ANDROID APP

การสร้างและการตรวจจับอีเวนต์
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case MotionEvent.ACTION_MOVE:
if (touchState == DRAG) {
//single finger drag, translate accordingly
matrix.set(eventMatrix);
matrix.setTranslate(event.getX(0) - centerX,
event.getY(0) - centerY);
} else if (touchState == ZOOM) {
//multi-finger zoom, scale accordingly around center
float dist = calcDistance(event);
if (dist > MIN_DIST) {
matrix.set(eventMatrix);
float scale = dist / eventDistance;
}
}
matrix.postScale(scale, scale, centerX, centerY);
// Perform the transformation
view.setImageMatrix(matrix);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
touchState = NONE;
break;
}
}
return true;
private float calcDistance(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
}
private void calcMidpoint(float centerX, float centerY,
MotionEvent event) {
centerX = (event.getX(0) + event.getX(1))/2;
centerY = (event.getY(0) + event.getY(1))/2;
}