Add public Field.isEmpty() and clear() (#15354)

Change-Id: I6bda7ff2a66a9ad172c899d855ca868881600be4

server/src/com/vaadin/ui/AbstractField.java

@@ -1502,25 +1502,12 @@ public abstract class AbstractField<T> extends AbstractComponent implements
         markAsDirty();
     }
 
-    /**
-     * Is the field empty?
-     * 
-     * In general, "empty" state is same as null. As an exception, TextField
-     * also treats empty string as "empty".
-     */
-    protected boolean isEmpty() {
+    @Override
+    public boolean isEmpty() {
         return (getFieldValue() == null);
     }
 
-    /**
-     * Clear the value of the field.
-     * <p>
-     * The field value is typically reset to the initial value of the field but
-     * this is not mandatory. Calling {@link #isEmpty()} on a cleared field must
-     * always returns true.
-     * 
-     * @since
-     */
+    @Override
     public void clear() {
         setValue(null);
     }

server/src/com/vaadin/ui/AbstractSelect.java

@@ -1782,7 +1782,7 @@ public abstract class AbstractSelect extends AbstractField<Object> implements
      * @see AbstractField#isEmpty().
      */
     @Override
-    protected boolean isEmpty() {
+    public boolean isEmpty() {
         if (!multiSelect) {
             return super.isEmpty();
         } else {

server/src/com/vaadin/ui/AbstractTextField.java

@@ -317,7 +317,7 @@ public abstract class AbstractTextField extends AbstractField<String> implements
     }
 
     @Override
-    protected boolean isEmpty() {
+    public boolean isEmpty() {
         return super.isEmpty() || getValue().length() == 0;
     }
 

server/src/com/vaadin/ui/Field.java

@@ -113,4 +113,26 @@ public interface Field<T> extends Component, BufferedValidatable, Property<T>,
             return (Property) getSource();
         }
     }
+
+    /**
+     * Is the field empty?
+     * 
+     * In general, "empty" state is same as null. As an exception, TextField
+     * also treats empty string as "empty".
+     * 
+     * @since
+     * @return true if the field is empty, false otherwise
+     */
+    public boolean isEmpty();
+
+    /**
+     * Clears the value of the field.
+     * <p>
+     * The field value is typically reset to the initial value of the field.
+     * Calling {@link #isEmpty()} on a cleared field must always returns true.
+     * 
+     * @since
+     */
+    public void clear();
+
 }

server/src/com/vaadin/ui/Form.java

@@ -1186,9 +1186,14 @@ public class Form extends AbstractField<Object> implements Item.Editor,
         }
     }
 
-    /** Form is empty if all of its fields are empty. */
+    /**
+     * {@inheritDoc}
+     * <p>
+     * A Form is empty if all of its fields are empty.
+     * 
+     */
     @Override
-    protected boolean isEmpty() {
+    public boolean isEmpty() {
 
         for (Iterator<Field<?>> i = fields.values().iterator(); i.hasNext();) {
             Field<?> f = i.next();

server/src/com/vaadin/ui/RichTextArea.java

@@ -285,7 +285,7 @@ public class RichTextArea extends AbstractField<String> implements
     }
 
     @Override
-    protected boolean isEmpty() {
+    public boolean isEmpty() {
         return super.isEmpty() || getValue().length() == 0;
     }
 

server/tests/src/com/vaadin/ui/AbstractSelectTest.java

@@ -16,10 +16,13 @@
 package com.vaadin.ui;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 
 import org.junit.Assert;
 import org.junit.Test;
 
+import com.vaadin.data.util.ObjectProperty;
+
 public class AbstractSelectTest {
 
     @Test
@@ -73,4 +76,72 @@ public class AbstractSelectTest {
                 .toArray());
 
     }
+
+    @Test
+    public void singleSelectInitiallyEmpty() {
+        AbstractSelect s = new ListSelect();
+        Assert.assertTrue(s.isEmpty());
+    }
+
+    @Test
+    public void singleSelectEmptyAfterClearUsingPDS() {
+        AbstractSelect s = new ListSelect();
+        s.addItem("foo");
+        s.addItem("bar");
+        s.setPropertyDataSource(new ObjectProperty<String>("foo"));
+
+        Assert.assertFalse(s.isEmpty());
+        s.clear();
+        Assert.assertTrue(s.isEmpty());
+    }
+
+    @Test
+    public void singleSelectEmptyAfterClear() {
+        AbstractSelect s = new ListSelect();
+        s.addItem("foo");
+        s.addItem("bar");
+        s.setValue("bar");
+
+        Assert.assertFalse(s.isEmpty());
+        s.clear();
+        Assert.assertTrue(s.isEmpty());
+    }
+
+    @Test
+    public void multiSelectInitiallyEmpty() {
+        AbstractSelect s = new ListSelect();
+        s.setMultiSelect(true);
+        Assert.assertTrue(s.isEmpty());
+    }
+
+    @Test
+    public void multiSelectEmptyAfterClearUsingPDS() {
+        AbstractSelect s = new ListSelect();
+        s.setMultiSelect(true);
+        s.addItem("foo");
+        s.addItem("bar");
+        HashSet<String> sel = new HashSet<String>();
+        sel.add("foo");
+        sel.add("bar");
+        s.setPropertyDataSource(new ObjectProperty<HashSet>(sel));
+
+        Assert.assertFalse(s.isEmpty());
+        s.clear();
+        Assert.assertTrue(s.isEmpty());
+    }
+
+    @Test
+    public void multiSelectEmptyAfterClear() {
+        AbstractSelect s = new ListSelect();
+        s.setMultiSelect(true);
+        s.addItem("foo");
+        s.addItem("bar");
+        s.select("foo");
+        s.select("bar");
+
+        Assert.assertFalse(s.isEmpty());
+        s.clear();
+        Assert.assertTrue(s.isEmpty());
+    }
+
 }

server/tests/src/com/vaadin/ui/RichTextAreaTest.java

@@ -0,0 +1,47 @@
+/*
+ * 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;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.vaadin.data.util.ObjectProperty;
+
+public class RichTextAreaTest {
+    @Test
+    public void initiallyEmpty() {
+        RichTextArea tf = new RichTextArea();
+        Assert.assertTrue(tf.isEmpty());
+    }
+
+    @Test
+    public void emptyAfterClearUsingPDS() {
+        RichTextArea tf = new RichTextArea(new ObjectProperty<String>("foo"));
+        Assert.assertFalse(tf.isEmpty());
+        tf.clear();
+        Assert.assertTrue(tf.isEmpty());
+    }
+
+    @Test
+    public void emptyAfterClear() {
+        RichTextArea tf = new RichTextArea();
+        tf.setValue("foobar");
+        Assert.assertFalse(tf.isEmpty());
+        tf.clear();
+        Assert.assertTrue(tf.isEmpty());
+    }
+
+}

server/tests/src/com/vaadin/ui/TextAreaTest.java

@@ -0,0 +1,47 @@
+/*
+ * 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;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.vaadin.data.util.ObjectProperty;
+
+public class TextAreaTest {
+    @Test
+    public void initiallyEmpty() {
+        TextArea tf = new TextArea();
+        Assert.assertTrue(tf.isEmpty());
+    }
+
+    @Test
+    public void emptyAfterClearUsingPDS() {
+        TextArea tf = new TextArea(new ObjectProperty<String>("foo"));
+        Assert.assertFalse(tf.isEmpty());
+        tf.clear();
+        Assert.assertTrue(tf.isEmpty());
+    }
+
+    @Test
+    public void emptyAfterClear() {
+        TextArea tf = new TextArea();
+        tf.setValue("foobar");
+        Assert.assertFalse(tf.isEmpty());
+        tf.clear();
+        Assert.assertTrue(tf.isEmpty());
+    }
+
+}