accessible/base/AccCollector.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef mozilla_a11y_AccCollector_h__
   6 #define mozilla_a11y_AccCollector_h__
   7
   8 #include "Filters.h"
   9
  10 #include "nsTArray.h"
  11
  12 namespace mozilla {
  13 namespace a11y {
  14
  15 class Accessible;
  16
  17 /**
  18  * Collect accessible children complying with filter function. Provides quick
  19  * access to accessible by index.
  20  */
  21 class AccCollector
  22 {
  23 public:
  24   AccCollector(Accessible* aRoot, filters::FilterFuncPtr aFilterFunc);
  25   virtual ~AccCollector();
  26
  27   /**
  28    * Return accessible count within the collection.
  29    */
  30   uint32_t Count();
  31
  32   /**
  33    * Return an accessible from the collection at the given index.
  34    */
  35   Accessible* GetAccessibleAt(uint32_t aIndex);
  36
  37   /**
  38    * Return index of the given accessible within the collection.
  39    */
  40   virtual int32_t GetIndexAt(Accessible* aAccessible);
  41
  42 protected:
  43   /**
  44    * Ensure accessible at the given index is stored and return it.
  45    */
  46   Accessible* EnsureNGetObject(uint32_t aIndex);
  47
  48   /**
  49    * Ensure index for the given accessible is stored and return it.
  50    */
  51   int32_t EnsureNGetIndex(Accessible* aAccessible);
  52
  53   /**
  54    * Append the object to collection.
  55    */
  56   virtual void AppendObject(Accessible* aAccessible);
  57
  58   filters::FilterFuncPtr mFilterFunc;
  59   Accessible* mRoot;
  60   uint32_t mRootChildIdx;
  61
  62   nsTArray<Accessible*> mObjects;
  63
  64 private:
  65   AccCollector();
  66   AccCollector(const AccCollector&);
  67   AccCollector& operator =(const AccCollector&);
  68 };
  69
  70 /**
  71  * Collect embedded objects. Provide quick access to accessible by index and
  72  * vice versa.
  73  */
  74 class EmbeddedObjCollector MOZ_FINAL : public AccCollector
  75 {
  76 public:
  77   virtual ~EmbeddedObjCollector() { }
  78
  79 public:
  80   virtual int32_t GetIndexAt(Accessible* aAccessible);
  81
  82 protected:
  83   // Make sure it's used by Accessible class only.
  84   EmbeddedObjCollector(Accessible* aRoot) :
  85     AccCollector(aRoot, filters::GetEmbeddedObject) { }
  86
  87   virtual void AppendObject(Accessible* aAccessible);
  88
  89   friend class Accessible;
  90 };
  91
  92 } // namespace a11y
  93 } // namespace mozilla
  94
  95 #endif