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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Drawing;
using Windows.Win32.System.Variant;
using Windows.Win32.UI.Accessibility;
namespace System.Windows.Forms;
internal static unsafe class AccessibleObjectExtensions
{
public static ComScope<IAccessible> TryGetIAccessible(this AgileComPointer<IAccessible>? agile, out HRESULT result)
{
if (agile is not null)
{
return agile.TryGetInterface(out result);
}
result = HRESULT.E_NOINTERFACE;
return default;
}
public static Rectangle TryGetLocation(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryGetLocation((VARIANT)child);
public static Rectangle TryGetLocation(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
// Use the system provided bounds
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
result = accessible.Value->accLocation(
out int pxLeft,
out int pyTop,
out int pcxWidth,
out int pcyHeight,
child);
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TryGetLocation)}: accLocation call for id {(int)child} failed with {result}");
return new Rectangle(pxLeft, pyTop, pcxWidth, pcyHeight);
}
public static BSTR TryGetDefaultAction(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryGetDefaultAction((VARIANT)child);
public static BSTR TryGetDefaultAction(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
BSTR bstr = default;
result = accessible.Value->get_accDefaultAction(child, &bstr);
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TryGetDefaultAction)}: get_accDefaultAction call for id {(int)child} failed with {result}");
return bstr;
}
public static void TryDoDefaultAction(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryDoDefaultAction((VARIANT)child);
public static void TryDoDefaultAction(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return;
}
result = accessible.Value->accDoDefaultAction(child);
}
public static BSTR TryGetDescription(this AgileComPointer<IAccessible>? agile, int child) =>
agile.TryGetDescription((VARIANT)child);
public static BSTR TryGetDescription(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
BSTR description = default;
accessible.Value->get_accDescription(child, &description);
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TryGetDescription)}: get_accDescription call for {(int)child} failed with {result}");
return description;
}
public static BSTR TryGetHelp(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryGetHelp((VARIANT)child);
public static BSTR TryGetHelp(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
BSTR bstr = default;
result = accessible.Value->get_accHelp(child, &bstr);
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TryGetHelp)}: get_accHelp call for id {(int)child} failed with {result}");
return bstr;
}
public static BSTR TryGetKeyboardShortcut(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryGetKeyboardShortcut((VARIANT)child);
public static BSTR TryGetKeyboardShortcut(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
BSTR bstr = default;
result = accessible.Value->get_accKeyboardShortcut(child, &bstr);
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TryGetKeyboardShortcut)}: get_accKeyboardShortcut call for id {(int)child} failed with {result}");
return bstr;
}
public static BSTR TryGetName(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryGetName((VARIANT)child);
public static BSTR TryGetName(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
BSTR bstr = default;
result = accessible.Value->get_accName(child, &bstr);
Debug.Assert(result.Succeeded, $"{nameof(TryGetName)}: get_accName call failed with {result}");
return bstr;
}
public static void TrySetName(this AgileComPointer<IAccessible>? agile, VARIANT child, BSTR name)
{
// This is not technically supported any more, unclear if this ever actually does anything.
// https://learn.microsoft.com/windows/win32/api/oleacc/nf-oleacc-iaccessible-put_accname
if (name.IsNull)
{
return;
}
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return;
}
result = accessible.Value->put_accName(child, name);
Debug.WriteLineIf(result.Failed, $"{nameof(TrySetName)}: put_accName call failed with {result}");
}
public static AccessibleRole TryGetRole(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryGetRole((VARIANT)child);
public static AccessibleRole TryGetRole(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return AccessibleRole.None;
}
using VARIANT role = default;
result = accessible.Value->get_accRole(child, &role);
Debug.Assert(result.Succeeded, $"{nameof(TryGetRole)}: get_accRole call failed with {result}");
return role.vt is VARENUM.VT_I4 or VARENUM.VT_INT ? (AccessibleRole)(int)role : AccessibleRole.None;
}
public static AccessibleStates TryGetState(this AgileComPointer<IAccessible>? agile, int child)
=> agile.TryGetState((VARIANT)child);
public static AccessibleStates TryGetState(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return AccessibleStates.None;
}
using VARIANT state = default;
result = accessible.Value->get_accState(child, &state);
Debug.Assert(
result.Succeeded,
$"{nameof(TryGetState)}: get_accState call for id {(int)child} failed with {result}");
return state.vt is VARENUM.VT_I4 or VARENUM.VT_INT ? (AccessibleStates)(int)state : AccessibleStates.None;
}
public static BSTR TryGetValue(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
BSTR bstr = default;
result = accessible.Value->get_accValue(child, &bstr);
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TryGetValue)}: get_accValue call failed with {result}");
return bstr;
}
public static void TrySetValue(this AgileComPointer<IAccessible>? agile, VARIANT child, BSTR value)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return;
}
result = accessible.Value->put_accValue(child, value);
if (result.Failed && result != HRESULT.DISP_E_MEMBERNOTFOUND)
{
result.ThrowOnFailure();
}
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TrySetValue)}: put_accValue call failed with {result}");
}
public static (int topic, BSTR helpFile) TryGetHelpTopic(this AgileComPointer<IAccessible>? agile, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return (-1, default);
}
BSTR file = default;
result = accessible.Value->get_accHelpTopic(&file, child, out int topicId);
Debug.Assert(
result.Succeeded || result == HRESULT.DISP_E_MEMBERNOTFOUND,
$"{nameof(TryGetHelpTopic)}: put_accValue call failed with {result}");
return result.Failed ? (-1, file) : (topicId, file);
}
public static void TrySelect(this AgileComPointer<IAccessible>? agile, AccessibleSelection flags, int child)
=> agile.TrySelect(flags, (VARIANT)child);
public static void TrySelect(this AgileComPointer<IAccessible>? agile, AccessibleSelection flags, VARIANT child)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return;
}
result = accessible.Value->accSelect((int)flags, child);
}
public static int TryGetChildCount(this AgileComPointer<IAccessible>? agile)
{
using var accessible = agile.TryGetIAccessible(out HRESULT result);
if (result.Failed)
{
return default;
}
result = accessible.Value->get_accChildCount(out int count);
return count;
}
/// <summary>
/// Gets the accessible object's owner control's accesssible role.
/// </summary>
public static AccessibleRole GetOwnerAccessibleRole<TAccessible>(
this TAccessible accessibleObject,
AccessibleRole defaultRole = AccessibleRole.Default)
where TAccessible : AccessibleObject, IOwnedObject<Control>
{
AccessibleRole role = accessibleObject.Owner?.AccessibleRole ?? AccessibleRole.Default;
return role == AccessibleRole.Default ? defaultRole : role;
}
/// <summary>
/// Gets the accessible object's owner control's accesssible name.
/// </summary>
[return: NotNullIfNotNull(nameof(defaultName))]
public static string? GetOwnerAccessibleName<TAccessible>(
this TAccessible accessibleObject,
string? defaultName = null) where TAccessible : AccessibleObject, IOwnedObject<Control>
=> accessibleObject.Owner?.AccessibleName ?? defaultName;
/// <summary>
/// Gets the accessible object's owner control's accesssible text.
/// </summary>
public static string GetOwnerText<TAccessible>(this TAccessible accessibleObject, string defaultText = "")
where TAccessible : AccessibleObject, IOwnedObject<Control>
=> accessibleObject.Owner?.Text ?? defaultText;
}
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