Mega Code Archive
Check if a control is partially covered by another window
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Title: check if a control is partially covered by another window?
{
You would have to iterate over all windows above yours in Z-order and
check for each window you find if it has the WS_EX_TOPMOST exstyle set
and is visible.
If it has, you have to get its window rectangle (GetWindowRect) and test
if that overlaps your window.
Example:
}
procedure TForm1.Button1Click(Sender: TObject);
var
wnd: HWND;
function IsTopMost(wnd: HWND): Boolean;
begin
Result := (GetWindowLong(wnd, GWL_EXSTYLE) and WS_EX_TOPMOST) 0;
end;
procedure logWindowInfo(wnd: HWND);
const
visString: array[Boolean] of string = ('not ', '');
var
buffer: array[0..256] of Char;
r: TRect;
begin
if wnd = 0 then Exit;
GetClassName(wnd, buffer, SizeOf(buffer));
with Memo1.Lines do
begin
Add(Format(' Window of class %s ', [buffer]));
GetWindowRect(wnd, r);
Add(Format(' at (%d,%d):(%d,%d)', [r.Left, r.Top, r.Right, r.Bottom]));
Add(Format(' Window is %svisible', [visString[IsWindowVisible(wnd)]]));
Add(Format(' Window is %stopmost', [visString[IsTopmost(wnd)]]));
end;
end;
begin
Memo1.Clear;
wnd := Handle;
repeat
wnd := GetNextWindow(wnd, GW_HWNDPREV);
LogWindowInfo(wnd);
until wnd = 0;
Memo1.Lines.Add('End log.');
end;
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