Development Team/Almanac/sugar.graphics.alert

= Class: Alert =

Alerts appear at the top of the body of your activity, just below the toolbox if it is visible. The image below shows what a simple alert looks like.



At a high level, Alert and its different variations (TimeoutAlert, ConfirmationAlert, etc.) have a title, an alert message and then a bunch of buttons that the user can click. The diagram shows that when you create Alert objects in your code, each button is connected to a specific response_id (in this case, gtk.RESPONSE_OK). The Alert class will pass "response" events to your activity when any of these buttons are clicked, along with a response_id to help you identify what button was clicked.



How do I create a simple alert message?
You can create the most basic alert message by first creating a new instance of the Alert class and then calling the add_alert method for your activity.

from sugar.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 sugar.graphics.Window superclass of Activity) # to add this alert to the activity window. self.add_alert(alert) alert.show

How do I create an alert message with a button that allows a user response to the alert?
The _alert_user method below is called to alert the user about something (here it is very generic). In this example, we add a simple 'OK' button that the user can click. When this button is clicked, the _alert_response_cb method gets called, which removes the alert from the screen.

from sugar.graphics.alert import Alert ...   def _alert_user(self): # 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')

#Add an 'OK' Button ok_icon = Icon(icon_name='ok-button') ok_icon.set_pixel_size(50) alert.add_button(gtk.RESPONSE_OK, _('Okay'), ok_icon) alert.connect('response', self._alert_response_cb)

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

def _alert_response_cb(self, alert, response_id): if response_id is gtk.RESPONSE_OK: self.remove_alert(alert)

= Class: ConfirmationAlert =

What is special about a confirmation alert and how do I use it in my activity?
A confirmation alert is a nice shortcut from a standard Alert because it comes with 'OK' and 'Cancel' buttons already built-in. When clicked, the 'OK' button will emit a response with a response_id of gtk.RESPONSE_OK, while the 'Cancel' button will emit gtk.RESPONSE_CANCEL.

The code below shows how a ConfirmationAlert is created. It also shows a response method that takes care of one of the two action buttons being clicked.

from sugar.graphics.alert import ConfirmationAlert ...   #### Method: _alert_confirmation, create a Confirmation alert (with ok and cancel buttons standard) # and add it to the UI. def _alert_confirmation(self): alert = ConfirmationAlert alert.props.title=_('Title of Alert Goes Here') alert.props.msg = _('Text message of alert goes here') alert.connect('response', self._alert_response_cb) self.add_alert(alert)

#### Method: _alert_response_cb, called when an alert object throws a response event. def _alert_response_cb(self, alert, response_id): #remove the alert from the screen, since either a response button was clicked or       #there was a timeout self.remove_alert(alert)

#Do any work that is specific to the type of button clicked. if response_id is gtk.RESPONSE_OK: print 'Ok Button was clicked. Do any work upon ok here ...' elif response_id is gtk.RESPONSE_CANCEL: print 'Cancel Button was clicked.'

= Class: TimeoutAlert =

What is special about a TimeoutAlert and how do I use it in my activity?
A TimeoutAlert is a special type of alert with two standard buttons ('Cancel' and 'Continue'). This alert also times out after a given number of seconds, returning with a positive response.

In the code below, we create a TimeoutAlert that will send a positive signal in 10 seconds if the user does not click any of the buttons. The callback method detects that a timeout occurred by checking that the response_id parameter is -1. If so, it simply removes the alert and prints out 'Timeout occurred'.

from sugar.graphics.alert import TimeoutAlert ...   #### Method: _alert_timeout, create a Timeout alert (with ok and cancel buttons standard) # and add it to the UI. def _alert_timeout(self): #Notice that for a TimeoutAlert, you pass the number of seconds in which to timeout. By       #default, this is 5. alert = TimeoutAlert(10) alert.props.title=_('Title of Alert Goes Here') alert.props.msg = _('Text message of timeout alert goes here') alert.connect('response', self._alert_response_cb) self.add_alert(alert)

#### Method: _alert_response_cb, called when an alert object throws a response event. def _alert_response_cb(self, alert, response_id): #remove the alert from the screen, since either a response button was clicked or       #there was a timeout self.remove_alert(alert)

#Do any work that is specific to the type of button clicked. if response_id is gtk.RESPONSE_OK: print 'Ok Button was clicked. Do any work upon ok here ...' elif response_id is gtk.RESPONSE_CANCEL: print 'Cancel Button was clicked.' elif response_id == -1: print 'Timout occurred'

= Class: NotifyAlert =

What is special about a NotifyAlert and how do I use it in my activity?
A NotifiyAlert is just like a TimeoutAlert except that it has only an 'OK' button. It is used just for user notifications. For brevity, no response callback method is included below; it would be just like the other alerts discussed thus far.

from sugar.graphics.alert import NotifyAlert ...   #### Method: _alert_notify, create a Notify alert (with only an 'OK' button) # and add it to the UI. def _alert_notify(self): #Notice that for a NotifyAlert, you pass the number of seconds in which to notify. By       #default, this is 5. alert = NotifyAlert(10) alert.props.title=_('Title of Alert Goes Here') alert.props.msg = _('Text message of notify alert goes here') alert.connect('response', self._alert_response_cb) self.add_alert(alert)