/**
* Shows an insertion line if there is one or more current children.
*
* @see LayoutEditPolicy#showLayoutTargetFeedback(Request)
*/
protected void showLayoutTargetFeedback(Request request) {
if (getHost().getChildren().size() == 0) return;
Polyline fb = getLineFeedback();
Transposer transposer = new Transposer();
transposer.setEnabled(!isLayoutHorizontal());
int epIndex = getFeedbackIndexFor(request);
Rectangle r = null;
if (epIndex == -1) {
epIndex = getHost().getChildren().size() - 1;
EditPart editPart = (EditPart) getHost().getChildren().get(epIndex);
r = transposer.t(getAbsoluteBounds((GraphicalEditPart) editPart));
} else {
EditPart editPart = (EditPart) getHost().getChildren().get(epIndex);
r = transposer.t(getAbsoluteBounds((GraphicalEditPart) editPart));
Point p = transposer.t(getLocationFromRequest(request));
if (p.x > r.x + (r.width / 2)) {
editPart = (EditPart) getHost().getChildren().get(epIndex);
r = transposer.t(getAbsoluteBounds((GraphicalEditPart) editPart));
}
}
int x = r.x;
Point p1 = new Point(x, r.y - 4);
p1 = transposer.t(p1);
fb.translateToRelative(p1);
Point p2 = new Point(x, r.y + r.height + 4);
p2 = transposer.t(p2);
fb.translateToRelative(p2);
fb.setPoint(p1, 0);
fb.setPoint(p2, 1);
}
/**
* @param request the Request
* @return the index for the insertion reference
*/
protected int getFeedbackIndexFor(Request request) {
List children = getHost().getChildren();
if (children.isEmpty()) return -1;
Transposer transposer = new Transposer();
transposer.setEnabled(!isLayoutHorizontal());
Point p = transposer.t(getLocationFromRequest(request));
if (children.size() == 0 || children.size() == 1) {
return -1;
}
int[] y = new int[children.size()];
for (int i = 0; i < children.size(); i++) {
EditPart child = (EditPart) children.get(i);
Rectangle rect = transposer.t(getAbsoluteBounds(((GraphicalEditPart) child)));
y[i] = rect.y;
}
int height = 5;
if (y[0] + height >= p.y) {
// add to first item;
return 0;
}
if (y[y.length - 1] - height <= p.y) {
// add to end item;
return y.length - 1;
}
int candidateIndex = -1;
for (int i = 0; i < y.length; i++) {
if (i + 1 == y.length) {
break;
}
if (p.y >= y[i] && p.y <= y[i + 1]) {
candidateIndex = i;
break;
}
}
return candidateIndex;
}