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// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_UI_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_
#define CHROME_BROWSER_UI_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_
#include <memory>
#include <optional>
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "chrome/browser/ui/thumbnails/thumbnail_capture_info.h"
#include "chrome/browser/ui/thumbnails/thumbnail_image.h"
#include "content/public/browser/navigation_handle.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_contents_user_data.h"
class BackgroundThumbnailCapturer;
class ThumbnailScheduler;
class ThumbnailTabHelper
: public content::WebContentsUserData<ThumbnailTabHelper>,
public content::WebContentsObserver {
public:
ThumbnailTabHelper(const ThumbnailTabHelper&) = delete;
ThumbnailTabHelper& operator=(const ThumbnailTabHelper&) = delete;
~ThumbnailTabHelper() override;
scoped_refptr<ThumbnailImage> thumbnail() const { return thumbnail_; }
bool is_tab_discarded() const { return is_tab_discarded_; }
// Notify the helper that the tab is being hidden by being put into the
// background. Allows for an updated preview image after swapping away from an
// active tab.
void CaptureThumbnailOnTabBackgrounded();
private:
class TabStateTracker;
friend class content::WebContentsUserData<ThumbnailTabHelper>;
// Metrics enums and helper functions:
enum class CaptureType;
explicit ThumbnailTabHelper(content::WebContents* contents);
static ThumbnailScheduler& GetScheduler();
// Begins periodic capture of thumbnails from a loading page.
// This can be triggered by someone starting to observe a web contents by
// incrementing its capture count, or it can happen opportunistically when a
// renderer is available, because we want to capture thumbnails while we can
// before a page is frozen or swapped out.
void StartVideoCapture();
void StopVideoCapture();
void StoreThumbnailForTabSwitch(base::TimeTicks start_time,
const SkBitmap& bitmap);
void StoreThumbnailForBackgroundCapture(const SkBitmap& bitmap,
uint64_t frame_id);
void StoreThumbnail(CaptureType type,
const SkBitmap& bitmap,
std::optional<uint64_t> frame_id);
// Clears the data associated to the currently set thumbnail. For when the
// thumbnail is no longer valid.
void ClearData();
// viz::mojom::FrameSinkVideoConsumer:
// Returns the dimensions of the multipurpose thumbnail that should be
// captured from an entire webpage. Can be cropped or compressed later.
// If |include_scrollbars_in_capture| is false, the area which is likely to
// contain scrollbars will be removed from both the result's |copy_rect| and
// |target_size|. In both cases, |scrollbar_insets| is calculated. This
// function always returns a result with |clip_result| = kSourceNotClipped.
static ThumbnailCaptureInfo GetInitialCaptureInfo(
const gfx::Size& source_size,
float scale_factor,
bool include_scrollbars_in_capture);
void AboutToBeDiscarded(content::WebContents* new_contents) override;
void DidStartNavigation(
content::NavigationHandle* navigation_handle) override;
// Copy info from the most recent frame we have captured.
ThumbnailCaptureInfo last_frame_capture_info_;
// Private implementation of state tracking.
std::unique_ptr<TabStateTracker> state_;
std::unique_ptr<BackgroundThumbnailCapturer> background_capturer_;
// Times for computing metrics.
base::TimeTicks start_video_capture_time_;
// Whether the first frame has been received after StartVideoCapture().
bool got_first_frame_ = false;
// The thumbnail maintained by this instance.
scoped_refptr<ThumbnailImage> thumbnail_;
bool is_tab_discarded_ = false;
WEB_CONTENTS_USER_DATA_KEY_DECL();
base::WeakPtrFactory<ThumbnailTabHelper>
weak_factory_for_thumbnail_on_tab_hidden_{this};
};
#endif // CHROME_BROWSER_UI_THUMBNAILS_THUMBNAIL_TAB_HELPER_H_
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