init

scratch-vm/src/compiler/compat-block-utility.js

@@ -0,0 +1,42 @@
+const BlockUtility = require('../engine/block-utility');
+
+class CompatibilityLayerBlockUtility extends BlockUtility {
+    constructor () {
+        super();
+        this._startedBranch = null;
+    }
+
+    get stackFrame () {
+        return this.thread.compatibilityStackFrame;
+    }
+
+    startBranch (branchNumber, isLoop) {
+        this._startedBranch = [branchNumber, isLoop];
+    }
+
+    startProcedure () {
+        throw new Error('startProcedure is not supported by this BlockUtility');
+    }
+
+    // Parameters are not used by compiled scripts.
+    initParams () {
+        throw new Error('initParams is not supported by this BlockUtility');
+    }
+    pushParam () {
+        throw new Error('pushParam is not supported by this BlockUtility');
+    }
+    getParam () {
+        throw new Error('getParam is not supported by this BlockUtility');
+    }
+
+    init (thread, fakeBlockId, stackFrame) {
+        this.thread = thread;
+        this.sequencer = thread.target.runtime.sequencer;
+        this._startedBranch = null;
+        thread.stack[0] = fakeBlockId;
+        thread.compatibilityStackFrame = stackFrame;
+    }
+}
+
+// Export a single instance to be reused.
+module.exports = new CompatibilityLayerBlockUtility();