package josx.platform.rcx; /** * Abstraction for an RCX button. * Example:
*
*/
public class Button implements ListenerCaller
{
/**
* The Run button.
*/
public static final Button RUN = new Button (0x01);
/**
* The View button.
*/
public static final Button VIEW = new Button (0x02);
/**
* The Prgm button.
*/
public static final Button PRGM = new Button (0x04);
/**
* Array containing VIEW, PRGM and RUN, in that order.
*/
public static final Button[] BUTTONS = { Button.RUN, Button.VIEW, Button.PRGM };
private int iCode;
private ButtonListener[] iListeners = new ButtonListener[4];
private int iNumListeners;
private Button (int aCode)
{
iCode = aCode;
}
/**
* Return the ID of the button. One of 1, 2 or 4.
*/
public final int getId()
{
return iCode;
}
/**
* @return
* Button.RUN.waitForPressAndRelease();
* Sound.playTone (1000, 1);
*
true
if button is pressed, false
otherwise.
*/
public final boolean isPressed()
{
return (readButtons() & iCode) != 0;
}
static Poll poller = new Poll();
/**
* Wait until the button is released.
*/
public final void waitForPressAndRelease() throws InterruptedException
{
do {
poller.poll(iCode << Poll.BUTTON_MASK_SHIFT, 0);
} while (isPressed());
}
/**
* Adds a listener of button events. Each button can serve at most
* 4 listeners.
*/
public synchronized void addButtonListener (ButtonListener aListener)
{
if (iListeners == null)
{
iListeners = new ButtonListener[4];
}
iListeners[iNumListeners++] = aListener;
ListenerThread.get().addButtonToMask(iCode, this);
}
/**
* Low-level API that reads status of buttons.
* @return An integer with possibly some bits set: 0x02 (view button pressed)
* 0x04 (prgm button pressed), 0x01 (run button pressed). If all buttons
* are released, this method returns 0.
*/
public static int readButtons()
{
synchronized (Memory.MONITOR)
{
int pAddr = Memory.iAuxDataAddr;
ROM.call ((short) 0x1fb6, (short) 0x3000, (short) pAddr);
return Memory.readShort (pAddr);
}
}
public synchronized void callListeners()
{
for( int i = 0; i < iNumListeners; i++) {
if( isPressed())
iListeners[i].buttonPressed( this);
else
iListeners[i].buttonReleased( this);
}
}
}