/// <summary>
/// <para>Process a color theme change for this widget.</para>
/// </summary>
public override void ThemeChange()
{
// Pass the theme change on to all of the child widgets.
base.ThemeChange();
// Change the background pixel to match the new theme
// settings, and then force a repaint on the widget.
try
{
IntPtr display = dpy.Lock();
XWindow window = GetWidgetHandle();
StandardColor sc = background.Index;
if (sc != StandardColor.Inherit &&
sc != StandardColor.Pixmap &&
sc != StandardColor.RGB)
{
Xlib.XSetWindowBackground
(display, window, ToPixel(background));
}
if (mapped && AncestorsMapped)
{
Xlib.XClearArea(display, window,
0, 0, (uint)0, (uint)0,
XBool.True);
}
}
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);
}
