// 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><p>Invalidate the given region and flush the request</p></summary>
*/
private void Invalidate(Region region)
{
if (drawBackground)
{
ClearRegion(region, XBool.True);
}
else
{
/* Don't flush to the X server cause we don't want it to draw
the background */
region.Intersect(0, 0, width, height);
if (exposeRegion == null)
{
exposeRegion = region;
dpy.AddPendingExpose(this);
}
else
{
exposeRegion.Union(region);
region.Dispose();
}
}
}
// Paint this widget in response to an "Expose" event.
protected override void OnPaint(Graphics graphics)
{
// Draw the thick 3D border around the outside first.
graphics.DrawEffect(0, 0, width, height, Effect.Raised);
// Get the rectangle containing the caption area.
Rectangle rect = new Rectangle
(FrameBorderSize, FrameBorderSize,
width - FrameBorderSize * 2,
captionHeight - FrameBorderSize);
// If the rectangle does not overlap the expose region,
// then there is no point drawing the main caption area.
if(!graphics.ExposeRegion.Overlaps(rect))
{
return;
}
// Get the colors to use for the foreground and background.
Color foreground, background, endBackground;
if((flags & CaptionFlags.Active) != 0)
{
foreground = new Color(StandardColor.HighlightForeground);
background = new Color(StandardColor.HighlightBackground);
endBackground =
new Color(StandardColor.HighlightEndBackground);
}
else
{
foreground = new Color(StandardColor.Background);
background = new Color(StandardColor.BottomShadow);
endBackground = new Color(StandardColor.EndBackground);
}
// Create a gradient for the title bar, if necessary.
if(gradient != null &&
(gradient.Width != rect.width ||
gradient.Height != rect.height))
{
// The size has changed and we need a new gradient.
gradient.Dispose();
gradient = null;
}
if(gradient == null && screen.DefaultDepth >= 15)
{
DotGNU.Images.Image image = CreateGradient
(rect.width, rect.height, background, endBackground);
gradient = new Xsharp.Image(screen, image.GetFrame(0));
image.Dispose();
}
// Clear the caption background.
if(gradient == null)
{
graphics.Foreground = background;
graphics.SetFillSolid();
graphics.FillRectangle(rect);
}
else
{
graphics.SetFillTiled(gradient.Pixmap, rect.x, rect.y);
graphics.FillRectangle(rect);
graphics.SetFillSolid();
}
// Draw the caption buttons and then subtract that
// region off the caption rectangle so we don't get
// bleed through when we draw the caption text.
rect.width -= DrawCaptionButtons
(graphics, rect, flags, (CaptionFlags)(~0));
// Bail out if the rectangle is too small for the text.
if(rect.width <= 2)
{
return;
}
// Position the caption text.
Font font = GetCaptionFont();
FontExtents extents = font.GetFontExtents(graphics);
int textY = (rect.height - extents.Ascent) / 2;
textY += rect.y + extents.Ascent;
// Draw the caption text, clipped to the caption area
// so that it won't overwrite the buttons on the right.
using(Region region = new Region(graphics.ExposeRegion))
{
region.Intersect(rect);
graphics.SetClipRegion(region);
graphics.Foreground = foreground;
graphics.DrawString(rect.x + 2, textY, child.Name, font);
}
}