andlabs-ui/imagelist_unix.go

79 lines
2.2 KiB
Go

// +build !windows,!darwin
// 16 august 2014
package ui
import (
"fmt"
"image"
"unsafe"
)
// #include "gtk_unix.h"
import "C"
type imagelist struct {
list []*C.GdkPixbuf
}
func newImageList() ImageList {
return new(imagelist)
}
// this is what GtkFileChooserWidget uses
// technically it uses max(width from that, height from that) if the call below fails and 16x16 otherwise, but we won't worry about that here (yet?)
const scaleTo = C.GTK_ICON_SIZE_MENU
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 (i *imagelist) Len() ImageIndex {
return ImageIndex(len(i.list))
}
type imageListApply interface {
apply(*[]*C.GdkPixbuf)
}
func (i *imagelist) apply(out *[]*C.GdkPixbuf) {
*out = make([]*C.GdkPixbuf, len(i.list))
copy(*out, i.list)
}