Add the partial screen magnifier to Chrome OS.

ui/compositor/layer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/compositor/layer.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 44 matching lines @@
       fills_bounds_opaquely_(true),
       layer_updated_externally_(false),
       opacity_(1.0f),
       background_blur_radius_(0),
       layer_saturation_(0.0f),
       layer_brightness_(0.0f),
       layer_grayscale_(0.0f),
       layer_inverted_(false),
       layer_mask_(NULL),
       layer_mask_back_link_(NULL),
+      zoom_x_offset_(0),
+      zoom_y_offset_(0),
+      zoom_(1),
       delegate_(NULL),
       web_layer_(NULL),
       scale_content_(true),
       device_scale_factor_(1.0f) {
   CreateWebLayer();
 }
 
 Layer::Layer(LayerType type)
     : type_(type),
       compositor_(NULL),
       parent_(NULL),
       visible_(true),
       force_render_surface_(false),
       fills_bounds_opaquely_(true),
       layer_updated_externally_(false),
       opacity_(1.0f),
       background_blur_radius_(0),
       layer_saturation_(0.0f),
       layer_brightness_(0.0f),
       layer_grayscale_(0.0f),
       layer_inverted_(false),
       layer_mask_(NULL),
       layer_mask_back_link_(NULL),
+      zoom_x_offset_(0),
+      zoom_y_offset_(0),
+      zoom_(1),
       delegate_(NULL),
       scale_content_(true),
       device_scale_factor_(1.0f) {
   CreateWebLayer();
 }
 
 Layer::~Layer() {
   // Destroying the animator may cause observers to use the layer (and
   // indirectly the WebLayer). Destroy the animator first so that the WebLayer
   // is still around.
@@ skipping 127 matching lines @@
   while (current) {
     opacity *= current->opacity_;
     current = current->parent_;
   }
   return opacity;
 }
 
 void Layer::SetBackgroundBlur(int blur_radius) {
   background_blur_radius_ = blur_radius;
 
-  WebKit::WebFilterOperations filters;
-  if (background_blur_radius_) {
-    filters.append(WebKit::WebFilterOperation::createBlurFilter(
-        background_blur_radius_));
-  }
-  web_layer_->setBackgroundFilters(filters);
+  SetLayerBackgroundFilters();
 }
 
 void Layer::SetLayerSaturation(float saturation) {
   layer_saturation_ = saturation;
   SetLayerFilters();
 }
 
 void Layer::SetLayerBrightness(float brightness) {
   GetAnimator()->SetBrightness(brightness);
 }
@@ skipping 38 matching lines @@
     layer_mask_->layer_mask_back_link_ = NULL;
   layer_mask_ = layer_mask;
   web_layer_->setMaskLayer(
       layer_mask ? layer_mask->web_layer() : NULL);
   // We need to reference the linked object so that it can properly break the
   // link to us when it gets deleted.
   if (layer_mask)
     layer_mask->layer_mask_back_link_ = this;
 }
 
+void Layer::SetBackgroundZoom(float x_offset, float y_offset, float zoom,
+                              int inset) {
+  zoom_x_offset_ = x_offset;
+  zoom_y_offset_ = y_offset;
+  zoom_ = zoom;
+  zoom_inset_ = inset;
+
+  SetLayerBackgroundFilters();
+}
+
 void Layer::SetLayerFilters() {
   WebKit::WebFilterOperations filters;
   if (layer_saturation_) {
     filters.append(WebKit::WebFilterOperation::createSaturateFilter(
         layer_saturation_));
   }
   if (layer_grayscale_) {
     filters.append(WebKit::WebFilterOperation::createGrayscaleFilter(
         layer_grayscale_));
   }
   if (layer_inverted_)
     filters.append(WebKit::WebFilterOperation::createInvertFilter(1.0));
   // Brightness goes last, because the resulting colors neeed clamping, which
   // cause further color matrix filters to be applied separately. In this order,
   // they all can be combined in a single pass.
   if (layer_brightness_) {
     filters.append(WebKit::WebFilterOperation::createBrightnessFilter(
         layer_brightness_));
   }
 
   web_layer_->setFilters(filters);
 }
 
+void Layer::SetLayerBackgroundFilters() {
+  WebKit::WebFilterOperations filters;
+  if (zoom_ != 1) {
+    filters.append(WebKit::WebFilterOperation::createZoomFilter(
+        WebKit::WebRect(zoom_x_offset_, zoom_y_offset_,
+                        (GetTargetBounds().width() / zoom_),
+                        (GetTargetBounds().height() / zoom_)),
+        zoom_inset_));
+  }
+
+  if (background_blur_radius_) {
+    filters.append(WebKit::WebFilterOperation::createBlurFilter(
+        background_blur_radius_));
+  }
+
+  web_layer_->setBackgroundFilters(filters);
+}
+
 float Layer::GetTargetOpacity() const {
   if (animator_.get() && animator_->IsAnimatingProperty(
       LayerAnimationElement::OPACITY))
     return animator_->GetTargetOpacity();
   return opacity_;
 }
 
 void Layer::SetVisible(bool visible) {
   GetAnimator()->SetVisibility(visible);
 }
@@ skipping 441 matching lines @@
     return;
   unsigned int color = 0xFF000000;
   color |= web_layer_is_accelerated_ ? 0x0000FF00 : 0x00FF0000;
   bool opaque = fills_bounds_opaquely_ && (GetCombinedOpacity() == 1.f);
   if (!opaque)
     color |= 0xFF;
   web_layer_->setDebugBorderColor(color);
 }
 
 }  // namespace ui