blob: eee3856278d9efcff1545d4c3025103cfd1ac45c [file] [log] [blame]
// Copyright (c) 2012 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 <memory>
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/observer_list.h"
#include "components/prefs/pref_member.h"
#include "content/public/browser/host_zoom_map.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_contents_user_data.h"
class ZoomControllerTest;
namespace content {
class WebContents;
namespace zoom {
class ZoomObserver;
class ZoomRequestClient : public base::RefCounted<ZoomRequestClient> {
ZoomRequestClient() {}
virtual bool ShouldSuppressBubble() const = 0;
virtual ~ZoomRequestClient() {}
friend class base::RefCounted<ZoomRequestClient>;
// Per-tab class to manage zoom changes and the Omnibox zoom icon. Lives on the
// UI thread.
class ZoomController : public content::WebContentsObserver,
public content::WebContentsUserData<ZoomController> {
// Defines how zoom changes are handled.
enum ZoomMode {
// Results in default zoom behavior, i.e. zoom changes are handled
// automatically and on a per-origin basis, meaning that other tabs
// navigated to the same origin will also zoom.
// Results in zoom changes being handled automatically, but on a per-tab
// basis. Tabs in this zoom mode will not be affected by zoom changes in
// other tabs, and vice versa.
// Overrides the automatic handling of zoom changes. The |onZoomChange|
// event will still be dispatched, but the page will not actually be zoomed.
// These zoom changes can be handled manually by listening for the
// |onZoomChange| event. Zooming in this mode is also on a per-tab basis.
// Disables all zooming in this tab. The tab will revert to the default
// zoom level, and all attempted zoom changes will be ignored.
enum RelativeZoom {
struct ZoomChangedEventData {
ZoomChangedEventData(content::WebContents* web_contents,
double old_zoom_level,
double new_zoom_level,
ZoomController::ZoomMode zoom_mode,
bool can_show_bubble)
: web_contents(web_contents),
can_show_bubble(can_show_bubble) {}
content::WebContents* web_contents;
double old_zoom_level;
double new_zoom_level;
ZoomController::ZoomMode zoom_mode;
bool can_show_bubble;
// Since it's possible for a WebContents to not have a ZoomController, provide
// a simple, safe and reliable method to find the current zoom level for a
// given WebContents*.
static double GetZoomLevelForWebContents(content::WebContents* web_contents);
~ZoomController() override;
ZoomMode zoom_mode() const { return zoom_mode_; }
// Convenience method to get default zoom level. Implemented here for
// inlining.
double GetDefaultZoomLevel() const {
return content::HostZoomMap::GetForWebContents(web_contents())
// Convenience method to quickly check if the tab's at default zoom.
// Virtual for testing.
virtual bool IsAtDefaultZoom() const;
// Returns which image should be loaded for the current zoom level.
RelativeZoom GetZoomRelativeToDefault() const;
const ZoomRequestClient* last_client() const { return last_client_.get(); }
void AddObserver(ZoomObserver* observer);
void RemoveObserver(ZoomObserver* observer);
// Used to set whether the zoom notification bubble can be shown when the
// zoom level is changed for this controller. Default behavior is to show
// the bubble.
void SetShowsNotificationBubble(bool can_show_bubble) {
can_show_bubble_ = can_show_bubble;
// Gets the current zoom level by querying HostZoomMap (if not in manual zoom
// mode) or from the ZoomController local value otherwise.
double GetZoomLevel() const;
// Calls GetZoomLevel() then converts the returned value to a percentage
// zoom factor.
// Virtual for testing.
virtual int GetZoomPercent() const;
// Sets the zoom level through HostZoomMap.
// Returns true on success.
bool SetZoomLevel(double zoom_level);
// Sets the zoom level via HostZoomMap (or stores it locally if in manual zoom
// mode), and attributes the zoom to |client|. Returns true on success.
bool SetZoomLevelByClient(
double zoom_level,
const scoped_refptr<const ZoomRequestClient>& client);
// Sets the zoom mode, which defines zoom behavior (see enum ZoomMode).
void SetZoomMode(ZoomMode zoom_mode);
// Set and query whether or not the page scale factor is one.
void SetPageScaleFactorIsOneForTesting(bool is_one);
bool PageScaleFactorIsOne() const;
// content::WebContentsObserver overrides:
void DidFinishNavigation(
content::NavigationHandle* navigation_handle) override;
void WebContentsDestroyed() override;
void RenderFrameHostChanged(content::RenderFrameHost* old_host,
content::RenderFrameHost* new_host) override;
// Protected for testing.
explicit ZoomController(content::WebContents* web_contents);
friend class content::WebContentsUserData<ZoomController>;
friend class ::ZoomControllerTest;
void ResetZoomModeOnNavigationIfNeeded(const GURL& url);
void OnZoomLevelChanged(const content::HostZoomMap::ZoomLevelChange& change);
// Updates the zoom icon and zoom percentage based on current values and
// notifies the observer if changes have occurred. |host| may be empty,
// meaning the change should apply to ~all sites. If it is not empty, the
// change only affects sites with the given host.
void UpdateState(const std::string& host);
// True if changes to zoom level can trigger the zoom notification bubble.
bool can_show_bubble_;
// The current zoom mode.
ZoomMode zoom_mode_;
// Current zoom level.
double zoom_level_;
std::unique_ptr<ZoomChangedEventData> event_data_;
// Keeps track of the extension (if any) that initiated the last zoom change
// that took effect.
scoped_refptr<const ZoomRequestClient> last_client_;
// Observer receiving notifications on state changes.
base::ObserverList<ZoomObserver>::Unchecked observers_;
content::BrowserContext* browser_context_;
// Keep track of the HostZoomMap we're currently subscribed to.
content::HostZoomMap* host_zoom_map_;
std::unique_ptr<content::HostZoomMap::Subscription> zoom_subscription_;
} // namespace zoom