[Sugar-devel] Getting a gtk.image from the get_preview function

[sumit singh]

Hi Tomeu,

Thanx for your reply. I tried this as well, but doesn't seems to work.
Here is my code--   http://pastebin.be/20215  , where get_preview2()
is similar to get_preview fn and it returns in a similar manner. This
is the get preview2 fn--- http://pastebin.be/20216
. The log error can be found at --- http://pastebin.be/20214 . Kindly
give your suggestions.

Regards,
VIJIT

On Thu, Aug 6, 2009 at 1:15 PM, Tomeu Vizoso<tomeu at sugarlabs.org> wrote:
> On Wed, Aug 5, 2009 at 13:05, sumit singh<sumit.coder at gmail.com> wrote:
>> Hi Tomeu,
>>
>> Thanx for your reply. I tried using the it , but it doesn't seem to
>> work, it gives an error that the image should be a gdkpixbuf or None.
>> Here is my code-  http://pastebin.be/20184  , isn't it so that while
>> creating the pixmap on line no15, we are just using the height and
>> width of the surface and not the surface anywhere. I mean how are we
>> transferring the data of the image to the pixmap.
>> Thinking this I also tried this approach but didn't worked----
>> http://pastebin.be/20185 .
>>
>> Kindly have a look as in where am I doing the mistake.
>
> Have written some code based on my earlier pointers, but haven't tested it:
>
> # wrap the png data in a "virtual file"
> import StringIO.StringIO
> png_file = StringIO.StringIO(preview_data)
>
> # create a cairo surface with the png data
> surface = cairo.ImageSurface.create_from_png(png_file)
>
> # create a pixmap with the same dimensions
> w, h = surface.get_width(), surface.get_height()
> pixmap = gtk.gdk.Pixmap (None, w, h, 24)
>
> # create a cairo graphics context dor drawing into the pixmap
> cr = pixmap.cairo_create ()
>
> # paint the surface to the graphics context
> cr.set_source_surface (surface, 0, 0)
> cr.paint ()
>
> # create an image widget and assign the pixmap to it
> im = gtk.Image()
> im.set_from_pixmap(pixmap, None)
>
> You may want to read a bit about pixmaps, pixbufs, etc. Both in the
> PyGtk and X11 documentation:
>
> http://www.pygtk.org/pygtktutorial/sec-pixmaps.html
> http://www.pygtk.org/docs/pygtk/class-gdkpixmap.html
> http://tronche.com/gui/x/xlib/pixmap-and-cursor/pixmap.html
>
> HTH,
>
> Tomeu
>
>> Regards,
>> sumit
>>
>> On Wed, Aug 5, 2009 at 12:33 PM, Tomeu Vizoso<tomeu at sugarlabs.org> wrote:
>>> On Wed, Aug 5, 2009 at 03:06, sumit singh<sumit.coder at gmail.com> wrote:
>>>> Hi all,
>>>>
>>>> I would like to ask what is the best way to get a gtk.Image from the
>>>> data returned by get_preview function of activity.Activity fn of
>>>> sugar. I want to make an image buttton using this data. Currently, I
>>>> am doing it by saving the data in a temp file using the tempfile
>>>> module of sugar and then by loading the image from this file, however,
>>>> as I will be req to load around 15-20 such images, I can't say how
>>>> fast the process will end into. Is there a faster method?
>>>>
>>>> For your reference , here is the code of how the journal activity uses
>>>> this data---- http://pastebin.be/20177 , but as I don't want to use
>>>> hippo canvas, so this method won't work. Kindly give your suggestions.
>>>
>>> Sorry, didn't remembered that the journal used hippo to display the
>>> previews when I recommended you to look at that.
>>>
>>> If you get a cairo surface like the journal does, you can draw it to a
>>> pixmap and then tell a gtk.Image to display it. More details in this
>>> post (disregard the pixbuf stuff):
>>>
>>> http://lethalman.blogspot.com/2009/04/create-pixbuf-from-cairo-surface.html
>>>
>>> HTH,
>>>
>>> Tomeu
>>>
>>>> Regards,
>>>> sumit
>>>>
>>>
>>
>