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/render_view_host.h"
  15 #include "content/public/browser/user_metrics.h"
  16 #include "content/public/browser/web_contents.h"
  17 #include "content/public/common/page_zoom.h"
  18 #include "content/public/common/renderer_preferences.h"
  19
  20 using content::UserMetricsAction;
  21
  22 namespace chrome_page_zoom {
  23
  24 enum PageZoomValueType {
  25   PAGE_ZOOM_VALUE_TYPE_FACTOR,
  26   PAGE_ZOOM_VALUE_TYPE_LEVEL,
  27 };
  28
  29 std::vector<double> PresetZoomValues(PageZoomValueType value_type,
  30                                      double custom_value) {
  31   // Generate a vector of zoom values from an array of known preset
  32   // factors. The values in content::kPresetZoomFactors will already be in
  33   // sorted order.
  34   std::vector<double> zoom_values;
  35   bool found_custom = false;
  36   for (size_t i = 0; i < kPresetZoomFactorsSize; i++) {
  37     double zoom_value = kPresetZoomFactors[i];
  38     if (value_type == PAGE_ZOOM_VALUE_TYPE_LEVEL)
  39       zoom_value = content::ZoomFactorToZoomLevel(zoom_value);
  40     if (content::ZoomValuesEqual(zoom_value, custom_value))
  41       found_custom = true;
  42     zoom_values.push_back(zoom_value);
  43   }
  44   // If the preset array did not contain the custom value, append it to the
  45   // vector and then sort.
  46   double min = value_type == PAGE_ZOOM_VALUE_TYPE_LEVEL ?
  47       content::ZoomFactorToZoomLevel(content::kMinimumZoomFactor) :
  48       content::kMinimumZoomFactor;
  49   double max = value_type == PAGE_ZOOM_VALUE_TYPE_LEVEL ?
  50       content::ZoomFactorToZoomLevel(content::kMaximumZoomFactor) :
  51       content::kMaximumZoomFactor;
  52   if (!found_custom && custom_value > min && custom_value < max) {
  53     zoom_values.push_back(custom_value);
  54     std::sort(zoom_values.begin(), zoom_values.end());
  55   }
  56   return zoom_values;
  57 }
  58
  59 std::vector<double> PresetZoomFactors(double custom_factor) {
  60   return PresetZoomValues(PAGE_ZOOM_VALUE_TYPE_FACTOR, custom_factor);
  61 }
  62
  63 std::vector<double> PresetZoomLevels(double custom_level) {
  64   return PresetZoomValues(PAGE_ZOOM_VALUE_TYPE_LEVEL, custom_level);
  65 }
  66
  67 void Zoom(content::WebContents* web_contents, content::PageZoom zoom) {
  68   content::RenderViewHost* host = web_contents->GetRenderViewHost();
  69   double current_zoom_level = web_contents->GetZoomLevel();
  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     host->SetZoomLevel(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         host->SetZoomLevel(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         host->SetZoomLevel(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