content/browser/accessibility/browser_accessibility_manager_android.h

   1 // Copyright 2013 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_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
   6 #define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
   7
   8 #include "base/android/scoped_java_ref.h"
   9 #include "content/browser/accessibility/browser_accessibility_manager.h"
  10 #include "content/browser/android/content_view_core_impl.h"
  11
  12 namespace content {
  13
  14 namespace aria_strings {
  15   extern const char kAriaLivePolite[];
  16   extern const char kAriaLiveAssertive[];
  17 }
  18
  19 class CONTENT_EXPORT BrowserAccessibilityManagerAndroid
  20     : public BrowserAccessibilityManager {
  21  public:
  22   BrowserAccessibilityManagerAndroid(
  23       base::android::ScopedJavaLocalRef<jobject> content_view_core,
  24       const ui::AXNodeData& src,
  25       BrowserAccessibilityDelegate* delegate,
  26       BrowserAccessibilityFactory* factory = new BrowserAccessibilityFactory());
  27
  28   virtual ~BrowserAccessibilityManagerAndroid();
  29
  30   static ui::AXNodeData GetEmptyDocument();
  31
  32   void SetContentViewCore(
  33       base::android::ScopedJavaLocalRef<jobject> content_view_core);
  34
  35   // Implementation of BrowserAccessibilityManager.
  36   virtual void NotifyAccessibilityEvent(
  37       ui::AXEvent event_type, BrowserAccessibility* node) OVERRIDE;
  38
  39   // --------------------------------------------------------------------------
  40   // Methods called from Java via JNI
  41   // --------------------------------------------------------------------------
  42
  43   // Tree methods.
  44   jint GetRootId(JNIEnv* env, jobject obj);
  45   jboolean IsNodeValid(JNIEnv* env, jobject obj, jint id);
  46   jint HitTest(JNIEnv* env, jobject obj, jint x, jint y);
  47
  48   // Populate Java accessibility data structures with info about a node.
  49   jboolean PopulateAccessibilityNodeInfo(
  50       JNIEnv* env, jobject obj, jobject info, jint id);
  51   jboolean PopulateAccessibilityEvent(
  52       JNIEnv* env, jobject obj, jobject event, jint id, jint event_type);
  53
  54   // Perform actions.
  55   void Click(JNIEnv* env, jobject obj, jint id);
  56   void Focus(JNIEnv* env, jobject obj, jint id);
  57   void Blur(JNIEnv* env, jobject obj);
  58   void ScrollToMakeNodeVisible(JNIEnv* env, jobject obj, int id);
  59
  60   // Return the id of the next node in tree order in the direction given by
  61   // |forwards|, starting with |start_id|, that matches |element_type|,
  62   // where |element_type| is a special uppercase string from TalkBack or
  63   // BrailleBack indicating general categories of web content like
  64   // "SECTION" or "CONTROL".  Return 0 if not found.
  65   jint FindElementType(JNIEnv* env, jobject obj, jint start_id,
  66                        jstring element_type, jboolean forwards);
  67
  68  protected:
  69   virtual void NotifyRootChanged() OVERRIDE;
  70
  71   virtual bool UseRootScrollOffsetsWhenComputingBounds() OVERRIDE;
  72
  73  private:
  74   // This gives BrowserAccessibilityManager::Create access to the class
  75   // constructor.
  76   friend class BrowserAccessibilityManager;
  77
  78   // A weak reference to the Java BrowserAccessibilityManager object.
  79   // This avoids adding another reference to BrowserAccessibilityManager and
  80   // preventing garbage collection.
  81   // Premature garbage collection is prevented by the long-lived reference in
  82   // ContentViewCore.
  83   JavaObjectWeakGlobalRef java_ref_;
  84
  85   // Searches through the children of start_node to find the nearest
  86   // accessibility focus candidate for a touch which has not landed directly on
  87   // an accessibility focus candidate.
  88   BrowserAccessibility* FuzzyHitTest(
  89       int x, int y, BrowserAccessibility* start_node);
  90
  91   static void FuzzyHitTestImpl(int x, int y, BrowserAccessibility* start_node,
  92       BrowserAccessibility** nearest_candidate, int* min_distance);
  93
  94   // Calculates the distance from the point (x, y) to the nearest point on the
  95   // edge of |node|.
  96   static int CalculateDistanceSquared(int x, int y, BrowserAccessibility* node);
  97
  98   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManagerAndroid);
  99 };
 100
 101 bool RegisterBrowserAccessibilityManager(JNIEnv* env);
 102
 103 }
 104
 105 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_