public static void VirtualPaint(Control child, PaintEventArgs args)
{
IVirtualTransparencyHost parent = VirtualParent(child);
Debug.Assert(parent != null, "No virtual transparency host found in ancestor chain of " + child.Name);
VirtualPaint(parent, child, args);
}
public static void VirtualPaint(IVirtualTransparencyHost host, Control child, PaintEventArgs args)
{
Control hostControl = (Control)host;
bool rtl = host is Form && ((Form)host).RightToLeft == RightToLeft.Yes && ((Form)host).RightToLeftLayout;
Point childLocation = child.PointToScreen(new Point(0, 0));
Point hostLocation = hostControl.PointToScreen(new Point(rtl ? hostControl.ClientSize.Width : 0, 0));
Point relativeChildLocation = new Point(childLocation.X - hostLocation.X, childLocation.Y - hostLocation.Y);
if (relativeChildLocation == Point.Empty)
{
// no translation transform required
host.Paint(args);
return;
}
Rectangle relativeClipRectangle = args.ClipRectangle;
relativeClipRectangle.Offset(relativeChildLocation);
args.Graphics.SetClip(relativeClipRectangle, CombineMode.Replace);
// Global transformations applied in GDI+ land don't apply to
// GDI calls. So we need to drop down to GDI, apply a transformation
// there, then wrap with GDI+.
IntPtr hdc = args.Graphics.GetHdc();
try
{
Gdi32.GraphicsMode oldGraphicsMode = Gdi32.SetGraphicsMode(hdc, Gdi32.GraphicsMode.Advanced);
Gdi32.XFORM xformOrig;
Gdi32.GetWorldTransform(hdc, out xformOrig);
try
{
Gdi32.XFORM xform = xformOrig;
xform.eDx -= relativeChildLocation.X;
xform.eDy -= relativeChildLocation.Y;
Gdi32.SetWorldTransform(hdc, ref xform);
using (Graphics g = Graphics.FromHdc(hdc))
{
host.Paint(new PaintEventArgs(g, relativeClipRectangle));
}
}
finally
{
Gdi32.SetWorldTransform(hdc, ref xformOrig);
Gdi32.SetGraphicsMode(hdc, oldGraphicsMode);
}
}
finally
{
args.Graphics.ReleaseHdc(hdc);
}
}
public static void VirtualPaint(IVirtualTransparencyHost host, Control child, PaintEventArgs args)
{
Control hostControl = (Control)host;
bool rtl = host is Form && ((Form)host).RightToLeft == RightToLeft.Yes && ((Form)host).RightToLeftLayout;
Point childLocation = child.PointToScreen(new Point(0, 0));
Point hostLocation = hostControl.PointToScreen(new Point(rtl ? hostControl.ClientSize.Width : 0, 0));
Point relativeChildLocation = new Point(childLocation.X - hostLocation.X, childLocation.Y - hostLocation.Y);
if (relativeChildLocation == Point.Empty)
{
// no translation transform required
host.Paint(args);
return;
}
Rectangle relativeClipRectangle = args.ClipRectangle;
relativeClipRectangle.Offset(relativeChildLocation);
args.Graphics.SetClip(relativeClipRectangle, CombineMode.Replace);
// Global transformations applied in GDI+ land don't apply to
// GDI calls. So we need to drop down to GDI, apply a transformation
// there, then wrap with GDI+.
IntPtr hdc = args.Graphics.GetHdc();
try
{
Gdi32.GraphicsMode oldGraphicsMode = Gdi32.SetGraphicsMode(hdc, Gdi32.GraphicsMode.Advanced);
Gdi32.XFORM xformOrig;
Gdi32.GetWorldTransform(hdc, out xformOrig);
try
{
Gdi32.XFORM xform = xformOrig;
xform.eDx -= relativeChildLocation.X;
xform.eDy -= relativeChildLocation.Y;
Gdi32.SetWorldTransform(hdc, ref xform);
using (Graphics g = Graphics.FromHdc(hdc))
{
host.Paint(new PaintEventArgs(g, relativeClipRectangle));
}
}
finally
{
Gdi32.SetWorldTransform(hdc, ref xformOrig);
Gdi32.SetGraphicsMode(hdc, oldGraphicsMode);
}
}
finally
{
args.Graphics.ReleaseHdc(hdc);
}
}
