Make ordered layout Slot customizable (#18703)

Change-Id: If425d7196e9393f87659462d5b4488549988ee0d

2 files changed, 69 insertions, 5 deletions

diff --git a/client/src/com/vaadin/client/ui/orderedlayout/Slot.java b/client/src/com/vaadin/client/ui/orderedlayout/Slot.java
index b97cf73989..5ecda3dca4 100644
--- a/client/src/com/vaadin/client/ui/orderedlayout/Slot.java
+++ b/client/src/com/vaadin/client/ui/orderedlayout/Slot.java
@@ -41,11 +41,12 @@ import com.vaadin.shared.ui.AlignmentInfo;
 /**
  * Represents a slot which contains the actual widget in the layout.
  */
-public final class Slot extends SimplePanel {
+public class Slot extends SimplePanel {
 
     private static final String ALIGN_CLASS_PREFIX = "v-align-";
 
-    private final VAbstractOrderedLayout layout;
+    // this must be set at construction time and not changed afterwards
+    private VAbstractOrderedLayout layout;
 
     public static final String SLOT_CLASSNAME = "v-slot";
 
@@ -90,13 +91,41 @@ public final class Slot extends SimplePanel {
     /**
      * Constructs a slot.
      * 
+     * When using this constructor, the layout and widget must be set before any
+     * other operations are performed on the slot.
+     */
+    public Slot() {
+        setStyleName(SLOT_CLASSNAME);
+    }
+
+    /**
+     * Set the layout in which this slot is. This method must be called exactly
+     * once at slot construction time when using the default constructor.
+     * 
+     * The method should normally only be called by
+     * {@link VAbstractOrderedLayout#createSlot(Widget)}.
+     * 
+     * @since
+     * @param layout
+     *            the layout containing the slot
+     */
+    public void setLayout(VAbstractOrderedLayout layout) {
+        this.layout = layout;
+    }
+
+    /**
+     * Constructs a slot.
+     * 
      * @param layout
      *            The layout to which this slot belongs
      * @param widget
      *            The widget to put in the slot
+     * @deprecated use {@link GWT#create(Class)}, {@link #setWidget(Widget)} and
+     *             {@link #setLayout(VAbstractOrderedLayout)} instead
      */
+    @Deprecated
     public Slot(VAbstractOrderedLayout layout, Widget widget) {
-        this.layout = layout;
+        setLayout(layout);
         setStyleName(SLOT_CLASSNAME);
         setWidget(widget);
     }
diff --git a/client/src/com/vaadin/client/ui/orderedlayout/VAbstractOrderedLayout.java b/client/src/com/vaadin/client/ui/orderedlayout/VAbstractOrderedLayout.java
index 2e6d4cf5c8..53ba9ddb28 100644
--- a/client/src/com/vaadin/client/ui/orderedlayout/VAbstractOrderedLayout.java
+++ b/client/src/com/vaadin/client/ui/orderedlayout/VAbstractOrderedLayout.java
@@ -18,6 +18,7 @@ package com.vaadin.client.ui.orderedlayout;
 import java.util.HashMap;
 import java.util.Map;
 
+import com.google.gwt.core.client.GWT;
 import com.google.gwt.dom.client.Element;
 import com.google.gwt.dom.client.Node;
 import com.google.gwt.dom.client.Style;
@@ -209,8 +210,23 @@ public class VAbstractOrderedLayout extends FlowPanel {
      */
     public void removeWidget(Widget widget) {
         Slot slot = widgetToSlot.get(widget);
+        removeSlot(slot);
+    }
+
+    /**
+     * Remove a slot from the layout.
+     * 
+     * This method is called automatically by {@link #removeWidget(Widget)} and
+     * should not be called directly by the user. When overridden, the super
+     * method must be called.
+     * 
+     * @since
+     * @param Slot
+     *            to remove
+     */
+    protected void removeSlot(Slot slot) {
         remove(slot);
-        widgetToSlot.remove(widget);
+        widgetToSlot.remove(slot.getWidget());
     }
 
     /**
@@ -225,13 +241,32 @@ public class VAbstractOrderedLayout extends FlowPanel {
     public Slot getSlot(Widget widget) {
         Slot slot = widgetToSlot.get(widget);
         if (slot == null) {
-            slot = new Slot(this, widget);
+            slot = createSlot(widget);
             widgetToSlot.put(widget, slot);
         }
         return slot;
     }
 
     /**
+     * Create a slot to be added to the layout.
+     * 
+     * This method is called automatically by {@link #getSlot(Widget)} when a
+     * new slot is needed. It should not be called directly by the user, but can
+     * be overridden to customize slot creation.
+     * 
+     * @since
+     * @param widget
+     *            the widget for which a slot is being created
+     * @return created Slot
+     */
+    protected Slot createSlot(Widget widget) {
+        Slot slot = GWT.create(Slot.class);
+        slot.setLayout(this);
+        slot.setWidget(widget);
+        return slot;
+    }
+
+    /**
      * Gets a slot based on the widget element. If no slot is found then null is
      * returned.
      *