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

Change-Id: I6bda7ff2a66a9ad172c899d855ca868881600be4

6 files changed, 35 insertions, 21 deletions

diff --git a/server/src/com/vaadin/ui/AbstractField.java b/server/src/com/vaadin/ui/AbstractField.java
index 369ad1253c..df7bbb68a2 100644
--- a/server/src/com/vaadin/ui/AbstractField.java
+++ b/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);
     }
diff --git a/server/src/com/vaadin/ui/AbstractSelect.java b/server/src/com/vaadin/ui/AbstractSelect.java
index 2c4dd5be5d..70f08c95d8 100644
--- a/server/src/com/vaadin/ui/AbstractSelect.java
+++ b/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 {
diff --git a/server/src/com/vaadin/ui/AbstractTextField.java b/server/src/com/vaadin/ui/AbstractTextField.java
index 9293d38119..ea0372bc8c 100644
--- a/server/src/com/vaadin/ui/AbstractTextField.java
+++ b/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;
     }
 
diff --git a/server/src/com/vaadin/ui/Field.java b/server/src/com/vaadin/ui/Field.java
index f191e1bdd7..6dee4de6cb 100644
--- a/server/src/com/vaadin/ui/Field.java
+++ b/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();
+
 }
diff --git a/server/src/com/vaadin/ui/Form.java b/server/src/com/vaadin/ui/Form.java
index 48239b09e3..45532756e5 100644
--- a/server/src/com/vaadin/ui/Form.java
+++ b/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();
diff --git a/server/src/com/vaadin/ui/RichTextArea.java b/server/src/com/vaadin/ui/RichTextArea.java
index 9d05181541..31327b3a6f 100644
--- a/server/src/com/vaadin/ui/RichTextArea.java
+++ b/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;
     }