public UsageNode doAppendUsage(@NotNull Usage usage) {
// invoke in ReadAction to be be sure that usages are not invalidated while the tree is being
// built
ApplicationManager.getApplication().assertReadAccessAllowed();
if (!usage.isValid()) {
// because the view is built incrementally, the usage may be already invalid, so need to
// filter such cases
return null;
}
UsageNode node = myBuilder.appendUsage(usage);
myUsageNodes.put(usage, node == null ? NULL_NODE : node);
if (!myIsFirstVisibleUsageFound && node != null) { // first visible usage found;
myIsFirstVisibleUsageFound = true;
showNode(node);
}
return node;
}
