/**
* Places the given end label of the given edge starting at the given node.
*
* @param node source node of the edge.
* @param edge the edge whose end label to place.
* @param label the end label to place.
* @param labelSpacing space between objects and labels.
*/
private void placeEndLabel(
final LNode node, final LEdge edge, final LLabel label, final double labelSpacing) {
// Get the nearest port (source port for tail labels, target port for head labels)
LPort port = null;
if (label.getProperty(LayeredOptions.EDGE_LABELS_PLACEMENT) == EdgeLabelPlacement.TAIL) {
port = edge.getSource();
} else if (label.getProperty(LayeredOptions.EDGE_LABELS_PLACEMENT) == EdgeLabelPlacement.HEAD) {
port = edge.getTarget();
}
// Initialize offset with zero if no offset was present
if (!northOffset.containsKey(port.getNode())) {
northOffset.put(port.getNode(), 0.0);
}
if (!southOffset.containsKey(port.getNode())) {
southOffset.put(port.getNode(), 0.0);
}
if (!portLabelOffsetHint.containsKey(port)) {
portLabelOffsetHint.put(port, 0.0);
}
// Calculate end label position based on side choice
// Port side undefined can be left out, because there would be no reasonable
// way of handling them
if (label.getProperty(InternalProperties.LABEL_SIDE) == LabelSide.ABOVE) {
placeEndLabelUpwards(node, label, port, labelSpacing);
} else {
placeEndLabelDownwards(node, label, port, labelSpacing);
}
}
/**
* Places the given end label below the edge.
*
* @param node source node of the edge the label belongs to.
* @param label the label to place.
* @param port the end port of the edge the label is nearest to.
* @param labelSpacing space between objects and labels.
*/
private void placeEndLabelUpwards(
final LNode node, final LLabel label, final LPort port, final double labelSpacing) {
// Remember some stuff
KVector labelPosition = label.getPosition();
KVector absolutePortPosition = KVector.sum(port.getPosition(), port.getNode().getPosition());
KVector absolutePortAnchor = port.getAbsoluteAnchor();
LMargin portMargin = port.getMargin();
// Actually calculate the coordinates
switch (port.getSide()) {
case WEST:
labelPosition.x =
Math.min(absolutePortPosition.x, absolutePortAnchor.x)
- portMargin.left
- label.getSize().x
- labelSpacing;
labelPosition.y = port.getAbsoluteAnchor().y - label.getSize().y - labelSpacing;
break;
case EAST:
labelPosition.x =
Math.max(absolutePortPosition.x + port.getSize().x, absolutePortAnchor.x)
+ portMargin.right
+ labelSpacing;
labelPosition.y = port.getAbsoluteAnchor().y - label.getSize().y - labelSpacing;
break;
case NORTH:
labelPosition.x = port.getAbsoluteAnchor().x + labelSpacing;
labelPosition.y =
Math.min(absolutePortPosition.y, absolutePortAnchor.y)
- portMargin.top
- label.getSize().y
- labelSpacing;
break;
case SOUTH:
labelPosition.x = port.getAbsoluteAnchor().x + labelSpacing;
labelPosition.y =
Math.max(absolutePortPosition.y + port.getSize().y, absolutePortAnchor.y)
+ portMargin.bottom
+ labelSpacing;
break;
}
}