This Spinner is stopped and started by pressing the spacebar.
#!/usr/bin/gjs
imports.gi.versions.Gdk = '3.0';
imports.gi.versions.Gtk = '3.0';
const Gio = imports.gi.Gio;
const GLib = imports.gi.GLib;
const Gtk = imports.gi.Gtk;
const Gdk = imports.gi.Gdk;
class SpinnerExample {
// Create the application itself
constructor() {
this.application = new Gtk.Application({
application_id: 'org.example.jsspinner',
flags: Gio.ApplicationFlags.FLAGS_NONE
});
// Connect 'activate' and 'startup' signals to the callback functions
this.application.connect('activate', this._onActivate.bind(this));
this.application.connect('startup', this._onStartup.bind(this));
}
// Callback function for 'activate' signal presents windows when active
_onActivate() {
this._window.present();
}
// Callback function for 'startup' signal builds the UI
_onStartup() {
this._buildUI();
}
// Build the application's UI
_buildUI() {
// Create the application window
this._window = new Gtk.ApplicationWindow({
application: this.application,
window_position: Gtk.WindowPosition.CENTER,
title: "Spinner Example",
default_height: 200,
default_width: 200,
border_width: 30
});
// Create a spinner which starts spinning automatically
this._spinner = new Gtk.Spinner ({active: true});
this._window.add (this._spinner);
// Connect a keypress event to the function that makes it start or stop spinning
this._window.connect("key-press-event", this._onKeyPress.bind(this));
// Show the window and all child widgets
this._window.show_all();
}
_onKeyPress(widget, event) {
// Get the value of the key that was pressed
let [, keyval] = event.get_keyval();
// If it was the spacebar, toggle the spinner to start or stop
if (keyval == Gdk.KEY_space) {
if (this._spinner.active == true)
this._spinner.stop();
else
this._spinner.start();
}
}
};
// Run the application
let app = new SpinnerExample ();
app.application.run (ARGV);
Neste exemplo empregaremos o seguinte:
Gdk - Key Values
Gtk.Application
Gtk.ApplicationWindow
Gtk.Spinner