A simple screenshoter (python + ImageMagick)

sc.py

#!/usr/bin/env python
# Zhihao Yuan <lichray at gmail.com>

SSCMD     = 'import -quality 04 -border -frame png:-'
SSCMD_ALT = 'import -quality 04 png:-'

from cStringIO import StringIO
import sys, os
from getopt import getopt
import pygtk
pygtk.require20()
import gtk, cairo

if __name__ == '__main__':
    cmd = SSCMD

    for k, v in getopt(sys.argv[1:], 'hn')[0]:
        if k == '-h':
            print '''%s: [options]...
options:
  -n       no window frame
  -h       display this help''' % os.path.basename(sys.argv[0])
            sys.exit(1)
        elif k == '-n':
            cmd = SSCMD_ALT

    shot = os.popen(cmd).read()
    sfce = cairo.ImageSurface.create_from_png(StringIO(shot))

    def expose(area, event):
        ctx = area.window.cairo_create()
        ctx.set_source_surface(sfce, 0, 0)
        ctx.paint()

    dragfrom = [0.0, 0.0]
    def pressat(x, y):
        dragfrom[0] = x
        dragfrom[1] = y

    def scrollto(area, event, scroll):
        h, v = scroll.get_hscrollbar(), scroll.get_vscrollbar()
        h.set_value(h.get_value() + dragfrom[0] - event.x)
        v.set_value(v.get_value() + dragfrom[1] - event.y)

    chooser = gtk.FileChooserDialog('Save the PNG file...',
            action=gtk.FILE_CHOOSER_ACTION_SAVE,
            buttons=(gtk.STOCK_SAVE, gtk.RESPONSE_OK))
    try:
        chooser.set_icon(gtk.icon_theme_get_default()
                .load_icon("camera", 48, gtk.ICON_LOOKUP_FORCE_SVG))
    except: pass
    chooser.set_do_overwrite_confirmation(1)
    chooser.set_current_folder(os.getcwd())
    preview = gtk.DrawingArea()
    preview.set_size_request(sfce.get_width(), sfce.get_height())
    preview.connect('expose-event', expose)
    wrapper = gtk.ScrolledWindow()
    wrapper.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_AUTOMATIC)
    wrapper.add_with_viewport(preview)
    wrapper.show_all()
    chooser.vbox.pack_start(wrapper)
    chooser.vbox.reorder_child(wrapper, 0)
    filter = gtk.FileFilter()
    filter.add_mime_type('image/png')
    chooser.set_filter(filter)

    preview.set_events(gtk.gdk.POINTER_MOTION_MASK
            | gtk.gdk.BUTTON_PRESS_MASK
            | gtk.gdk.BUTTON_RELEASE_MASK)
    scrollto_id = preview.connect('motion-notify-event', scrollto, wrapper)
    preview.handler_block(scrollto_id)
    preview.connect('button-press-event', lambda w, e:
            e.button == 1 and e.type == gtk.gdk.BUTTON_PRESS
            and preview.handler_unblock(scrollto_id) or pressat(e.x, e.y))
    preview.connect('button-release-event', lambda w, e:
            e.button == 1 and e.type == gtk.gdk.BUTTON_RELEASE
            and preview.handler_block(scrollto_id))
    preview.connect('realize', lambda w:
            w.window.set_cursor(gtk.gdk.Cursor(gtk.gdk.FLEUR)))

    if chooser.run() == gtk.RESPONSE_OK:
        with open(chooser.get_filename(), 'wb') as f:
            f.write(shot)
    chooser.destroy()