1 files changed, 61 insertions, 0 deletions
diff --git a/src/com/vaadin/terminal/JavaScriptCallbackHelper.java b/src/com/vaadin/terminal/JavaScriptCallbackHelper.java
new file mode 100644
index 0000000000..5ea5e56255
--- /dev/null
+++ b/src/com/vaadin/terminal/JavaScriptCallbackHelper.java
@@ -0,0 +1,61 @@
+/* 
+@VaadinApache2LicenseForJavaFiles@
+ */
+
+package com.vaadin.terminal;
+
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.vaadin.external.json.JSONArray;
+import com.vaadin.external.json.JSONException;
+import com.vaadin.tools.ReflectTools;
+import com.vaadin.ui.JavaScript.JavaScriptCallbackRpc;
+import com.vaadin.ui.JavaScriptCallback;
+
+public class JavaScriptCallbackHelper {
+
+    private static final Method CALL_METHOD = ReflectTools.findMethod(
+            JavaScriptCallbackRpc.class, "call", String.class, JSONArray.class);
+    private AbstractClientConnector connector;
+
+    private Map<String, JavaScriptCallback> callbacks = new HashMap<String, JavaScriptCallback>();
+    private JavaScriptCallbackRpc javascriptCallbackRpc;
+
+    public JavaScriptCallbackHelper(AbstractClientConnector connector) {
+        this.connector = connector;
+    }
+
+    public void registerCallback(String functionName,
+            JavaScriptCallback javaScriptCallback) {
+        callbacks.put(functionName, javaScriptCallback);
+        ensureRpc();
+    }
+
+    private void ensureRpc() {
+        if (javascriptCallbackRpc == null) {
+            javascriptCallbackRpc = new JavaScriptCallbackRpc() {
+                public void call(String name, JSONArray arguments) {
+                    JavaScriptCallback callback = callbacks.get(name);
+                    try {
+                        callback.call(arguments);
+                    } catch (JSONException e) {
+                        throw new IllegalArgumentException(e);
+                    }
+                }
+            };
+            connector.registerRpc(javascriptCallbackRpc);
+        }
+    }
+
+    public void invokeCallback(String name, Object... arguments) {
+        JSONArray args = new JSONArray(Arrays.asList(arguments));
+        connector.addMethodInvocationToQueue(
+                JavaScriptCallbackRpc.class.getName(), CALL_METHOD,
+                new Object[] { name, args });
+        connector.requestRepaint();
+    }
+
+}