Zoom Extension API (work in progress)

chrome/browser/ui/zoom/zoom_controller.cc

 // 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 "chrome/browser/ui/zoom/zoom_controller.h"
 
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/page_zoom.h"
 #include "grit/theme_resources.h"
 #include "net/base/net_util.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(ZoomController);
 
 ZoomController::ZoomController(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       zoom_percent_(100),
       observer_(NULL),
       browser_context_(web_contents->GetBrowserContext()) {
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
-  default_zoom_level_.Init(prefs::kDefaultZoomLevel, profile->GetPrefs(),
-                           base::Bind(&ZoomController::UpdateState,
-                                      base::Unretained(this),
-                                      std::string()));
+  default_zoom_level_.Init(
+      prefs::kDefaultZoomLevel, profile->GetPrefs(),
+      base::Bind(static_cast<void(ZoomController::*)(
+          const std::string&)>(&ZoomController::UpdateState),
+                 base::Unretained(this),
+                 std::string()));
 
   zoom_subscription_ = content::HostZoomMap::GetForBrowserContext(
       browser_context_)->AddZoomLevelChangedCallback(
           base::Bind(&ZoomController::OnZoomLevelChanged,
                      base::Unretained(this)));
 
   UpdateState(std::string());
 }
 
 ZoomController::~ZoomController() {}
 
 bool ZoomController::IsAtDefaultZoom() const {
   return content::ZoomValuesEqual(web_contents()->GetZoomLevel(),
                                   default_zoom_level_.GetValue());
 }
 
 int ZoomController::GetResourceForZoomLevel() const {
   if (IsAtDefaultZoom())
     return IDR_ZOOM_NORMAL;
   double zoom = web_contents()->GetZoomLevel();
   return zoom > default_zoom_level_.GetValue() ? IDR_ZOOM_PLUS : IDR_ZOOM_MINUS;
 }
 
+const extensions::Extension* ZoomController::last_extension() const {
+  return last_extension_.get();
+}
+
+bool ZoomController::SetZoomLevel(double zoom_level) {
+  // Cannot zoom in disabled mode.
+  if (zoom_mode_ == kZoomModeDisabled)
+    return false;
+
+  // An extension did not initiate this zoom change.
+  extensions_.push(NULL);
+
+  // Do not actually rescale the page in manual mode.
+  if (zoom_mode_ == kZoomModeManual) {
+    content::HostZoomMap* zoom_map = content::HostZoomMap::GetForBrowserContext(
+        web_contents()->GetBrowserContext());
+    DCHECK(zoom_map);
+    int render_process_id = web_contents()->GetRenderProcessHost()->GetID();
+    int render_view_id = web_contents()->GetRenderViewHost()->GetRoutingID();
+    std::string host = net::GetHostOrSpecFromURL(
+        web_contents()->GetController().GetLastCommittedEntry()->GetURL());
+    zoom_map->SetTemporaryZoomLevel(render_process_id, render_view_id,
+                                    host, zoom_level);
+  } else {
+    web_contents()->SetZoomLevel(zoom_level);
+  }
+  observer_->OnZoomChangeInitiated(web_contents(),
+                                   web_contents()->GetZoomLevel(),
+                                   zoom_level,
+                                   zoom_mode_);
+
+  return true;
+}
+
+bool ZoomController::SetZoomLevelByExtension(
+    double zoom_level,
+    scoped_refptr<const extensions::Extension> extension) {
+  if (!SetZoomLevel(zoom_level))
+    return false;
+
+  // Store extension data so that |extension| can be attributed when the zoom
+  // change completes..
+  extensions_.front() = extension.get();
+  return true;
+}
+
+void ZoomController::SetZoomMode(ZoomMode new_mode) {
+  if (new_mode == zoom_mode_)
+    return;
+
+  content::HostZoomMap* zoom_map = content::HostZoomMap::GetForBrowserContext(
+      web_contents()->GetBrowserContext());
+  DCHECK(zoom_map);
+  int render_process_id = web_contents()->GetRenderProcessHost()->GetID();
+  int render_view_id = web_contents()->GetRenderViewHost()->GetRoutingID();
+  std::string host = net::GetHostOrSpecFromURL(
+      web_contents()->GetController().GetLastCommittedEntry()->GetURL());
+  double original_zoom_level = web_contents()->GetZoomLevel();
+
+  switch (new_mode) {
+    case kZoomModeDefault: {
+      zoom_map->SetZoomLevelForHost(host, original_zoom_level);
+      // Remove per-tab zoom data for this tab.
+      zoom_map->EraseTemporaryZoomLevel(render_process_id, render_view_id);
+      break;
+    }
+    case kZoomModeIsolated: {
+      // Unless the zoom mode was |kZoomModeDisabled| before this call, the page
+      // needs an initial isolated zoom back to the same level it was at in the
+      // other mode.
+      if (zoom_mode_ != kZoomModeDisabled) {
+        zoom_map->SetTemporaryZoomLevel(render_process_id, render_view_id,
+                                        host, original_zoom_level);
+      }
+      break;
+    }
+    case kZoomModeManual: {
+      // Unless the zoom mode was |kZoomModeDisabled| before this call, the page
+      // needs to be resized to the default zoom before calling SetZoomLevel()
+      // so that the page can be resized manually to the same zoom as before.
+      if (zoom_mode_ != kZoomModeDisabled) {
+        zoom_map->SetTemporaryZoomLevel(render_process_id, render_view_id,
+                                        host, 0);
+        zoom_mode_ = new_mode;
+        SetZoomLevel(original_zoom_level);
+      }
+      break;
+    }
+    case kZoomModeDisabled: {
+      // The page needs to be zoomed back to default before disabling the zoom
+      // (unless it was just in |kZoomModeManual| mode, in which case this is
+      // already done).
+      if (zoom_mode_ != kZoomModeManual)
+        zoom_map->SetTemporaryZoomLevel(render_process_id, render_view_id,
+                                        host, 0);
+      break;
+    }
+  }
+
+  zoom_mode_ = new_mode;
+  web_contents()->SetTemporaryZoomSettings(new_mode != kZoomModeDefault);
+}
+
 void ZoomController::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   // If the main frame's content has changed, the new page may have a different
   // zoom level from the old one.
   UpdateState(std::string());
 }
 
 void ZoomController::OnZoomLevelChanged(
     const content::HostZoomMap::ZoomLevelChange& change) {
-  UpdateState(change.host);
+  UpdateState(change.host,
+              change.mode == content::HostZoomMap::ZOOM_CHANGED_TEMPORARY_ZOOM);
 }
 
 void ZoomController::UpdateState(const std::string& host) {
+  UpdateState(host, false);
+}
+
+void ZoomController::UpdateState(const std::string& host,
+                                 bool is_temporary_zoom) {
+  // Update |last_extension_|.
+  DCHECK(!extensions_.empty());
+  last_extension_ = extensions_.front().get();
+  extensions_.pop();
+
   // If |host| is empty, all observers should be updated.
   if (!host.empty()) {
     // Use the navigation entry's URL instead of the WebContents' so virtual
     // URLs work (e.g. chrome://settings). http://crbug.com/153950
     content::NavigationEntry* entry =
         web_contents()->GetController().GetLastCommittedEntry();
     if (!entry ||
         host != net::GetHostOrSpecFromURL(entry->GetURL())) {
       return;
     }
   }
-
   bool dummy;
   zoom_percent_ = web_contents()->GetZoomPercent(&dummy, &dummy);
 
-  if (observer_)
-    observer_->OnZoomChanged(web_contents(), !host.empty());
+  if (observer_) {
+    // The zoom bubble can be shown for all normal, per-origin zoom changes
+    // (where the host will not be empty and the zoom is not temporary), or any
+    // special zoom changes (where the zoom mode will not be "default").
+    bool can_show_bubble =
+        zoom_mode_ != kZoomModeDefault ||
+        (!host.empty() && !is_temporary_zoom);
+    observer_->OnZoomChanged(web_contents(), can_show_bubble);
+  }
+
+  last_extension_ = NULL;
 }