This ProgressBar is stopped and started by pressing any key.
#!/usr/bin/gjs
imports.gi.versions.Gtk = '3.0';
const Gio = imports.gi.Gio;
const GLib = imports.gi.GLib;
const Gtk = imports.gi.Gtk;
class ProgressBarExample {
// Create the application itself
constructor() {
this.application = new Gtk.Application({
application_id: 'org.example.jsprogressbar',
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,
default_height: 20,
default_width: 220,
title: "ProgressBar Example"});
// Create the progress bar
this.progressBar = new Gtk.ProgressBar ();
this._window.add(this.progressBar);
// Start the function that pulses the bar every 100 milliseconds
this.sourceID = GLib.timeout_add(GLib.PRIORITY_DEFAULT, 100,
this._barPulse.bind(this));
// Connect a keypress event to the function that toggles the bar to start or stop pulsing
this._window.connect("key-press-event", this._onKeyPress.bind(this));
// Show the window and all child widgets
this._window.show_all();
}
// Pulse the progressbar (unless it has been disabled by a keypress)
_barPulse() {
this.progressBar.pulse();
return true;
}
// Start or stop the progressbar when a key is pressed
_onKeyPress() {
if (this.sourceID == 0)
this.sourceID = GLib.timeout_add(GLib.PRIORITY_DEFAULT, 100,
this._barPulse.bind(this));
else {
GLib.source_remove(this.sourceID);
this.sourceID = 0;
}
}
};
// Run the application
let app = new ProgressBarExample ();
app.application.run (ARGV);
In this sample we used the following:
GLib
Gtk.Application
Gtk.ApplicationWindow
Gtk.ProgressBar