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Python: Drawing preview in GTK Window?


I'm trying to write a script in Python that is similar to the built-in "animation-play" plugin. I am currently trying to figure out how to draw a preview of my image in a GTK window. "animation-play" does this by copying pixel regions from the image and then "manually" (> 400 lines of C code) converting them into a buffer that can then be drawn using "gdk_draw_rgb_image()".

I'd rather not (for performance reasons alone) re-implement this pixel buffer conversion in my skript, so I wonder if there is a more convenient way for doing this.

Are there plugins/procedures available (preferrably written in C) to do this "pixel buffer" conversion?

Is there a Python script/plugin out there that has a custom UI with a preview function? (I only found one that uses a temporary layer in the orginial Image for the preview)

I found a "GimpPreview" in the C API, but that does not seem to be available in the Python API?

(EDIT: Moved this to the plugins forum)

Update: For now I just limit my script to RGBA images and use the byte string from the pixel region directly:

buffer = pr[ pr.x : pr.x + pr.w, pr.y : pr.y + pr.h ]

window.draw_rgb_32_image( gc,
                          0, 0,
                          pr.w, pr.h,
                          buffer, pr.w * 4 )

GDK also has functions for RGB, grayscale and indexed images, so maybe I don't have to convert the buffer after all...

There is supposed to be a preview widget exposed in python, but I have never been able to get it to work.

I've asked i a couple of places.

Looking at the source for the pygimp plugin (gimpui.c) there appears
to be widget constructors exposed in python:

/* ----------- GimpDrawablePreview ----------- */

#line 1952 "gimpui.override"
static int
_wrap_gimp_drawable_preview_new(PyGObject *self, PyObject *args,
PyObject *kwargs)
static char *kwlist[] = { "drawable", NULL };
PyGimpDrawable *py_drawable;

if (!PyArg_ParseTupleAndKeywords(args, kwargs,
"O!|:GimpDrawablePreview.__init__", kwlist,
PyGimpDrawable_Type, &py_drawable))
return -1;

if (!py_drawable->drawable)
py_drawable->drawable = gimp_drawable_get(py_drawable->ID);

if (pygobject_construct(self, "drawable", py_drawable->drawable, NULL))
return -1;

g_object_set_data_full(self->obj, "pygimp-drawable-preview-pydrawable",


return 0;

along with all the methods in the docs
exposed as well.

Looking in the binary_gimpui.pyd these objects exist, specifically,
the pygimp-drawable-preview-pydrawable one.

Also mentioned here:

I've been trying to get anything to work with this but no luck yet. I'm hoping someone who actually understands python will give this a shot ;)

-Rob A>

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