PAYPAL $5: Debugging a runtime problem in my QuadTree inplementation...

Question

The following is a QuadTree implementation. It splits a map into four quadrants (and nodes) determined by a split point. The split point is the middle of two points clicked by the user. If a sub-quadrant (child node) already has a point, and you've selected another point in that quadrant, that quadrant is split into four quadrants (the kids on the tree).
Almost Everything works fine except every once in a while you have to click twice to split a quadrant already containing a point (totally 3 points).
I cannot figure out why it is skipping over a node that already contains a point, as if it doesn't exist. any help is appreciated, the one who helps me lose this headache/problem gets $5 cash through paypal.
The insert method is the meat of what I'm doing. TIA.
public class QuadTree {
    public QuadTree(Rectangle range) {
        mRoot = new QTNode(range);
     * insert the point into the tree
     * assume all inseted points are distinct
    public void insert(Point point) {
        mRoot.insert(point);
    } // insert()
private QTNode  mRoot;
} // class QuadTree
class QTNode {
     * constructor
    QTNode() {
        mParent = null;
        mKids   = new QTNode[4];
        mDataPoint  = null;
        mRange      = null;
        mSplitPoint = null;
     * the constructor used by the QuadTree class
    QTNode(Rectangle range) {
        this();
        mRange = range;
     * inser the point to the subtree rooted at "this" node
     * @param  point the point to be inserted
    void insert(Point point) {
        int j;
        System.out.println(point);
        if ( mSplitPoint != null ) {
             if ((point.getX()) >= (mSplitPoint.getX())){
                  if ((point.getY()) >= (mSplitPoint.getY())){ j=3; }
                  else { j=1; }
             else {
                  if ((point.getY()) < (mSplitPoint.getY())){ j=0; }
                  else { j=2; }
               mKids[j].insert(point);
               System.out.println("Point inserted in" + j);
          else {
               if ( mDataPoint != null ){
                  //sets the split point of the next layer of nodes    
                  Point tempSplit = new Point();
                  tempSplit.setLocation(((mDataPoint.getX()+(point.getX()))/2),((mDataPoint.getY()+point.getY())/2));              
                         setSplitPoint(tempSplit);
                  for (int k=0; k<4 ; k++){
                       mKids[k] = new QTNode();
                       mKids[k].setParent(this);
                       Rectangle tempRange = (getRange());
                       Rectangle tempRect = new Rectangle();
                       if (k == 0) {
                       tempRect.setRect(tempRange.getX(),tempRange.getY(),(mSplitPoint.getX()-tempRange.getX()),(mSplitPoint.getY()-tempRange.getY()));
                       mKids[k].setRange(tempRect);
                       System.out.println("rect0" + tempRect);
                       if (k == 1) {
                       tempRect.setRect(mSplitPoint.getX(),tempRange.getY(),(tempRange.getWidth()-(mSplitPoint.getX()-tempRange.getX())),(mSplitPoint.getY()-tempRange.getY()));
                       mKids[k].setRange(tempRect);
                       System.out.println("rect1" + tempRect);
                       if (k == 2) {
                       tempRect.setRect(tempRange.getX(),mSplitPoint.getY(),(mSplitPoint.getX()-tempRange.getX()),(tempRange.getHeight()-(mSplitPoint.getY()-tempRange.getY())));
                       mKids[k].setRange(tempRect);
                       System.out.println("rect2" + tempRect);
                       if (k == 3) {
                       tempRect.setRect(mSplitPoint.getX(),mSplitPoint.getY(),(tempRange.getWidth()-(mSplitPoint.getX()-tempRange.getX())),(tempRange.getHeight()-(mSplitPoint.getY()-tempRange.getY())));
                       mKids[k].setRange(tempRect);
                       System.out.println("rect3" + tempRect);
                       if ((mKids[k].getRange().contains(point)) == true){
                                 mKids[k].setDataPoint(point);
               else { mDataPoint = point; }
    // FILL ANY METHOD AS NEEDED
    private void setSplitPoint(Point split) {
        mSplitPoint = split;
    private void setParent(QTNode parent) {
        mParent = parent;
    private void setRange(Rectangle range) {
        mRange = range;
    private void setDataPoint(Point point) {
        mDataPoint = point;
    QTNode getParent() {
        return mParent;
    QTNode getChild(int pick) {
        return mKids[pick];
    Point getDataPoint() {
        return mDataPoint;
    Rectangle getRange() {
        return mRange;
    private final int eTR = 0;  // index of the Top    Right  region/kid
    private final int eTL = 1;  // index of the Top    Left   region/kid
    private final int eBR = 2;  // index of the Buttom Right  region/kid
    private final int eBL = 3;  // index of the Buttom Left   region/kid
     * All the point data are stored in the leaf nodes of the quadtree.
     * That is, after a node splitted (then it has four kids)
     * the point data originally stored has been moved to one of its kid
     * whose range covers the point.
    QTNode    mParent;      // reference to the parent
    QTNode    mKids[];      // reference to the 4 kids
    Point     mDataPoint;   // the point data if any
    Rectangle mRange;       // the range covered by this node
    Point     mSplitPoint;  // where the vertical and horizontal
                            //   split lines meet
} // class QTNodeThe area is question is in bold, it has been coded by myself.

Answer 1

selfbump, please hellp me :-)