hellobudgie.plugin

[Plugin]
Loader=python3
Module=hellobudgie
Name=Python Sample Applet
Description=Python Sample Applet
Authors=Yurizal Susanto
Copyright=Copyright © 2019 Yurizal Susanto
Website=https://getsol.us
Icon=user-desktop-symbolic

hellobudgie.py

#!/usr/bin/env python3
import gi
gi.require_version('Gtk', '3.0')
gi.require_version('Budgie', '1.0')
from gi.repository import Budgie, Gdk, Gio, GLib, GObject, Gtk

class BudgieHello(GObject.Object, Budgie.Plugin):
    """BudgieHello is top-level object to initialize the applet
    """
    
    def __init__(self):
        GObject.Object.__init__(self)

    def do_get_panel_widget(self, uuid):
        """Show the Applet"""
        return HelloApplet(uuid)


class HelloSettings(Gtk.Grid):
    def __init__(self, setting):
        super().__init__(row_spacing=8, column_spacing=6)
        self.setting = setting

        # Prepare Applet Settings
        notify_label = Gtk.Label("Enable Notification", halign=Gtk.Align.START)
        self.add(notify_label)
        notify_switch = Gtk.Switch(halign=Gtk.Align.END, hexpand=True)
        self.attach_next_to(notify_switch, notify_label, Gtk.PositionType.RIGHT, 1, 1)

        # Bind settings to widget value
        setting.bind("enable-notification", notify_switch, "active",
            Gio.SettingsBindFlags.DEFAULT)
        
        self.show_all()
        

class HelloApplet(Budgie.Applet):
    def __init__(self, uuid):
        # You can't use shorthand super().__init__() to initialize the Applet
        Budgie.Applet.__init__(self)
        self.uuid = uuid
        self.manager = None

        # Ensure schema and prefix is set properly
        self.set_settings_prefix("/com/github/yursan9/budgie-caffeine-applet")
        self.set_settings_schema("com.github.yursan9.budgie-caffeine-applet")
        self.settings = self.get_applet_settings(self.uuid)

        # Button Trigger
        self.box = Gtk.EventBox()
        self.icon = Gtk.Image.new_from_icon_name("user-desktop-symbolic", Gtk.IconSize.BUTTON)
        self.box.add(self.icon)
        self.add(self.box)

        # Popover
        self.popover = Budgie.Popover.new(self.box)
        self.popover.get_style_context().add_class("hello-popover")

        label = Gtk.Label("Hello World")
        self.popover.add(label)

        self.popover.get_child().show_all()
        self.box.show_all()
        self.show_all()

        # Connect Callback
        self.box.connect("button-press-event", self._on_press)

    def do_get_settings_ui(self):
        """Return the applet settings with given uuid"""
        return HelloSettings(self.get_applet_settings(self.uuid))

    def do_supports_settings(self):
        """Return True if support setting through Budgie Setting,
        False otherwise.
        """
        return True

    def do_update_popovers(self, manager):
        """Register popover to manager"""
        manager.register_popover(self.box, self.popover)
        self.manager = manager

    def	_on_press(self, box, e):
        # Stop if not left mouse click button
        if e.button != 1:
            return Gdk.EVENT_PROPAGATE

        # Popover show and hide
        if self.popover.get_visible():
            self.popover.hide()
        else:
            self.manager.show_popover(self.box)
        return Gdk.EVENT_STOP

To write Budgie Applet you need 2 file, the applet script (.py file) and the .plugin file. You need to place the file in /usr/lib/budgie-desktop/plugins/<plugin-directory>

Code Explanation

BudgieHello is the entry class for the applet, it inherits Budgie.Plugin. BudgieHello construct the applet in virtual method do_get_panel_widget.

HelloApplet is the main class for the applet. You need to implement button and popover in here. If the applet support settings, you need to override virtual method do_supports_settings and do_get_settings_ui.

HelloSettings is the class for applet's settings. It accept Gio.Setting, and you can use setting.bind to bind a widget value to setting.