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      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 AccessibilityNodeData& src,
     25       BrowserAccessibilityDelegate* delegate,
     26       BrowserAccessibilityFactory* factory = new BrowserAccessibilityFactory());
     27 
     28   virtual ~BrowserAccessibilityManagerAndroid();
     29 
     30   static AccessibilityNodeData GetEmptyDocument();
     31 
     32   void SetContentViewCore(
     33       base::android::ScopedJavaLocalRef<jobject> content_view_core);
     34 
     35   // Implementation of BrowserAccessibilityManager.
     36   virtual void NotifyAccessibilityEvent(
     37       blink::WebAXEvent 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 
     59  protected:
     60   virtual void NotifyRootChanged() OVERRIDE;
     61 
     62   virtual bool UseRootScrollOffsetsWhenComputingBounds() OVERRIDE;
     63 
     64  private:
     65   // This gives BrowserAccessibilityManager::Create access to the class
     66   // constructor.
     67   friend class BrowserAccessibilityManager;
     68 
     69   // A weak reference to the Java BrowserAccessibilityManager object.
     70   // This avoids adding another reference to BrowserAccessibilityManager and
     71   // preventing garbage collection.
     72   // Premature garbage collection is prevented by the long-lived reference in
     73   // ContentViewCore.
     74   JavaObjectWeakGlobalRef java_ref_;
     75 
     76   // Searches through the children of start_node to find the nearest
     77   // accessibility focus candidate for a touch which has not landed directly on
     78   // an accessibility focus candidate.
     79   BrowserAccessibility* FuzzyHitTest(
     80       int x, int y, BrowserAccessibility* start_node);
     81 
     82   static void FuzzyHitTestImpl(int x, int y, BrowserAccessibility* start_node,
     83       BrowserAccessibility** nearest_candidate, int* min_distance);
     84 
     85   // Calculates the distance from the point (x, y) to the nearest point on the
     86   // edge of |node|.
     87   static int CalculateDistanceSquared(int x, int y, BrowserAccessibility* node);
     88 
     89   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManagerAndroid);
     90 };
     91 
     92 bool RegisterBrowserAccessibilityManager(JNIEnv* env);
     93 
     94 }
     95 
     96 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
     97