Zoom Extension API

chrome/browser/extensions/api/tabs/tabs_api.cc

Index: chrome/browser/extensions/api/tabs/tabs_api.cc
diff --git a/chrome/browser/extensions/api/tabs/tabs_api.cc b/chrome/browser/extensions/api/tabs/tabs_api.cc
index 39607d2b0f7f2532c3d2d37871f069edea697e07..50ec90df8b06971a51e3388146f0ebaf44f16697 100644
--- a/chrome/browser/extensions/api/tabs/tabs_api.cc
+++ b/chrome/browser/extensions/api/tabs/tabs_api.cc
@@ -44,6 +44,7 @@
 #include "chrome/browser/ui/panels/panel_manager.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/window_sizer/window_sizer.h"
+#include "chrome/browser/ui/zoom/zoom_controller.h"
 #include "chrome/browser/web_applications/web_app.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/api/i18n/default_locale_handler.h"
@@ -60,6 +61,7 @@
 #include "content/public/browser/navigation_controller.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_source.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
@@ -215,6 +217,35 @@ Browser* CreateBrowserWindow(const Browser::CreateParams& params,
 
 }  // namespace
 
+void ZoomModeToZoomSettings(content::ZoomMode zoom_mode,
+                            base::DictionaryValue* zoom_settings) {
+  std::string zoom_settings_mode;
+  std::string zoom_settings_scope;
+  switch (zoom_mode) {
+    case content::kZoomModeDefault:
+      zoom_settings_mode = "automatic";
+      zoom_settings_scope = "per-origin";
+      break;
+    case content::kZoomModeIsolated:
+      zoom_settings_mode = "automatic";
+      zoom_settings_scope = "per-tab";
+      break;
+    case content::kZoomModeManual:
+      zoom_settings_mode = "manual";
+      zoom_settings_scope = "per-tab";
+      break;
+    case content::kZoomModeDisabled:
+      zoom_settings_mode = "disabled";
+      zoom_settings_scope = "per-tab";
+      break;
+    default:
+      NOTREACHED();
+  }
+
+  zoom_settings->SetString(keys::kZoomSettingsMode, zoom_settings_mode);
+  zoom_settings->SetString(keys::kZoomSettingsScope, zoom_settings_scope);
+}
+
 // Windows ---------------------------------------------------------------------
 
 bool WindowsGetFunction::RunImpl() {
@@ -1597,7 +1628,7 @@ bool TabsReloadFunction::RunImpl() {
                     &web_contents,
                     NULL,
                     &error_))
-    return false;
+      return false;

[Fady Samuel, 2014/04/07 20:01:14]

Spacing looks wrong here.

[paulmeyer, 2014/04/07 20:56:10]

Done.

   }
 
   if (web_contents->ShowingInterstitialPage()) {
@@ -1917,4 +1948,181 @@ bool TabsInsertCSSFunction::ShouldInsertCSS() const {
   return true;
 }
 
+bool ZoomAPIFunction::GetWebContents(int* tab_id,
+                                     content::WebContents** web_contents) {
+  if (tab_id) {
+    if (!GetTabById(*tab_id,
+                    GetProfile(),
+                    include_incognito(),
+                    NULL,
+                    NULL,
+                    web_contents,
+                    NULL,
+                    &error_)) {
+      return false;
+    }
+  } else {
+    Browser* browser = GetCurrentBrowser();
+    if (!browser) {
+      error_ = keys::kNoCurrentWindowError;
+      return false;
+    }
+    if (!ExtensionTabUtil::GetDefaultTab(browser, web_contents, NULL)) {
+      error_ = keys::kNoCurrentTabError;
+      return false;
+    }
+  }
+  return true;
+}
+
+TabsSetZoomFunction::TabsSetZoomFunction() : zoom_id_(0) {}
+
+bool TabsSetZoomFunction::RunImpl() {
+  scoped_ptr<tabs::SetZoom::Params> params(
+      tabs::SetZoom::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+
+  WebContents* web_contents = NULL;
+  if (!GetWebContents(params->tab_id.get(), &web_contents)) {
+    SendResponse(false);
+    return false;
+  } else if (web_contents->GetURL().SchemeIs("chrome")) {

[Fady Samuel, 2014/04/07 20:01:14]

Are we sure this API is also isolated from <webview>?

[paulmeyer, 2014/04/07 20:56:10]

Perhaps not for now due to the existing <webview> zooming per-origin bug, but
this can be fixed in a separate patch.

+    error_ = keys::kCannotZoomChromePagesError;
+    SendResponse(false);
+    return false;
+  }
+
+  ZoomController* zoom_controller =
+      ZoomController::FromWebContents(web_contents);
+  double zoom_level = content::ZoomFactorToZoomLevel(params->zoom_factor);
+  zoom_id_ = zoom_controller->SetZoomLevelByExtension(zoom_level,
+                                                      GetExtension());
+
+  if (!zoom_id_) {
+    // Tried to zoom a tab in disabled mode.
+    error_ = keys::kCannotZoomDisabledTabError;
+    SendResponse(false);
+    return false;
+  }
+
+  // Keep this function alive so that it can call its callback once the zoom
+  // change has completed.
+  AddRef();
+  registrar_.Add(this, chrome::NOTIFICATION_TAB_ZOOM_CHANGE_COMPLETE,

[Fady Samuel, 2014/04/07 20:04:53]

So you don't need this notification if you have a callback.

[paulmeyer, 2014/04/07 20:56:10]

I believe that is true.

+                 content::NotificationService::AllSources());
+
+  return true;
+}
+
+void TabsSetZoomFunction::Observe(int type,
+                                  const content::NotificationSource& source,
+                                  const content::NotificationDetails& details) {
+  DCHECK(type == chrome::NOTIFICATION_TAB_ZOOM_CHANGE_COMPLETE);

[Fady Samuel, 2014/04/07 20:01:14]

If we switch to a callback approach, would this notification still be necessary?

[paulmeyer, 2014/04/07 20:56:10]

I believe it can be taken out if callbacks are used.

+
+  // Make sure it is this zoom change that has completed.
+  int zoom_id = *content::Details<int>(details).ptr();
+  if (zoom_id != zoom_id_) {
+    return;
+  }
+
+  // Release the function once it has called its callback.
+  SendResponse(true);
+  registrar_.RemoveAll();
+  Release();
+}
+
+bool TabsGetZoomFunction::RunImpl() {
+  scoped_ptr<tabs::GetZoom::Params> params(
+      tabs::GetZoom::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+
+  WebContents* web_contents = NULL;
+  if (!GetWebContents(params->tab_id.get(), &web_contents)) {
+    SendResponse(false);
+    return false;
+  }
+
+  double zoom_level = web_contents->GetZoomLevel();
+  double zoom_factor = content::ZoomLevelToZoomFactor(zoom_level);
+  SetResult(new base::FundamentalValue(zoom_factor));
+  SendResponse(true);
+  return true;
+}
+
+bool TabsSetZoomSettingsFunction::RunImpl() {
+  scoped_ptr<tabs::SetZoomSettings::Params> params(
+      tabs::SetZoomSettings::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+
+  WebContents* web_contents = NULL;
+  if (!GetWebContents(params->tab_id.get(), &web_contents)) {
+    SendResponse(false);
+    return false;
+  } else if (web_contents->GetURL().SchemeIs("chrome")) {

[Fady Samuel, 2014/04/07 20:01:14]

What about <webview>?

[paulmeyer, 2014/04/07 20:56:10]

Can be fixed in a separate patch.

+    error_ = keys::kCannotChangeChromePageZoomSettingsError;
+    SendResponse(false);
+    return false;
+  }
+
+  if (params->zoom_settings.scope ==

[Fady Samuel, 2014/04/07 20:01:14]

This is very confusing. I think it would be nice to better explain what these
conditions are. Perhaps store this in temporary variables and add comments.

[paulmeyer, 2014/04/07 20:56:10]

I made this clearer by setting the default mode and scope before this block, and
adding comments.

+      api::tabs::ZoomSettings::SCOPE_PER_ORIGIN &&
+      params->zoom_settings.mode != api::tabs::ZoomSettings::MODE_NONE &&
+      params->zoom_settings.mode != api::tabs::ZoomSettings::MODE_AUTOMATIC) {
+    error_ = keys::kPerOriginOnlyInAutomaticError;
+    SendResponse(false);
+    return false;
+  }
+
+  content::ZoomMode zoom_mode = content::kZoomModeDefault;
+  switch (params->zoom_settings.mode) {
+    case api::tabs::ZoomSettings::MODE_NONE:
+    case api::tabs::ZoomSettings::MODE_AUTOMATIC:
+      switch (params->zoom_settings.scope) {
+        case api::tabs::ZoomSettings::SCOPE_NONE:
+        case api::tabs::ZoomSettings::SCOPE_PER_ORIGIN:
+          zoom_mode = content::kZoomModeDefault;
+          break;
+        case api::tabs::ZoomSettings::SCOPE_PER_TAB:
+          zoom_mode = content::kZoomModeIsolated;
+          break;
+        default:
+          NOTREACHED();
+      }
+      break;
+    case api::tabs::ZoomSettings::MODE_MANUAL:
+      zoom_mode = content::kZoomModeManual;
+      break;
+    case api::tabs::ZoomSettings::MODE_DISABLED:
+      zoom_mode = content::kZoomModeDisabled;
+      break;
+    default:
+      NOTREACHED();
+  }
+
+  web_contents->SetZoomMode(zoom_mode);
+
+  SendResponse(true);
+  return true;
+}
+
+bool TabsGetZoomSettingsFunction::RunImpl() {
+  scoped_ptr<tabs::GetZoomSettings::Params> params(
+      tabs::GetZoomSettings::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+
+  WebContents* web_contents = NULL;
+  if (!GetWebContents(params->tab_id.get(), &web_contents)) {
+    SendResponse(false);
+    return false;
+  }
+
+  content::ZoomMode zoom_mode = web_contents->GetZoomMode();
+  base::DictionaryValue* zoom_settings = new base::DictionaryValue();
+  ZoomModeToZoomSettings(zoom_mode, zoom_settings);
+
+  SetResult(zoom_settings->DeepCopy());

[Fady Samuel, 2014/04/07 20:01:14]

You're leaking memory here. Just SetResult(zoom_settings);

[paulmeyer, 2014/04/07 20:56:10]

Done.

+  SendResponse(true);
+  return true;
+}
+
 }  // namespace extensions