Font size in DomDistiller prefs syncs with local scaling

components/dom_distiller/core/distilled_page_prefs.cc

 // Copyright 2014 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 "components/dom_distiller/core/distilled_page_prefs.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/prefs/pref_service.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 
 namespace {
 
 // Path to the integer corresponding to user's preference theme.
 const char kFontPref[] = "dom_distiller.font_family";
 // Path to the integer corresponding to user's preference font family.
 const char kThemePref[] = "dom_distiller.theme";
+// Path to the float corresponding to user's preference font scaling.
+const char kFontScalePref[] = "dom_distiller.font_scale";
 }
 
 namespace dom_distiller {
 
 DistilledPagePrefs::DistilledPagePrefs(PrefService* pref_service)
     : pref_service_(pref_service), weak_ptr_factory_(this) {
 }
 
 DistilledPagePrefs::~DistilledPagePrefs() {
 }
 
 // static
 void DistilledPagePrefs::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterIntegerPref(
       kThemePref,
       DistilledPagePrefs::LIGHT,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterIntegerPref(
       kFontPref,
       DistilledPagePrefs::SANS_SERIF,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterDoublePref(
+      kFontScalePref,
+      1.0);
 }
 
 void DistilledPagePrefs::SetFontFamily(
     DistilledPagePrefs::FontFamily new_font_family) {
   pref_service_->SetInteger(kFontPref, new_font_family);
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(&DistilledPagePrefs::NotifyOnChangeFontFamily,
                             weak_ptr_factory_.GetWeakPtr(), new_font_family));
 }
 
@@ skipping 19 matching lines @@
   int theme = pref_service_->GetInteger(kThemePref);
   if (theme < 0 || theme >= DistilledPagePrefs::THEME_COUNT) {
     // Persisted data was incorrect, trying to clean it up by storing the
     // default.
     SetTheme(DistilledPagePrefs::LIGHT);
     return DistilledPagePrefs::LIGHT;
   }
   return static_cast<Theme>(theme);
 }
 
+void DistilledPagePrefs::SetFontScaling(float scaling) {
+  pref_service_->SetDouble(kFontScalePref, scaling);
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::Bind(&DistilledPagePrefs::NotifyOnChangeFontScaling,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 scaling));
+}
+
+float DistilledPagePrefs::GetFontScaling() {
+  float scaling = pref_service_->GetDouble(kFontScalePref);
+  if (scaling < 0.4 || scaling > 2.5) {
+    // Persisted data was incorrect, trying to clean it up by storing the
+    // default.
+    SetFontScaling(1.0);
+    return 1.0;
+  }
+  return scaling;
+}
+
 void DistilledPagePrefs::AddObserver(Observer* obs) {
   observers_.AddObserver(obs);
 }
 
 void DistilledPagePrefs::RemoveObserver(Observer* obs) {
   observers_.RemoveObserver(obs);
 }
 
 void DistilledPagePrefs::NotifyOnChangeFontFamily(
     DistilledPagePrefs::FontFamily new_font_family) {
   FOR_EACH_OBSERVER(Observer, observers_, OnChangeFontFamily(new_font_family));
 }
 
 void DistilledPagePrefs::NotifyOnChangeTheme(
     DistilledPagePrefs::Theme new_theme) {
   FOR_EACH_OBSERVER(Observer, observers_, OnChangeTheme(new_theme));
 }
 
+void DistilledPagePrefs::NotifyOnChangeFontScaling(
+    float scaling) {
+  FOR_EACH_OBSERVER(Observer, observers_, OnChangeFontScaling(scaling));
+}
+
 }  // namespace dom_distiller