content/renderer/page_properties.h

// Copyright 2019 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.

#ifndef CONTENT_RENDERER_PAGE_PROPERTIES_H_
#define CONTENT_RENDERER_PAGE_PROPERTIES_H_

#include "content/common/content_export.h"
#include "content/public/common/screen_info.h"

namespace content {

class CompositorDependencies;

// This interface exposes "page global" concepts to child frames. Historically
// such state was managed by the RenderView API. However RenderView also has
// to be have as the WebViewClient as well as the IPC anchor for content. As
// such it is hard to separate what APIs are needed by blink, IPC, and other
// content renderer objects.
//
// Splitting out an explicit concept aligned with a "page" better fits the
// abstractions and clarifies which APIs can be coupled.
class CONTENT_EXPORT PageProperties {
 public:
  explicit PageProperties(CompositorDependencies* compositor_deps);
  ~PageProperties();

  const ScreenInfo& GetScreenInfo() const { return screen_info_; }
  void SetScreenInfo(const ScreenInfo& screen_info) {
    screen_info_ = screen_info;
  }

  // Convenience method for reading the device scale factor from
  // ScreenInfo. This is probably the most commonly used field in ScreenInfo
  // so having the added accessor clarifies information coupling and
  // reduces boilerplate code.
  float GetDeviceScaleFactor() { return screen_info_.device_scale_factor; }

  CompositorDependencies* GetCompositorDependencies();

 private:
  // Properties of the screen hosting the page.
  ScreenInfo screen_info_;

  CompositorDependencies* compositor_deps_ = nullptr;
};

}  // namespace content

#endif  // CONTENT_RENDERER_PAGE_PROPERTIES_H_