andlabs-ui/experiments/winclientsize.go

48 lines
1.6 KiB
Go

func (s *sysData) setWindowSize(width int, height int) error {
var rect _RECT
ret := make(chan uiret)
defer close(ret)
// we need the size to cover only the client rect
// unfortunately, Windows only provides general client->window rect conversion functions (AdjustWindowRect()/AdjustWindowRectEx()), not any that can pull from an existing window
// so as long as we don't change the window styles during execution we're good
// now we tell it to adjust (0,0)..(width,height); this will give us the approrpiate rect to get the proper width/height from
// then we call SetWindowPos() to set the size without moving the window
// see also: http://blogs.msdn.com/b/oldnewthing/archive/2003/09/11/54885.aspx
// TODO do the WM_NCCALCSIZE stuff on that post when adding menus
rect.Right = int32(width)
rect.Bottom = int32(height)
uitask <- &uimsg{
call: _adjustWindowRectEx,
p: []uintptr{
uintptr(unsafe.Pointer(&rect)),
uintptr(classTypes[c_window].style),
uintptr(_FALSE), // TODO change this when adding menus
uintptr(classTypes[c_window].xstyle),
},
ret: ret,
}
r := <-ret
if r.ret == 0 { // failure
panic(fmt.Errorf("error computing window rect from client rect for resize: %v", r.err))
}
uitask <- &uimsg{
call: _setWindowPos,
p: []uintptr{
uintptr(s.hwnd),
uintptr(_NULL), // not changing the Z-order
uintptr(0),
uintptr(0),
uintptr(rect.Right - rect.Left),
uintptr(rect.Bottom - rect.Top),
uintptr(_SWP_NOMOVE | _SWP_NOZORDER),
},
ret: ret,
}
r = <-ret
if r.ret == 0 { // failure
return fmt.Errorf("error actually resizing window: %v", r.err)
}
return nil
}