func (le *LineEdit) initCharWidth() {
font := le.Font()
if font == le.charWidthFont {
return
}
le.charWidthFont = font
le.charWidth = 8
hdc := win.GetDC(le.hWnd)
if hdc == 0 {
newError("GetDC failed")
return
}
defer win.ReleaseDC(le.hWnd, hdc)
defer win.SelectObject(hdc, win.SelectObject(hdc, win.HGDIOBJ(font.handleForDPI(0))))
buf := []uint16{'M'}
var s win.SIZE
if !win.GetTextExtentPoint32(hdc, &buf[0], int32(len(buf)), &s) {
newError("GetTextExtentPoint32 failed")
return
}
le.charWidth = int(s.CX)
}
func (wb *WindowBase) calculateTextSizeImpl(text string) Size {
hdc := win.GetDC(wb.hWnd)
if hdc == 0 {
newError("GetDC failed")
return Size{}
}
defer win.ReleaseDC(wb.hWnd, hdc)
hFontOld := win.SelectObject(hdc, win.HGDIOBJ(wb.Font().handleForDPI(0)))
defer win.SelectObject(hdc, hFontOld)
var size Size
lines := strings.Split(text, "\n")
for _, line := range lines {
var s win.SIZE
str := syscall.StringToUTF16(strings.TrimRight(line, "\r "))
if !win.GetTextExtentPoint32(hdc, &str[0], int32(len(str)-1), &s) {
newError("GetTextExtentPoint32 failed")
return Size{}
}
size.Width = maxi(size.Width, int(s.CX))
size.Height += int(s.CY)
}
return size
}
func (cb *ComboBox) calculateMaxItemTextWidth() int {
hdc := win.GetDC(cb.hWnd)
if hdc == 0 {
newError("GetDC failed")
return -1
}
defer win.ReleaseDC(cb.hWnd, hdc)
hFontOld := win.SelectObject(hdc, win.HGDIOBJ(cb.Font().handleForDPI(0)))
defer win.SelectObject(hdc, hFontOld)
var maxWidth int
count := cb.model.ItemCount()
for i := 0; i < count; i++ {
var s win.SIZE
str := syscall.StringToUTF16(cb.itemString(i))
if !win.GetTextExtentPoint32(hdc, &str[0], int32(len(str)-1), &s) {
newError("GetTextExtentPoint32 failed")
return -1
}
maxWidth = maxi(maxWidth, int(s.CX))
}
return maxWidth
}
func (wb *WindowBase) dialogBaseUnits() Size {
// The window may use a font different from that in WindowBase,
// like e.g. NumberEdit does, so we try to use the right one.
window := windowFromHandle(wb.hWnd)
hdc := win.GetDC(wb.hWnd)
defer win.ReleaseDC(wb.hWnd, hdc)
hFont := window.Font().handleForDPI(0)
hFontOld := win.SelectObject(hdc, win.HGDIOBJ(hFont))
defer win.SelectObject(hdc, win.HGDIOBJ(hFontOld))
var tm win.TEXTMETRIC
if !win.GetTextMetrics(hdc, &tm) {
newError("GetTextMetrics failed")
}
var size win.SIZE
if !win.GetTextExtentPoint32(
hdc,
dialogBaseUnitsUTF16StringPtr,
52,
&size) {
newError("GetTextExtentPoint32 failed")
}
return Size{int((size.CX/26 + 1) / 2), int(tm.TmHeight)}
}
func (c *Canvas) fontHeight(font *Font) (height int, err error) {
err = c.withFontAndTextColor(font, 0, func() error {
var size win.SIZE
if !win.GetTextExtentPoint32(c.hdc, gM, 2, &size) {
return newError("GetTextExtentPoint32 failed")
}
height = int(size.CY)
if height == 0 {
return newError("invalid font height")
}
return nil
})
return
}