Add an allInputsConnected method to Block and Workspace to test whether all trees in the block forest have their inputs filled. An optional argument controls whether or not shadow blocks are counted as being filled. Recommitting changes off develop instead of master as per discussion in PR #791.

core/block.js

@@ -1335,3 +1335,37 @@ Blockly.Block.prototype.moveBy = function(dx, dy) {
 Blockly.Block.prototype.makeConnection_ = function(type) {
   return new Blockly.Connection(this, type);
 };
+
+/**
+ * Recursively checks whether all statement and value inputs are filled with
+ * blocks. Also checks all following statement blocks in this stack.
+ * @param {boolean=} opt_shadowBlocksAreFilled An optional argument controlling
+ *     whether shadow blocks are counted as filled. Defaults to true.
+ * @return {boolean} True if all inputs are filled, false otherwise.
+ */
+Blockly.Block.prototype.allInputsFilled = function(opt_shadowBlocksAreFilled) {
+  // Handle the default value for the optional argument.
+  if (opt_shadowBlocksAreFilled === undefined) {
+    opt_shadowBlocksAreFilled = true;
+  }
+
+  for (var i = 0, input; input = this.inputList[i]; i++) {
+    if (!input.connection) {
+      continue;
+    }
+    var target = input.connection.targetBlock();
+    if (!target || !target.allInputsFilled(opt_shadowBlocksAreFilled)) {
+      return false;
+    }
+    if (!opt_shadowBlocksAreFilled && target.isShadow()) {
+      return false;
+    }
+  }
+
+  var next = this.getNextBlock();
+  if (next) {
+    return next.allInputsFilled(opt_shadowBlocksAreFilled);
+  }
+
+  return true;
+};

core/workspace.js

@@ -478,6 +478,23 @@ Blockly.Workspace.prototype.getBlockById = function(id) {
   return this.blockDB_[id] || null;
 };
 
+/**
+ * Checks whether all value and statement inputs in the workspace are filled
+ * with blocks.
+ * @param {boolean=} opt_shadowBlocksAreFilled An optional argument controlling
+ *     whether shadow blocks are counted as filled. Defaults to true.
+ * @return {boolean} True if all inputs are filled, false otherwise.
+ */
+Blockly.Workspace.prototype.allInputsFilled = function(opt_shadowBlocksAreFilled) {
+  var blocks = this.getTopBlocks(false);
+  for (var i = 0, block; block = blocks[i]; i++) {
+    if (!block.allInputsFilled(opt_shadowBlocksAreFilled)) {
+      return false;
+    }
+  }
+  return true;
+};
+
 /**
  * Database of all workspaces.
  * @private