Mr. Nom Invades Android - Beginning Android Games - page 244

int len = touchEvents.size();
for ( int i = 0; i < len; i++) {
TouchEvent event = touchEvents.get(i);
if (event.type == TouchEvent. TOUCH_UP ) {
if if(inBounds(event, 0, g.getHeight() - 64, 64, 64)) {
Settings. soundEnabled = !Settings. soundEnabled ;
if (Settings. soundEnabled )
Assets. click .play(1);
}
if if(inBounds(event, 64, 220, 192, 42) ) {
game.setScreen( new GameScreen(game));
if (Settings. soundEnabled )
Assets. click .play(1);
return ;
}
if if(inBounds(event, 64, 220 + 42, 192, 42) ) {
game.setScreen( new HighscoreScreen(game));
if (Settings. soundEnabled )
Assets. click .play(1);
return ;
}
if if(inBounds(event, 64, 220 + 84, 192, 42) ) {
game.setScreen( new HelpScreen(game));
if (Settings. soundEnabled )
Assets. click .play(1);
return ;
}
}
}
}
Next, we have the update() method, in which we'll do all our touch event checking. We first
fetch the TouchEvent and KeyEvent instances from the Input instance the Game provides us.
Note that we do not use the KeyEvent instances, but we fetch them anyway in order to clear
the internal buffer (yes, that's a tad bit nasty, but let's make it a habit). We then loop over all
the TouchEvent instances until we find one with the type TouchEvent.TOUCH_UP . (We could
alternatively look for TouchEvent.TOUCH_DOWN events, but in most UIs the up event is used to
indicate that a UI component was pressed.)
Once we have a fitting event, we check whether it pressed either the sound toggle button or one of
the menu entries. To make that code a little cleaner, we wrote a method called inBounds() , which
takes a touch event, x and y coordinates, and a width and height. The method checks whether the
touch event is inside the rectangle defined by those parameters, and it returns either true or false .
If the sound toggle button is pressed, we simply invert the Settings.soundEnabled Boolean
value. In case any of the main menu entries are pressed, we transition to the appropriate screen
by instancing it and setting it via Game.setScreen() . We can immediately return in that case, as
the MainMenuScreen doesn't have anything to do anymore. We also play the click sounds if either
the toggle button or a main menu entry is pressed and sound is enabled.
Remember that all the touch events will be reported relative to our target resolution of
320 × 480 pixels, thanks to the scaling magic we performed in the touch event handlers
discussed in Chapter 5.