Game Development Reference
In-Depth Information
GameFileDownloader.java
: This class is capable of downloading shareware
game files from the Internet into the SD card.
•
LibraryLoader.java
: This class loads the DSO, which is required before the
native methods can be invoked.
•
WebDownload.java
: This is a web download tool used by the
GameFileDownloader
class.
Again, before we look at these components in more detail, make sure you have the chapter code at
hand; most of the listings have been stripped down for simplicity.
•
Java Main Activity
The main activity class is invoked when the user starts the game and controls the life cycle of the
application. In Doom, this life cycle is handled by the following:
Creation handler
: This handler is implemented by
onCreate
and it is called when
the activity is first created. It sets the UI layout XML (
doom.xml
) and initializes the
game.
•
Menu handlers
: Here, we have
onCreateOptionsMenu
and
onOptionsItemSelected
.
The first method creates the game menu, and the latter processes the menu when
the user selects an option.
•
•
Key and touch handlers
: These methods receive key and touch events and dispatch
them to the right JNI component.
•
Native callback handlers
: These methods receive video and sound updates from
the native interface and dispatch them.
•
Controller toolbar
: The controller toolbar is a set of image buttons displayed at the
bottom of the screen for navigation. It is helpful for devices that do not have a
keyboard.
Creation Handler
The creation handler is defined by
onCreate
(see Listing 7-2). For Doom, this method performs the
following steps:
•
Sets the display to full screen and hides the title
Sets the content view layout to
R.layout.doom
, which maps to
doom.xml
•
•
Gets a reference to the video buffer (
R.id.doom_iv
), which will be used to display
the pixels sent by the DSO
•
Sets the navigation controls
