使用OnTouchListener监听滑动事件

<pre name="code" class="java">import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;

public abstract class ExtendedTouchListener implements OnTouchListener {
private final int MOVE_LEFT = 1011;
private final int MOVE_RIGHT = 1012;
private final int MOVE_TOP = 1013;
private final int MOVE_BOTTOM = 1014;

private int preX;
private int preY;

@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
preX = (int) event.getX();
preY = (int) event.getY();
break;
case MotionEvent.ACTION_UP:
spearEvent(compare((int) event.getX(), (int) event.getY()), event);
break;
}
return true;
}

private void spearEvent(int compare, MotionEvent event) {
onFingerDown(event);
switch (compare) {
case MOVE_LEFT:
onLeftTouch(event);
break;
case MOVE_RIGHT:
onRightTouch(event);
break;
case MOVE_TOP:
onTopTouch(event);
break;
case MOVE_BOTTOM:
onBottomTouch(event);
break;
default:
break;
}
}

private int compare(int x, int y) {
int dltX = x - preX, dltY = y - preY;
if (Math.abs(dltX) > Math.abs(dltY) {
return dltX > 0 ? MOVE_RIGHT : MOVE_LEFT;
} else {
return dltX > 0 ? MOVE_TOP : MOVE_BOTTOM;
}
}

abstract void onFingerDown(MotionEvent event);

abstract void onLeftTouch(MotionEvent event);

abstract void onRightTouch(MotionEvent event);

abstract void onTopTouch(MotionEvent event);

abstract void onBottomTouch(MotionEvent event);
}