Golang C.cairo_surface_status函數代碼示例

func (s CairoSurface) status() error {
	status := C.cairo_surface_status(s.nativePointer())
	if status != 0 {
		return cairoStatusToError(status)
	}
	return nil
}

// pdf, ps, and svg surfaces use the current surface (page)
func (g *Graphic) Image() (image.Image, error) {
	var surface *C.cairo_surface_t
	switch g.format {
	case "eps", "pdf", "ps", "svg":
		// map vector surfaces to an image surface
		surface = C.cairo_surface_map_to_image(g.surface, nil)
		defer C.cairo_surface_unmap_image(g.surface, surface)

		status := C.cairo_surface_status(surface)
		err := statusToError(status)
		if err != nil {
			return nil, err
		}
	case "png", "jpeg":
		// no conversion needed
		surface = g.surface
	}

	width := int(C.cairo_image_surface_get_width(surface))
	height := int(C.cairo_image_surface_get_height(surface))
	stride := int(C.cairo_image_surface_get_stride(surface))
	format := C.cairo_image_surface_get_format(surface)
	dataPtr := C.cairo_image_surface_get_data(surface)
	data := C.GoBytes(unsafe.Pointer(dataPtr), C.int(stride*height))

	var img image.Image
	switch format {
	case C.CAIRO_FORMAT_ARGB32:
		img = &extimage.ARGB{
			Pix:    data,
			Stride: stride,
			Rect:   image.Rect(0, 0, width, height),
		}
	case C.CAIRO_FORMAT_RGB24:
		img = &extimage.RGB{
			Pix:    data,
			Stride: stride,
			Rect:   image.Rect(0, 0, width, height),
		}
	case C.CAIRO_FORMAT_A8:
		img = &image.Alpha{
			Pix:    data,
			Stride: stride,
			Rect:   image.Rect(0, 0, width, height),
		}
	default:
		// known unsupported formats:
		// CAIRO_FORMAT_INVALID   = -1,
		// CAIRO_FORMAT_A1        = 3,
		// CAIRO_FORMAT_RGB16_565 = 4,
		// CAIRO_FORMAT_RGB30     = 5
		panic(fmt.Sprintf("unsupported cairo image surface format: %d", int(format)))
	}

	return img, nil
}

func RedrawWindow(W *XWindow, tweetsList []*TweetInfo, mouseClick [2]int) {
	var Attribs C.XWindowAttributes
	C.XGetWindowAttributes(W.Display, W.Window, &Attribs)
	// TODO -- Do this only when resizing?
	C.cairo_xlib_surface_set_size(W.Surface, Attribs.width, Attribs.height)

	C.cairo_set_source_rgb(W.Cairo, 0.1, 0.1, 0.1)
	C.cairo_paint(W.Cairo)

	var Rect C.PangoRectangle
	yPos := 10.0 + W.Scroll

	WindowWidth := Attribs.width

	maxTweetWidth := PixelsToPango(float64(WindowWidth - 5*UIPadding - UserImageSize))

	for i := 0; i < len(tweetsList); i++ {
		t := tweetsList[i]

		C.pango_layout_set_width(t.Layout, maxTweetWidth)
		C.pango_layout_get_extents(t.Layout, nil, &Rect)

		// Get tweet text size
		_, ry, _, rh := PangoRectToPixels(&Rect)

		// Position and add padding
		ry += yPos
		if rh < UserImageSize+2*UIPadding-UIPadding {
			rh = UserImageSize + 2*UIPadding
		} else {
			rh += UIPadding
		}

		// Draw rectangle around tweet
		C.cairo_set_source_rgb(W.Cairo, 0.2, 0.2, 0.2)
		C.cairo_rectangle(W.Cairo, UIPadding, C.double(ry), C.double(WindowWidth-2*UIPadding), C.double(rh))
		C.cairo_fill(W.Cairo)
		if mouseClick[0] >= UIPadding && float64(mouseClick[1]) >= ry && float64(mouseClick[1]) <= ry+rh {
			fmt.Println("Clicked tweet", t.Text)
		}

		// Draw user image
		userImage := GetCachedImage(W.UserImages, t.UserImage)
		if userImage == nil || C.cairo_surface_status(userImage) != C.CAIRO_STATUS_SUCCESS {
			userImage = placeholderImage
		}
		C.cairo_set_source_surface(W.Cairo, userImage, 2*UIPadding, C.double(yPos+UIPadding))
		C.cairo_paint(W.Cairo)

		// Draw tweet text
		C.cairo_move_to(W.Cairo, 63, C.double(yPos+SmallPadding))
		C.cairo_set_source_rgb(W.Cairo, 0.95, 0.95, 0.95)
		C.pango_cairo_show_layout(W.Cairo, t.Layout)
		yPos += 5 + rh
	}
}

//Index returns the ith surface of this tee.
//
//The returned error is set if there's an error on the returned surface.
//If the index does not exist, Index returns (nil, nil).
//
//Originally cairo_tee_surface_index.
func (s Surface) Index(i int) (cairo.Surface, error) {
	if i < 0 {
		return nil, nil
	}
	sir := C.cairo_tee_surface_index(s.XtensionRaw(), C.uint(i))
	if C.cairo_surface_status(sir) == C.CAIRO_STATUS_INVALID_INDEX {
		return nil, nil
	}
	si, err := cairo.XtensionRevivifySurface(sir)
	if err != nil {
		return nil, err
	}
	return si, nil
}

func NewSurfaceFromPNG(fileName string) (*Surface, error) {

	cstr := C.CString(fileName)
	defer C.free(unsafe.Pointer(cstr))

	surfaceNative := C.cairo_image_surface_create_from_png(cstr)

	status := Status(C.cairo_surface_status(surfaceNative))
	if status != STATUS_SUCCESS {
		return nil, ErrorStatus(status)
	}

	return &Surface{surfaceNative}, nil
}

//export our_area_draw_callback
func our_area_draw_callback(widget *C.GtkWidget, cr *C.cairo_t, data C.gpointer) C.gboolean {
	var x0, y0, x1, y1 C.double
	var maxwid, maxht C.gint

	s := (*sysData)(unsafe.Pointer(data))
	// thanks to desrt in irc.gimp.net/#gtk+
	// these are in user coordinates, which match what coordinates we want by default, even out of a draw event handler (thanks johncc3, mclasen, and Company in irc.gimp.net/#gtk+)
	C.cairo_clip_extents(cr, &x0, &y0, &x1, &y1)
	// we do not need to clear the cliprect; GtkDrawingArea did it for us beforehand
	cliprect := image.Rect(int(x0), int(y0), int(x1), int(y1))
	// the cliprect can actually fall outside the size of the Area; clip it by intersecting the two rectangles
	C.gtk_widget_get_size_request(widget, &maxwid, &maxht)
	cliprect = image.Rect(0, 0, int(maxwid), int(maxht)).Intersect(cliprect)
	if cliprect.Empty() { // no intersection; nothing to paint
		return C.FALSE // signals handled without stopping the event chain (thanks to desrt again)
	}
	i := s.handler.Paint(cliprect)
	surface := C.cairo_image_surface_create(
		C.CAIRO_FORMAT_ARGB32, // alpha-premultiplied; native byte order
		C.int(i.Rect.Dx()),
		C.int(i.Rect.Dy()))
	if status := C.cairo_surface_status(surface); status != C.CAIRO_STATUS_SUCCESS {
		panic(fmt.Errorf("cairo_create_image_surface() failed: %s\n",
			C.GoString(C.cairo_status_to_string(status))))
	}
	// the flush and mark_dirty calls are required; see the cairo docs and https://git.gnome.org/browse/gtk+/tree/gdk/gdkcairo.c#n232 (thanks desrt in irc.gimp.net/#gtk+)
	C.cairo_surface_flush(surface)
	toARGB(i, uintptr(unsafe.Pointer(C.cairo_image_surface_get_data(surface))),
		int(C.cairo_image_surface_get_stride(surface)))
	C.cairo_surface_mark_dirty(surface)
	C.cairo_set_source_surface(cr,
		surface,
		0, 0) // origin of the surface
	// that just set the brush that cairo uses: we have to actually draw now
	// (via https://developer.gnome.org/gtkmm-tutorial/stable/sec-draw-images.html.en)
	C.cairo_rectangle(cr, x0, y0, x1, y1) // breaking the nrom here since we have the coordinates as a C double already
	C.cairo_fill(cr)
	C.cairo_surface_destroy(surface) // free surface
	return C.FALSE                   // signals handled without stopping the event chain (thanks to desrt again)
}

func (i *imagelist) Append(img *image.RGBA) {
	var width, height C.gint

	surface := C.cairo_image_surface_create(C.CAIRO_FORMAT_ARGB32,
		C.int(img.Rect.Dx()),
		C.int(img.Rect.Dy()))
	if status := C.cairo_surface_status(surface); status != C.CAIRO_STATUS_SUCCESS {
		panic(fmt.Errorf("cairo_create_image_surface() failed in ImageList.Append(): %s\n",
			C.GoString(C.cairo_status_to_string(status))))
	}
	C.cairo_surface_flush(surface)
	toARGB(img, uintptr(unsafe.Pointer(C.cairo_image_surface_get_data(surface))),
		int(C.cairo_image_surface_get_stride(surface)), false) // not NRGBA
	C.cairo_surface_mark_dirty(surface)
	basepixbuf := C.gdk_pixbuf_get_from_surface(surface, 0, 0, C.gint(img.Rect.Dx()), C.gint(img.Rect.Dy()))
	if basepixbuf == nil {
		panic(fmt.Errorf("gdk_pixbuf_get_from_surface() failed in ImageList.Append() (no reason available)"))
	}

	if C.gtk_icon_size_lookup(scaleTo, &width, &height) == C.FALSE {
		panic(fmt.Errorf("gtk_icon_size_lookup() failed in ImageList.Append() (no reason available)"))
	}
	if int(width) == img.Rect.Dx() && int(height) == img.Rect.Dy() {
		// just add the base pixbuf; we're good
		i.list = append(i.list, basepixbuf)
		C.cairo_surface_destroy(surface)
		return
	}
	// else scale
	pixbuf := C.gdk_pixbuf_scale_simple(basepixbuf, C.int(width), C.int(height), C.GDK_INTERP_NEAREST)
	if pixbuf == nil {
		panic(fmt.Errorf("gdk_pixbuf_scale_simple() failed in ImageList.Append() (no reason available)"))
	}

	i.list = append(i.list, pixbuf)
	C.gdk_pixbuf_unref(basepixbuf)
	C.cairo_surface_destroy(surface)
}

func NewSurfaceFromPNG(filename string) (*Surface, Status) {

	cstr := C.CString(filename)
	defer C.free(unsafe.Pointer(cstr))

	surfaceNative := C.cairo_image_surface_create_from_png(cstr)
	status := Status(C.cairo_surface_status(surfaceNative))
	if status != STATUS_SUCCESS {
		return nil, status
	}

	contextNative := C.cairo_create(surfaceNative)
	status = Status(C.cairo_status(contextNative))
	if status != STATUS_SUCCESS {
		return nil, status
	}

	surface := &Surface{
		surface: surfaceNative,
		context: contextNative,
	}

	return surface, STATUS_SUCCESS
}

func (self *Surface) GetStatus() Status {
	return Status(C.cairo_surface_status(self.surface))
}

// Status is a wrapper around cairo_surface_status().
func (v *Surface) Status() Status {
	c := C.cairo_surface_status(v.native())
	return Status(c)
}

func (surface *Surface) SurfaceStatus() int {
	return int(C.cairo_surface_status(surface.surface))
}

//Err reports any errors on the surface.
//
//Originally cairo_surface_status.
func (e *XtensionSurface) Err() error {
	if e.s == nil {
		return ErrInvalidLibcairoHandle
	}
	return toerrIded(C.cairo_surface_status(e.s), e)
}

// gets the status of the cairo surface and returns it as an error
func (g *Graphic) cairoSurfaceStatus() error {
	status := C.cairo_surface_status(g.surface)
	return statusToError(status)
}