Validate all drag and drop events

Signed-off-by: SirWayne <dennis.melzer@bosch-si.com>

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/artifacts/smtable/SoftwareModuleTable.java

@@ -40,7 +40,6 @@ import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
-import com.vaadin.event.dd.DropHandler;
 import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
 import com.vaadin.server.FontAwesome;
 import com.vaadin.spring.annotation.SpringComponent;
@@ -215,21 +214,13 @@ public class SoftwareModuleTable extends AbstractNamedVersionTable<SoftwareModul
     }
 
     @Override
-    protected DropHandler getTableDropHandler() {
+    protected AcceptCriterion getDropAcceptCriterion() {
-        return new DropHandler() {
-
-            private static final long serialVersionUID = 1L;
-
-            @Override
-            public AcceptCriterion getAcceptCriterion() {
         return uploadViewAcceptCriteria;
     }
 
     @Override
-            public void drop(final DragAndDropEvent event) {
+    protected boolean isDropValid(final DragAndDropEvent dragEvent) {
-                /* Not required */
+        return false;
-            }
-        };
     }
 
     @Override
@@ -237,8 +228,7 @@ public class SoftwareModuleTable extends AbstractNamedVersionTable<SoftwareModul
         artifactUploadState.setNoDataAvilableSoftwareModule(!available);
     }
 
-    
+    private Button createManageMetadataButton(final String nameVersionStr) {
-    private Button createManageMetadataButton(String nameVersionStr) {
         final Button manageMetadataBtn = SPUIComponentProvider.getButton(
                 SPUIComponentIdProvider.SW_TABLE_MANAGE_METADATA_ID + "." + nameVersionStr, "", "", null, false,
                 FontAwesome.LIST_ALT, SPUIButtonStyleSmallNoBorder.class);
@@ -254,9 +244,9 @@ public class SoftwareModuleTable extends AbstractNamedVersionTable<SoftwareModul
         return name + "." + version;
     }
 
-    private void showMetadataDetails(Long itemId, String nameVersionStr) {
+    private void showMetadataDetails(final Long itemId, final String nameVersionStr) {
-        SoftwareModule swmodule = softwareManagement.findSoftwareModuleWithDetails(itemId);
+        final SoftwareModule swmodule = softwareManagement.findSoftwareModuleWithDetails(itemId);
         /* display the window */
-        UI.getCurrent().addWindow(swMetadataPopupLayout.getWindow(swmodule,null));
+        UI.getCurrent().addWindow(swMetadataPopupLayout.getWindow(swmodule, null));
     }
 }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/table/AbstractNamedVersionTable.java

@@ -15,6 +15,8 @@ import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.TableColumn;
 
 import com.vaadin.data.Item;
+import com.vaadin.event.dd.DragAndDropEvent;
+import com.vaadin.ui.DragAndDropWrapper;
 
 /**
  * Abstract table to handling {@link NamedVersionedEntity}
@@ -54,4 +56,30 @@ public abstract class AbstractNamedVersionTable<E extends NamedVersionedEntity,
         item.getItemProperty(SPUILabelDefinitions.VAR_VERSION).setValue(baseEntity.getVersion());
     }
 
+    @Override
+    protected void onDropEventFromTable(final DragAndDropEvent event) {
+        // subclass can implement
+
+    }
+
+    @Override
+    protected void onDropEventFromWrapper(final DragAndDropEvent event) {
+        // subclass can implement
+    }
+
+    @Override
+    protected boolean hasDropPermission() {
+        return true;
+    }
+
+    @Override
+    protected String getDropTableId() {
+        return null;
+    }
+
+    @Override
+    protected boolean validateDragAndDropWrapper(final DragAndDropWrapper wrapperSource) {
+        return false;
+    }
+
 }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/table/AbstractTable.java

@@ -26,13 +26,20 @@ import org.eclipse.hawkbit.ui.utils.SPDateTimeUtil;
 import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.TableColumn;
+import org.eclipse.hawkbit.ui.utils.UINotification;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.vaadin.spring.events.EventBus;
 
 import com.google.gwt.thirdparty.guava.common.collect.Iterables;
+import com.google.gwt.thirdparty.guava.common.collect.Sets;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
+import com.vaadin.event.Transferable;
+import com.vaadin.event.dd.DragAndDropEvent;
 import com.vaadin.event.dd.DropHandler;
+import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
+import com.vaadin.ui.Component;
+import com.vaadin.ui.DragAndDropWrapper;
 import com.vaadin.ui.Table;
 import com.vaadin.ui.UI;
 import com.vaadin.ui.themes.ValoTheme;
@@ -51,12 +58,17 @@ public abstract class AbstractTable<E extends NamedEntity, I> extends Table {
 
     private static final long serialVersionUID = 4856562746502217630L;
 
+    protected static final String ACTION_NOT_ALLOWED_MSG = "message.action.not.allowed";
+
     @Autowired
     protected transient EventBus.SessionEventBus eventBus;
 
     @Autowired
     protected I18N i18n;
 
+    @Autowired
+    protected UINotification notification;
+
     /**
      * Initialize the components.
      */
@@ -359,12 +371,100 @@ public abstract class AbstractTable<E extends NamedEntity, I> extends Table {
         return DEFAULT_COLUMN_NAME_MIN_SIZE;
     }
 
-    /**
+    private DropHandler getTableDropHandler() {
-     * Get drop handler for the table.
+        return new DropHandler() {
-     * 
+            private static final long serialVersionUID = 1L;
-     * @return reference of {@link DropHandler}
+
-     */
+            @Override
-    protected abstract DropHandler getTableDropHandler();
+            public AcceptCriterion getAcceptCriterion() {
+                return getDropAcceptCriterion();
+            }
+
+            @Override
+            public void drop(final DragAndDropEvent event) {
+                if (!isDropValid(event)) {
+                    return;
+                }
+                if (event.getTransferable().getSourceComponent() instanceof Table) {
+                    onDropEventFromTable(event);
+                } else if (event.getTransferable().getSourceComponent() instanceof DragAndDropWrapper) {
+                    onDropEventFromWrapper(event);
+                }
+            }
+        };
+    }
+
+    protected Set<I> getDraggedTargetList(final DragAndDropEvent event) {
+        final com.vaadin.event.dd.TargetDetails taregtDet = event.getTargetDetails();
+        final Table targetTable = (Table) taregtDet.getTarget();
+        final Set<I> targetSelected = getTableValue(targetTable);
+
+        final AbstractSelectTargetDetails dropData = (AbstractSelectTargetDetails) event.getTargetDetails();
+        final Object targetItemId = dropData.getItemIdOver();
+
+        if (!targetSelected.contains(targetItemId)) {
+            return Sets.newHashSet((I) targetItemId);
+        }
+
+        return targetSelected;
+    }
+
+    private Set<Object> getDraggedTargetList(final TableTransferable transferable, final Table source) {
+        @SuppressWarnings("unchecked")
+        final AbstractTable<NamedEntity, Object> table = (AbstractTable<NamedEntity, Object>) source;
+        return table.getDeletedEntityByTransferable(transferable);
+    }
+
+    private boolean validateDropList(final Set<?> droplist) {
+        if (droplist.isEmpty()) {
+            final String actionDidNotWork = i18n.get("message.action.did.not.work", new Object[] {});
+            notification.displayValidationError(actionDidNotWork);
+            return false;
+        }
+        return true;
+    }
+
+    protected boolean isDropValid(final DragAndDropEvent dragEvent) {
+        final Transferable transferable = dragEvent.getTransferable();
+        final Component compsource = transferable.getSourceComponent();
+
+        if (!hasDropPermission()) {
+            notification.displayValidationError(i18n.get("message.permission.insufficient"));
+            return false;
+        }
+
+        if (compsource instanceof Table) {
+            return validateTable((Table) compsource)
+                    && validateDropList(getDraggedTargetList((TableTransferable) transferable, (Table) compsource));
+        }
+
+        if (compsource instanceof DragAndDropWrapper) {
+            return validateDragAndDropWrapper((DragAndDropWrapper) compsource)
+                    && validateDropList(getDraggedTargetList(dragEvent));
+        }
+        notification.displayValidationError(i18n.get(ACTION_NOT_ALLOWED_MSG));
+        return false;
+    }
+
+    private boolean validateTable(final Table compsource) {
+        if (!compsource.getId().equals(getDropTableId())) {
+            notification.displayValidationError(ACTION_NOT_ALLOWED_MSG);
+            return false;
+        }
+        return true;
+    }
+
+    protected abstract boolean hasDropPermission();
+
+    protected abstract boolean validateDragAndDropWrapper(final DragAndDropWrapper wrapperSource);
+
+    protected abstract void onDropEventFromWrapper(DragAndDropEvent event);
+
+    protected abstract void onDropEventFromTable(DragAndDropEvent event);
+
+    protected abstract String getDropTableId();
+
+    protected abstract AcceptCriterion getDropAcceptCriterion();
 
     protected abstract void setDataAvailable(boolean available);
 

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/dstable/DistributionSetTable.java

@@ -45,7 +45,6 @@ import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUIStyleDefinitions;
 import org.eclipse.hawkbit.ui.utils.TableColumn;
-import org.eclipse.hawkbit.ui.utils.UINotification;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -58,7 +57,6 @@ import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
-import com.vaadin.event.dd.DropHandler;
 import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
 import com.vaadin.server.FontAwesome;
 import com.vaadin.spring.annotation.SpringComponent;
@@ -97,9 +95,6 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
     @Autowired
     private DistributionsViewAcceptCriteria distributionsViewAcceptCriteria;
 
-    @Autowired
-    private UINotification notification;
-
     @Autowired
     private transient TargetManagement targetManagement;
 
@@ -189,9 +184,9 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
     protected void publishEntityAfterValueChange(final DistributionSet distributionSet) {
         eventBus.publish(this, new DistributionTableEvent(BaseEntityEventType.SELECTED_ENTITY, distributionSet));
         eventBus.publish(this, DistributionsUIEvent.ORDER_BY_DISTRIBUTION);
-        if(distributionSet!=null){
+        if (distributionSet != null) {
             manageDistUIState.setLastSelectedEntity(new DistributionSetIdName(distributionSet.getId(),
-                    distributionSet.getName(),distributionSet.getVersion()));
+                    distributionSet.getName(), distributionSet.getVersion()));
         }
     }
 
@@ -201,25 +196,12 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
     }
 
     @Override
-    protected DropHandler getTableDropHandler() {
+    public AcceptCriterion getDropAcceptCriterion() {
-        return new DropHandler() {
-            private static final long serialVersionUID = 1L;
-
-            @Override
-            public AcceptCriterion getAcceptCriterion() {
         return distributionsViewAcceptCriteria;
     }
 
     @Override
-            public void drop(final DragAndDropEvent event) {
+    protected void onDropEventFromTable(final DragAndDropEvent event) {
-                if (doValidation(event)) {
-                    onDrop(event);
-                }
-            }
-        };
-    }
-
-    private void onDrop(final DragAndDropEvent event) {
         final TableTransferable transferable = (TableTransferable) event.getTransferable();
         @SuppressWarnings("unchecked")
         final AbstractTable<?, Long> source = (AbstractTable<SoftwareModule, Long>) transferable.getSourceComponent();
@@ -232,6 +214,22 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
         if (item != null && item.getItemProperty("id") != null && item.getItemProperty("name") != null) {
             handleDropEvent(source, softwareModulesIdList, item);
         }
+
+    }
+
+    @Override
+    protected void onDropEventFromWrapper(final DragAndDropEvent event) {
+        // nothing to do
+    }
+
+    @Override
+    protected boolean isDropValid(final DragAndDropEvent dragEvent) {
+        final Component compsource = dragEvent.getTransferable().getSourceComponent();
+        if (!(compsource instanceof Table)) {
+            notification.displayValidationError(i18n.get(ACTION_NOT_ALLOWED_MSG));
+            return false;
+        }
+        return super.isDropValid(dragEvent);
     }
 
     private void handleDropEvent(final Table source, final Set<Long> softwareModulesIdList, final Item item) {
@@ -334,7 +332,8 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
         }
 
         if (distributionSetManagement.isDistributionSetInUse(ds)) {
-            notification.displayValidationError(i18n.get("message.error.notification.ds.target.assigned", ds.getName(), ds.getVersion()));
+            notification.displayValidationError(
+                    i18n.get("message.error.notification.ds.target.assigned", ds.getName(), ds.getVersion()));
             return false;
         }
         return true;
@@ -385,31 +384,14 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
         return true;
     }
 
-    /**
+    @Override
-     * Validate event.
+    protected String getDropTableId() {
-     *
+        return SPUIComponentIdProvider.UPLOAD_SOFTWARE_MODULE_TABLE;
-     * @param dragEvent
-     *            as event
-     * @return boolean as flag
-     */
-    private Boolean doValidation(final DragAndDropEvent dragEvent) {
-        if (!permissionChecker.hasUpdateDistributionPermission()) {
-            notification.displayValidationError(i18n.get("message.permission.insufficient"));
-            return false;
-        } else {
-            final Component compsource = dragEvent.getTransferable().getSourceComponent();
-            final Table source = (Table) compsource;
-            if (compsource instanceof Table) {
-                if (!source.getId().equals(SPUIComponentIdProvider.UPLOAD_SOFTWARE_MODULE_TABLE)) {
-                    notification.displayValidationError(i18n.get("message.action.not.allowed"));
-                    return false;
     }
-            } else {
+
-                notification.displayValidationError(i18n.get("message.action.not.allowed"));
+    @Override
-                return false;
+    protected boolean hasDropPermission() {
-            }
+        return permissionChecker.hasUpdateDistributionPermission();
-        }
-        return true;
     }
 
     private void addTableStyleGenerator() {
@@ -488,13 +470,13 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
             public Object generateCell(final Table source, final Object itemId, final Object columnId) {
                 final String nameVersionStr = getNameAndVerion(itemId);
                 final Button manageMetaDataBtn = createManageMetadataButton(nameVersionStr);
-                manageMetaDataBtn.addClickListener(event -> showMetadataDetails(((DistributionSetIdName) itemId).getId()));
+                manageMetaDataBtn
+                        .addClickListener(event -> showMetadataDetails(((DistributionSetIdName) itemId).getId()));
                 return manageMetaDataBtn;
             }
         });
     }
 
-
     @Override
     protected List<TableColumn> getTableVisibleColumns() {
         final List<TableColumn> columnList = super.getTableVisibleColumns();
@@ -515,7 +497,7 @@ public class DistributionSetTable extends AbstractNamedVersionTable<Distribution
 
     private void showMetadataDetails(final Long itemId) {
         final DistributionSet ds = distributionSetManagement.findDistributionSetByIdWithDetails(itemId);
-        UI.getCurrent().addWindow(dsMetadataPopupLayout.getWindow(ds,null));
+        UI.getCurrent().addWindow(dsMetadataPopupLayout.getWindow(ds, null));
     }
 
     private String getNameAndVerion(final Object itemId) {

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/smtable/SwModuleTable.java

@@ -43,7 +43,6 @@ import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
-import com.vaadin.event.dd.DropHandler;
 import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
 import com.vaadin.server.FontAwesome;
 import com.vaadin.server.Page;
@@ -180,9 +179,10 @@ public class SwModuleTable extends AbstractNamedVersionTable<SoftwareModule, Lon
 
         addGeneratedColumn(SPUILabelDefinitions.ARTIFACT_ICON, new ColumnGenerator() {
             private static final long serialVersionUID = -5982361782989980277L;
+
             @Override
             public Object generateCell(final Table source, final Object itemId, final Object columnId) {
-                HorizontalLayout iconLayout = new HorizontalLayout();
+                final HorizontalLayout iconLayout = new HorizontalLayout();
                 // add artifactory details popup
                 final String nameVersionStr = getNameAndVerion(itemId);
                 final Button showArtifactDtlsBtn = createShowArtifactDtlsButton(nameVersionStr);
@@ -214,7 +214,7 @@ public class SwModuleTable extends AbstractNamedVersionTable<SoftwareModule, Lon
     @Override
     protected void publishEntityAfterValueChange(final SoftwareModule selectedLastEntity) {
         eventBus.publish(this, new SoftwareModuleEvent(BaseEntityEventType.SELECTED_ENTITY, selectedLastEntity));
-        if(selectedLastEntity!=null){
+        if (selectedLastEntity != null) {
             manageDistUIState.setSelectedBaseSwModuleId(selectedLastEntity.getId());
         }
     }
@@ -252,21 +252,13 @@ public class SwModuleTable extends AbstractNamedVersionTable<SoftwareModule, Lon
     }
 
     @Override
-    protected DropHandler getTableDropHandler() {
+    protected AcceptCriterion getDropAcceptCriterion() {
-        return new DropHandler() {
-
-            private static final long serialVersionUID = -6175865860867652573L;
-
-            @Override
-            public AcceptCriterion getAcceptCriterion() {
         return distributionsViewAcceptCriteria;
     }
 
     @Override
-            public void drop(final DragAndDropEvent event) {
+    protected boolean isDropValid(final DragAndDropEvent dragEvent) {
-                /* sw module dont accept drops */
+        return false;
-            }
-        };
     }
 
     /* All Private Methods */
@@ -326,7 +318,7 @@ public class SwModuleTable extends AbstractNamedVersionTable<SoftwareModule, Lon
         return showArtifactDtlsBtn;
     }
 
-    private Button createManageMetadataButton(String nameVersionStr) {
+    private Button createManageMetadataButton(final String nameVersionStr) {
         final Button manageMetadataBtn = SPUIComponentProvider.getButton(
                 SPUIComponentIdProvider.SW_TABLE_MANAGE_METADATA_ID + "." + nameVersionStr, "", "", null, false,
                 FontAwesome.LIST_ALT, SPUIButtonStyleSmallNoBorder.class);
@@ -407,9 +399,9 @@ public class SwModuleTable extends AbstractNamedVersionTable<SoftwareModule, Lon
 
     }
 
-    private void showMetadataDetails(Long itemId) {
+    private void showMetadataDetails(final Long itemId) {
-        SoftwareModule swmodule = softwareManagement.findSoftwareModuleWithDetails(itemId);
+        final SoftwareModule swmodule = softwareManagement.findSoftwareModuleWithDetails(itemId);
-        UI.getCurrent().addWindow(swMetadataPopupLayout.getWindow(swmodule,null));
+        UI.getCurrent().addWindow(swMetadataPopupLayout.getWindow(swmodule, null));
     }
 
 }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/management/dstable/DistributionTable.java

@@ -56,14 +56,12 @@ import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
-import com.vaadin.event.dd.DropHandler;
 import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
 import com.vaadin.server.FontAwesome;
 import com.vaadin.spring.annotation.SpringComponent;
 import com.vaadin.spring.annotation.ViewScope;
 import com.vaadin.ui.Button;
 import com.vaadin.ui.Button.ClickEvent;
-import com.vaadin.ui.Component;
 import com.vaadin.ui.DragAndDropWrapper;
 import com.vaadin.ui.HorizontalLayout;
 import com.vaadin.ui.Table;
@@ -308,36 +306,23 @@ public class DistributionTable extends AbstractNamedVersionTable<DistributionSet
     }
 
     @Override
-    protected DropHandler getTableDropHandler() {
+    public AcceptCriterion getDropAcceptCriterion() {
-        return new DropHandler() {
-            private static final long serialVersionUID = 1L;
-
-            @Override
-            public AcceptCriterion getAcceptCriterion() {
         return managementViewAcceptCriteria;
     }
 
     @Override
-            public void drop(final DragAndDropEvent event) {
+    protected void onDropEventFromTable(final DragAndDropEvent event) {
-                if (doValidation(event)) {
-                    if (event.getTransferable().getSourceComponent() instanceof Table) {
         assignTargetToDs(event);
-                    } else if (event.getTransferable().getSourceComponent() instanceof DragAndDropWrapper) {
-                        processWrapperDrop(event);
-                    }
-                }
-            }
-        };
     }
 
-    private void processWrapperDrop(final DragAndDropEvent event) {
+    @Override
+    protected void onDropEventFromWrapper(final DragAndDropEvent event) {
         if (event.getTransferable().getSourceComponent().getId()
                 .startsWith(SPUIDefinitions.DISTRIBUTION_TAG_ID_PREFIXS)) {
             assignDsTag(event);
         } else {
             assignTargetTag(event);
         }
-
     }
 
     private void assignDsTag(final DragAndDropEvent event) {
@@ -410,43 +395,27 @@ public class DistributionTable extends AbstractNamedVersionTable<DistributionSet
         }
     }
 
-    private Boolean doValidation(final DragAndDropEvent dragEvent) {
+    @Override
-        final Component compsource = dragEvent.getTransferable().getSourceComponent();
+    protected boolean hasDropPermission() {
-        if (compsource instanceof Table) {
+        return permissionChecker.hasUpdateTargetPermission();
-            return validateTable(compsource);
-        } else if (compsource instanceof DragAndDropWrapper) {
-            return validateDragAndDropWrapper(compsource);
-        } else {
-            notification.displayValidationError(notAllowedMsg);
-            return false;
-        }
     }
 
-    private Boolean validateTable(final Component compsource) {
+    @Override
-        if (!permissionChecker.hasUpdateTargetPermission()) {
+    protected String getDropTableId() {
-            notification.displayValidationError(i18n.get("message.permission.insufficient"));
+        return SPUIComponentIdProvider.TARGET_TABLE_ID;
-            return false;
-        } else {
-            if (compsource instanceof Table && !compsource.getId().equals(SPUIComponentIdProvider.TARGET_TABLE_ID)) {
-                notification.displayValidationError(notAllowedMsg);
-                return false;
-            }
-        }
-        return true;
     }
 
-    private Boolean validateDragAndDropWrapper(final Component compsource) {
+    @Override
-        final DragAndDropWrapper wrapperSource = (DragAndDropWrapper) compsource;
+    protected boolean validateDragAndDropWrapper(final DragAndDropWrapper wrapperSource) {
         final String tagData = wrapperSource.getData().toString();
         if (wrapperSource.getId().startsWith(SPUIDefinitions.DISTRIBUTION_TAG_ID_PREFIXS)) {
             return !isNoTagButton(tagData, SPUIDefinitions.DISTRIBUTION_TAG_BUTTON);
         } else if (wrapperSource.getId().startsWith(SPUIDefinitions.TARGET_TAG_ID_PREFIXS)) {
             return !isNoTagButton(tagData, SPUIDefinitions.TARGET_TAG_BUTTON);
-        } else {
+        }
         notification.displayValidationError(notAllowedMsg);
         return false;
     }
-    }
 
     private Boolean isNoTagButton(final String tagData, final String targetNoTagData) {
         if (tagData.equals(targetNoTagData)) {

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/management/targettable/TargetTable.java

@@ -22,6 +22,7 @@ import org.eclipse.hawkbit.repository.SpPermissionChecker;
 import org.eclipse.hawkbit.repository.TargetManagement;
 import org.eclipse.hawkbit.repository.eventbus.event.TargetCreatedEvent;
 import org.eclipse.hawkbit.repository.eventbus.event.TargetInfoUpdateEvent;
+import org.eclipse.hawkbit.repository.model.NamedEntity;
 import org.eclipse.hawkbit.repository.model.Target;
 import org.eclipse.hawkbit.repository.model.TargetIdName;
 import org.eclipse.hawkbit.repository.model.TargetInfo;
@@ -57,7 +58,6 @@ import org.eclipse.hawkbit.ui.utils.SPUIDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUILabelDefinitions;
 import org.eclipse.hawkbit.ui.utils.SPUIStyleDefinitions;
 import org.eclipse.hawkbit.ui.utils.TableColumn;
-import org.eclipse.hawkbit.ui.utils.UINotification;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -71,7 +71,6 @@ import com.google.common.base.Strings;
 import com.vaadin.data.Container;
 import com.vaadin.data.Item;
 import com.vaadin.event.dd.DragAndDropEvent;
-import com.vaadin.event.dd.DropHandler;
 import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
 import com.vaadin.server.FontAwesome;
 import com.vaadin.shared.ui.label.ContentMode;
@@ -79,7 +78,6 @@ import com.vaadin.spring.annotation.SpringComponent;
 import com.vaadin.spring.annotation.ViewScope;
 import com.vaadin.ui.Button;
 import com.vaadin.ui.Button.ClickEvent;
-import com.vaadin.ui.Component;
 import com.vaadin.ui.DragAndDropWrapper;
 import com.vaadin.ui.Label;
 import com.vaadin.ui.Table;
@@ -99,7 +97,6 @@ public class TargetTable extends AbstractTable<Target, TargetIdName> {
     private static final long serialVersionUID = -2300392868806614568L;
 
     private static final int PROPERTY_DEPT = 3;
-    private static final String ACTION_NOT_ALLOWED_MSG = "message.action.not.allowed";
 
     @Autowired
     private transient TargetManagement targetManagement;
@@ -110,9 +107,6 @@ public class TargetTable extends AbstractTable<Target, TargetIdName> {
     @Autowired
     private SpPermissionChecker permChecker;
 
-    @Autowired
-    private UINotification notification;
-
     @Autowired
     private ManagementViewAcceptCriteria managementViewAcceptCriteria;
 
@@ -307,24 +301,10 @@ public class TargetTable extends AbstractTable<Target, TargetIdName> {
     }
 
     @Override
-    protected DropHandler getTableDropHandler() {
+    public AcceptCriterion getDropAcceptCriterion() {
-        return new DropHandler() {
-            private static final long serialVersionUID = 1L;
-
-            @Override
-            public AcceptCriterion getAcceptCriterion() {
         return managementViewAcceptCriteria;
     }
 
-            @Override
-            public void drop(final DragAndDropEvent event) {
-                if (doValidations(event)) {
-                    doAssignments(event);
-                }
-            }
-        };
-    }
-
     private void onTargetDeletedEvent(final List<TargetDeletedEvent> events) {
         final LazyQueryContainer targetContainer = (LazyQueryContainer) getContainerDataSource();
         final List<Object> visibleItemIds = (List<Object>) getVisibleItemIds();
@@ -522,14 +502,16 @@ public class TargetTable extends AbstractTable<Target, TargetIdName> {
         setCellStyleGenerator((source, itemId, propertyId) -> null);
     }
 
-    private void doAssignments(final DragAndDropEvent event) {
+    @Override
-        if (event.getTransferable().getSourceComponent() instanceof Table) {
+    protected void onDropEventFromTable(final DragAndDropEvent event) {
         dsToTargetAssignment(event);
-        } else if (event.getTransferable().getSourceComponent() instanceof DragAndDropWrapper
-                && isNoTagAssigned(event)) {
-            tagAssignment(event);
     }
 
+    @Override
+    protected void onDropEventFromWrapper(final DragAndDropEvent event) {
+        if (isNoTagAssigned(event)) {
+            tagAssignment(event);
+        }
     }
 
     private Boolean isNoTagAssigned(final DragAndDropEvent event) {
@@ -544,17 +526,9 @@ public class TargetTable extends AbstractTable<Target, TargetIdName> {
     }
 
     private void tagAssignment(final DragAndDropEvent event) {
-        final com.vaadin.event.dd.TargetDetails taregtDet = event.getTargetDetails();
+        final List<String> targetList = getDraggedTargetList(event).stream()
-        final Table targetTable = (Table) taregtDet.getTarget();
+                .map(targetIdName -> targetIdName.getControllerId()).collect(Collectors.toList());
-        final Set<TargetIdName> targetSelected = getTableValue(targetTable);
+
-        final Set<String> targetList = new HashSet<>();
-        final AbstractSelectTargetDetails dropData = (AbstractSelectTargetDetails) event.getTargetDetails();
-        final Object targetItemId = dropData.getItemIdOver();
-        if (!targetSelected.contains(targetItemId)) {
-            targetList.add(((TargetIdName) targetItemId).getControllerId());
-        } else {
-            targetList.addAll(targetSelected.stream().map(t -> t.getControllerId()).collect(Collectors.toList()));
-        }
         final String targTagName = HawkbitCommonUtil.removePrefix(event.getTransferable().getSourceComponent().getId(),
                 SPUIDefinitions.TARGET_TAG_ID_PREFIXS);
         if (targetList.isEmpty()) {
@@ -572,52 +546,9 @@ public class TargetTable extends AbstractTable<Target, TargetIdName> {
         }
     }
 
-    /**
+    @Override
-     * Check Validation on Drop.
+    protected boolean validateDragAndDropWrapper(final DragAndDropWrapper wrapperSource) {
-     *
+        final String tagName = HawkbitCommonUtil.removePrefix(wrapperSource.getId(),
-     * @param dragEvent
-     *            as drop event
-     * @return Boolean as flag
-     */
-    private Boolean doValidations(final DragAndDropEvent dragEvent) {
-        final Component compsource = dragEvent.getTransferable().getSourceComponent();
-        if (compsource instanceof Table) {
-            return validateTable(compsource, (TableTransferable) dragEvent.getTransferable());
-        } else if (compsource instanceof DragAndDropWrapper) {
-            validateDragAndDropWrapper(compsource);
-        } else {
-            notification.displayValidationError(i18n.get(ACTION_NOT_ALLOWED_MSG));
-            return false;
-        }
-        return true;
-    }
-
-    private Boolean validateTable(final Component compsource, final TableTransferable transferable) {
-        final Table source = (Table) compsource;
-        if (!(source.getId().equals(SPUIComponentIdProvider.DIST_TABLE_ID)
-                || source.getId().startsWith(SPUIDefinitions.TARGET_TAG_ID_PREFIXS))) {
-            notification.displayValidationError(i18n.get(ACTION_NOT_ALLOWED_MSG));
-            return false;
-        } else if (!permChecker.hasUpdateTargetPermission()) {
-            notification.displayValidationError(i18n.get("message.permission.insufficient"));
-            return false;
-        } else if (getDraggedDistributionSet(transferable, source).size() > 1) {
-            notification.displayValidationError(i18n.get("message.onlyone.distribution.assigned"));
-            return false;
-        }
-        return true;
-    }
-
-    private static Set<DistributionSetIdName> getDraggedDistributionSet(final TableTransferable transferable,
-            final Table source) {
-        @SuppressWarnings("unchecked")
-        final AbstractTable<?, DistributionSetIdName> distTable = (AbstractTable<?, DistributionSetIdName>) source;
-        return distTable.getDeletedEntityByTransferable(transferable);
-    }
-
-    private Boolean validateDragAndDropWrapper(final Component compsource) {
-        final DragAndDropWrapper wrapperSource = (DragAndDropWrapper) compsource;
-        final String tagName = HawkbitCommonUtil.removePrefix(compsource.getId(),
                 SPUIDefinitions.TARGET_TAG_ID_PREFIXS);
         if (wrapperSource.getId().startsWith(SPUIDefinitions.TARGET_TAG_ID_PREFIXS)) {
             if ("NO TAG".equals(tagName)) {
@@ -628,19 +559,32 @@ public class TargetTable extends AbstractTable<Target, TargetIdName> {
             notification.displayValidationError(i18n.get(ACTION_NOT_ALLOWED_MSG));
             return false;
         }
+
         return true;
     }
 
+    @Override
+    protected String getDropTableId() {
+        return SPUIComponentIdProvider.DIST_TABLE_ID;
+    }
+
+    @Override
+    protected boolean hasDropPermission() {
+        return permChecker.hasUpdateTargetPermission();
+    }
+
     private void dsToTargetAssignment(final DragAndDropEvent event) {
         final TableTransferable transferable = (TableTransferable) event.getTransferable();
-        final Table source = transferable.getSourceComponent();
+        final AbstractTable<NamedEntity, DistributionSetIdName> source = (AbstractTable<NamedEntity, DistributionSetIdName>) transferable
+                .getSourceComponent();
         final AbstractSelectTargetDetails dropData = (AbstractSelectTargetDetails) event.getTargetDetails();
         final Object targetItemId = dropData.getItemIdOver();
         LOG.debug("Adding a log to check if targetItemId is null : {} ", targetItemId);
         if (targetItemId != null) {
             final TargetIdName targetId = (TargetIdName) targetItemId;
             String message = null;
-            for (final DistributionSetIdName distributionNameId : getDraggedDistributionSet(transferable, source)) {
+
+            for (final DistributionSetIdName distributionNameId : source.getDeletedEntityByTransferable(transferable)) {
                 if (null != distributionNameId) {
                     if (managementUIState.getAssignedList().keySet().contains(targetId)
                             && managementUIState.getAssignedList().get(targetId).equals(distributionNameId)) {

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/management/targettag/TargetTagFilterButtons.java

@@ -41,6 +41,7 @@ import org.vaadin.spring.events.EventScope;
 import org.vaadin.spring.events.annotation.EventBusListenerMethod;
 
 import com.vaadin.data.Item;
+import com.vaadin.event.Transferable;
 import com.vaadin.event.dd.DragAndDropEvent;
 import com.vaadin.event.dd.DropHandler;
 import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
@@ -183,18 +184,28 @@ public class TargetTagFilterButtons extends AbstractFilterButtons {
      * @return Boolean
      */
     private Boolean validate(final DragAndDropEvent event) {
-        final Component compsource = event.getTransferable().getSourceComponent();
+        final Transferable transferable = event.getTransferable();
-        if (!(compsource instanceof Table)) {
+        final Component compsource = transferable.getSourceComponent();
-
+        if (!(compsource instanceof AbstractTable)) {
             notification.displayValidationError(i18n.get(SPUILabelDefinitions.ACTION_NOT_ALLOWED));
             return false;
-        } else {
+        }
-            final Table source = ((TableTransferable) event.getTransferable()).getSourceComponent();
+
+        final TableTransferable tabletransferable = (TableTransferable) transferable;
+
+        final AbstractTable<?, ?> source = (AbstractTable<?, ?>) tabletransferable.getSourceComponent();
 
         if (!validateIfSourceisTargetTable(source) && !checkForTargetUpdatePermission()) {
             return false;
         }
+
+        final Set<?> deletedEntityByTransferable = source.getDeletedEntityByTransferable(tabletransferable);
+        if (deletedEntityByTransferable.isEmpty()) {
+            final String actionDidNotWork = i18n.get("message.action.did.not.work", new Object[] {});
+            notification.displayValidationError(actionDidNotWork);
+            return false;
         }
+
         return true;
     }
 
@@ -222,11 +233,6 @@ public class TargetTagFilterButtons extends AbstractFilterButtons {
                 .getSourceComponent();
 
         final Set<TargetIdName> targetSelected = targetTable.getDeletedEntityByTransferable(transferable);
-        if (targetSelected.isEmpty()) {
-            final String actionDidNotWork = i18n.get("message.action.did.not.work", new Object[] {});
-            notification.displayValidationError(actionDidNotWork);
-            return;
-        }
 
         final Set<String> targetList = targetSelected.stream().map(t -> t.getControllerId())
                 .collect(Collectors.toSet());