seb-win-refactoring/SafeExamBrowser.UserInterface.Shared/Utilities/VisualExtensions.cs

63 lines
1.7 KiB
C#

/*
* Copyright (c) 2023 ETH Zürich, Educational Development and Technology (LET)
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;
namespace SafeExamBrowser.UserInterface.Shared.Utilities
{
/// <summary>
/// WPF works with device-independent pixels. These methods are required to transform
/// such values to their absolute, device-specific pixel values and vice versa.
///
/// Source: https://stackoverflow.com/questions/3286175/how-do-i-convert-a-wpf-size-to-physical-pixels
/// </summary>
public static class VisualExtensions
{
public static Vector TransformToPhysical(this Visual visual, double x, double y)
{
var matrix = default(Matrix);
var source = PresentationSource.FromVisual(visual);
if (source != null)
{
matrix = source.CompositionTarget.TransformToDevice;
}
else
{
using (var newSource = new HwndSource(new HwndSourceParameters()))
{
matrix = newSource.CompositionTarget.TransformToDevice;
}
}
return matrix.Transform(new Vector(x, y));
}
public static Vector TransformFromPhysical(this Visual visual, double x, double y)
{
var matrix = default(Matrix);
var source = PresentationSource.FromVisual(visual);
if (source != null)
{
matrix = source.CompositionTarget.TransformFromDevice;
}
else
{
using (var newSource = new HwndSource(new HwndSourceParameters()))
{
matrix = newSource.CompositionTarget.TransformFromDevice;
}
}
return matrix.Transform(new Vector(x, y));
}
}
}