Implement webview.captureVisibleRegion()

extensions/browser/api/capture_web_contents_function.h

-// Copyright 2013 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 EXTENSIONS_BROWSER_API_CAPTURE_WEB_CONTENTS_FUNCTION_H_
-#define EXTENSIONS_BROWSER_API_CAPTURE_WEB_CONTENTS_FUNCTION_H_
-
-#include "base/macros.h"
-#include "content/public/browser/readback_types.h"
-#include "extensions/browser/extension_function.h"
-#include "extensions/common/api/extension_types.h"
-
-class SkBitmap;
-
-namespace content {
-class WebContents;
-}
-
-namespace extensions {
-
-// Base class for capturing visibile area of a WebContents.
-// This is used by both webview.captureVisibleRegion and tabs.captureVisibleTab.
-class CaptureWebContentsFunction : public AsyncExtensionFunction {
- public:
-  CaptureWebContentsFunction() {}
-
- protected:
-  ~CaptureWebContentsFunction() override {}
-
-  // ExtensionFunction implementation.
-  bool HasPermission() override;
-  bool RunAsync() override;
-
-  virtual bool IsScreenshotEnabled() = 0;
-  virtual content::WebContents* GetWebContentsForID(int context_id) = 0;
-
-  enum FailureReason {
-    FAILURE_REASON_UNKNOWN,
-    FAILURE_REASON_ENCODING_FAILED,
-    FAILURE_REASON_VIEW_INVISIBLE
-  };
-  virtual void OnCaptureFailure(FailureReason reason) = 0;
-
- private:
-
-  void CopyFromBackingStoreComplete(const SkBitmap& bitmap,
-                                    content::ReadbackResponse response);
-  void OnCaptureSuccess(const SkBitmap& bitmap);
-
-  // |context_id_| is the ID used to find the relevant WebContents. In the
-  // |tabs.captureVisibleTab()| api, this represents the window-id, and in the
-  // |webview.captureVisibleRegion()| api, this represents the instance-id of
-  // the guest.
-  int context_id_;
-
-  // The format (JPEG vs PNG) of the resulting image.  Set in RunAsync().
-  api::extension_types::ImageFormat image_format_;
-
-  // Quality setting to use when encoding jpegs.  Set in RunAsync().
-  int image_quality_;
-
-  DISALLOW_COPY_AND_ASSIGN(CaptureWebContentsFunction);
-};
-
-}  // namespace extensions
-
-#endif  // EXTENSIONS_BROWSER_API_CAPTURE_WEB_CONTENTS_FUNCTION_H_