/**
* A childless stran is a "problem" in general because they break the evenness of the tree There
* are three types of such strands, extra nodes to the left, extra to the right, or extra in
* between parents. This method places those strands in spot.
*
* @param childlessStrand - the childless node to be laid out.
* @param parentLeft - the nearest parent on the left (or <value>null</value> if none such exists)
* @param parentRight - the nearest parent on the right (or <value>null</value> if none such
* exists)
* @param yLoc - the vertical location to lay out the nodes on.
*/
private void placeChildless(
List<GXMoreThanNode> childlessStrand,
GXMoreThanNode parentLeft,
GXMoreThanNode parentRight,
int yLoc) {
int startMark = 0;
int spacing =
(int) (childlessStrand.get(0).getNode().getLayoutEntity().getWidthInLayout() + horSpacing);
// There's only a parent on the right
if (parentLeft == null && parentRight != null) {
startMark = parentRight.getX() - (spacing * childlessStrand.size());
} // there's a parent on the left
else if (parentLeft != null) {
startMark = parentLeft.getX() + spacing;
// there's a parent on the right as well meaning the childless are between two parents
// we need to make there's enough room to place them
if (parentRight != null) {
int endMark = startMark + (spacing * childlessStrand.size());
// if there isn't enough room to place the childless between the parents
if (endMark > parentRight.getX()) {
// shift everything on the right to the right by the missing amount of space.
shiftTreesRightOfMark(parentRight, endMark - parentRight.getX());
}
}
}
// now the room has been assured, place strand.
placeStrand(childlessStrand, startMark, yLoc, spacing);
}
/**
* Returns the right most child of parent
*
* @param parent
* @return the right most child of parent given.
*/
private GXMoreThanNode getRightMostChild(GXMoreThanNode parent) {
GXMoreThanNode rightMost = parent.getChildren().get(0);
// run through children
for (GXMoreThanNode child : parent.getChildren()) {
if (child.getX() < rightMost.getX()) {
rightMost = child;
}
}
return rightMost;
}
/**
* Shifts the trees right of mark node
*
* @param mark to shift from
* @param shift - factor by which to move right by.
*/
private void shiftTreesRightOfMark(GXMoreThanNode mark, int shift) {
mark.setLocation(mark.getX() + shift, mark.getY());
GXMoreThanNode leftMostChild = getRightMostChild(mark);
List<GXMoreThanNode> treeRoots =
leftMostChild
.getRow()
.subList(leftMostChild.getRow().indexOf(leftMostChild), leftMostChild.getRow().size());
for (GXMoreThanNode root : treeRoots) {
shiftTree(root, shift);
}
}
/**
* Lays out row with respect to it's children.
*
* @param yLocation - the vertical location to start placing the nodes.
* @param row - the row who's nodes we'd like to lay out.
*/
private void placeRow(List<GXMoreThanNode> row, int yLocation) {
List<GXMoreThanNode> childlessStrand = new ArrayList<GXMoreThanNode>();
GXMoreThanNode parentLeft = null;
// for each parent in this parent row
for (int j = 0; j < row.size(); j++) {
GXMoreThanNode parentRight = row.get(j);
// if the node has children
if (!parentRight.getChildren().isEmpty()) {
// place the node in the center above his children
int parentX = 0;
for (GXMoreThanNode child : parentRight.getChildren()) {
parentX += child.getX();
}
parentX /= parentRight.getChildren().size();
parentRight.setLocation(parentX, yLocation);
// and layout the childless strand
if (!childlessStrand.isEmpty()) {
placeChildless(childlessStrand, parentLeft, parentRight, yLocation);
childlessStrand.clear();
}
parentLeft = parentRight;
} else { // accumulate the childless nodes
childlessStrand.add(parentRight);
}
}
// place childless who are extra on the right. as in did not get taken care of when
// the parents were laid out.
if (!childlessStrand.isEmpty()) {
placeChildless(childlessStrand, parentLeft, null, yLocation);
}
}
/**
* Shifts the given tree by the shift factor given to the right.
*
* @param root - root of tree to shift
* @param shift - factor to shirt by
*/
private void shiftTree(GXMoreThanNode root, int shift) {
root.setLocation(root.getX() + shift, root.getY());
for (GXMoreThanNode child : root.getChildren()) {
shiftTree(child, shift);
}
}