Implemented function `focus()` for tree, view, and form mode.

HISTORY.md

@@ -3,6 +3,11 @@
 https://github.com/josdejong/jsoneditor
 
 
+## not yet released, version 4.1.0
+
+- Implemented a function `focus()` for modes tree, view, and form.
+
+
 ## 2015-02-28, version 4.0.0
 
 - Ace editor and jsonlint are now packed with jsoneditor.js by default.

docs/api.md

@@ -54,6 +54,10 @@ Collapse all fields. Only applicable for mode 'tree', 'view', and 'form'.
 
 Expand all fields. Only applicable for mode 'tree', 'view', and 'form'.
 
+#### `JSONEditor.focus()`
+
+Set focus to the JSONEditor.
+
 #### `JSONEditor.set(json)`
 
 Set JSON data.

src/js/treemode.js

@@ -178,6 +178,33 @@ treemode.getName = function () {
   return this.options.name;
 };
 
+/**
+ * Set focus to the editor. Focus will be set to:
+ * - the first editable field or value, or else
+ * - to the expand button of the root node, or else
+ * - to the context menu button of the root node, or else
+ * - to the first button in the top menu
+ */
+treemode.focus = function () {
+  var input = this.content.querySelector('[contenteditable=true]');
+  if (input) {
+    input.focus();
+  }
+  else if (this.node.dom.expand) {
+    this.node.dom.expand.focus();
+  }
+  else if (this.node.dom.menu) {
+    this.node.dom.menu.focus();
+  }
+  else {
+    // focus to the first button in the menu
+    input = this.frame.querySelector('button');
+    if (input) {
+      input.focus();
+    }
+  }
+};
+
 /**
  * Remove the root node from the editor
  */