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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
#define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
#include "base/android/scoped_java_ref.h"
#include "content/browser/accessibility/browser_accessibility_manager.h"
#include "content/browser/android/content_view_core_impl.h"
namespace content {
namespace aria_strings {
extern const char kAriaLivePolite[];
extern const char kAriaLiveAssertive[];
}
// A Java counterpart will be generated for this enum.
// GENERATED_JAVA_ENUM_PACKAGE: org.chromium.content.browser.accessibility
enum ScrollDirection {
FORWARD,
BACKWARD,
UP,
DOWN,
LEFT,
RIGHT
};
// From android.view.accessibility.AccessibilityNodeInfo in Java:
enum AndroidMovementGranularity {
ANDROID_ACCESSIBILITY_NODE_INFO_MOVEMENT_GRANULARITY_CHARACTER = 1,
ANDROID_ACCESSIBILITY_NODE_INFO_MOVEMENT_GRANULARITY_WORD = 2,
ANDROID_ACCESSIBILITY_NODE_INFO_MOVEMENT_GRANULARITY_LINE = 4
};
// From android.view.accessibility.AccessibilityEvent in Java:
enum {
ANDROID_ACCESSIBILITY_EVENT_TEXT_CHANGED = 16,
ANDROID_ACCESSIBILITY_EVENT_TEXT_SELECTION_CHANGED = 8192,
ANDROID_ACCESSIBILITY_EVENT_TEXT_TRAVERSED_AT_MOVEMENT_GRANULARITY = 131072
};
class BrowserAccessibilityAndroid;
class CONTENT_EXPORT BrowserAccessibilityManagerAndroid
: public BrowserAccessibilityManager {
public:
BrowserAccessibilityManagerAndroid(
base::android::ScopedJavaLocalRef<jobject> content_view_core,
const ui::AXTreeUpdate& initial_tree,
BrowserAccessibilityDelegate* delegate,
BrowserAccessibilityFactory* factory = new BrowserAccessibilityFactory());
~BrowserAccessibilityManagerAndroid() override;
static ui::AXTreeUpdate GetEmptyDocument();
void SetContentViewCore(
base::android::ScopedJavaLocalRef<jobject> content_view_core);
// By default, the tree is pruned for a better screen reading experience,
// including:
// * If the node has only static text children
// * If the node is focusable and has no focusable children
// * If the node is a heading
// This can be turned off to generate a tree that more accurately reflects
// the DOM and includes style changes within these nodes.
void set_prune_tree_for_screen_reader(bool prune) {
prune_tree_for_screen_reader_ = prune;
}
bool prune_tree_for_screen_reader() { return prune_tree_for_screen_reader_; }
// Implementation of BrowserAccessibilityManager.
void NotifyAccessibilityEvent(ui::AXEvent event_type,
BrowserAccessibility* node) override;
// --------------------------------------------------------------------------
// Methods called from Java via JNI
// --------------------------------------------------------------------------
// Tree methods.
jint GetRootId(JNIEnv* env, jobject obj);
jboolean IsNodeValid(JNIEnv* env, jobject obj, jint id);
void HitTest(JNIEnv* env, jobject obj, jint x, jint y);
// Methods to get information about a specific node.
jboolean IsEditableText(JNIEnv* env, jobject obj, jint id);
jint GetEditableTextSelectionStart(JNIEnv* env, jobject obj, jint id);
jint GetEditableTextSelectionEnd(JNIEnv* env, jobject obj, jint id);
// Populate Java accessibility data structures with info about a node.
jboolean PopulateAccessibilityNodeInfo(
JNIEnv* env, jobject obj, jobject info, jint id);
jboolean PopulateAccessibilityEvent(
JNIEnv* env, jobject obj, jobject event, jint id, jint event_type);
// Perform actions.
void Click(JNIEnv* env, jobject obj, jint id);
void Focus(JNIEnv* env, jobject obj, jint id);
void Blur(JNIEnv* env, jobject obj);
void ScrollToMakeNodeVisible(JNIEnv* env, jobject obj, jint id);
void SetTextFieldValue(JNIEnv* env, jobject obj, jint id, jstring value);
void SetSelection(JNIEnv* env, jobject obj, jint id, jint start, jint end);
jboolean AdjustSlider(JNIEnv* env, jobject obj, jint id, jboolean increment);
// Return the id of the next node in tree order in the direction given by
// |forwards|, starting with |start_id|, that matches |element_type|,
// where |element_type| is a special uppercase string from TalkBack or
// BrailleBack indicating general categories of web content like
// "SECTION" or "CONTROL". Return 0 if not found.
jint FindElementType(JNIEnv* env, jobject obj, jint start_id,
jstring element_type, jboolean forwards);
// Respond to a ACTION_[NEXT/PREVIOUS]_AT_MOVEMENT_GRANULARITY action
// and move the cursor/selection within the given node id. We keep track
// of our own selection in BrowserAccessibilityManager.java for static
// text, but if this is an editable text node, updates the selected text
// in Blink, too, and either way calls
// Java_BrowserAccessibilityManager_finishGranularityMove with the
// result.
jboolean NextAtGranularity(JNIEnv* env, jobject obj,
jint granularity, jboolean extend_selection,
jint id, jint cursor_index);
jboolean PreviousAtGranularity(JNIEnv* env, jobject obj,
jint granularity, jboolean extend_selection,
jint id, jint cursor_index);
// Helper functions to compute the next start and end index when moving
// forwards or backwards by character, word, or line. This part is
// unit-tested; the Java interfaces above are just wrappers. Both of these
// take a single cursor index as input and return the boundaries surrounding
// the next word or line. If moving by character, the output start and
// end index will be the same.
bool NextAtGranularity(
int32 granularity, int cursor_index,
BrowserAccessibilityAndroid* node, int32* start_index, int32* end_index);
bool PreviousAtGranularity(
int32 granularity, int cursor_index,
BrowserAccessibilityAndroid* node, int32* start_index, int32* end_index);
// Set accessibility focus. This sends a message to the renderer to
// asynchronously load inline text boxes for this node only, enabling more
// accurate movement by granularities on this node.
void SetAccessibilityFocus(JNIEnv* env, jobject obj, jint id);
// Returns true if the object is a slider.
bool IsSlider(JNIEnv* env, jobject obj, jint id);
// Scrolls any scrollable container by about 80% of one page in the
// given direction.
bool Scroll(JNIEnv* env, jobject obj, jint id, int direction);
protected:
// AXTreeDelegate overrides.
void OnAtomicUpdateFinished(
ui::AXTree* tree,
bool root_changed,
const std::vector<ui::AXTreeDelegate::Change>& changes) override;
bool UseRootScrollOffsetsWhenComputingBounds() override;
private:
// This gives BrowserAccessibilityManager::Create access to the class
// constructor.
friend class BrowserAccessibilityManager;
// A weak reference to the Java BrowserAccessibilityManager object.
// This avoids adding another reference to BrowserAccessibilityManager and
// preventing garbage collection.
// Premature garbage collection is prevented by the long-lived reference in
// ContentViewCore.
JavaObjectWeakGlobalRef java_ref_;
// Handle a hover event from the renderer process.
void HandleHoverEvent(BrowserAccessibility* node);
// See docs for set_prune_tree_for_screen_reader, above.
bool prune_tree_for_screen_reader_;
DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManagerAndroid);
};
bool RegisterBrowserAccessibilityManager(JNIEnv* env);
}
#endif // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
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