Singleton Toast
On Android you may have experienced delayed toasts or overlapping toasts. This causes the toasts being displayed with irrelevant context/activity (e.g. user may have pressed backed, or previous toast is still overriding new one, or when too many toasts are displayed on screen).
Consider the code below. It defines a single function for toast, that makes use of context object of Application. The class MyApplication needs to be declared in manifest.xml. The main advantage of such design is
- reduced footprint for activity’s context object.
- at any moment only one toast remains on screen
- reusing single toast object, rather than creating for each show.
public class MyApplication extends Application {
private static Resources resources;
private static Context context;
private static Toast toast;
/**
* Called when the application is starting, before any other application
* objects have been created. Implementations should be as quick as possible
* (for example using lazy initialization of state) since the time spent in
* this function directly impacts the performance of starting the first
* activity, service, or receiver in a process. If you override this method,
* be sure to call super.onCreate().
* */
@Override
public void onCreate() {
super.onCreate();
Log.i("MyApplication", "Starting app...");
MyApplication.resources = getResources();
MyApplication.context = getApplicationContext();
MyApplication.toast = Toast.makeText(MyApplication.context, "", Toast.LENGTH_SHORT);
}
/** Returns the global resources object. */
public static Resources getResourcesObject() {
return MyApplication.resources;
}
/** Returns the global context object. */
public static Context getContextObject() {
return MyApplication.context;
}
public static void toast(String message)
{
MyApplication.toast(message, Toast.LENGTH_SHORT);
}
public static void toast(String message, int duration)
{
MyApplication.toast.cancel();
MyApplication.toast.setText(message);
MyApplication.toast.setDuration(duration);
MyApplication.toast.show();
}
}