private void _InitializeCaptionButtonLocation()
{
// There is a completely different way to do this on XP.
if (!Utility.IsOSVistaOrNewer || !NativeMethods.IsThemeActive())
{
_LegacyInitializeCaptionButtonLocation();
return;
}
var tbix = new TITLEBARINFOEX {
cbSize = Marshal.SizeOf(typeof(TITLEBARINFOEX))
};
IntPtr lParam = Marshal.AllocHGlobal(tbix.cbSize);
try
{
Marshal.StructureToPtr(tbix, lParam, false);
// This might flash a window in the taskbar while being calculated.
// WM_GETTITLEBARINFOEX doesn't work correctly unless the window is visible while processing.
NativeMethods.ShowWindow(_messageHwnd.Handle, SW.SHOW);
NativeMethods.SendMessage(_messageHwnd.Handle, WM.GETTITLEBARINFOEX, IntPtr.Zero, lParam);
tbix = (TITLEBARINFOEX)Marshal.PtrToStructure(lParam, typeof(TITLEBARINFOEX));
}
finally
{
NativeMethods.ShowWindow(_messageHwnd.Handle, SW.HIDE);
Utility.SafeFreeHGlobal(ref lParam);
}
// TITLEBARINFOEX has information relative to the screen. We need to convert the containing rect
// to instead be relative to the top-right corner of the window.
RECT rcAllCaptionButtons = RECT.Union(tbix.rgrect_CloseButton, tbix.rgrect_MinimizeButton);
// For all known themes, the RECT for the maximize box shouldn't add anything to the union of the minimize and close boxes.
Assert.AreEqual(rcAllCaptionButtons, RECT.Union(rcAllCaptionButtons, tbix.rgrect_MaximizeButton));
RECT rcWindow = NativeMethods.GetWindowRect(_messageHwnd.Handle);
// Reorient the Top/Right to be relative to the top right edge of the Window.
var deviceCaptionLocation = new Rect(
rcAllCaptionButtons.Left - rcWindow.Width - rcWindow.Left,
rcAllCaptionButtons.Top - rcWindow.Top,
rcAllCaptionButtons.Width,
rcAllCaptionButtons.Height);
Rect logicalCaptionLocation = DpiHelper.DeviceRectToLogical(deviceCaptionLocation);
WindowCaptionButtonsLocation = logicalCaptionLocation;
}