Adding new SimpleLayoutPanel widget, which is a subclass of SimplePanel that ProvidesResize to its child.  This is useful when an application needs a content container to hold a Widget that RequiresResize.

Issue: 5501

Review at http://gwt-code-reviews.appspot.com/1291801

Review by: rjrjr@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@9548 8db76d5a-ed1c-0410-87a9-c151d255dfc7

user/src/com/google/gwt/user/client/ui/SimpleLayoutPanel.java

diff --git a/user/src/com/google/gwt/user/client/ui/SimpleLayoutPanel.java b/user/src/com/google/gwt/user/client/ui/SimpleLayoutPanel.java
new file mode 100644
index 0000000..66bd402
--- /dev/null
+++ b/user/src/com/google/gwt/user/client/ui/SimpleLayoutPanel.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2011 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.user.client.ui;
+
+import com.google.gwt.dom.client.Style.Unit;
+import com.google.gwt.layout.client.Layout;
+import com.google.gwt.layout.client.Layout.Layer;
+
+/**
+ * A simple panel that {@link ProvidesResize} to its one child.
+ */
+public class SimpleLayoutPanel extends SimplePanel implements RequiresResize,
+    ProvidesResize {
+
+  private Layer layer;
+  private final Layout layout;
+
+  public SimpleLayoutPanel() {
+    layout = new Layout(getElement());
+  }
+
+  public void onResize() {
+    if (widget instanceof RequiresResize) {
+      ((RequiresResize) widget).onResize();
+    }
+  }
+
+  @Override
+  public boolean remove(Widget w) {
+    // Validate.
+    if (widget != w) {
+      return false;
+    }
+
+    // Orphan.
+    try {
+      orphan(w);
+    } finally {
+      // Physical detach.
+      layout.removeChild(layer);
+      layer = null;
+
+      // Logical detach.
+      widget = null;
+    }
+    return true;
+  }
+
+  @Override
+  public void setWidget(Widget w) {
+    // Validate
+    if (w == widget) {
+      return;
+    }
+
+    // Detach new child.
+    if (w != null) {
+      w.removeFromParent();
+    }
+
+    // Remove old child.
+    if (widget != null) {
+      remove(widget);
+    }
+
+    // Logical attach.
+    widget = w;
+
+    if (w != null) {
+      // Physical attach.
+      layer = layout.attachChild(widget.getElement(), widget);
+      layer.setTopHeight(0.0, Unit.PX, 100.0, Unit.PCT);
+      layer.setLeftWidth(0.0, Unit.PX, 100.0, Unit.PCT);
+
+      adopt(w);
+
+      // Update the layout.
+      layout.layout();
+      onResize();
+    }
+  }
+
+  @Override
+  protected void onLoad() {
+    layout.onAttach();
+  }
+
+  @Override
+  protected void onUnload() {
+    layout.onDetach();
+  }
+}

user/src/com/google/gwt/user/client/ui/SimplePanel.java

diff --git a/user/src/com/google/gwt/user/client/ui/SimplePanel.java b/user/src/com/google/gwt/user/client/ui/SimplePanel.java
index 651fe47..98a482e 100644
--- a/user/src/com/google/gwt/user/client/ui/SimplePanel.java
+++ b/user/src/com/google/gwt/user/client/ui/SimplePanel.java
@@ -26,7 +26,7 @@
  */
 public class SimplePanel extends Panel implements HasOneWidget {
 
-  private Widget widget;
+  Widget widget;
 
   /**
    * Creates an empty panel that uses a DIV for its contents.

user/test/com/google/gwt/user/UISuite.java

diff --git a/user/test/com/google/gwt/user/UISuite.java b/user/test/com/google/gwt/user/UISuite.java
index 7f5a403..0befacf 100644
--- a/user/test/com/google/gwt/user/UISuite.java
+++ b/user/test/com/google/gwt/user/UISuite.java
@@ -86,6 +86,7 @@
 import com.google.gwt.user.client.ui.RootPanelTest;
 import com.google.gwt.user.client.ui.ScrollPanelTest;
 import com.google.gwt.user.client.ui.SimpleCheckBoxTest;
+import com.google.gwt.user.client.ui.SimpleLayoutPanelTest;
 import com.google.gwt.user.client.ui.SimplePanelTest;
 import com.google.gwt.user.client.ui.SimpleRadioButtonTest;
 import com.google.gwt.user.client.ui.SplitLayoutPanelTest;
@@ -199,6 +200,7 @@
     suite.addTestSuite(SimpleCheckBoxTest.class);
     suite.addTestSuite(SimpleRadioButtonTest.class);
     suite.addTestSuite(SimplePanelTest.class);
+    suite.addTestSuite(SimpleLayoutPanelTest.class);
     suite.addTestSuite(SplitLayoutPanelTest.class);
     suite.addTestSuite(StackLayoutPanelTest.class);
     suite.addTestSuite(StackPanelTest.class);

user/test/com/google/gwt/user/client/ui/SimpleLayoutPanelTest.java

diff --git a/user/test/com/google/gwt/user/client/ui/SimpleLayoutPanelTest.java b/user/test/com/google/gwt/user/client/ui/SimpleLayoutPanelTest.java
new file mode 100644
index 0000000..273f3bc
--- /dev/null
+++ b/user/test/com/google/gwt/user/client/ui/SimpleLayoutPanelTest.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2011 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.user.client.ui;
+
+/**
+ * Tests for {@link SimpleLayoutPanel}.
+ */
+public class SimpleLayoutPanelTest extends
+    SimplePanelTestBase<SimpleLayoutPanel> {
+
+  @Override
+  public String getModuleName() {
+    return "com.google.gwt.user.User";
+  }
+
+  @Override
+  protected SimpleLayoutPanel createPanel() {
+    return new SimpleLayoutPanel();
+  }
+}