Implement ImageRenderer (#13334)

Change-Id: I5b04f10f5d8b312ace8a3b5f1df28f37aa8b97d8

1 files changed, 57 insertions, 0 deletions

diff --git a/server/src/com/vaadin/ui/components/grid/renderers/ImageRenderer.java b/server/src/com/vaadin/ui/components/grid/renderers/ImageRenderer.java
new file mode 100644
index 0000000000..b7134aab01
--- /dev/null
+++ b/server/src/com/vaadin/ui/components/grid/renderers/ImageRenderer.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2000-2014 Vaadin Ltd.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.ui.components.grid.renderers;
+
+import com.vaadin.server.ExternalResource;
+import com.vaadin.server.Resource;
+import com.vaadin.server.ResourceReference;
+import com.vaadin.server.ThemeResource;
+import com.vaadin.shared.communication.URLReference;
+import com.vaadin.ui.components.grid.AbstractRenderer;
+
+import elemental.json.JsonValue;
+
+/**
+ * A renderer for presenting images.
+ * <p>
+ * The image for each rendered cell is read from a Resource-typed property in
+ * the data source. Only {@link ExternalResource}s and {@link ThemeResource}s
+ * are currently supported.
+ * 
+ * @since
+ * @author Vaadin Ltd
+ */
+public class ImageRenderer extends AbstractRenderer<Resource> {
+
+    /**
+     * Creates a new image renderer.
+     */
+    public ImageRenderer() {
+        super(Resource.class);
+    }
+
+    @Override
+    public JsonValue encode(Resource resource) {
+        if (!(resource instanceof ExternalResource || resource instanceof ThemeResource)) {
+            throw new IllegalArgumentException(
+                    "ImageRenderer only supports ExternalResource and ThemeResource ("
+                            + resource.getClass().getSimpleName() + "given )");
+        }
+
+        return encode(ResourceReference.create(resource, this, null),
+                URLReference.class);
+    }
+}