Method handleWMCTLCOLOR

window.go:2263–2321

(wParam, lParam uintptr)

}

func (wb *WindowBase) handleWMCTLCOLOR(wParam, lParam uintptr) uintptr {
	hwnd := win.HWND(lParam)
	hdc := win.HDC(wParam)

	type TextColorer interface {
		TextColor() Color
	}

	wnd := windowFromHandle(hwnd)
	if wnd == nil {
		switch windowFromHandle(win.GetParent(hwnd)).(type) {
		case *ComboBox:
			// nop
			return 0
		}

		wnd = wb
	} else if tc, ok := wnd.(TextColorer); ok {
		color := tc.TextColor()
		if color == 0 {
			color = Color(win.GetSysColor(win.COLOR_WINDOWTEXT))
		}
		win.SetTextColor(hdc, win.COLORREF(color))
	}

	if bg, wnd := wnd.AsWindowBase().backgroundEffective(); bg != nil {
		wb.prepareDCForBackground(hdc, hwnd, wnd)

		type Colorer interface {
			Color() Color
		}

		if c, ok := bg.(Colorer); ok {
			win.SetBkColor(hdc, win.COLORREF(c.Color()))
		}

		return uintptr(bg.handle())
	}

	switch wnd.(type) {
	case *LineEdit, *numberLineEdit, *TextEdit:
		type ReadOnlyer interface {
			ReadOnly() bool
		}

		var sysColor int
		if ro, ok := wnd.(ReadOnlyer); ok && ro.ReadOnly() {
			sysColor = win.COLOR_BTNFACE
		} else {
			sysColor = win.COLOR_WINDOW
		}

		win.SetBkColor(hdc, win.COLORREF(win.GetSysColor(sysColor)))

		return uintptr(win.GetSysColorBrush(sysColor))
	}

	return 0