func (doc *Document) withSurface(f func(surface *drawing.Surface) os.Error) os.Error {
hdc := doc.nextPageInfo.createDC()
defer DeleteDC(hdc)
surface, err := drawing.NewSurfaceFromHDC(hdc)
if err != nil {
return err
}
defer surface.Dispose()
return f(surface)
}
func (doc *Document) Print() (err os.Error) {
defer func() {
if x := recover(); x != nil {
err = toError(x)
}
}()
hdc := doc.pages[0].info.createDC()
defer DeleteDC(hdc)
var di DOCINFO
di.CbSize = unsafe.Sizeof(di)
di.LpszDocName = syscall.StringToUTF16Ptr(doc.name)
if StartDoc(hdc, &di) <= 0 {
return newError("StartDoc failed")
}
defer func() {
if EndDoc(hdc) <= 0 {
err = newError("EndDoc failed")
}
}()
surface, err := drawing.NewSurfaceFromHDC(hdc)
if err != nil {
return err
}
defer surface.Dispose()
for i, page := range doc.pages {
if i > 0 {
// TODO: Only reset dc if required.
page.info.resetDC(hdc)
}
if StartPage(hdc) <= 0 {
return newError("StartPage failed")
}
err = page.Draw(surface)
if err != nil {
return err
}
if EndPage(hdc) <= 0 {
return newError("EndPage failed")
}
}
return nil
}
func (cw *CustomWidget) wndProc(msg *MSG, origWndProcPtr uintptr) uintptr {
switch msg.Message {
case WM_PAINT:
if cw.paint == nil {
// TODO: log?
break
}
var ps PAINTSTRUCT
hdc := BeginPaint(cw.hWnd, &ps)
if hdc == 0 {
// TODO: log?
break
}
defer EndPaint(cw.hWnd, &ps)
surface, err := drawing.NewSurfaceFromHDC(hdc)
if err != nil {
// TODO: log?
break
}
defer surface.Dispose()
r := &ps.RcPaint
err = cw.paint(surface, drawing.Rectangle{r.Left, r.Top, r.Right - r.Left, r.Bottom - r.Top})
if err != nil {
// TODO: log?
break
}
return 0
case WM_ERASEBKGND:
if !cw.ClearsBackground() {
return 1
}
case WM_SIZE, WM_SIZING:
if cw.InvalidatesOnResize() {
cw.Invalidate()
}
}
return cw.Widget.wndProc(msg, origWndProcPtr)
}