/// <summary>
/// Updates the horizontal scrollbar.
/// </summary>
protected virtual void UpdateHorizontalScrollbar()
{
NativeMethods.SCROLLINFO scrollInfo;
int scrollWidth;
int pageWidth;
scrollWidth = this.ScrollSize.Width - 1;
pageWidth = this.PageSize.Width;
if (scrollWidth < 1)
{
scrollWidth = 0;
pageWidth = 1;
}
scrollInfo = new NativeMethods.SCROLLINFO();
scrollInfo.fMask = NativeMethods.SIF.SIF_PAGE | NativeMethods.SIF.SIF_RANGE;
if (this.AlwaysShowHScroll || !this.Enabled)
{
scrollInfo.fMask |= NativeMethods.SIF.SIF_DISABLENOSCROLL;
}
scrollInfo.nMin = 0;
scrollInfo.nMax = scrollWidth;
scrollInfo.nPage = pageWidth;
this.SetScrollInfo(ScrollOrientation.HorizontalScroll, scrollInfo, true);
}
/// <summary>
/// Updates the vertical scrollbar.
/// </summary>
protected virtual void UpdateVerticalScrollbar()
{
NativeMethods.SCROLLINFO scrollInfo;
int scrollHeight;
int pageHeight;
scrollHeight = this.ScrollSize.Height - 1;
pageHeight = this.PageSize.Height;
if (scrollHeight < 1)
{
scrollHeight = 0;
pageHeight = 1;
}
scrollInfo = new NativeMethods.SCROLLINFO();
scrollInfo.fMask = NativeMethods.SIF.SIF_PAGE | NativeMethods.SIF.SIF_RANGE;
if (AlwaysShowVScroll)
{
scrollInfo.fMask |= NativeMethods.SIF.SIF_DISABLENOSCROLL;
}
scrollInfo.nMin = 0;
scrollInfo.nMax = scrollHeight;
scrollInfo.nPage = pageHeight;
this.SetScrollInfo(ScrollOrientation.VerticalScroll, scrollInfo, true);
}
/// <summary>
/// Set the given scrollbar's tracking position to the specified value
/// </summary>
/// <param name="scrollbar">The scrollbar.</param>
/// <param name="value">The value.</param>
protected virtual void ScrollTo(ScrollOrientation scrollbar, int value)
{
NativeMethods.SCROLLINFO oldInfo;
oldInfo = this.GetScrollInfo(scrollbar);
if (value > ((oldInfo.nMax - oldInfo.nMin) + 1) - oldInfo.nPage)
{
value = ((oldInfo.nMax - oldInfo.nMin) + 1) - oldInfo.nPage;
}
if (value < oldInfo.nMin)
{
value = oldInfo.nMin;
}
if (oldInfo.nPos != value)
{
NativeMethods.SCROLLINFO scrollInfo;
scrollInfo = new NativeMethods.SCROLLINFO();
scrollInfo.fMask = NativeMethods.SIF.SIF_POS;
scrollInfo.nPos = value;
this.SetScrollInfo(scrollbar, scrollInfo, true);
this.OnScroll(new ScrollEventArgs(ScrollEventType.ThumbPosition, oldInfo.nPos, value, scrollbar));
}
}
/// <summary>
/// Gets scrollbar properties
/// </summary>
/// <param name="scrollbar">The bar.</param>
/// <returns></returns>
private NativeMethods.SCROLLINFO GetScrollInfo(ScrollOrientation scrollbar)
{
NativeMethods.SCROLLINFO info;
info = new NativeMethods.SCROLLINFO();
info.fMask = NativeMethods.SIF.SIF_ALL;
NativeMethods.GetScrollInfo(this.Handle, (int)scrollbar, info);
return(info);
}
/// <summary>
/// Sets scrollbar properties.
/// </summary>
/// <param name="scrollbar">The scrollbar.</param>
/// <param name="scrollInfo">The scrollbar properties.</param>
/// <param name="refresh">
/// if set to <c>true</c> the scrollbar will be repainted.
/// </param>
/// <returns></returns>
// ReSharper disable UnusedMethodReturnValue.Local
private int SetScrollInfo(ScrollOrientation scrollbar, NativeMethods.SCROLLINFO scrollInfo, bool refresh) // ReSharper restore UnusedMethodReturnValue.Local
{
return(NativeMethods.SetScrollInfo(this.Handle, (int)scrollbar, scrollInfo, refresh));
}
