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)
}