Features/GTK3/Porting/InfoSlicer

This page is being performed while I'm porting InfoSlicer Activity to Gtk3.

There is a ticket with some useful information that I'm using on the porting and to keep tracking this port. Besides, this wiki page will be useful to write some code snippets about what are the difficulties that I'm having on the port and maybe can be useful for someone else.

I will take this guide as reference on the Gtk3 porting.

Remove hippo

First of all, I had to remove the hippo related things and the sugar-port (ticket) wrapper.

Code Snippets

Signals

Change TYPE_PYOBJECT type from a signal

We should replace the TYPE_PYOBJECT

'article-selected' : (SIGNAL_RUN_FIRST, None, [TYPE_PYOBJECT]),

by the Python's object type

'article-selected' : (GObject.SignalFlags.RUN_FIRST, None, [object]),

Working with threads

InfoSlicer uses threads to retrieve the information from internet (Wikipedia articles). The pygi script will replace it by Gdk.threads_init() by I found this is not the correct way to do this. In fact, I was dealing with some strange behaviour of the Activity because of this. So, I used:

from gi.repository import GObject
GObject.threads_init()

gtk.gdk._2BUTTON_PRESS

We should replace:

gtk.gdk._2BUTTON_PRESS
gtk.gdk._3BUTTON_PRESS

by:

Gdk.EventType._2BUTTON_PRESS
Gdk.EventType._3BUTTON_PRESS

Gtk.TextBuffer.get_slice() needs a new argument

We need a new argument to indicate if we want to include the hidden_chars as well. It wasn't required in gtk2 and by default it was True

buf = gtk.TextBuffer()
buf.get_slice(start, end)

replaced by:

buf = Gtk.TextBuffer()
buf.get_slice(start, end, include_hidden_chars)

Alerts

We have to change the way that alerts were shown because self.notify_alert is no longer available after applying this patch

Example about how to use the different types of alerts:

• http://git.sugarlabs.org/sugar-toolkit-gtk3/sugar-toolkit-gtk3/blobs/master/src/sugar3/graphics/alert.py#line11

• A simple alert:

 from sugar3.graphics.alert import Alert

 # Create a new simple alert
 alert = Alert()

 # Populate the title and text body of the alert.
 alert.props.title = _('Title of Alert Goes Here')
 alert.props.msg = _('Text message of alert goes here')

 # Call the add_alert() method (inherited via the sugar3.graphics.Window
 # superclass of Activity) to add this alert to the activity window.
 self.add_alert(alert)
 alert.show()

• NotifyAlert

from sugar3.graphics.alert import NotifyAlert

def __alert_notify_response_cb(alert, response_id, activity):
    activity.remove_alert(alert)

alert = NotifyAlert(5)
alert.props.title = _('Nothing to publish')
alert.props.msg = _('Mark arcticles from "Custom" '
                    'panel and try again.')
alert.connect('response', __alert_notify_response_cb, activity)
activity.add_alert(alert)
alert.show()

Missing / Problematic things (not ported yet)

• Select text from the Edit View (TextView) and the Home View. This error happens in many places of the code.
  • http://developer.gnome.org/gdk3/stable/gdk3-Event-Structures.html#GdkEventMotion

Traceback (most recent call last):
  File "/home/humitos/Activities/InfoSlicer.activity/infoslicer/widgets/Readonly_Textbox.py", line 116, in motion_notify
    self.emit("motion-notify-event", event)
TypeError: could not convert type EventMotion to GdkEvent required for parameter 0

• In the Edit View I cannot drag & drop images to my article (there is no error in the log)
• Issue related with "adding rows to the TreeView": https://bugzilla.gnome.org/show_bug.cgi?id=679415
• Drag and Drop Images from the Edit View is not working. Line #52 (infoslicer/widgets/Gallery_View.py)
  • Example about how to use the drag-n-drop http://git.gnome.org/browse/pygobject/tree/demos/gtk-demo/demos/clipboard.py#n96

# FIXME
# http://developer.gnome.org/gtk3/3.5/gtk3-Drag-and-Drop.html#gtk-drag-source-set
# self.imagebox.drag_source_set(Gdk.ModifierType.BUTTON1_MASK, ("text/plain", Gtk.TargetFlags.SAME_APP, 80), Gdk.DragAction.COPY)

• After drag-n-drop an arrow is added inside the article (right side) that is being edited. This is not working due: https://bugzilla.gnome.org/show_bug.cgi?id=651962
  • Line #641 (infoslicer/processing/Article.py)

Useful links

• Ticket that removes hippo and sugar-port: http://bugs.sugarlabs.org/ticket/3743