content/browser/android/composited_touch_handle_drawable.cc

   1 // Copyright 2014 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 "content/browser/android/composited_touch_handle_drawable.h"
   6
   7 #include "base/lazy_instance.h"
   8 #include "base/logging.h"
   9 #include "base/trace_event/trace_event.h"
  10 #include "cc/layers/ui_resource_layer.h"
  11 #include "jni/HandleViewResources_jni.h"
  12 #include "ui/gfx/android/java_bitmap.h"
  13
  14 namespace content {
  15
  16 namespace {
  17
  18 static SkBitmap CreateSkBitmapFromJavaBitmap(
  19     base::android::ScopedJavaLocalRef<jobject> jbitmap) {
  20   return jbitmap.is_null()
  21              ? SkBitmap()
  22              : CreateSkBitmapFromJavaBitmap(gfx::JavaBitmap(jbitmap.obj()));
  23 }
  24
  25 class HandleResources {
  26  public:
  27   HandleResources() : loaded_(false) {
  28   }
  29
  30   void LoadIfNecessary(jobject context) {
  31     if (loaded_)
  32       return;
  33
  34     loaded_ = true;
  35
  36     TRACE_EVENT0("browser", "HandleResources::Create");
  37     JNIEnv* env = base::android::AttachCurrentThread();
  38     if (!context)
  39       context = base::android::GetApplicationContext();
  40
  41     left_bitmap_ = CreateSkBitmapFromJavaBitmap(
  42         Java_HandleViewResources_getLeftHandleBitmap(env, context));
  43     right_bitmap_ = CreateSkBitmapFromJavaBitmap(
  44         Java_HandleViewResources_getRightHandleBitmap(env, context));
  45     center_bitmap_ = CreateSkBitmapFromJavaBitmap(
  46         Java_HandleViewResources_getCenterHandleBitmap(env, context));
  47
  48     left_bitmap_.setImmutable();
  49     right_bitmap_.setImmutable();
  50     center_bitmap_.setImmutable();
  51   }
  52
  53   const SkBitmap& GetBitmap(ui::TouchHandleOrientation orientation) {
  54     DCHECK(loaded_);
  55     switch (orientation) {
  56       case ui::TouchHandleOrientation::LEFT:
  57         return left_bitmap_;
  58       case ui::TouchHandleOrientation::RIGHT:
  59         return right_bitmap_;
  60       case ui::TouchHandleOrientation::CENTER:
  61         return center_bitmap_;
  62       case ui::TouchHandleOrientation::UNDEFINED:
  63         NOTREACHED() << "Invalid touch handle orientation.";
  64     };
  65     return center_bitmap_;
  66   }
  67
  68  private:
  69   SkBitmap left_bitmap_;
  70   SkBitmap right_bitmap_;
  71   SkBitmap center_bitmap_;
  72   bool loaded_;
  73
  74   DISALLOW_COPY_AND_ASSIGN(HandleResources);
  75 };
  76
  77 base::LazyInstance<HandleResources>::Leaky g_selection_resources;
  78
  79 }  // namespace
  80
  81 CompositedTouchHandleDrawable::CompositedTouchHandleDrawable(
  82     cc::Layer* root_layer,
  83     float dpi_scale,
  84     jobject context)
  85     : dpi_scale_(dpi_scale),
  86       orientation_(ui::TouchHandleOrientation::UNDEFINED),
  87       layer_(cc::UIResourceLayer::Create()) {
  88   g_selection_resources.Get().LoadIfNecessary(context);
  89   DCHECK(root_layer);
  90   root_layer->AddChild(layer_.get());
  91 }
  92
  93 CompositedTouchHandleDrawable::~CompositedTouchHandleDrawable() {
  94   DetachLayer();
  95 }
  96
  97 void CompositedTouchHandleDrawable::SetEnabled(bool enabled) {
  98   layer_->SetIsDrawable(enabled);
  99   // Force a position update in case the disabled layer's properties are stale.
 100   if (enabled)
 101     UpdateLayerPosition();
 102 }
 103
 104 void CompositedTouchHandleDrawable::SetOrientation(
 105     ui::TouchHandleOrientation orientation) {
 106   DCHECK(layer_->parent());
 107   orientation_ = orientation;
 108
 109   const SkBitmap& bitmap = g_selection_resources.Get().GetBitmap(orientation);
 110   layer_->SetBitmap(bitmap);
 111   layer_->SetBounds(gfx::Size(bitmap.width(), bitmap.height()));
 112
 113   switch (orientation_) {
 114     case ui::TouchHandleOrientation::LEFT:
 115       focal_offset_from_origin_ = gfx::Vector2dF(bitmap.width() * 0.75f, 0);
 116       break;
 117     case ui::TouchHandleOrientation::RIGHT:
 118       focal_offset_from_origin_ = gfx::Vector2dF(bitmap.width() * 0.25f, 0);
 119       break;
 120     case ui::TouchHandleOrientation::CENTER:
 121       focal_offset_from_origin_ = gfx::Vector2dF(bitmap.width() * 0.5f, 0);
 122       break;
 123     case ui::TouchHandleOrientation::UNDEFINED:
 124       NOTREACHED() << "Invalid touch handle orientation.";
 125       break;
 126   };
 127
 128   UpdateLayerPosition();
 129 }
 130
 131 void CompositedTouchHandleDrawable::SetAlpha(float alpha) {
 132   DCHECK(layer_->parent());
 133   alpha = std::max(0.f, std::min(1.f, alpha));
 134   bool hidden = alpha <= 0;
 135   layer_->SetOpacity(alpha);
 136   layer_->SetHideLayerAndSubtree(hidden);
 137 }
 138
 139 void CompositedTouchHandleDrawable::SetFocus(const gfx::PointF& position) {
 140   DCHECK(layer_->parent());
 141   focal_position_ = gfx::ScalePoint(position, dpi_scale_);
 142   UpdateLayerPosition();
 143 }
 144
 145 gfx::RectF CompositedTouchHandleDrawable::GetVisibleBounds() const {
 146   return gfx::ScaleRect(gfx::RectF(layer_->position().x(),
 147                                    layer_->position().y(),
 148                                    layer_->bounds().width(),
 149                                    layer_->bounds().height()),
 150                         1.f / dpi_scale_);
 151 }
 152
 153 void CompositedTouchHandleDrawable::DetachLayer() {
 154   layer_->RemoveFromParent();
 155 }
 156
 157 void CompositedTouchHandleDrawable::UpdateLayerPosition() {
 158   layer_->SetPosition(focal_position_ - focal_offset_from_origin_);
 159 }
 160
 161 // static
 162 bool CompositedTouchHandleDrawable::RegisterHandleViewResources(JNIEnv* env) {
 163   return RegisterNativesImpl(env);
 164 }
 165
 166 }  // namespace content