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