Fixes DragAndDropWrapper does not support choosing a custom component as the drag image (#13836)

Amend : Fixes the comments for the last commit.
Amend 2: Fixes a nullpointer found in a certain test scenario

Change-Id: I72327f5f8ab9e46d88e1ebed8f1db3a7da39d7d8

2 files changed, 30 insertions, 2 deletions

diff --git a/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModes.java b/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModes.java
index b143ddf2dc..8539f70b17 100644
--- a/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModes.java
+++ b/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModes.java
@@ -3,26 +3,53 @@ package com.vaadin.tests.components.draganddropwrapper;
 import com.vaadin.tests.components.TestBase;
 import com.vaadin.tests.util.TestUtils;
 import com.vaadin.ui.Component;
+import com.vaadin.ui.CssLayout;
 import com.vaadin.ui.DragAndDropWrapper;
 import com.vaadin.ui.DragAndDropWrapper.DragStartMode;
 import com.vaadin.ui.Label;
+import com.vaadin.ui.VerticalLayout;
 
 public class DragStartModes extends TestBase {
 
     @Override
     protected void setup() {
 
-        TestUtils.injectCSS(getMainWindow(),
-                ".v-ddwrapper { background: #ACF; }");
+        TestUtils
+                .injectCSS(getMainWindow(),
+                        ".v-ddwrapper { background: #ACF; } .extra{ background: #FFA500; }");
 
         addComponent(makeWrapper(DragStartMode.NONE));
         addComponent(makeWrapper(DragStartMode.COMPONENT));
         addComponent(makeWrapper(DragStartMode.WRAPPER));
         addComponent(makeWrapper(DragStartMode.HTML5));
+        addComponent(makeOtherComponentWrapper(DragStartMode.COMPONENT_OTHER));
 
         addComponent(new Label("Drop here"));
     }
 
+    private Component makeOtherComponentWrapper(DragStartMode componentOther) {
+        VerticalLayout parent = new VerticalLayout();
+        parent.setWidth("200px");
+        parent.setSpacing(true);
+
+        CssLayout header = new CssLayout();
+        header.addComponent(new Label("Drag start mode : COMPONENT_OTHER"));
+        header.setSizeUndefined();
+
+        DragAndDropWrapper wrapper = new DragAndDropWrapper(header);
+        wrapper.setDragStartMode(DragStartMode.COMPONENT_OTHER);
+        wrapper.setDragImageComponent(parent);
+        wrapper.setId("label" + "COMPONENT_OTHER");
+        parent.addComponent(wrapper);
+
+        Label extra = new Label(
+                "Extra label that is not part of the wrapper. This should be dragged along with COMPONENT_OTHER.");
+        extra.addStyleName("extra");
+        parent.addComponent(extra);
+
+        return parent;
+    }
+
     private Component makeWrapper(DragStartMode mode) {
         Label label = new Label("Drag start mode: " + mode);
         label.setId("label" + mode);
diff --git a/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModesTest.java b/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModesTest.java
index 25aef1b815..ba27ee293e 100644
--- a/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModesTest.java
+++ b/uitest/src/com/vaadin/tests/components/draganddropwrapper/DragStartModesTest.java
@@ -31,6 +31,7 @@ public class DragStartModesTest extends MultiBrowserTest {
         WebElement dropTarget = vaadinElement("/VVerticalLayout[0]/VVerticalLayout[0]/VLabel[0]");
         dragToTarget("COMPONENT", dropTarget);
         dragToTarget("WRAPPER", dropTarget);
+        dragToTarget("COMPONENT_OTHER", dropTarget);
     }
 
     private void dragToTarget(String dragMode, WebElement dropTarget)