mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
9d98d886ad
Add a class to track onscreen text via SemanticsNodes from the accessibility layer, and report this text to the ContextEngine.
84 lines
2.8 KiB
C++
84 lines
2.8 KiB
C++
// Copyright 2017 The Fuchsia Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
#include "flutter/content_handler/accessibility_bridge.h"
|
|
|
|
#include <unordered_set>
|
|
|
|
#include "apps/maxwell/services/context/context_writer.fidl.h"
|
|
#include "flutter/lib/ui/semantics/semantics_node.h"
|
|
#include "lib/app/cpp/application_context.h"
|
|
#include "lib/fxl/macros.h"
|
|
#include "third_party/rapidjson/rapidjson/document.h"
|
|
#include "third_party/rapidjson/rapidjson/stringbuffer.h"
|
|
#include "third_party/rapidjson/rapidjson/writer.h"
|
|
|
|
namespace flutter_runner {
|
|
|
|
AccessibilityBridge::AccessibilityBridge(app::ApplicationContext* context)
|
|
: writer_(context->ConnectToEnvironmentService<maxwell::ContextWriter>()) {
|
|
writer_.set_connection_error_handler(
|
|
[] { FXL_LOG(ERROR) << "Error connecting to ContextWriter."; });
|
|
}
|
|
|
|
void AccessibilityBridge::UpdateSemantics(
|
|
const std::vector<blink::SemanticsNode>& update) {
|
|
for (const auto& node : update) {
|
|
semantics_nodes_[node.id] = node;
|
|
}
|
|
std::vector<int> visited_nodes;
|
|
UpdateVisitedForNodeAndChildren(0, &visited_nodes);
|
|
EraseUnvisitedNodes(visited_nodes);
|
|
|
|
// The data sent to the Context Service is a JSON formatted list of labels
|
|
// for all on screen widgets.
|
|
rapidjson::Document nodes_json(rapidjson::kArrayType);
|
|
for (const int node_index : visited_nodes) {
|
|
const auto& node = semantics_nodes_[node_index];
|
|
if (!node.label.empty()) {
|
|
rapidjson::Value value;
|
|
value.SetString(node.label.data(), node.label.size());
|
|
nodes_json.PushBack(value, nodes_json.GetAllocator());
|
|
}
|
|
}
|
|
|
|
if (nodes_json.Size() > 0) {
|
|
rapidjson::StringBuffer buffer;
|
|
rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
|
|
nodes_json.Accept(writer);
|
|
writer_->WriteEntityTopic("/inferred/accessibility_text",
|
|
buffer.GetString());
|
|
}
|
|
}
|
|
|
|
void AccessibilityBridge::UpdateVisitedForNodeAndChildren(
|
|
const int id,
|
|
std::vector<int>* visited_nodes) {
|
|
std::map<int, blink::SemanticsNode>::const_iterator it =
|
|
semantics_nodes_.find(id);
|
|
if (it == semantics_nodes_.end()) {
|
|
return;
|
|
}
|
|
|
|
visited_nodes->push_back(id);
|
|
for (const int child : it->second.children) {
|
|
UpdateVisitedForNodeAndChildren(child, visited_nodes);
|
|
}
|
|
}
|
|
|
|
void AccessibilityBridge::EraseUnvisitedNodes(
|
|
const std::vector<int>& visited_nodes) {
|
|
const std::unordered_set<int> visited_nodes_lookup(visited_nodes.begin(),
|
|
visited_nodes.end());
|
|
for (auto it = semantics_nodes_.begin(); it != semantics_nodes_.end();) {
|
|
if (visited_nodes_lookup.find((*it).first) == visited_nodes_lookup.end()) {
|
|
it = semantics_nodes_.erase(it);
|
|
} else {
|
|
++it;
|
|
}
|
|
}
|
|
}
|
|
|
|
} // namespace flutter_runner
|