/// <summary>
/// Adds mouse wheel support to a <see cref="ScrollViewer"/>.
/// As long as the <see cref="ScrollViewer"/> has focus, the mouse wheel can be used to scroll up and down.
/// </summary>
/// <param name="parentScrollViewer">The parent <see cref="ScrollViewer"/> which contains another <see cref="ScrollViewer" /> which should have mouse wheel scrolling support.</param>
/// <param name="childScrollViewer">A child <see cref="ScrollViewer"/> to add mouse wheel scrolling support to.</param>
/// <param name="scrollAmount">The amount to scroll by when the mouse wheel is moved.</param>
/// <returns>The child <see cref="ScrollViewer"/>.</returns>
public static ScrollViewer AddMouseWheelSupport(this ScrollViewer parentScrollViewer, ScrollViewer childScrollViewer, double scrollAmount)
{
MouseWheelSupport mouseWheelHelper = new MouseWheelSupport(childScrollViewer, parentScrollViewer);
mouseWheelHelper.MouseWheelMoved += (source, eventArgs) =>
{
double delta = eventArgs.WheelDelta;
delta *= scrollAmount;
double newOffset = childScrollViewer.VerticalOffset - delta;
if (newOffset > childScrollViewer.ScrollableHeight)
newOffset = childScrollViewer.ScrollableHeight;
else
if (newOffset < 0)
newOffset = 0;
childScrollViewer.ScrollToVerticalOffset(newOffset);
eventArgs.BrowserEventHandled = true;
};
return childScrollViewer;
}
/// <summary>
/// Adds mouse wheel support to a <see cref="Slider"/>.
/// As long as the <see cref="Slider"/> has focus, the mouse wheel can be used to scroll up and down.
/// </summary>
/// <param name="slider">The slider.</param>
/// <param name="scrollAmount">The amount to scroll by when the mouse wheel is moved.</param>
/// <returns>The <see cref="Slider"/>.</returns>
public static Slider AddMouseWheelSupport(this Slider slider, double scrollAmount)
{
MouseWheelSupport mouseWheelHelper = new MouseWheelSupport(slider, null/*parentSlider*/);
mouseWheelHelper.MouseWheelMoved += (source, eventArgs) =>
{
double delta = eventArgs.WheelDelta;
delta *= scrollAmount;
double newOffset = slider.Value - delta;
if (newOffset < slider.Minimum)
newOffset = slider.Minimum;
else
if (newOffset > slider.Maximum)
newOffset = slider.Maximum;
slider.Value = newOffset;
eventArgs.BrowserEventHandled = true;
};
return slider;
}
