Game Development Reference
In-Depth Information
Now, the cycle starts over by handling (new) system events once again. Another
system event that can occur during runtime is the
exit
event. When it occurs, LibGDX
will first change to the
pause()
state, which is a very good place to save any data that
would be lost otherwise, after the application is terminated. Subsequently, LibGDX
changes to the
dispose()
state where an application should do its final cleanup to
free all the resources that it is still using.
This is also almost true for Android, except that
pause()
is an intermediate state
that is not directly followed by the
dispose()
state at first. Be aware that this event
might occur anytime during an application runtime when the user has pressed the
Home
button or if there is an incoming phone call in the meanwhile. In fact, as long
as the Android operating system does not need the occupied memory of the paused
application, its state will not be changed to
dispose()
. Moreover, it is possible that
a paused application might receive a
resume
system event, which in this case would
change its state to
resume()
, and it would eventually arrive at the system event
handler again.
Starter classes
A starter class defines the entry point (starting point) of a LibGDX application.
It is specifically written for a certain platform. Usually, these kinds of classes are
very simple and mostly consist of not more than a few lines of code to set certain
parameters that apply to the corresponding platform. Think of them as a kind of
bootup sequence for each platform. Once booting is finished, the LibGDX framework
hands over control from the starter class (for example, the
demo-desktop
project) to
your shared application code (for example, the
demo
/
demo-core
project) by calling
different methods from the
ApplicationListener
interface that the
MyDemo
class
implements. Remember that the
MyDemo
class is where the shared application
code begins.
We will now take a look at each of the starter classes that were generated during
the project setup.
Running the demo application on a desktop
The starter class for the desktop application is called
Main.java
. The following
listing is
Main.java
from the
demo-desktop
project:
package com.packtpub.libgdx.demo;
import com.badlogic.gdx.backends.lwjgl.LwjglApplication;
import com.badlogic.gdx.backends.lwjgl.LwjglApplicationConfiguration;
public class Main {
