chrome/browser/chrome_page_zoom.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/chrome_page_zoom.h"
   6
   7 #include <algorithm>
   8 #include <cmath>
   9
  10 #include "base/prefs/pref_service.h"
  11 #include "chrome/browser/chrome_page_zoom_constants.h"
  12 #include "chrome/browser/profiles/profile.h"
  13 #include "chrome/common/pref_names.h"
  14 #include "content/public/browser/host_zoom_map.h"
  15 #include "content/public/browser/render_view_host.h"
  16 #include "content/public/browser/user_metrics.h"
  17 #include "content/public/browser/web_contents.h"
  18 #include "content/public/common/page_zoom.h"
  19 #include "content/public/common/renderer_preferences.h"
  20
  21 using base::UserMetricsAction;
  22
  23 namespace chrome_page_zoom {
  24
  25 enum PageZoomValueType {
  26   PAGE_ZOOM_VALUE_TYPE_FACTOR,
  27   PAGE_ZOOM_VALUE_TYPE_LEVEL,
  28 };
  29
  30 std::vector<double> PresetZoomValues(PageZoomValueType value_type,
  31                                      double custom_value) {
  32   // Generate a vector of zoom values from an array of known preset
  33   // factors. The values in content::kPresetZoomFactors will already be in
  34   // sorted order.
  35   std::vector<double> zoom_values;
  36   bool found_custom = false;
  37   for (size_t i = 0; i < kPresetZoomFactorsSize; i++) {
  38     double zoom_value = kPresetZoomFactors[i];
  39     if (value_type == PAGE_ZOOM_VALUE_TYPE_LEVEL)
  40       zoom_value = content::ZoomFactorToZoomLevel(zoom_value);
  41     if (content::ZoomValuesEqual(zoom_value, custom_value))
  42       found_custom = true;
  43     zoom_values.push_back(zoom_value);
  44   }
  45   // If the preset array did not contain the custom value, append it to the
  46   // vector and then sort.
  47   double min = value_type == PAGE_ZOOM_VALUE_TYPE_LEVEL ?
  48       content::ZoomFactorToZoomLevel(content::kMinimumZoomFactor) :
  49       content::kMinimumZoomFactor;
  50   double max = value_type == PAGE_ZOOM_VALUE_TYPE_LEVEL ?
  51       content::ZoomFactorToZoomLevel(content::kMaximumZoomFactor) :
  52       content::kMaximumZoomFactor;
  53   if (!found_custom && custom_value > min && custom_value < max) {
  54     zoom_values.push_back(custom_value);
  55     std::sort(zoom_values.begin(), zoom_values.end());
  56   }
  57   return zoom_values;
  58 }
  59
  60 std::vector<double> PresetZoomFactors(double custom_factor) {
  61   return PresetZoomValues(PAGE_ZOOM_VALUE_TYPE_FACTOR, custom_factor);
  62 }
  63
  64 std::vector<double> PresetZoomLevels(double custom_level) {
  65   return PresetZoomValues(PAGE_ZOOM_VALUE_TYPE_LEVEL, custom_level);
  66 }
  67
  68 void Zoom(content::WebContents* web_contents, content::PageZoom zoom) {
  69   double current_zoom_level = content::HostZoomMap::GetZoomLevel(web_contents);
  70   double default_zoom_level =
  71       Profile::FromBrowserContext(web_contents->GetBrowserContext())->
  72           GetPrefs()->GetDouble(prefs::kDefaultZoomLevel);
  73
  74   if (zoom == content::PAGE_ZOOM_RESET) {
  75     content::HostZoomMap::SetZoomLevel(web_contents, default_zoom_level);
  76     content::RecordAction(UserMetricsAction("ZoomNormal"));
  77     return;
  78   }
  79
  80   // Generate a vector of zoom levels from an array of known presets along with
  81   // the default level added if necessary.
  82   std::vector<double> zoom_levels = PresetZoomLevels(default_zoom_level);
  83
  84   if (zoom == content::PAGE_ZOOM_OUT) {
  85     // Iterate through the zoom levels in reverse order to find the next
  86     // lower level based on the current zoom level for this page.
  87     for (std::vector<double>::reverse_iterator i = zoom_levels.rbegin();
  88          i != zoom_levels.rend(); ++i) {
  89       double zoom_level = *i;
  90       if (content::ZoomValuesEqual(zoom_level, current_zoom_level))
  91         continue;
  92       if (zoom_level < current_zoom_level) {
  93         content::HostZoomMap::SetZoomLevel(web_contents, zoom_level);
  94         content::RecordAction(UserMetricsAction("ZoomMinus"));
  95         return;
  96       }
  97       content::RecordAction(UserMetricsAction("ZoomMinus_AtMinimum"));
  98     }
  99   } else {
 100     // Iterate through the zoom levels in normal order to find the next
 101     // higher level based on the current zoom level for this page.
 102     for (std::vector<double>::const_iterator i = zoom_levels.begin();
 103          i != zoom_levels.end(); ++i) {
 104       double zoom_level = *i;
 105       if (content::ZoomValuesEqual(zoom_level, current_zoom_level))
 106         continue;
 107       if (zoom_level > current_zoom_level) {
 108         content::HostZoomMap::SetZoomLevel(web_contents, zoom_level);
 109         content::RecordAction(UserMetricsAction("ZoomPlus"));
 110         return;
 111       }
 112     }
 113     content::RecordAction(UserMetricsAction("ZoomPlus_AtMaximum"));
 114   }
 115 }
 116
 117 }  // namespace chrome_page_zoom