chrome/browser/banners/app_banner_manager.h

// Copyright 2015 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 CHROME_BROWSER_BANNERS_APP_BANNER_MANAGER_H_
#define CHROME_BROWSER_BANNERS_APP_BANNER_MANAGER_H_

#include <vector>

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "chrome/browser/engagement/site_engagement_observer.h"
#include "chrome/browser/installable/installable_logging.h"
#include "chrome/browser/installable/installable_manager.h"
#include "content/public/browser/web_contents_observer.h"
#include "mojo/public/cpp/bindings/binding.h"
#include "third_party/WebKit/public/platform/modules/app_banner/app_banner.mojom.h"

class SkBitmap;
struct WebApplicationInfo;

namespace content {
class RenderFrameHost;
class WebContents;
}

// This forward declaration exists solely for the DidFinishCreatingBookmarkApp
// callback, implemented and called on desktop platforms only.
namespace extensions {
class Extension;
}

namespace banners {

// Coordinates the creation of an app banner, from detecting eligibility to
// fetching data and creating the infobar. Sites declare that they want an app
// banner using the web app manifest. One web/native app may occupy the pipeline
// at a time; navigation resets the manager and discards any work in progress.
//
// This class contains the generic functionality shared between all platforms,
// as well as no-op callbacks that the platform-specific implementations pass to
// base::Bind. This allows a WeakPtrFactory to be housed in this class.
//
// The InstallableManager fetches and validates whether a site is eligible for
// banners. The manager is first called to fetch the manifest, so we can verify
// whether the site is already installed (and on Android, divert the flow to a
// native app banner if requested). The second call completes the checking for a
// web app banner (checking manifest validity, service worker, and icon).
class AppBannerManager : public content::WebContentsObserver,
                         public blink::mojom::AppBannerService,
                         public SiteEngagementObserver {
 public:
  // Returns the current time.
  static base::Time GetCurrentTime();

  // Fast-forwards the current time for testing.
  static void SetTimeDeltaForTesting(int days);

  // Sets the total engagement required for triggering the banner in testing.
  static void SetTotalEngagementToTrigger(double engagement);

  // Requests an app banner. If |is_debug_mode| is true, any failure in the
  // pipeline will be reported to the devtools console.
  virtual void RequestAppBanner(const GURL& validated_url, bool is_debug_mode);

  // Informs the page that it has been installed via an app banner.
  // This is redundant for the beforeinstallprompt event's promise being
  // resolved, but is required by the install event spec.
  void OnInstall();

  // Sends a message to the renderer that the user accepted the banner. Does
  // nothing if |request_id| does not match the current request.
  void SendBannerAccepted(int request_id);

  // Sends a message to the renderer that the user dismissed the banner. Does
  // nothing if |request_id| does not match the current request.
  void SendBannerDismissed(int request_id);

  // Returns a WeakPtr to this object. Exposed so subclasses/infobars may
  // may bind callbacks without needing their own WeakPtrFactory.
  base::WeakPtr<AppBannerManager> GetWeakPtr();

  // Overridden and passed through base::Bind on desktop platforms. Called when
  // the bookmark app install initiated by a banner has completed. Not used on
  // Android.
  virtual void DidFinishCreatingBookmarkApp(
      const extensions::Extension* extension,
      const WebApplicationInfo& web_app_info) {}

  // Overridden and passed through base::Bind on Android. Called when the
  // download of a native app's icon is complete, as native banners use an icon
  // provided from the Play Store rather than the web manifest. Not used on
  // desktop platforms.
  virtual void OnAppIconFetched(const SkBitmap& bitmap) {}

 protected:
  enum class State {
    // The banner pipeline has not yet been triggered for this page load.
    INACTIVE,

    // The banner pipeline is currently running for this page load.
    ACTIVE,

    // The banner pipeline has finished running, but is waiting for sufficient
    // engagement to trigger the banner.
    PENDING_ENGAGEMENT,

    // The banner pipeline has finished running, but is waiting for an event to
    // trigger the banner.
    PENDING_EVENT,

    // The banner pipeline has finished running for this page load and no more
    // processing is to be done.
    COMPLETE,
  };

  explicit AppBannerManager(content::WebContents* web_contents);
  ~AppBannerManager() override;

  // Returns true if the banner should be shown. Returns false if the banner has
  // been shown too recently, or if the app has already been installed.
  // GetAppIdentifier() must return a valid value for this method to work.
  bool CheckIfShouldShowBanner();

  // Return a string identifying this app for metrics.
  virtual std::string GetAppIdentifier();

  // Return a string describing what type of banner is being created. Used when
  // alerting websites that a banner is about to be created.
  virtual std::string GetBannerType();

  // Returns a string parameter for a devtools console message corresponding to
  // |code|. Returns the empty string if |code| requires no parameter.
  std::string GetStatusParam(InstallableStatusCode code);

  // Returns the ideal and minimum primary icon size requirements.
  virtual int GetIdealPrimaryIconSizeInPx();
  virtual int GetMinimumPrimaryIconSizeInPx();

  // Returns true if |is_debug_mode_| is true or the
  // kBypassAppBannerEngagementChecks flag is set.
  virtual bool IsDebugMode() const;

  // Returns true if the webapp at |start_url| has already been installed.
  virtual bool IsWebAppInstalled(content::BrowserContext* browser_context,
                                 const GURL& start_url,
                                 const GURL& manifest_url);

  // Callback invoked by the InstallableManager once it has fetched the page's
  // manifest.
  void OnDidGetManifest(const InstallableData& result);

  // Returns an InstallableParams object that requests all checks necessary for
  // a web app banner.
  virtual InstallableParams ParamsToPerformInstallableCheck();

  // Run at the conclusion of OnDidGetManifest. For web app banners, this calls
  // back to the InstallableManager to continue checking criteria. For native
  // app banners, this checks whether native apps are preferred in the manifest,
  // and calls to Java to verify native app details. If a native banner isn't or
  // can't be requested, it continues with the web app banner checks.
  virtual void PerformInstallableCheck();

  // Callback invoked by the InstallableManager once it has finished checking
  // all other installable properties.
  virtual void OnDidPerformInstallableCheck(const InstallableData& result);

  // Records that a banner was shown. The |event_name| corresponds to the RAPPOR
  // metric being recorded.
  void RecordDidShowBanner(const std::string& event_name);

  // Logs an error message corresponding to |code| to the devtools console
  // attached to |web_contents|. Does nothing if IsDebugMode() returns false.
  void ReportStatus(content::WebContents* web_contents,
                    InstallableStatusCode code);

  // Resets all fetched data for the current page.
  virtual void ResetCurrentPageData();

  // Stops the banner pipeline, preventing any outstanding callbacks from
  // running and resetting the manager state. This method is virtual to allow
  // tests to intercept it and verify correct behaviour.
  virtual void Stop();

  // Sends a message to the renderer that the page has met the requirements to
  // show a banner. The page can respond to cancel the banner (and possibly
  // display it later), or otherwise allow it to be shown.
  void SendBannerPromptRequest();

  // Updates the current state to |state|. Virtual to allow overriding in tests.
  virtual void UpdateState(State state);

  // content::WebContentsObserver overrides.
  void DidStartNavigation(content::NavigationHandle* handle) override;
  void DidFinishNavigation(content::NavigationHandle* handle) override;
  void DidFinishLoad(content::RenderFrameHost* render_frame_host,
                     const GURL& validated_url) override;
  void MediaStartedPlaying(const MediaPlayerInfo& media_info,
                           const MediaPlayerId& id) override;
  void MediaStoppedPlaying(const MediaPlayerInfo& media_info,
                           const MediaPlayerId& id) override;
  void WebContentsDestroyed() override;

  // SiteEngagementObserver overrides.
  void OnEngagementIncreased(content::WebContents* web_contents,
                             const GURL& url,
                             double score) override;

  // Subclass accessors for private fields which should not be changed outside
  // this class.
  InstallableManager* manager() const { return manager_; }
  int event_request_id() const { return event_request_id_; }
  bool is_active() const { return state_ == State::ACTIVE; }
  bool is_active_or_pending() const {
    return state_ == State::ACTIVE || state_ == State::PENDING_ENGAGEMENT ||
           state_ == State::PENDING_EVENT;
  }
  bool is_complete() const { return state_ == State::COMPLETE; }
  bool is_pending_engagement() const {
    return state_ == State::PENDING_ENGAGEMENT;
  }
  bool is_pending_event() const {
    return state_ == State::PENDING_EVENT || page_requested_prompt_;
  }

  // The title to display in the banner.
  base::string16 app_title_;

  // The URL for which the banner check is being conducted.
  GURL validated_url_;

  // The URL of the manifest.
  GURL manifest_url_;

  // The manifest object.
  content::Manifest manifest_;

  // The URL of the primary icon.
  GURL primary_icon_url_;

  // The primary icon object.
  SkBitmap primary_icon_;

  // The referrer string (if any) specified in the app URL. Used only for native
  // app banners.
  std::string referrer_;

  // The current banner pipeline state for this page load.
  State state_;

 private:
  friend class AppBannerManagerTest;

  // Record that the banner could be shown at this point, if the triggering
  // heuristic allowed.
  void RecordCouldShowBanner();

  // Creates a banner for the app. Overridden by subclasses as the infobar is
  // platform-specific.
  virtual void ShowBanner() = 0;

  // Called after the manager sends a message to the renderer regarding its
  // intention to show a prompt. The renderer will send a message back with the
  // opportunity to cancel.
  void OnBannerPromptReply(blink::mojom::AppBannerPromptReply reply,
                           const std::string& referrer);

  // blink::mojom::AppBannerService overrides.
  // Called when Blink has prevented a banner from being shown, and is now
  // requesting that it be shown later.
  void DisplayAppBanner() override;

  // Fetches the data required to display a banner for the current page.
  InstallableManager* manager_;

  // A monotonically increasing id to verify the response to the
  // beforeinstallprompt event from the renderer.
  int event_request_id_;

  // We do not want to trigger a banner when the manager is attached to
  // a WebContents that is playing video. Banners triggering on a site in the
  // background will appear when the tab is reactivated.
  std::vector<MediaPlayerId> active_media_players_;

  // Mojo bindings and interface pointers.
  mojo::Binding<blink::mojom::AppBannerService> binding_;
  blink::mojom::AppBannerEventPtr event_;
  blink::mojom::AppBannerControllerPtr controller_;

  // If a banner is requested before the page has finished loading, defer
  // triggering the pipeline until the load is complete.
  bool has_sufficient_engagement_;
  bool load_finished_;

  // Record whether the page requests for a banner to be shown later on.
  bool page_requested_prompt_;

  // Whether we should be logging errors to the console for this request.
  bool is_debug_mode_;

  // Whether the installable status has been logged for this run.
  bool need_to_log_status_;

  // The concrete subclasses of this class are expected to have their lifetimes
  // scoped to the WebContents which they are observing. This allows us to use
  // weak pointers for callbacks.
  base::WeakPtrFactory<AppBannerManager> weak_factory_;

  DISALLOW_COPY_AND_ASSIGN(AppBannerManager);
};

}  // namespace banners

#endif  // CHROME_BROWSER_BANNERS_APP_BANNER_MANAGER_H_