Some Checkstyle tweaks. (#12376)

- Added and updated JavaDocs.
- Formatting fixes.
- Suppressed deprecation warnings.

client/src/main/java/com/vaadin/client/ui/VPasswordField.java

@@ -25,8 +25,12 @@ import com.google.gwt.user.client.DOM;
  */
 public class VPasswordField extends VTextField {
 
+    /** Default classname for this widget. */
     public static final String CLASSNAME = "v-passwordfield";
 
+    /**
+     * Constructs a widget for a PasswordField.
+     */
     public VPasswordField() {
         super(DOM.createInputPassword());
         setStyleName(CLASSNAME);

client/src/main/java/com/vaadin/client/ui/VSlider.java

@@ -35,9 +35,16 @@ import com.vaadin.client.BrowserInfo;
 import com.vaadin.client.WidgetUtil;
 import com.vaadin.shared.ui.slider.SliderOrientation;
 
+/**
+ * Widget class for the Slider component.
+ *
+ * @author Vaadin Ltd
+ *
+ */
 public class VSlider extends SimpleFocusablePanel
         implements Field, HasValue<Double>, SubPartAware {
 
+    /** Default classname for this widget. */
     public static final String CLASSNAME = "v-slider";
 
     /**

client/src/main/java/com/vaadin/client/ui/VTextArea.java

@@ -34,8 +34,10 @@ import com.vaadin.client.ui.dd.DragImageModifier;
  * @author Vaadin Ltd.
  *
  */
+@SuppressWarnings("deprecation")
 public class VTextArea extends VTextField implements DragImageModifier {
 
+    /** Default classname for this widget. */
     public static final String CLASSNAME = "v-textarea";
 
     private EnterDownHandler enterDownHandler = new EnterDownHandler();
@@ -56,6 +58,9 @@ public class VTextArea extends VTextField implements DragImageModifier {
         }
     }
 
+    /**
+     * Constructs a widget for a TextArea.
+     */
     public VTextArea() {
         super(DOM.createTextArea());
         setStyleName(CLASSNAME);
@@ -63,14 +68,31 @@ public class VTextArea extends VTextField implements DragImageModifier {
         getElement().getStyle().setOverflowX(Overflow.HIDDEN);
     }
 
+    /**
+     * Gets the base TextAreaElement of this widget.
+     *
+     * @return the base element
+     */
     public TextAreaElement getTextAreaElement() {
         return super.getElement().cast();
     }
 
+    /**
+     * Sets the number of text rows that should be displayed.
+     *
+     * @param rows
+     *            the number of text rows
+     */
     public void setRows(int rows) {
         getTextAreaElement().setRows(rows);
     }
 
+    /**
+     * Sets whether the words should wrap or not.
+     *
+     * @param wordWrap
+     *            {@code true} if the words should wrap, {@code false} otherwise
+     */
     public void setWordWrap(boolean wordWrap) {
         if (wordWrap == this.wordWrap) {
             return;

client/src/main/java/com/vaadin/client/ui/VTextField.java

@@ -33,13 +33,28 @@ import com.google.gwt.user.client.ui.TextBoxBase;
 public class VTextField extends TextBoxBase
         implements Field, FocusHandler, BlurHandler, AbstractTextFieldWidget {
 
+    /** Default classname for this widget. */
     public static final String CLASSNAME = "v-textfield";
+    /**
+     * Classname suffix for this widget when focused.
+     *
+     * @see #addStyleDependentName(String)
+     */
     public static final String CLASSNAME_FOCUS = "focus";
 
+    /**
+     * Constructs a widget for a TextField.
+     */
     public VTextField() {
         this(DOM.createInputText());
     }
 
+    /**
+     * Constructs a text entry widget that wraps the given input element.
+     *
+     * @param node
+     *            the input element to wrap
+     */
     protected VTextField(Element node) {
         super(node);
         setStyleName(CLASSNAME);
@@ -47,6 +62,13 @@ public class VTextField extends TextBoxBase
         addBlurHandler(this);
     }
 
+    /**
+     * Sets the {@code maxLength} Integer property for this widget's base
+     * element. If the given value is negative, the property is removed.
+     *
+     * @param maxLength
+     *            the new maximum length
+     */
     public void setMaxLength(int maxLength) {
         if (maxLength >= 0) {
             getElement().setPropertyInt("maxLength", maxLength);
@@ -55,6 +77,13 @@ public class VTextField extends TextBoxBase
         }
     }
 
+    /**
+     * Sets the {@code placeholder} String property for this widget's base
+     * element. If the given value is {@code null}, the property is removed.
+     *
+     * @param placeholder
+     *            the new placeholder text
+     */
     public void setPlaceholder(String placeholder) {
         if (placeholder != null) {
             getElement().setAttribute("placeholder", placeholder);

client/src/main/java/com/vaadin/client/ui/VTwinColSelect.java

@@ -38,7 +38,6 @@ import com.google.gwt.event.dom.client.KeyDownHandler;
 import com.google.gwt.event.dom.client.MouseDownEvent;
 import com.google.gwt.event.dom.client.MouseDownHandler;
 import com.google.gwt.event.shared.HandlerRegistration;
-import com.google.gwt.user.client.Element;
 import com.google.gwt.user.client.ui.Composite;
 import com.google.gwt.user.client.ui.FlowPanel;
 import com.google.gwt.user.client.ui.HTML;
@@ -351,7 +350,7 @@ public class VTwinColSelect extends Composite implements MultiSelectWidget,
             listBox.setItemSelected(i, isSelected);
             if (isSelected) {
                 // Ensure that last selected item is visible
-                scrollToView(listBox,i);
+                scrollToView(listBox, i);
             }
         }
         // remove extra
@@ -364,9 +363,11 @@ public class VTwinColSelect extends Composite implements MultiSelectWidget,
         if (scheduledScrollToItem == -1) {
             scheduledScrollToItem = i;
             Scheduler.get().scheduleDeferred(() -> {
-                 Element el = (Element) listBox.getElement().getChild(scheduledScrollToItem);
-                 el.scrollIntoView();
-                 scheduledScrollToItem = -1;
+                @SuppressWarnings("deprecation")
+                com.google.gwt.user.client.Element el = (com.google.gwt.user.client.Element) listBox
+                        .getElement().getChild(scheduledScrollToItem);
+                el.scrollIntoView();
+                scheduledScrollToItem = -1;
             });
         } else {
             scheduledScrollToItem = i;
@@ -684,6 +685,7 @@ public class VTwinColSelect extends Composite implements MultiSelectWidget,
 
     }
 
+    @SuppressWarnings("deprecation")
     @Override
     public com.google.gwt.user.client.Element getSubPartElement(
             String subPart) {
@@ -715,6 +717,7 @@ public class VTwinColSelect extends Composite implements MultiSelectWidget,
         return null;
     }
 
+    @SuppressWarnings("deprecation")
     @Override
     public String getSubPartName(
             com.google.gwt.user.client.Element subElement) {

client/src/main/java/com/vaadin/client/ui/VUI.java

@@ -42,6 +42,12 @@ import com.vaadin.client.ui.TouchScrollDelegate.TouchScrollHandler;
 import com.vaadin.client.ui.ui.UIConnector;
 import com.vaadin.shared.ApplicationConstants;
 
+/**
+ * Widget class for the UI.
+ *
+ * @author Vaadin Ltd
+ *
+ */
 public class VUI extends SimplePanel implements ResizeHandler,
         Window.ClosingHandler, ShortcutActionHandlerOwner, Focusable,
         com.google.gwt.user.client.ui.Focusable, HasResizeHandlers,
@@ -97,6 +103,9 @@ public class VUI extends SimplePanel implements ResizeHandler,
 
     private Element storedFocus;
 
+    /**
+     * Constructs a widget for an UI.
+     */
     public VUI() {
         super();
         // Allow focusing the view by using the focus() method, the view
@@ -319,6 +328,14 @@ public class VUI extends SimplePanel implements ResizeHandler,
         Profiler.leave("VUI.sendClientResized");
     }
 
+    /**
+     *
+     * Opens the given URL in the current browser window. If this UI needs to be
+     * closed as a result it should be handled separately.
+     *
+     * @param url
+     *            the URL to navigate to
+     */
     public static native void goTo(String url)
     /*-{
        $wnd.location = url;

client/src/main/java/com/vaadin/client/ui/VVerticalLayout.java

@@ -23,6 +23,7 @@ import com.vaadin.client.ui.orderedlayout.VAbstractOrderedLayout;
  */
 public class VVerticalLayout extends VAbstractOrderedLayout {
 
+    /** Default classname for this widget. */
     public static final String CLASSNAME = "v-verticallayout";
 
     /**

client/src/main/java/com/vaadin/client/ui/VVideo.java

@@ -22,12 +22,22 @@ import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.dom.client.VideoElement;
 import com.vaadin.client.Util;
 
+/**
+ * Widget class for the Video component.
+ *
+ * @author Vaadin Ltd
+ *
+ */
 public class VVideo extends VMediaBase {
 
+    /** Default classname for this widget. */
     public static String CLASSNAME = "v-video";
 
     private VideoElement video;
 
+    /**
+     * Constructs a widget for the Video component.
+     */
     public VVideo() {
         video = Document.get().createVideoElement();
         setMediaElement(video);
@@ -41,6 +51,7 @@ public class VVideo extends VMediaBase {
      * video metadata has been loaded.
      *
      * @param el
+     *            the root element of this widget
      */
     private native void updateDimensionsWhenMetadataLoaded(Element el)
     /*-{
@@ -48,21 +59,30 @@ public class VVideo extends VMediaBase {
               el.addEventListener('loadedmetadata', $entry(function(e) {
                   self.@com.vaadin.client.ui.VVideo::updateElementDynamicSize(II)(el.videoWidth, el.videoHeight);
               }), false);
-
+    
     }-*/;
 
     /**
      * Updates the dimensions of the widget.
      *
-     * @param w
-     * @param h
+     * @param width
+     *            width to set (in pixels)
+     * @param height
+     *            height to set (in pixels)
      */
-    private void updateElementDynamicSize(int w, int h) {
-        video.getStyle().setWidth(w, Unit.PX);
-        video.getStyle().setHeight(h, Unit.PX);
+    @SuppressWarnings("deprecation")
+    private void updateElementDynamicSize(int width, int height) {
+        video.getStyle().setWidth(width, Unit.PX);
+        video.getStyle().setHeight(height, Unit.PX);
         Util.notifyParentOfSizeChange(this, true);
     }
 
+    /**
+     * Sets the poster URL.
+     *
+     * @param poster
+     *            the poster image URL
+     */
     public void setPoster(String poster) {
         video.setPoster(poster);
     }