1. New Design of
OneRing
2011.02

2. Old Design
3 components, 4 communication types
WebKit
JS-QObject AJAX
bridge
JS-QObject pub/sub
Signal-Slot
bridge
OS App

3. WebKit -> OS
JS-QObject Bridge
var tray = _OneRing.new_SystemTrayIcon();
tray.show();
class SystemTrayIcon : public QSystemTrayIcon
{
public:
Q_INVOKABLE void show(void);
}

4. OS -> WebKit
tray.click.connect(function() {...});
class SystemTrayIcon : public QSystemTrayIcon {
signals:
void click(void);
}
...
emit click();
...

5. WebKit -> App
ONERING.getJSON('onering://radio/get_bid',
function(bid) {...});
class get_bid:
GET(self):
return dict(bid=b64encode(os.urandom(8)).rstrip('='))

6. App -> WebKit
ONERING.subscribe('new-instance',
function(){...});
def new_instance_launched():
print "new instance"
onering.publish("new-instance")

7. Problems
• Communication between WebKit and OS is Qt-
bound
• Hard to trace callings of QtWebKit bridge
• QtWebKit signal-slot bridge has memory
management issue
• Hard to handle cases where function returns object
• JavaScript binding cause endless code bloating
• sync calling is more friendly than Ajax

8. New Design
Unify OS and App
WebKit
call_app call_app
pub/sub pub/sub
OS App
collection of apps collection of apps

9. WebKit -> OS
var tray = new SystemTrayIcon();
tray.show();
SystemTrayIcon.prototype.show = function()
{
// POST onering://systray/show
// with body: {"id": "12345678"}
ONERING.call_app("systray", "SystemTrayIcon.show")
}

10. QByteArray SysTrayApp::processCall(const QString &command, const QVariantMap &param)
{
if (command == "show") {
QSystamTrayIcon *icon = static_cast<QSystemTrayIcon *>(getInstance(param["id"]);
icon->show();
return "null";
}
return "{"err":"invalid command"}";
}

11. OS -> WebKit
tray.bind('click', function(){...});
SystemTrayIcon.prototype.bind = function(event, callback)
{
// subscribe to "systray.SystemTrayIcon.123456.click"
ONERING.subscribe(self.appname+"."+self.type+"."
+self.id+"."+event, callback)
}

12. void * SysTrayApp::create()
{
QSystemTrayIcon *icon = new QSystemTrayIcon();
connect(icon, SIGNAL(activated(QSystemTrayIcon::ActivationReason)),
this, SLOT(notifyClicked(QSystemTrayIcon::ActivationReason)));
return icon;
}
void SystamTrayApp::notifyClicked(QSystemTrayIcon::ActivationReason reason)
{
QSystemTrayIcon *icon = static_cast<QSystemTrayIcon *>(sender());
if (reason == QSystemTrayIcon::Trigger) {
// onering_publish("systray.SystemTrayIcon.123456.click", "{}")
publishEvent("SystemTrayIcon", icon, "click");
}
}

13. Pros
• small core
• app could be Qt independent
• explicit and flexible js binding interface
• less memory management issue
• easy to trace

14. Cons
• extra layers
• URL dispatch to C++ code
• JSON <--> C++ object
• slightly more code and slower

15. Future: Plugin
• Every app can be considered as a plugin
• plugin: js + (optional) native code
• /onering-plugins/systray.dll (or directory)
• auto discovery and load
• plugin repository and community