Added new SafeImageCell class wich uses SafeUris instead of Strings.

Review at http://gwt-code-reviews.appspot.com/1673803

Review by: jlabanca@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@10928 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/cell/client/SafeImageCell.java b/user/src/com/google/gwt/cell/client/SafeImageCell.java
new file mode 100644
index 0000000..954644c
--- /dev/null
+++ b/user/src/com/google/gwt/cell/client/SafeImageCell.java
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * 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.google.gwt.cell.client;
+
+import com.google.gwt.core.client.GWT;
+import com.google.gwt.safehtml.client.SafeHtmlTemplates;
+import com.google.gwt.safehtml.shared.SafeHtml;
+import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
+import com.google.gwt.safehtml.shared.SafeUri;
+
+/**
+ * <p>
+ * An {@link AbstractCell} used to render an image by using a {@link SafeUri}.
+ * </p>
+ * <p>
+ * If the images being displayed are static or available at compile time, using
+ * {@link ImageResourceCell} will usually be more efficient.
+ * </p>
+ *
+ * @see ImageCell
+ * @see ImageResourceCell
+ */
+public class SafeImageCell extends AbstractCell<SafeUri> {
+
+  interface Template extends SafeHtmlTemplates {
+    @Template("<img src=\"{0}\"/>")
+    SafeHtml img(SafeUri url);
+  }
+
+  private static Template template;
+
+  /**
+   * Construct a new SafeImageCell.
+   */
+  public SafeImageCell() {
+    if (template == null) {
+      template = GWT.create(Template.class);
+    }
+  }
+
+  @Override
+  public void render(Context context, SafeUri value, SafeHtmlBuilder sb) {
+    if (value != null) {
+      sb.append(template.img(value));
+    }
+  }
+}