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// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_ACCESSIBILITY_PLATFORM_FUCHSIA_SEMANTIC_PROVIDER_H_
#define UI_ACCESSIBILITY_PLATFORM_FUCHSIA_SEMANTIC_PROVIDER_H_
#include <fidl/fuchsia.accessibility.semantics/cpp/fidl.h>
#include "base/component_export.h"
#include "base/functional/callback_forward.h"
namespace ui {
// Manages the connection with the Fuchsia Semantics API.
//
// Semantic nodes can be added or deleted. When a batch of nodes would leave the
// Fuchsia semantic tree in a valid state, they are committed. Please see
// |fuchsia.accessibility.semantics| API for more documentation on valid
// semantic trees.
class COMPONENT_EXPORT(AX_PLATFORM) AXFuchsiaSemanticProvider {
public:
// Fuchsia root node id.
static constexpr uint32_t kFuchsiaRootNodeId = 0u;
// A delegate that can be registered by clients of this library to be notified
// about Semantic changes.
class Delegate {
public:
Delegate();
virtual ~Delegate();
using HitTestCallback = base::OnceCallback<void(
const fidl::Response<
fuchsia_accessibility_semantics::SemanticListener::HitTest>&)>;
// Called when the FIDL channel to the Semantics Manager is closed. If this
// callback returns true, an attempt to reconnect will be made.
virtual bool OnSemanticsManagerConnectionClosed(zx_status_t status) = 0;
// Processes an incoming accessibility action from Fuchsia. It
// receives the Fuchsia node ID and the action requested. If this
// method returns true, this means that the action will be handled.
virtual bool OnAccessibilityAction(
uint32_t node_id,
fuchsia_accessibility_semantics::Action action) = 0;
// Processes an incoming hit test request from Fuchsia. It
// receives a point in Scenic View pixel coordinates and a callback to
// return the result when the hit test is done. Please see
// |fuchsia.accessibility.semantics.SemanticListener| for documentation on
// hit tests.
virtual void OnHitTest(fuchsia_math::PointF point,
HitTestCallback callback) = 0;
// Called whenever Fuchsia enables / disables semantic updates.
virtual void OnSemanticsEnabled(bool enabled) = 0;
};
AXFuchsiaSemanticProvider() = default;
virtual ~AXFuchsiaSemanticProvider() = default;
// Adds a semantic node to be updated. It is mandatory that the node has at
// least an unique ID.
virtual bool Update(fuchsia_accessibility_semantics::Node node) = 0;
// Marks a semantic node to be deleted. Returns false if the node is not
// present in the list of semantic nodes known by this provider.
virtual bool Delete(uint32_t node_id) = 0;
// Clears the semantic tree.
virtual bool Clear() = 0;
// Sends an accessibility event to Fuchsia. Please consult
// https://cs.opensource.google/fuchsia/fuchsia/+/main:sdk/fidl/fuchsia.accessibility.semantics/semantics_manager.fidl
// for documentation on events.
virtual void SendEvent(
fuchsia_accessibility_semantics::SemanticEvent event) = 0;
// Returns true if there are pending updates or deletions to be made.
virtual bool HasPendingUpdates() const = 0;
// Returns the pixel scale.
virtual float GetPixelScale() const = 0;
// Sets the pixel scale.
virtual void SetPixelScale(float pixel_scale) = 0;
};
} // namespace ui
#endif // UI_ACCESSIBILITY_PLATFORM_FUCHSIA_SEMANTIC_PROVIDER_H_
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