Introdcue AshWindowTreeHost and move ash/chrome specific code in WTH to ash.

ash/host/transformer_helper.cc

+// Copyright 2014 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 "ash/host/transformer_helper.h"
+
+#include "ash/host/ash_window_tree_host.h"
+#include "ash/host/root_window_transformer.h"
+#include "ui/aura/window.h"
+#include "ui/aura/window_tree_host.h"
+#include "ui/compositor/dip_util.h"
+#include "ui/gfx/geometry/insets.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/geometry/rect_f.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/size_conversions.h"
+#include "ui/gfx/transform.h"
+
+namespace ash {
+namespace {
+
+// A simple RootWindowTransformer without host insets.
+class SimpleRootWindowTransformer : public RootWindowTransformer {
+ public:
+  SimpleRootWindowTransformer(const aura::Window* root_window,
+                              const gfx::Transform& transform)
+      : root_window_(root_window), transform_(transform) {}
+
+  // RootWindowTransformer overrides:
+  virtual gfx::Transform GetTransform() const OVERRIDE { return transform_; }
+
+  virtual gfx::Transform GetInverseTransform() const OVERRIDE {
+    gfx::Transform invert;
+    if (!transform_.GetInverse(&invert))
+      return transform_;
+    return invert;
+  }
+
+  virtual gfx::Rect GetRootWindowBounds(const gfx::Size& host_size) const
+      OVERRIDE {
+    gfx::Rect bounds(host_size);
+    gfx::RectF new_bounds(ui::ConvertRectToDIP(root_window_->layer(), bounds));
+    transform_.TransformRect(&new_bounds);
+    return gfx::Rect(gfx::ToFlooredSize(new_bounds.size()));
+  }
+
+  virtual gfx::Insets GetHostInsets() const OVERRIDE { return gfx::Insets(); }
+
+ private:
+  virtual ~SimpleRootWindowTransformer() {}
+
+  const aura::Window* root_window_;
+  const gfx::Transform transform_;
+
+  DISALLOW_COPY_AND_ASSIGN(SimpleRootWindowTransformer);
+};
+
+}  // namespace
+
+TransformerHelper::TransformerHelper(AshWindowTreeHost* ash_host)
+    : ash_host_(ash_host) {
+  SetTransform(gfx::Transform());
+}
+
+TransformerHelper::~TransformerHelper() {}
+
+gfx::Insets TransformerHelper::GetHostInsets() const {
+  return transformer_->GetHostInsets();
+}
+
+void TransformerHelper::SetTransform(const gfx::Transform& transform) {
+  scoped_ptr<RootWindowTransformer> transformer(new SimpleRootWindowTransformer(
+      ash_host_->AsWindowTreeHost()->window(), transform));
+  SetRootWindowTransformer(transformer.Pass());
+}
+
+void TransformerHelper::SetRootWindowTransformer(
+    scoped_ptr<RootWindowTransformer> transformer) {
+  transformer_ = transformer.Pass();
+  aura::WindowTreeHost* host = ash_host_->AsWindowTreeHost();
+  aura::Window* window = host->window();
+  window->SetTransform(transformer_->GetTransform());
+  // If the layer is not animating, then we need to update the root window
+  // size immediately.
+  if (!window->layer()->GetAnimator()->is_animating())
+    host->UpdateRootWindowSize(host->GetBounds().size());
+}
+
+gfx::Transform TransformerHelper::GetTransform() const {
+  float scale = ui::GetDeviceScaleFactor(
+      ash_host_->AsWindowTreeHost()->window()->layer());
+  gfx::Transform transform;
+  transform.Scale(scale, scale);
+  transform *= transformer_->GetTransform();
+  return transform;
+}
+
+gfx::Transform TransformerHelper::GetInverseTransform() const {
+  float scale = ui::GetDeviceScaleFactor(
+      ash_host_->AsWindowTreeHost()->window()->layer());
+  gfx::Transform transform;
+  transform.Scale(1.0f / scale, 1.0f / scale);
+  return transformer_->GetInverseTransform() * transform;
+}
+
+void TransformerHelper::UpdateWindowSize(const gfx::Size& host_size) {
+  ash_host_->AsWindowTreeHost()->window()->SetBounds(
+      transformer_->GetRootWindowBounds(host_size));
+}
+
+}  // namespace ash