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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.
namespace Windows.Win32.Graphics.Gdi;
/// <summary>
/// Helper to scope selecting a given text alignment mode into a HDC. Restores the original text alignment
/// mode into the HDC when disposed.
/// </summary>
/// <remarks>
/// <para>
/// Use in a <see langword="using" /> statement. If you must pass this around, always pass by
/// <see langword="ref" /> to avoid duplicating the handle and resetting multiple times.
/// </para>
/// </remarks>
#if DEBUG
internal class SetTextAlignmentScope : DisposalTracking.Tracker, IDisposable
#else
internal readonly ref struct SetTextAlignmentScope
#endif
{
private readonly TEXT_ALIGN_OPTIONS _previousTa;
private readonly HDC _hdc;
/// <summary>
/// Sets <paramref name="ta"/> in the given <paramref name="hdc"/>
/// using <see cref="PInvokeCore.SetTextAlign(HDC, TEXT_ALIGN_OPTIONS)"/>.
/// </summary>
public SetTextAlignmentScope(HDC hdc, TEXT_ALIGN_OPTIONS ta)
{
_previousTa = (TEXT_ALIGN_OPTIONS)PInvokeCore.SetTextAlign(hdc, ta);
// If we didn't actually change the TA, don't keep the HDC so we skip putting back the same state.
_hdc = _previousTa == ta ? default : hdc;
}
public void Dispose()
{
if (!_hdc.IsNull)
{
PInvokeCore.SetTextAlign(_hdc, _previousTa);
}
#if DEBUG
GC.SuppressFinalize(this);
#endif
}
}
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