Add green flag and stop button functions

src/engine/runtime.js

@@ -195,6 +195,34 @@ Runtime.prototype.toggleStack = function (stackId) {
     this._pushThread(stackId);
 };
 
+/**
+ * Green flag, which stops currently running threads
+ * and adds all top-level stacks that start with the green flag
+ */
+Runtime.prototype.greenFlag = function () {
+    // Remove all existing threads
+    for (var i = 0; i < this.threads.length; i++) {
+        this._removeThread(this.threads[i]);
+    }
+    // Add all top stacks with green flag
+    for (var j = 0; j < this.stacks.length; j++) {
+        var topBlock = this.stacks[j];
+        if (this.blocks[topBlock].opcode === 'event_whenflagclicked') {
+            this._pushThread(this.stacks[j]);
+        }
+    }
+};
+
+/**
+ * Stop "everything"
+ */
+Runtime.prototype.stopAll = function () {
+    for (var i = 0; i < this.threads.length; i++) {
+        this._removeThread(this.threads[i]);
+    }
+    // @todo call stop function in all extensions/packages/WeDo stub
+};
+
 /**
  * Repeatedly run `sequencer.stepThreads` and filter out
  * inactive threads after each iteration.

vm.js

@@ -1373,6 +1373,34 @@
 	    this._pushThread(stackId);
 	};
 
+	/**
+	 * Green flag, which stops currently running threads
+	 * and adds all top-level stacks that start with the green flag
+	 */
+	Runtime.prototype.greenFlag = function () {
+	    // Remove all existing threads
+	    for (var i = 0; i < this.threads.length; i++) {
+	        this._removeThread(this.threads[i]);
+	    }
+	    // Add all top stacks with green flag
+	    for (var j = 0; j < this.stacks.length; j++) {
+	        var topBlock = this.stacks[j];
+	        if (this.blocks[topBlock].opcode === 'event_whenflagclicked') {
+	            this._pushThread(this.stacks[j]);
+	        }
+	    }
+	};
+
+	/**
+	 * Stop "everything"
+	 */
+	Runtime.prototype.stopAll = function () {
+	    for (var i = 0; i < this.threads.length; i++) {
+	        this._removeThread(this.threads[i]);
+	    }
+	    // @todo call stop function in all extensions/packages/WeDo stub
+	};
+
 	/**
 	 * Repeatedly run `sequencer.stepThreads` and filter out
 	 * inactive threads after each iteration.