* Collapsable trees.

src/log2xml/treebits.js

@@ -0,0 +1,50 @@
+/* Acknowledgement: this is based on the Wikipedia table-of-contents
+ * toggle. */
+
+
+var idCounter = 0;
+
+
+function showTreeToggle(show,hide) {
+    if (document.getElementById) {
+        var id = "toggle_" + idCounter;
+        document.writeln(
+            '<a href="javascript:toggleTree(\'' + id + '\')" class="toggle" id="' + id + '">' +
+            '<span class="showTree" style="display: none;">+</span>' +
+            '<span class="hideTree">-</span>' +
+            '</a>');
+        idCounter = idCounter + 1;
+    }
+}
+
+
+function toggleTree(id) {
+
+    var href = document.getElementById(id);
+
+    var node = href;
+    var tree = null;
+    while (node != null) {
+        if (node.className == "nesting") tree = node;
+        node = node.nextSibling;
+    }
+
+    node = href.firstChild;
+    var hideTree = null;
+    var showTree = null;
+    while (node != null) {
+        if (node.className == "showTree") showTree = node;
+        else if (node.className == "hideTree") hideTree = node;
+        node = node.nextSibling;
+    }
+    
+    if (tree.style.display == 'none') {
+        tree.style.display = '';
+        hideTree.style.display = '';
+        showTree.style.display = 'none';
+    } else {
+        tree.style.display = 'none';
+        hideTree.style.display = 'none';
+        showTree.style.display = '';
+    }
+}