/**
* Calculate the minimum or preferred size of every row or column.
*
* @param dim the minimum or preferred size of every child
* @param row true if row sizes should be calculated, false if column sizes should be calculated
* @return the size required for every row or column
*/
private int[] calculateRequiredSizes(Dimension dim[], boolean row) {
// Build a linked list of size requirements of every child.
LinkedList<int[]> requiredList = new LinkedList<int[]>();
for (int i = 0; i < dim.length; i++) {
ChildInfo info = child.get(i);
if (row) requiredList.addLast(new int[] {info.y, info.height, dim[i].height});
else requiredList.addLast(new int[] {info.x, info.width, dim[i].width});
}
// Find the required size for each row or column.
int width[] = new int[row ? rowWeight.length : colWeight.length];
double weight[] = (row ? rowWeight : colWeight);
for (int currentWidth = 1; requiredList.size() > 0; currentWidth++) {
// Apply constraints for all children which occupy currentWidth rows or columns.
Iterator<int[]> iter = requiredList.iterator();
while (iter.hasNext()) {
int req[] = iter.next();
if (req[1] != currentWidth) continue;
iter.remove();
if (currentWidth == 1) {
width[req[0]] = Math.max(width[req[0]], req[2]);
continue;
}
// Find how much space is currently available.
int total = 0;
for (int i = 0; i < currentWidth; i++) total += width[req[0] + i];
if (total >= req[2]) continue; // It is already wide enough.
// Allocate additional space to the rows or columns, based on their weights.
double totalWeight = 0.0;
for (int i = 0; i < currentWidth; i++) totalWeight += weight[req[0] + i];
int extra[] = new int[currentWidth];
int totalExtra = 0;
for (int i = 0; i < currentWidth - 1; i++) {
double w = (totalWeight > 0.0 ? weight[req[0] + i] / totalWeight : 1.0 / currentWidth);
extra[i] += w * (req[2] - total);
totalExtra += extra[i];
}
extra[extra.length - 1] = req[2] - total - totalExtra;
for (int i = 0; i < currentWidth; i++) width[req[0] + i] += extra[i];
}
}
return width;
}
