// Copyright 2013 The Chromium Authors
// 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 <unordered_set>
#include <utility>
#include "content/common/content_export.h"
#include "ui/accessibility/platform/browser_accessibility_manager.h"
namespace ui {
class MotionEventAndroid;
class AXPlatformTreeManagerDelegate;
} // namespace ui
namespace content {
// 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 WebContentsAccessibilityAndroid;
class CONTENT_EXPORT BrowserAccessibilityManagerAndroid
: public ui::BrowserAccessibilityManager {
public:
// Creates the platform-specific BrowserAccessibilityManager.
static BrowserAccessibilityManager* Create(
const ui::AXTreeUpdate& initial_tree,
ui::AXNodeIdDelegate& node_id_delegate,
ui::AXPlatformTreeManagerDelegate* delegate);
static BrowserAccessibilityManager* Create(
ui::AXNodeIdDelegate& node_id_delegate,
ui::AXPlatformTreeManagerDelegate* delegate);
BrowserAccessibilityManagerAndroid(
const ui::AXTreeUpdate& initial_tree,
base::WeakPtr<WebContentsAccessibilityAndroid> web_contents_accessibility,
ui::AXNodeIdDelegate& node_id_delegate,
ui::AXPlatformTreeManagerDelegate* delegate);
BrowserAccessibilityManagerAndroid(
const BrowserAccessibilityManagerAndroid&) = delete;
BrowserAccessibilityManagerAndroid& operator=(
const BrowserAccessibilityManagerAndroid&) = delete;
~BrowserAccessibilityManagerAndroid() override;
static ui::AXTreeUpdate GetEmptyDocument();
void set_allow_image_descriptions_for_testing(bool is_allowed) {
allow_image_descriptions_for_testing_ = is_allowed;
}
// 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_; }
void set_web_contents_accessibility(
base::WeakPtr<WebContentsAccessibilityAndroid> wcax) {
web_contents_accessibility_ = std::move(wcax);
}
void ResetWebContentsAccessibility();
// State properties defined from Java-side code.
bool ShouldAllowImageDescriptions();
// Consume hover event if necessary, and return true if it did.
bool OnHoverEvent(const ui::MotionEventAndroid& event);
// AXTreeManager overrides.
void FireFocusEvent(ui::AXNode* node) override;
// BrowserAccessibilityManager overrides.
ui::BrowserAccessibility* GetFocus() const override;
void SendLocationChangeEvents(
const std::vector<ui::AXLocationChanges>& changes) override;
ui::AXNode* RetargetForEvents(ui::AXNode* node,
RetargetEventType type) const override;
void FireBlinkEvent(ax::mojom::Event event_type,
ui::BrowserAccessibility* node,
int action_request_id) override;
void FireGeneratedEvent(ui::AXEventGenerator::Event event_type,
const ui::AXNode* node) override;
void FireAriaNotificationEvent(
ui::BrowserAccessibility* node,
const std::string& announcement,
const std::string& notification_id,
ax::mojom::AriaNotificationInterrupt interrupt_property,
ax::mojom::AriaNotificationPriority priority_property) override;
void FireLocationChanged(ui::BrowserAccessibility* node);
// 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_t granularity,
int cursor_index,
BrowserAccessibilityAndroid* node,
int32_t* start_index,
int32_t* end_index);
bool PreviousAtGranularity(int32_t granularity,
int cursor_index,
BrowserAccessibilityAndroid* node,
int32_t* start_index,
int32_t* end_index);
// Helper method to clear AccessibilityNodeInfo cache on given node
void ClearNodeInfoCacheForGivenId(int32_t unique_id);
std::u16string GenerateAccessibilityNodeInfoString(int32_t unique_id);
std::vector<std::string> GetMetadataForTree() const;
protected:
std::unique_ptr<ui::BrowserAccessibility> CreateBrowserAccessibility(
ui::AXNode* node) override;
private:
// AXTreeObserver overrides.
void OnAtomicUpdateFinished(
ui::AXTree* tree,
bool root_changed,
const std::vector<ui::AXTreeObserver::Change>& changes) override;
void OnNodeWillBeDeleted(ui::AXTree* tree, ui::AXNode* node) override;
WebContentsAccessibilityAndroid* GetWebContentsAXFromRootManager();
// This gives BrowserAccessibilityManager::Create access to the class
// constructor.
friend class ui::BrowserAccessibilityManager;
// Handle a hover event from the renderer process.
void HandleHoverEvent(ui::BrowserAccessibility* node);
// A weak reference to WebContentsAccessibility for reaching Java layer.
// Only the root manager has the reference. Should be accessed through
// |GetWebContentsAXFromRootManager| rather than directly.
base::WeakPtr<WebContentsAccessibilityAndroid> web_contents_accessibility_;
// See docs for set_prune_tree_for_screen_reader, above.
bool prune_tree_for_screen_reader_;
// True if this instance should force enable the image descriptions feature
// for testing. This allows us to mock generated image descriptions and test
// tree dumps for nodes without creating web_contents_accessibility_android.
bool allow_image_descriptions_for_testing_ = false;
// An unordered_set of |unique_id| values for nodes cleared from the cache
// with each atomic update to prevent superfluous cache clear calls.
std::unordered_set<int32_t> nodes_already_cleared_ =
std::unordered_set<int32_t>();
};
} // namespace content
#endif // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_MANAGER_ANDROID_H_
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