Changes
Jump to navigation
Jump to search
Development Team/Almanac/Code Snippets (view source)
Revision as of 18:34, 5 October 2007
, 18:34, 5 October 2007no edit summary
{{OLPC}}
{{Translations}}
== Toolbar ==
=== Toolbar icons ===
button = sugar.graphics.toolbutton.ToolButton("some-icon-name")
button.show()
toolbar.insert(button,-1)
In addition to the standard icons in /usr/share/icons/sugar/scalable/ (eg, "go-next"), you can create additional icons by putting an svg in your activity's icons/ directory. Eg,
icons/my-icon.svg
=== Other notes ===
*Do ''not'' use sugar.graphics.toolbar and its Toolbar. It is old broken left-over code, now deleted. [[User:MitchellNCharity|MitchellNCharity]] 17:06, 21 June 2007 (EDT)
== Files ==
This snippet shows how to get a [http://mailman.laptop.org/pipermail/sugar/2007-February/001459.html path to files in the running Activity]:
from sugar.activity import activity
bundle_path = activity.get_bundle_path()
== Images ==
* [http://mailman.laptop.org/pipermail/sugar/2007-February/001528.html Loading an SVG file onto a surface with a transparent background]:
target = ctx.get_target()
buf = target.create_similar(cairo.CONTENT_COLOR_ALPHA, w, h)
ctx.set_source_surface(buf, x, y)
ctx.paint()
* [http://mailman.laptop.org/pipermail/sugar/2007-February/001547.html Measuring an SVG file's original dimensions]
width, height = handle.get_dimension_data()
* Loading a JPEG file onto a surface:
pixbuf = gtk.gdk.pixbuf_new_from_file("foo.jpg")
ctx = # a cairo context
ctx.set_source_pixbuf(pixbuf, 0, 0)
ctx.paint()
libjpeg is said to be an alternative to using pixbuf. Which is better? Perhaps Sugar/[[HippoCanvas]] provides an easier way to do this?
[[Cairo]] image expansion is good quality, but expensive. Shrinking is fine and notably faster. So for images rendered large (ie, screen-size), you might want to start with a big image, rather than expanding a small one. A speed/space tradeoff. And use SVG instead if appropriate, of course. [[User:MitchellNCharity|MitchellNCharity]] 10:37, 10 May 2007 (EDT)
== Not yet sorted ==
* [http://mailman.laptop.org/pipermail/sugar/2007-March/002028.html Getting a unique ID for the XO user]:
from sugar import profile
key = profile.get_pubkey()
# If you want a shorter key, you can hash that like:
from sugar import util
key_hash = util._sha_data(key)
hashed_key = util.printable_hash(key_hash)
* Avoid memory exhaustion from large dead pgtk objects by using
import gc
gc.collect()
Not all trash pygtk objects are garbage collected promptly. If you are throwing away large pixmaps, for instance, this can be deadly. gc.collect() forces a garbage collection pass.
== Performance Tips ==
''This section belongs on a different, as yet non-existent page. But a good organization for software development tips is currently unclear to me, so I'll stash this here for now.'' [[User:MitchellNCharity|MitchellNCharity]] 14:05, 10 May 2007 (EDT)
* ctx.stroke() several lines at once. stroke() currently has significant overhead. So it is faster to stroke several, than to stroke them individually. They need not be contiguous. [[User:MitchellNCharity|MitchellNCharity]] 14:05, 10 May 2007 (EDT)
== Old snippets which need to be overhauled ==
=== Toolbar ===
This snippet shows how an activity would have a toolbar with a button and a gtk.TextView widget embedded in a hippo Canvas:
import logging
import hippo
import gtk
from gettext import gettext as _
from sugar.activity import activity
from sugar.graphics.toolbar import Toolbar
from sugar.graphics.iconbutton import IconButton
from sugar.graphics.entry import Entry
from sugar.graphics.optionmenu import OptionMenu
from sugar.graphics.menu import MenuItem
class FooActivity(activity.Activity):
_ACTION_ANYTHING = 1
_ACTION_APPLES = 2
_ACTION_ORANGES = 3
def __init__(self, handle):
activity.Activity.__init__(self, handle)
vbox = hippo.CanvasBox()
self.set_root(vbox)
toolbar = Toolbar()
vbox.append(toolbar)
button = IconButton(icon_name='theme:stock-close')
button.connect("activated", self._button_activated_cb)
toolbar.append(button)
entry = Entry()
button.connect("activated", self._entry_activated_cb)
toolbar.append(entry)
option_menu = OptionMenu()
option_menu.add_item(MenuItem(self._ACTION_ANYTHING, _('Anything')))
option_menu.add_item(MenuItem(self._ACTION_APPLES, _('Apples'),
'theme:stock-close'))
option_menu.add_item(MenuItem(self._ACTION_ORANGES, _('Oranges')))
option_menu.add_separator()
toolbar.append(option_menu)
text_view_widget = hippo.CanvasWidget()
vbox.append(text_view_widget, hippo.PACK_EXPAND)
text_view = gtk.TextView()
text_view.get_buffer().set_text('Write here!', -1)
text_view_widget.props.widget = text_view
def _button_activated_cb(self, button):
logging.debug('FooActivity._button_activated_cb')
def _entry_activated_cb(self, entry):
logging.debug('FooActivity._entry_activated_cb')
:In build 443 (June '07), <tt>from sugar.graphics.entry import Entry</tt> yields ''ImportError: No module named entry''. [[User:MitchellNCharity|MitchellNCharity]] 19:52, 15 June 2007 (EDT)
:And obsolete, now deleted code like sugar.graphics.toolbar is being used. Snippet needs to be overhauled. [[User:MitchellNCharity|MitchellNCharity]] 18:04, 21 June 2007 (EDT)
[[Category:HowTo]]
[[Category:Sugar]]
{{Translations}}
== Toolbar ==
=== Toolbar icons ===
button = sugar.graphics.toolbutton.ToolButton("some-icon-name")
button.show()
toolbar.insert(button,-1)
In addition to the standard icons in /usr/share/icons/sugar/scalable/ (eg, "go-next"), you can create additional icons by putting an svg in your activity's icons/ directory. Eg,
icons/my-icon.svg
=== Other notes ===
*Do ''not'' use sugar.graphics.toolbar and its Toolbar. It is old broken left-over code, now deleted. [[User:MitchellNCharity|MitchellNCharity]] 17:06, 21 June 2007 (EDT)
== Files ==
This snippet shows how to get a [http://mailman.laptop.org/pipermail/sugar/2007-February/001459.html path to files in the running Activity]:
from sugar.activity import activity
bundle_path = activity.get_bundle_path()
== Images ==
* [http://mailman.laptop.org/pipermail/sugar/2007-February/001528.html Loading an SVG file onto a surface with a transparent background]:
target = ctx.get_target()
buf = target.create_similar(cairo.CONTENT_COLOR_ALPHA, w, h)
ctx.set_source_surface(buf, x, y)
ctx.paint()
* [http://mailman.laptop.org/pipermail/sugar/2007-February/001547.html Measuring an SVG file's original dimensions]
width, height = handle.get_dimension_data()
* Loading a JPEG file onto a surface:
pixbuf = gtk.gdk.pixbuf_new_from_file("foo.jpg")
ctx = # a cairo context
ctx.set_source_pixbuf(pixbuf, 0, 0)
ctx.paint()
libjpeg is said to be an alternative to using pixbuf. Which is better? Perhaps Sugar/[[HippoCanvas]] provides an easier way to do this?
[[Cairo]] image expansion is good quality, but expensive. Shrinking is fine and notably faster. So for images rendered large (ie, screen-size), you might want to start with a big image, rather than expanding a small one. A speed/space tradeoff. And use SVG instead if appropriate, of course. [[User:MitchellNCharity|MitchellNCharity]] 10:37, 10 May 2007 (EDT)
== Not yet sorted ==
* [http://mailman.laptop.org/pipermail/sugar/2007-March/002028.html Getting a unique ID for the XO user]:
from sugar import profile
key = profile.get_pubkey()
# If you want a shorter key, you can hash that like:
from sugar import util
key_hash = util._sha_data(key)
hashed_key = util.printable_hash(key_hash)
* Avoid memory exhaustion from large dead pgtk objects by using
import gc
gc.collect()
Not all trash pygtk objects are garbage collected promptly. If you are throwing away large pixmaps, for instance, this can be deadly. gc.collect() forces a garbage collection pass.
== Performance Tips ==
''This section belongs on a different, as yet non-existent page. But a good organization for software development tips is currently unclear to me, so I'll stash this here for now.'' [[User:MitchellNCharity|MitchellNCharity]] 14:05, 10 May 2007 (EDT)
* ctx.stroke() several lines at once. stroke() currently has significant overhead. So it is faster to stroke several, than to stroke them individually. They need not be contiguous. [[User:MitchellNCharity|MitchellNCharity]] 14:05, 10 May 2007 (EDT)
== Old snippets which need to be overhauled ==
=== Toolbar ===
This snippet shows how an activity would have a toolbar with a button and a gtk.TextView widget embedded in a hippo Canvas:
import logging
import hippo
import gtk
from gettext import gettext as _
from sugar.activity import activity
from sugar.graphics.toolbar import Toolbar
from sugar.graphics.iconbutton import IconButton
from sugar.graphics.entry import Entry
from sugar.graphics.optionmenu import OptionMenu
from sugar.graphics.menu import MenuItem
class FooActivity(activity.Activity):
_ACTION_ANYTHING = 1
_ACTION_APPLES = 2
_ACTION_ORANGES = 3
def __init__(self, handle):
activity.Activity.__init__(self, handle)
vbox = hippo.CanvasBox()
self.set_root(vbox)
toolbar = Toolbar()
vbox.append(toolbar)
button = IconButton(icon_name='theme:stock-close')
button.connect("activated", self._button_activated_cb)
toolbar.append(button)
entry = Entry()
button.connect("activated", self._entry_activated_cb)
toolbar.append(entry)
option_menu = OptionMenu()
option_menu.add_item(MenuItem(self._ACTION_ANYTHING, _('Anything')))
option_menu.add_item(MenuItem(self._ACTION_APPLES, _('Apples'),
'theme:stock-close'))
option_menu.add_item(MenuItem(self._ACTION_ORANGES, _('Oranges')))
option_menu.add_separator()
toolbar.append(option_menu)
text_view_widget = hippo.CanvasWidget()
vbox.append(text_view_widget, hippo.PACK_EXPAND)
text_view = gtk.TextView()
text_view.get_buffer().set_text('Write here!', -1)
text_view_widget.props.widget = text_view
def _button_activated_cb(self, button):
logging.debug('FooActivity._button_activated_cb')
def _entry_activated_cb(self, entry):
logging.debug('FooActivity._entry_activated_cb')
:In build 443 (June '07), <tt>from sugar.graphics.entry import Entry</tt> yields ''ImportError: No module named entry''. [[User:MitchellNCharity|MitchellNCharity]] 19:52, 15 June 2007 (EDT)
:And obsolete, now deleted code like sugar.graphics.toolbar is being used. Snippet needs to be overhauled. [[User:MitchellNCharity|MitchellNCharity]] 18:04, 21 June 2007 (EDT)
[[Category:HowTo]]
[[Category:Sugar]]