1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/accessibility/accessibility_tree_snapshot_combiner.h"
#include "base/metrics/histogram_macros.h"
#include "content/browser/renderer_host/render_frame_host_impl.h"
namespace content {
AccessibilityTreeSnapshotCombiner::AccessibilityTreeSnapshotCombiner(
base::OnceCallback<void(ui::AXTreeUpdate&)> callback,
mojom::SnapshotAccessibilityTreeParamsPtr params)
: callback_(std::move(callback)), params_(std::move(params)) {}
void AccessibilityTreeSnapshotCombiner::RequestSnapshotOnRenderFrameHost(
RenderFrameHostImpl* rfhi) {
// The callback creates a reference to this, which is needed to keep the
// object alive using base::RefCounted. Once all frames have received their
// responses from the renderer and run their respective callbacks, all
// references to this will be removed and the destructor will be called.
rfhi->RequestAXTreeSnapshot(
base::BindOnce(&AccessibilityTreeSnapshotCombiner::
ReceiveSnapshotFromRenderFrameHost,
this, rfhi->AccessibilityIsRootFrame()),
params_.Clone());
}
void AccessibilityTreeSnapshotCombiner::ReceiveSnapshotFromRenderFrameHost(
bool is_root_frame,
ui::AXTreeUpdate& snapshot) {
combiner_.AddTree(snapshot, is_root_frame);
}
// This is called automatically after the last call to
// ReceiveSnapshotFromRenderFrameHost when there are no more references to this
// object.
AccessibilityTreeSnapshotCombiner::~AccessibilityTreeSnapshotCombiner() {
combiner_.Combine();
CHECK(combiner_.combined());
// This ensures a move of `combiner_.combined()`. It should be safe to steal
// `combiner_`'s resources since we're being destroyed.
ui::AXTreeUpdate update = std::move(combiner_.combined().value());
std::move(callback_).Run(update);
}
} // namespace content
|
