowAnimator::ImageShadowAnimator(Delegate* delegate)
  39     : delegate_(delegate), animation_(this) {
  40 }
  41
  42 ImageShadowAnimator::~ImageShadowAnimator() {
  43 }
  44
  45 void ImageShadowAnimator::SetOriginalImage(const gfx::ImageSkia& image) {
  46   original_image_ = image;
  47   animation_.Reset();
  48   UpdateShadowImageForProgress(0);
  49 }
  50
  51 void ImageShadowAnimator::SetStartAndEndShadows(
  52     const gfx::ShadowValues& start_shadow,
  53     const gfx::ShadowValues& end_shadow) {
  54   start_shadow_ = start_shadow;
  55   end_shadow_ = end_shadow;
  56 }
  57
  58 void ImageShadowAnimator::AnimationProgressed(const gfx::Animation* animation) {
  59   UpdateShadowImageForProgress(animation->GetCurrentValue());
  60 }
  61
  62 gfx::ShadowValues ImageShadowAnimator::GetShadowValuesForProgress(
  63     double progress) const {
  64   DCHECK_EQ(start_shadow_.size(), end_shadow_.size())
  65       << "Only equally sized ShadowValues are supported";
  66
  67   gfx::ShadowValues shadows;
  68   for (size_t i = 0; i < start_shadow_.size(); ++i) {
  69     shadows.push_back(
  70         LinearShadowValueBetween(progress, start_shadow_[i], end_shadow_[i]));
  71   }
  72   return shadows;
  73 }
  74
  75 void ImageShadowAnimator::UpdateShadowImageForProgress(double progress) {
  76   shadow_image_ = gfx::ImageSkiaOperations::CreateImageWithDropShadow(
  77       original_image_, GetShadowValuesForProgress(progress));
  78
  79   if (delegate_)
  80     delegate_->ImageShadowAnimationProgressed(this);
  81 }
  82
  83 }  // namespace app_list