/// <summary>
/// <para>Set the clip area to a region object, with a
/// specified origin.</para>
/// </summary>
///
/// <param name="r">
/// <para>The clipping region to set.</para>
/// </param>
///
/// <param name="xorigin">
/// <para>The X co-ordinate of the clipping origin.</para>
/// </param>
///
/// <param name="yorigin">
/// <para>The Y co-ordinate of the clipping origin.</para>
/// </param>
///
/// <exception cref="T:System.ArgumentNullException">
/// <para>The <paramref name="r"/> value is
/// <see langword="null"/>.</para>
/// </exception>
///
/// <exception cref="T:Xsharp.XException">
/// <para>The <paramref name="xorigin"/> or <paramref name="yorigin"/>
/// value is out of range.</para>
/// </exception>
public void SetClipRegion(Region r, int xorigin, int yorigin)
{
if(r == null)
{
throw new ArgumentNullException("r");
}
if(xorigin < -32768 || xorigin > 32767 ||
yorigin < -32768 || yorigin > 32767)
{
throw new XException(S._("X_PointCoordRange"));
}
try
{
IntPtr display = Lock();
Xlib.XSetClipOrigin(display, gc, xorigin, yorigin);
Xlib.XSetRegion(display, gc, r.GetRegion());
if(clipRegion != r)
{
if(clipRegion != null)
clipRegion.Dispose();
clipRegion = new Region(r);
}
}
finally
{
dpy.Unlock();
}
}
// Clear a region to the background and optionally queue expose events.
private bool ClearRegion(Region region, XBool exposures)
{
// Intersect the region with the widget boundaries.
region.Intersect(0, 0, width, height);
// Remove areas that are occupied by mapped child widgets.
Widget child = TopChild;
while(child != null)
{
if(child.mapped)
{
region.Subtract(child.x, child.y,
child.width, child.height);
}
child = child.NextBelow;
}
// Bail out if the region is now empty.
if(region.IsEmpty())
{
return false;
}
// Lock down the display and send the "XClearArea" requests.
try
{
IntPtr display = dpy.Lock();
XWindow handle = GetWidgetHandle();
IntPtr xregion = region.GetRegion();
XRectangle xrect;
int size, index;
size = Xlib.XSharpGetRegionSize(xregion);
for(index = 0; index < size; ++index)
{
Xlib.XSharpGetRegionRect(xregion, index, out xrect);
Xlib.XClearArea(display, handle, xrect.x, xrect.y,
xrect.width, xrect.height, exposures);
}
}
finally
{
dpy.Unlock();
}
return true;
}
/// <summary>
/// <para>Set the clip area to a region object.</para>
/// </summary>
///
/// <param name="r">
/// <para>The clipping region to set.</para>
/// </param>
///
/// <exception cref="T:System.ArgumentNullException">
/// <para>The <paramref name="r"/> value is
/// <see langword="null"/>.</para>
/// </exception>
public void SetClipRegion(Region r)
{
if(r == null)
{
throw new ArgumentNullException("r");
}
try
{
IntPtr display = Lock();
Xlib.XSetClipOrigin(display, gc, 0, 0);
Xlib.XSetRegion(display, gc, r.GetRegion());
if(clipRegion != r)
{
if(clipRegion != null)
clipRegion.Dispose();
clipRegion = new Region(r);
}
}
finally
{
dpy.Unlock();
}
}