Allow using element resize listeners from javascript connectors (#11996)

Change-Id: I97b280c2e260752be87ce85d2eda81ec4f14d4fe

1 files changed, 80 insertions, 1 deletions

diff --git a/client/src/com/vaadin/client/JavaScriptConnectorHelper.java b/client/src/com/vaadin/client/JavaScriptConnectorHelper.java
index b144603be0..52d2eeb6dc 100644
--- a/client/src/com/vaadin/client/JavaScriptConnectorHelper.java
+++ b/client/src/com/vaadin/client/JavaScriptConnectorHelper.java
@@ -25,11 +25,13 @@ import java.util.Set;
 
 import com.google.gwt.core.client.JavaScriptObject;
 import com.google.gwt.core.client.JsArray;
+import com.google.gwt.dom.client.Element;
 import com.google.gwt.json.client.JSONArray;
-import com.google.gwt.user.client.Element;
 import com.vaadin.client.communication.JavaScriptMethodInvocation;
 import com.vaadin.client.communication.StateChangeEvent;
 import com.vaadin.client.communication.StateChangeEvent.StateChangeHandler;
+import com.vaadin.client.ui.layout.ElementResizeEvent;
+import com.vaadin.client.ui.layout.ElementResizeListener;
 import com.vaadin.shared.JavaScriptConnectorState;
 import com.vaadin.shared.communication.MethodInvocation;
 
@@ -42,6 +44,7 @@ public class JavaScriptConnectorHelper {
 
     private final Map<String, JavaScriptObject> rpcObjects = new HashMap<String, JavaScriptObject>();
     private final Map<String, Set<String>> rpcMethods = new HashMap<String, Set<String>>();
+    private final Map<Element, Map<JavaScriptObject, ElementResizeListener>> resizeListeners = new HashMap<Element, Map<JavaScriptObject, ElementResizeListener>>();
 
     private JavaScriptObject connectorWrapper;
     private int tag;
@@ -204,9 +207,71 @@ public class JavaScriptConnectorHelper {
             'translateVaadinUri': $entry(function(uri) {
                 return c.@com.vaadin.client.ApplicationConnection::translateVaadinUri(Ljava/lang/String;)(uri);
             }),
+            'addResizeListener': function(element, resizeListener) {
+                if (!element || element.nodeType != 1) throw "element must be defined";
+                if (typeof resizeListener != "function") throw "resizeListener must be defined";
+                $entry(h.@com.vaadin.client.JavaScriptConnectorHelper::addResizeListener(*)).call(h, element, resizeListener);
+            },
+            'removeResizeListener': function(element, resizeListener) {
+                if (!element || element.nodeType != 1) throw "element must be defined";
+                if (typeof resizeListener != "function") throw "resizeListener must be defined";
+                $entry(h.@com.vaadin.client.JavaScriptConnectorHelper::removeResizeListener(*)).call(h, element, resizeListener);
+            }
         };
     }-*/;
 
+    // Called from JSNI to add a listener
+    private void addResizeListener(Element element,
+            final JavaScriptObject callbackFunction) {
+        Map<JavaScriptObject, ElementResizeListener> elementListeners = resizeListeners
+                .get(element);
+        if (elementListeners == null) {
+            elementListeners = new HashMap<JavaScriptObject, ElementResizeListener>();
+            resizeListeners.put(element, elementListeners);
+        }
+
+        ElementResizeListener listener = elementListeners.get(callbackFunction);
+        if (listener == null) {
+            LayoutManager layoutManager = LayoutManager.get(connector
+                    .getConnection());
+            listener = new ElementResizeListener() {
+                @Override
+                public void onElementResize(ElementResizeEvent e) {
+                    invokeElementResizeCallback(e.getElement(),
+                            callbackFunction);
+                }
+            };
+            layoutManager.addElementResizeListener(element, listener);
+            elementListeners.put(callbackFunction, listener);
+        }
+    }
+
+    private static native void invokeElementResizeCallback(Element element,
+            JavaScriptObject callbackFunction)
+    /*-{
+        // Call with a simple event object and 'this' pointing to the global scope
+        callbackFunction.call($wnd, {'element': element});
+    }-*/;
+
+    // Called from JSNI to remove a listener
+    private void removeResizeListener(Element element,
+            JavaScriptObject callbackFunction) {
+        Map<JavaScriptObject, ElementResizeListener> listenerMap = resizeListeners
+                .get(element);
+        if (listenerMap == null) {
+            return;
+        }
+
+        ElementResizeListener listener = listenerMap.remove(callbackFunction);
+        if (listener != null) {
+            LayoutManager.get(connector.getConnection())
+                    .removeElementResizeListener(element, listener);
+            if (listenerMap.isEmpty()) {
+                resizeListeners.remove(element);
+            }
+        }
+    }
+
     private native void attachRpcMethod(JavaScriptObject rpc, String iface,
             String method)
     /*-{
@@ -377,6 +442,20 @@ public class JavaScriptConnectorHelper {
 
     public void onUnregister() {
         invokeIfPresent(connectorWrapper, "onUnregister");
+
+        if (!resizeListeners.isEmpty()) {
+            LayoutManager layoutManager = LayoutManager.get(connector
+                    .getConnection());
+            for (Entry<Element, Map<JavaScriptObject, ElementResizeListener>> entry : resizeListeners
+                    .entrySet()) {
+                Element element = entry.getKey();
+                for (ElementResizeListener listener : entry.getValue().values()) {
+                    layoutManager
+                            .removeElementResizeListener(element, listener);
+                }
+            }
+            resizeListeners.clear();
+        }
     }
 
     private static native void invokeIfPresent(