Zoom Extension API (chrome)

chrome/browser/extensions/api/tabs/tabs_api.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/extensions/api/tabs/tabs_api.h"
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 26 matching lines @@
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_iterator.h"
 #include "chrome/browser/ui/browser_navigator.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/host_desktop.h"
 #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"
 #include "chrome/common/extensions/api/tabs.h"
 #include "chrome/common/extensions/api/windows.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/translate/core/browser/language_state.h"
@@ skipping 99 matching lines @@
 template <typename T>
 void AssignOptionalValue(const scoped_ptr<T>& source,
                          scoped_ptr<T>& destination) {
   if (source.get()) {
     destination.reset(new T(*source.get()));
   }
 }
 
 }  // namespace
 
+void ZoomModeToZoomSettings(ZoomMode zoom_mode,
+                            api::tabs::ZoomSettings* zoom_settings) {
+  DCHECK(zoom_settings);
+  switch (zoom_mode) {
+    case kZoomModeDefault:
+      zoom_settings->mode = api::tabs::ZoomSettings::MODE_AUTOMATIC;
+      zoom_settings->scope = api::tabs::ZoomSettings::SCOPE_PER_ORIGIN;
+      break;
+    case kZoomModeIsolated:
+      zoom_settings->mode = api::tabs::ZoomSettings::MODE_AUTOMATIC;
+      zoom_settings->scope = api::tabs::ZoomSettings::SCOPE_PER_TAB;
+      break;
+    case kZoomModeManual:
+      zoom_settings->mode = api::tabs::ZoomSettings::MODE_MANUAL;
+      zoom_settings->scope = api::tabs::ZoomSettings::SCOPE_PER_TAB;
+      break;
+    case kZoomModeDisabled:
+      zoom_settings->mode = api::tabs::ZoomSettings::MODE_DISABLED;
+      zoom_settings->scope = api::tabs::ZoomSettings::SCOPE_PER_TAB;
+      break;
+  }
+}
+
 // Windows ---------------------------------------------------------------------
 
 bool WindowsGetFunction::RunSync() {
   scoped_ptr<windows::Get::Params> params(windows::Get::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
   bool populate_tabs = false;
   if (params->get_info.get() && params->get_info->populate.get())
     populate_tabs = *params->get_info->populate;
 
@@ skipping 1237 matching lines @@
     int tab_id = *params->tab_id;
 
     Browser* browser = NULL;
     if (!GetTabById(tab_id,
                     GetProfile(),
                     include_incognito(),
                     &browser,
                     NULL,
                     &web_contents,
                     NULL,
-                    &error_))
-    return false;
+                    &error_)) {
+      return false;
+    }
   }
 
   if (web_contents->ShowingInterstitialPage()) {
     // This does as same as Browser::ReloadInternal.
     NavigationEntry* entry = web_contents->GetController().GetVisibleEntry();
     OpenURLParams params(entry->GetURL(), Referrer(), CURRENT_TAB,
                          content::PAGE_TRANSITION_RELOAD, false);
     GetCurrentBrowser()->OpenURL(params);
   } else if (bypass_cache) {
     web_contents->GetController().ReloadIgnoringCache(true);
@@ skipping 307 matching lines @@
 
   execute_tab_id_ = tab_id;
   details_ = details.Pass();
   return true;
 }
 
 bool TabsInsertCSSFunction::ShouldInsertCSS() const {
   return true;
 }
 
+bool ZoomAPIFunction::GetWebContents(int* tab_id,

[Devlin, 2014/06/16 19:04:47]

Why not content::WebContents* GetWebContents(int* tab_id), which returns NULL if
it's not found?

[wjmaclean, 2014/06/18 19:03:52]

I inherited this code from Paul Meyer, and I suspect he was trying mimic the
style of similar utility functions in the class. I've converted it to return a
pointer as requested.

+                                     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;

[Devlin, 2014/06/16 19:04:47]

It's odd that a function called GetWebContents also sets the error.  That should
be mentioned somewhere.

[wjmaclean, 2014/06/18 19:03:52]

I've mentioned in the .h file that this function may set the value of error_.

+      return false;
+    }
+    if (!ExtensionTabUtil::GetDefaultTab(browser, web_contents, NULL)) {
+      error_ = keys::kNoSelectedTabError;
+      return false;
+    }
+  }
+  return true;
+}
+
+bool TabsSetZoomFunction::RunAsync() {
+  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))
+    return false;
+  if (web_contents->GetURL().SchemeIs(content::kChromeUIScheme)) {

[Devlin, 2014/06/16 19:04:47]

WebContents::GetURL() is deprecated.  See web_contents.h for more details.

[wjmaclean, 2014/06/18 19:03:52]

Done.

+    error_ = keys::kCannotZoomChromePagesError;

[Devlin, 2014/06/16 19:04:47]

This looks like it should probably be using PermissionsData::CanAccessPage(). 
Is there a reason to have the more lax behavior here?

[Devlin, 2014/06/17 19:10:20]

Going back to this - I thought developers would need explicit access to the page
for the zoom API.  Talking to Ben, it seems this isn't the case.  If we want to
keep in any restriction, we should keep the chrome check and add in
ExtensionsClient::IsScriptableUrl().  If we don't require any checks (Ben thinks
this is what was decided, but isn't certain - and it's not documented in the
linked design doc), then we can take out the checks entirely.

[wjmaclean, 2014/06/18 19:03:52]

Possibly. It seems to mean that any extension wanting to be able to zoom a page
must either explicitly request permission for the domain(s) (which seems
restrictive since we just want to zoom) or specify <all_urls>, which may have
other baggage.

I've included CanAccessPage() in this version of the CL (please let me know if
I've done it correctly, as I wasn't sure how to handle the top_frame_url part).

+    return false;
+  }
+
+  ZoomController* zoom_controller =
+      ZoomController::FromWebContents(web_contents);
+  double zoom_level = content::ZoomFactorToZoomLevel(params->zoom_factor);
+
+  if (!zoom_controller->SetZoomLevelByExtension(zoom_level, GetExtension())) {
+    // Tried to zoom a tab in disabled mode.
+    error_ = keys::kCannotZoomDisabledTabError;
+    return false;
+  }
+
+  SendResponse(true);
+  return true;
+}
+
+bool TabsGetZoomFunction::RunAsync() {
+  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)) {
+    return false;

[Devlin, 2014/06/16 19:04:47]

nit: no braces around single-line conditionals.

[wjmaclean, 2014/06/18 19:03:52]

Done.

+  }
+
+  double zoom_level =
+      ZoomController::FromWebContents(web_contents)->GetZoomLevel();
+  double zoom_factor = content::ZoomLevelToZoomFactor(zoom_level);
+  results_ = tabs::GetZoom::Results::Create(zoom_factor);
+  SendResponse(true);
+  return true;
+}
+
+bool TabsSetZoomSettingsFunction::RunAsync() {
+  using api::tabs::ZoomSettings;
+
+  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))
+    return false;
+  if (web_contents->GetURL().SchemeIs(content::kChromeUIScheme)) {

[Devlin, 2014/06/16 19:04:47]

Same comments as above.

[wjmaclean, 2014/06/18 19:03:52]

Done.

+    error_ = keys::kCannotChangeChromePageZoomSettingsError;
+    return false;
+  }
+  ZoomController* zoom_controller =

[Devlin, 2014/06/16 19:04:47]

nit: Move this down where it's used.

[wjmaclean, 2014/06/18 19:03:52]

Done.

+      ZoomController::FromWebContents(web_contents);
+
+  // "per-origin" scope is only available in "automatic" mode.
+  if (params->zoom_settings.scope == ZoomSettings::SCOPE_PER_ORIGIN &&
+      params->zoom_settings.mode != ZoomSettings::MODE_AUTOMATIC &&
+      params->zoom_settings.mode != ZoomSettings::MODE_NONE) {
+    error_ = keys::kPerOriginOnlyInAutomaticError;
+    return false;
+  }
+
+  // Determine the correct internal zoom mode to set |web_contents| to from the
+  // user-specified |zoom_settings|.
+  ZoomMode zoom_mode = kZoomModeDefault;
+  switch (params->zoom_settings.mode) {
+    case ZoomSettings::MODE_NONE:
+    case ZoomSettings::MODE_AUTOMATIC:
+      switch (params->zoom_settings.scope) {
+        case ZoomSettings::SCOPE_NONE:
+        case ZoomSettings::SCOPE_PER_ORIGIN:
+          zoom_mode = kZoomModeDefault;
+          break;
+        case ZoomSettings::SCOPE_PER_TAB:
+          zoom_mode = kZoomModeIsolated;
+          break;

[Devlin, 2014/06/16 19:04:47]

nit: Remove trailing break.

[wjmaclean, 2014/06/18 19:03:52]

Done.

+      }
+      break;
+    case ZoomSettings::MODE_MANUAL:
+      zoom_mode = kZoomModeManual;
+      break;
+    case ZoomSettings::MODE_DISABLED:
+      zoom_mode = kZoomModeDisabled;
+      break;

[Devlin, 2014/06/16 19:04:47]

nit: Remove trailing break.

[wjmaclean, 2014/06/18 19:03:52]

Done.

+  }
+
+  zoom_controller->SetZoomMode(zoom_mode);
+
+  SendResponse(true);
+  return true;
+}
+
+bool TabsGetZoomSettingsFunction::RunAsync() {
+  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))
+    return false;
+  ZoomController* zoom_controller =
+      ZoomController::FromWebContents(web_contents);
+
+  ZoomMode zoom_mode = zoom_controller->zoom_mode();
+  api::tabs::ZoomSettings zoom_settings;
+  ZoomModeToZoomSettings(zoom_mode, &zoom_settings);
+
+  results_ = api::tabs::GetZoomSettings::Results::Create(zoom_settings);
+  SendResponse(true);
+  return true;
+}
+
 }  // namespace extensions