Flutter Engine
The Flutter Engine
ax_coordinate_system.h
Go to the documentation of this file.
1// Copyright 2019 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef UI_ACCESSIBILITY_AX_COORDINATE_SYSTEM_H_
6#define UI_ACCESSIBILITY_AX_COORDINATE_SYSTEM_H_
7
8namespace ui {
9
10// The coordinate system of bounds or points. The origin for all coordinate
11// systems is the upper left hand corner of the region. Frame coordinates
12// correspond to the current frame and root frame coordinates are relative to
13// the topmost accessibility tree of the same type. For web content, root frame
14// coordinates are relative to the root frame of the web page. From within an
15// accessibility tree whose root is an iframe, frame coordinates are relative to
16// the region of the iframe. From an iframe leaf accessibility node, frame
17// coordinates are relative to the containing accessibility tree. For native UI,
18// frame coordinates are relative to the current window whereas root frame
19// coordinates are relative to the top-level window. The frame coordinates are
20// equivalent to the root frame coordinates when the current accessibility tree
21// is the root accessibility tree.
22// kScreenPhysicalPixels: Relative to screen space in hardware pixels
23// kScreenDIPs: Relative to screen space in device-independent pixels
24// (i.e. accounting for display DPI)
25// kRootFrame: Relative to the top-level accessibility tree of
26// the same type
27// kFrame: Relative to the current accessibility tree
32 kFrame
33};
34} // namespace ui
35
36#endif // UI_ACCESSIBILITY_AX_COORDINATE_SYSTEM_H_