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      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 #ifndef CONTENT_COMMON_ACCESSIBILITY_NODE_DATA_H_
      6 #define CONTENT_COMMON_ACCESSIBILITY_NODE_DATA_H_
      7 
      8 #include <map>
      9 #include <string>
     10 #include <vector>
     11 
     12 #include "base/strings/string16.h"
     13 #include "content/common/content_export.h"
     14 #include "third_party/WebKit/public/web/WebAXEnums.h"
     15 #include "ui/gfx/rect.h"
     16 
     17 namespace content {
     18 
     19 // A compact representation of the accessibility information for a
     20 // single web object, in a form that can be serialized and sent from
     21 // the renderer process to the browser process.
     22 struct CONTENT_EXPORT AccessibilityNodeData {
     23   // Additional optional attributes that can be optionally attached to
     24   // a node.
     25   enum StringAttribute {
     26     // Document attributes.
     27     ATTR_DOC_URL,
     28     ATTR_DOC_TITLE,
     29     ATTR_DOC_MIMETYPE,
     30     ATTR_DOC_DOCTYPE,
     31 
     32     // Attributes that could apply to any node.
     33     ATTR_ACCESS_KEY,
     34     ATTR_ACTION,
     35     ATTR_CONTAINER_LIVE_RELEVANT,
     36     ATTR_CONTAINER_LIVE_STATUS,
     37     ATTR_DESCRIPTION,
     38     ATTR_DISPLAY,
     39     ATTR_HELP,
     40     ATTR_HTML_TAG,
     41     ATTR_NAME,
     42     ATTR_LIVE_RELEVANT,
     43     ATTR_LIVE_STATUS,
     44     ATTR_ROLE,
     45     ATTR_SHORTCUT,
     46     ATTR_URL,
     47     ATTR_VALUE,
     48   };
     49 
     50   enum IntAttribute {
     51     // Scrollable container attributes.
     52     ATTR_SCROLL_X,
     53     ATTR_SCROLL_X_MIN,
     54     ATTR_SCROLL_X_MAX,
     55     ATTR_SCROLL_Y,
     56     ATTR_SCROLL_Y_MIN,
     57     ATTR_SCROLL_Y_MAX,
     58 
     59     // Editable text attributes.
     60     ATTR_TEXT_SEL_START,
     61     ATTR_TEXT_SEL_END,
     62 
     63     // Table attributes.
     64     ATTR_TABLE_ROW_COUNT,
     65     ATTR_TABLE_COLUMN_COUNT,
     66     ATTR_TABLE_HEADER_ID,
     67 
     68     // Table row attributes.
     69     ATTR_TABLE_ROW_INDEX,
     70     ATTR_TABLE_ROW_HEADER_ID,
     71 
     72     // Table column attributes.
     73     ATTR_TABLE_COLUMN_INDEX,
     74     ATTR_TABLE_COLUMN_HEADER_ID,
     75 
     76     // Table cell attributes.
     77     ATTR_TABLE_CELL_COLUMN_INDEX,
     78     ATTR_TABLE_CELL_COLUMN_SPAN,
     79     ATTR_TABLE_CELL_ROW_INDEX,
     80     ATTR_TABLE_CELL_ROW_SPAN,
     81 
     82     // Tree control attributes.
     83     ATTR_HIERARCHICAL_LEVEL,
     84 
     85     // Relationships between this element and other elements.
     86     ATTR_TITLE_UI_ELEMENT,
     87 
     88     // Color value for blink::WebAXRoleColorWell, each component is 0..255
     89     ATTR_COLOR_VALUE_RED,
     90     ATTR_COLOR_VALUE_GREEN,
     91     ATTR_COLOR_VALUE_BLUE,
     92 
     93     // Inline text attributes.
     94     ATTR_TEXT_DIRECTION
     95   };
     96 
     97   enum FloatAttribute {
     98     // Document attributes.
     99     ATTR_DOC_LOADING_PROGRESS,
    100 
    101     // Range attributes.
    102     ATTR_VALUE_FOR_RANGE,
    103     ATTR_MIN_VALUE_FOR_RANGE,
    104     ATTR_MAX_VALUE_FOR_RANGE,
    105   };
    106 
    107   enum BoolAttribute {
    108     // Document attributes.
    109     ATTR_DOC_LOADED,
    110 
    111     // True if a checkbox or radio button is in the "mixed" state.
    112     ATTR_BUTTON_MIXED,
    113 
    114     // Live region attributes.
    115     ATTR_CONTAINER_LIVE_ATOMIC,
    116     ATTR_CONTAINER_LIVE_BUSY,
    117     ATTR_LIVE_ATOMIC,
    118     ATTR_LIVE_BUSY,
    119 
    120     // ARIA readonly flag.
    121     ATTR_ARIA_READONLY,
    122 
    123     // Writeable attributes
    124     ATTR_CAN_SET_VALUE,
    125 
    126     // If this is set, all of the other fields in this struct should
    127     // be ignored and only the locations should change.
    128     ATTR_UPDATE_LOCATION_ONLY,
    129 
    130     // Set on a canvas element if it has fallback content.
    131     ATTR_CANVAS_HAS_FALLBACK,
    132   };
    133 
    134   enum IntListAttribute {
    135     // Ids of nodes that are children of this node logically, but are
    136     // not children of this node in the tree structure. As an example,
    137     // a table cell is a child of a row, and an 'indirect' child of a
    138     // column.
    139     ATTR_INDIRECT_CHILD_IDS,
    140 
    141     // Character indices where line breaks occur.
    142     ATTR_LINE_BREAKS,
    143 
    144     // For a table, the cell ids in row-major order, with duplicate entries
    145     // when there's a rowspan or colspan, and with -1 for missing cells.
    146     // There are always exactly rows * columns entries.
    147     ATTR_CELL_IDS,
    148 
    149     // For a table, the unique cell ids in row-major order of their first
    150     // occurrence.
    151     ATTR_UNIQUE_CELL_IDS,
    152 
    153     // For inline text. This is the pixel position of the end of this
    154     // character within the bounding rectangle of this object, in the
    155     // direction given by ATTR_TEXT_DIRECTION. For example, for left-to-right
    156     // text, the first offset is the right coordinate of the first character
    157     // within the object's bounds, the second offset is the right coordinate
    158     // of the second character, and so on.
    159     ATTR_CHARACTER_OFFSETS,
    160 
    161     // For inline text. These int lists must be the same size; they represent
    162     // the start and end character index of each word within this text.
    163     ATTR_WORD_STARTS,
    164     ATTR_WORD_ENDS,
    165   };
    166 
    167   AccessibilityNodeData();
    168   virtual ~AccessibilityNodeData();
    169 
    170   void AddStringAttribute(StringAttribute attribute,
    171                           const std::string& value);
    172   void AddIntAttribute(IntAttribute attribute, int value);
    173   void AddFloatAttribute(FloatAttribute attribute, float value);
    174   void AddBoolAttribute(BoolAttribute attribute, bool value);
    175   void AddIntListAttribute(IntListAttribute attribute,
    176                            const std::vector<int32>& value);
    177 
    178   // Convenience functions, mainly for writing unit tests.
    179   // Equivalent to AddStringAttribute(ATTR_NAME, name).
    180   void SetName(std::string name);
    181   // Equivalent to AddStringAttribute(ATTR_VALUE, value).
    182   void SetValue(std::string value);
    183 
    184   #ifndef NDEBUG
    185   virtual std::string DebugString(bool recursive) const;
    186   #endif
    187 
    188   // This is a simple serializable struct. All member variables should be
    189   // public and copyable.
    190   int32 id;
    191   blink::WebAXRole role;
    192   uint32 state;
    193   gfx::Rect location;
    194   std::vector<std::pair<StringAttribute, std::string> > string_attributes;
    195   std::vector<std::pair<IntAttribute, int32> > int_attributes;
    196   std::vector<std::pair<FloatAttribute, float> > float_attributes;
    197   std::vector<std::pair<BoolAttribute, bool> > bool_attributes;
    198   std::vector<std::pair<IntListAttribute, std::vector<int32> > >
    199       intlist_attributes;
    200   std::vector<std::pair<std::string, std::string> > html_attributes;
    201   std::vector<int32> child_ids;
    202 };
    203 
    204 // For testing and debugging only: this subclass of AccessibilityNodeData
    205 // is used to represent a whole tree of accessibility nodes, where each
    206 // node owns its children. This makes it easy to print the tree structure
    207 // or search it recursively.
    208 struct CONTENT_EXPORT AccessibilityNodeDataTreeNode
    209     : public AccessibilityNodeData {
    210   AccessibilityNodeDataTreeNode();
    211   virtual ~AccessibilityNodeDataTreeNode();
    212 
    213   AccessibilityNodeDataTreeNode& operator=(const AccessibilityNodeData& src);
    214 
    215   #ifndef NDEBUG
    216   virtual std::string DebugString(bool recursive) const OVERRIDE;
    217   #endif
    218 
    219   std::vector<AccessibilityNodeDataTreeNode> children;
    220 };
    221 
    222 // Given a vector of accessibility nodes that represent a complete
    223 // accessibility tree, where each node appears before its children,
    224 // build a tree of AccessibilityNodeDataTreeNode objects for easier
    225 // testing and debugging, where each node contains its children.
    226 // The |dst| argument will become the root of the new tree.
    227 void MakeAccessibilityNodeDataTree(
    228     const std::vector<AccessibilityNodeData>& src,
    229     AccessibilityNodeDataTreeNode* dst);
    230 
    231 }  // namespace content
    232 
    233 #endif  // CONTENT_COMMON_ACCESSIBILITY_NODE_DATA_H_
    234