ios/web/public/web_state/page_display_state.h

   1 // Copyright 2015 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 #ifndef IOS_WEB_PUBLIC_WEB_STATE_PAGE_DISPLAY_STATE_H_
   6 #define IOS_WEB_PUBLIC_WEB_STATE_PAGE_DISPLAY_STATE_H_
   7
   8 namespace web {
   9
  10 // Class used to represent the scrolling offset of a webview.
  11 class PageScrollState {
  12  public:
  13   // Default constructor.  Initializes scroll offsets to NAN.
  14   PageScrollState();
  15   // Constructor with initial values.
  16   PageScrollState(double offset_x, double offset_y);
  17   ~PageScrollState();
  18
  19   // The scroll offset is valid if its x and y values are both non-NAN.
  20   bool IsValid() const;
  21
  22   // Accessors for scroll offsets and zoom scale.
  23   double offset_x() const { return offset_x_; }
  24   void set_offset_x(double offset_x) { offset_x_ = offset_x; }
  25   double offset_y() const { return offset_y_; }
  26   void set_offset_y(double offset_y) { offset_y_ = offset_y; }
  27
  28   // Comparator operators.
  29   bool operator==(const PageScrollState& other) const;
  30   bool operator!=(const PageScrollState& other) const;
  31
  32  private:
  33   // The x value of the page's UIScrollView contentOffset.
  34   double offset_x_;
  35   // The y value of the page's UIScrollView contentOffset.
  36   double offset_y_;
  37 };
  38
  39 // Class used to represent the scrolling offset and the zoom scale of a webview.
  40 class PageZoomState {
  41  public:
  42   // Default constructor.  Initializes scroll offsets and zoom scales to NAN.
  43   PageZoomState();
  44   // Constructor with initial values.
  45   PageZoomState(double minimum_zoom_scale,
  46                 double maximum_zoom_scale,
  47                 double zoom_scale);
  48   ~PageZoomState();
  49
  50   // Non-legacy zoom scales are valid if all three values are non-NAN and the
  51   // zoom scale is within the minimum and maximum scales.  Legacy-format
  52   // PageScrollStates are considered valid if the minimum and maximum scales
  53   // are NAN and the zoom scale is greater than zero.
  54   bool IsValid() const;
  55
  56   // PageScrollStates restored from the legacy serialization format make
  57   // assumptions about the web view's implementation of zooming, and contain a
  58   // non-NAN zoom scale and a NAN minimum and maximum scale.  Legacy zoom scales
  59   // can only be applied to CRWUIWebViewWebControllers.
  60   bool IsLegacyFormat() const;
  61
  62   // Returns the allowed zoom scale range for this scroll state.
  63   double GetMinMaxZoomDifference() const {
  64     return maximum_zoom_scale_ - minimum_zoom_scale_;
  65   }
  66
  67   // Accessors.
  68   double minimum_zoom_scale() const { return minimum_zoom_scale_; }
  69   void set_minimum_zoom_scale(double minimum_zoom_scale) {
  70     minimum_zoom_scale_ = minimum_zoom_scale;
  71   }
  72   double maximum_zoom_scale() const { return maximum_zoom_scale_; }
  73   void set_maximum_zoom_scale(double maximum_zoom_scale) {
  74     maximum_zoom_scale_ = maximum_zoom_scale;
  75   }
  76   double zoom_scale() const { return zoom_scale_; }
  77   void set_zoom_scale(double zoom_scale) { zoom_scale_ = zoom_scale; }
  78
  79   // Comparator operators.
  80   bool operator==(const PageZoomState& other) const;
  81   bool operator!=(const PageZoomState& other) const;
  82
  83  private:
  84   // The minimumZoomScale value of the page's UIScrollView.
  85   double minimum_zoom_scale_;
  86   // The maximumZoomScale value of the page's UIScrollView.
  87   double maximum_zoom_scale_;
  88   // The zoomScale value of the page's UIScrollView.
  89   double zoom_scale_;
  90 };
  91
  92 // Class used to represent the scroll offset and zoom scale of a webview.
  93 class PageDisplayState {
  94  public:
  95   // Default constructor.  Initializes scroll offsets and zoom scales to NAN.
  96   PageDisplayState();
  97   // Constructor with initial values.
  98   PageDisplayState(const PageScrollState& scroll_state,
  99                    const PageZoomState& zoom_state);
 100   PageDisplayState(double offset_x,
 101                    double offset_y,
 102                    double minimum_zoom_scale,
 103                    double maximum_zoom_scale,
 104                    double zoom_scale);
 105   ~PageDisplayState();
 106
 107   // PageScrollStates cannot be applied until the scroll offset and zoom scale
 108   // are both valid.
 109   bool IsValid() const;
 110
 111   // Accessors.
 112   const PageScrollState& scroll_state() const { return scroll_state_; }
 113   PageScrollState& scroll_state() { return scroll_state_; }
 114   void set_scroll_state(const PageScrollState& scroll_state) {
 115     scroll_state_ = scroll_state;
 116   }
 117   const PageZoomState& zoom_state() const { return zoom_state_; }
 118   PageZoomState& zoom_state() { return zoom_state_; }
 119   void set_zoom_state(const PageZoomState& zoom_state) {
 120     zoom_state_ = zoom_state;
 121   }
 122
 123   // Comparator operators.
 124   bool operator==(const PageDisplayState& other) const;
 125   bool operator!=(const PageDisplayState& other) const;
 126
 127  private:
 128   // The scroll state for the page's UIScrollView.
 129   PageScrollState scroll_state_;
 130   // The zoom state for the page's UIScrollView.
 131   PageZoomState zoom_state_;
 132 };
 133
 134 }  // namespace web
 135
 136 #endif  // IOS_WEB_PUBLIC_WEB_STATE_PAGE_DISPLAY_STATE_H_