/*
* This method takes two elements and exchanges their parents and previous
* elements. It then makes sure spacing is correct by calling
* focusPositionAndLines
*
* This method assumes index1 < index2
*/
private synchronized void swapElements(Object newParam, int index1, int index2) {
// the two elements to be swapped
LinearElement firstElement = root.getVector().get(index1);
LinearElement secondElement = root.getVector().get(index2);
// the two elements after each of the elements to be swapped
LinearElement secondElementNext;
LinearElement firstElementNext;
/*
* There is a corner case where secondElement.previousChild is
* firstElement
*/
// the first element's previous child before it is reassigned
LinearElement tempPrevChild = firstElement.getPreviousChild();
if (index2 != index1 + 1) { // the elements are not adjacent
// set previous elements for the two nodes
firstElement.setPreviousChild(secondElement.getPreviousChild());
secondElement.setPreviousChild(tempPrevChild);
// set previous elements for the nodes referencing the swapped nodes
if (index1 + 1 < root.getVector().size()) {
firstElementNext = root.getVector().get(index1 + 1);
firstElementNext.setPreviousChild(secondElement);
}
if (index2 + 1 < root.getVector().size()) {
secondElementNext = root.getVector().get(index2 + 1);
secondElementNext.setPreviousChild(firstElement);
}
} else { // the elements are adjacent
firstElement.setPreviousChild(secondElement);
secondElement.setPreviousChild(tempPrevChild);
// set previous elements for the nodes referencing the second node
if (index2 + 1 < root.getVector().size()) {
secondElementNext = root.getVector().get(index2 + 1);
secondElementNext.setPreviousChild(firstElement);
}
}
// swap the elements in root
root.getVector().swap(index1, index2);
root.focusPosition();
}
public synchronized void elementRemoved(Object source, int pos, int newSize) {
LinearElement toBeRemoved = root.getVector().get(pos);
shapes.getShapes().remove(toBeRemoved.getShape());
visualizer.removeLine(toBeRemoved.getVerticalLine());
visualizer.removeLine(toBeRemoved.getHorizontalLine());
LinearElement parent = root;
LinearElement previousChild = toBeRemoved.getPreviousChild();
if (pos + 1 <= newSize) // If it is not the last element
root.getVector().get(pos + 1).setPreviousChild(previousChild);
parent.getVector().remove(toBeRemoved);
root.focusPosition();
}
public synchronized void elementInserted(
Object source, ElementType element, int pos, int newSize) {
LinearElement parent = root;
LinearElement previousChild = pos - 1 >= 0 ? root.getVector().get(pos - 1) : null;
LinearElement newElement = visualizer.initElement(element, parent, previousChild);
if (pos + 1 < newSize) // if there is a child after us
// use pos not pos + 1 because the element has not been
// added to the vector yet, so pos + 1 in the user's
// vector is pos in the roots vector.
root.getVector().get(pos).setPreviousChild(newElement);
parent.getVector().insertElementAt(newElement, pos);
root.focusPosition();
}