NEW - bug 378032: provide support for required attributes

https://bugs.eclipse.org/bugs/show_bug.cgi?id=378032

Change-Id: Ib3cfcb8c8cb489fab5afbb0565f6da0643ab4b97
Signed-off-by: Benjamin Muskalla <benjamin.muskalla@tasktop.com>

10 files changed, 346 insertions, 3 deletions

diff --git a/org.eclipse.mylyn.bugzilla.core/src/org/eclipse/mylyn/internal/bugzilla/core/BugzillaTaskDataHandler.java b/org.eclipse.mylyn.bugzilla.core/src/org/eclipse/mylyn/internal/bugzilla/core/BugzillaTaskDataHandler.java
index b50cca6da..ba1f3f4dd 100644
--- a/org.eclipse.mylyn.bugzilla.core/src/org/eclipse/mylyn/internal/bugzilla/core/BugzillaTaskDataHandler.java
+++ b/org.eclipse.mylyn.bugzilla.core/src/org/eclipse/mylyn/internal/bugzilla/core/BugzillaTaskDataHandler.java
@@ -546,6 +546,7 @@ public class BugzillaTaskDataHandler extends AbstractTaskDataHandler {
 		createAttribute(taskData, BugzillaAttribute.SHORT_DESC);
 
 		TaskAttribute attributeVersion = createAttribute(taskData, BugzillaAttribute.VERSION);
+		attributeVersion.getMetaData().setRequired(true);
 		optionValues = repositoryConfiguration.getProductOptionValues(BugzillaAttribute.VERSION,
 				productAttribute.getValue());
 		Collections.sort(optionValues);
@@ -557,6 +558,7 @@ public class BugzillaTaskDataHandler extends AbstractTaskDataHandler {
 		}
 
 		TaskAttribute attributeComponent = createAttribute(taskData, BugzillaAttribute.COMPONENT);
+		attributeComponent.getMetaData().setRequired(true);
 		optionValues = repositoryConfiguration.getProductOptionValues(BugzillaAttribute.COMPONENT,
 				productAttribute.getValue());
 		Collections.sort(optionValues);
@@ -607,6 +609,7 @@ public class BugzillaTaskDataHandler extends AbstractTaskDataHandler {
 		}
 
 		TaskAttribute attributeOPSYS = createAttribute(taskData, BugzillaAttribute.OP_SYS);
+		attributeOPSYS.getMetaData().setRequired(true);
 		optionValues = repositoryConfiguration.getOptionValues(BugzillaAttribute.OP_SYS);
 		for (String option : optionValues) {
 			attributeOPSYS.putOption(option, option);
@@ -617,6 +620,7 @@ public class BugzillaTaskDataHandler extends AbstractTaskDataHandler {
 		}
 
 		TaskAttribute attributePriority = createAttribute(taskData, BugzillaAttribute.PRIORITY);
+		attributePriority.getMetaData().setRequired(true);
 		optionValues = repositoryConfiguration.getOptionValues(BugzillaAttribute.PRIORITY);
 		for (String option : optionValues) {
 			attributePriority.putOption(option, option);
@@ -627,6 +631,7 @@ public class BugzillaTaskDataHandler extends AbstractTaskDataHandler {
 		}
 
 		TaskAttribute attributeSeverity = createAttribute(taskData, BugzillaAttribute.BUG_SEVERITY);
+		attributeSeverity.getMetaData().setRequired(true);
 		optionValues = repositoryConfiguration.getOptionValues(BugzillaAttribute.BUG_SEVERITY);
 		for (String option : optionValues) {
 			attributeSeverity.putOption(option, option);
diff --git a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttribute.java b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttribute.java
index 12f96bbc6..0f555f39a 100644
--- a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttribute.java
+++ b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttribute.java
@@ -149,6 +149,11 @@ public final class TaskAttribute {
 	public static final String META_READ_ONLY = "task.meta.readOnly"; //$NON-NLS-1$
 
 	/**
+	 * @since 3.8
+	 */
+	public static final String META_REQUIRED = "task.meta.required"; //$NON-NLS-1$
+
+	/**
 	 * @since 3.6
 	 */
 	public static final String COMMENT_ISPRIVATE = "task.common.comment.isprivate"; //$NON-NLS-1$
diff --git a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttributeMetaData.java b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttributeMetaData.java
index 7518b411b..ee3b0f599 100644
--- a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttributeMetaData.java
+++ b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/tasks/core/data/TaskAttributeMetaData.java
@@ -40,6 +40,7 @@ public class TaskAttributeMetaData {
 		setKind(null);
 		setReadOnly(true);
 		setType(TaskAttribute.TYPE_SHORT_TEXT);
+		setRequired(false);
 		// only for test
 		// putValue(TaskAttribute.META_DESCRIPTION, "Tooltip Defaul Text"); //$NON-NLS-1$
 		return this;
@@ -98,6 +99,14 @@ public class TaskAttributeMetaData {
 		return Boolean.parseBoolean(taskAttribute.getMetaDatum(TaskAttribute.META_READ_ONLY));
 	}
 
+	/**
+	 * @since 3.11
+	 * @see TaskAttribute#META_REQUIRED
+	 */
+	public boolean isRequired() {
+		return Boolean.parseBoolean(taskAttribute.getMetaDatum(TaskAttribute.META_REQUIRED));
+	}
+
 	public TaskAttributeMetaData putValue(String key, String value) {
 		taskAttribute.putMetaDatum(key, value);
 		return this;
@@ -173,4 +182,14 @@ public class TaskAttributeMetaData {
 		return this;
 	}
 
+	/**
+	 * @since 3.11
+	 * @see TaskAttribute#META_REQUIRED
+	 * @return this
+	 */
+	public TaskAttributeMetaData setRequired(boolean value) {
+		taskAttribute.putMetaDatum(TaskAttribute.META_REQUIRED, Boolean.toString(value));
+		return this;
+	}
+
 }
diff --git a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/AllTasksTests.java b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/AllTasksTests.java
index 1c4070d98..88730ef7f 100644
--- a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/AllTasksTests.java
+++ b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/AllTasksTests.java
@@ -23,6 +23,7 @@ import org.eclipse.mylyn.tasks.tests.core.PriorityLevelTest;
 import org.eclipse.mylyn.tasks.tests.core.RepositoryClientManagerTest;
 import org.eclipse.mylyn.tasks.tests.core.RepositoryConnectorContributorTest;
 import org.eclipse.mylyn.tasks.tests.core.SynchronizeTasksJobTest;
+import org.eclipse.mylyn.tasks.tests.core.TaskAttributeMetaDataTest;
 import org.eclipse.mylyn.tasks.tests.core.TaskInitializationDataTest;
 import org.eclipse.mylyn.tasks.tests.core.TaskListUnmatchedContainerTest;
 import org.eclipse.mylyn.tasks.tests.core.TaskRepositoryLocationTest;
@@ -33,6 +34,7 @@ import org.eclipse.mylyn.tasks.tests.data.TaskDataDiffTest;
 import org.eclipse.mylyn.tasks.tests.data.TaskDataExternalizerTest;
 import org.eclipse.mylyn.tasks.tests.data.Xml11InputStreamTest;
 import org.eclipse.mylyn.tasks.tests.ui.AbstractRepositoryConnectorUiTest;
+import org.eclipse.mylyn.tasks.tests.ui.AttributeEditorTest;
 import org.eclipse.mylyn.tasks.tests.ui.MultipleTaskHyperlinkDetectorTest;
 import org.eclipse.mylyn.tasks.tests.ui.ScheduledTaskContainerTest;
 import org.eclipse.mylyn.tasks.tests.ui.TaskAttachmentPropertyTesterTest;
@@ -150,6 +152,8 @@ public class AllTasksTests {
 		suite.addTestSuite(TaskAttributeTest.class);
 		suite.addTestSuite(TaskAttributeMapperTest.class);
 		suite.addTestSuite(SupportHandlerManagerTest.class);
+		suite.addTestSuite(TaskAttributeMetaDataTest.class);
+		suite.addTestSuite(AttributeEditorTest.class);
 		suite.addTestSuite(RepositoryClientManagerTest.class);
 		suite.addTestSuite(AbstractRepositoryConnectorUiTest.class);
 		suite.addTestSuite(SynchronizeTasksJobTest.class);
diff --git a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/core/TaskAttributeMetaDataTest.java b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/core/TaskAttributeMetaDataTest.java
new file mode 100644
index 000000000..a63364ff9
--- /dev/null
+++ b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/core/TaskAttributeMetaDataTest.java
@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2012 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.tasks.tests.core;
+
+import junit.framework.TestCase;
+
+import org.eclipse.mylyn.tasks.core.TaskRepository;
+import org.eclipse.mylyn.tasks.core.data.TaskAttribute;
+import org.eclipse.mylyn.tasks.core.data.TaskAttributeMapper;
+import org.eclipse.mylyn.tasks.core.data.TaskData;
+import org.eclipse.mylyn.tasks.tests.connector.MockRepositoryConnector;
+
+/**
+ * @author Benjamin Muskalla
+ */
+public class TaskAttributeMetaDataTest extends TestCase {
+
+	private TaskData data;
+
+	@Override
+	protected void setUp() throws Exception {
+		TaskRepository taskRepository = new TaskRepository("kind", "url");
+		data = new TaskData(new TaskAttributeMapper(taskRepository), MockRepositoryConnector.CONNECTOR_KIND,
+				MockRepositoryConnector.REPOSITORY_URL, "taskid");
+	}
+
+	public void testInitialRequiredAttribute() {
+		TaskAttribute attribute = new TaskAttribute(data.getRoot(), "attributeId");
+		boolean required = attribute.getMetaData().isRequired();
+		assertFalse(required);
+	}
+
+	public void testLifecycleRequiredAttribute() {
+		TaskAttribute attribute = new TaskAttribute(data.getRoot(), "attributeId");
+		attribute.getMetaData().setRequired(true);
+		assertTrue(attribute.getMetaData().isRequired());
+		attribute.getMetaData().setRequired(false);
+		assertFalse(attribute.getMetaData().isRequired());
+	}
+
+}
diff --git a/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/ui/AttributeEditorTest.java b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/ui/AttributeEditorTest.java
new file mode 100644
index 000000000..77f3a15a1
--- /dev/null
+++ b/org.eclipse.mylyn.tasks.tests/src/org/eclipse/mylyn/tasks/tests/ui/AttributeEditorTest.java
@@ -0,0 +1,209 @@
+/*******************************************************************************
+ * Copyright (c) 2012 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.tasks.tests.ui;
+
+import junit.framework.TestCase;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.mylyn.commons.workbench.WorkbenchUtil;
+import org.eclipse.mylyn.internal.tasks.core.data.TaskDataState;
+import org.eclipse.mylyn.internal.tasks.ui.TasksUiPlugin;
+import org.eclipse.mylyn.tasks.core.TaskRepository;
+import org.eclipse.mylyn.tasks.core.data.TaskAttribute;
+import org.eclipse.mylyn.tasks.core.data.TaskAttributeMapper;
+import org.eclipse.mylyn.tasks.core.data.TaskData;
+import org.eclipse.mylyn.tasks.core.data.TaskDataModel;
+import org.eclipse.mylyn.tasks.tests.connector.MockRepositoryConnector;
+import org.eclipse.mylyn.tasks.tests.connector.MockTask;
+import org.eclipse.mylyn.tasks.ui.editors.AbstractAttributeEditor;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Label;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.ui.forms.widgets.FormToolkit;
+
+/**
+ * @author Benjamin Muskalla
+ */
+public class AttributeEditorTest extends TestCase {
+
+	private class MockAttributeEditor extends AbstractAttributeEditor {
+
+		private MockAttributeEditor(TaskDataModel manager, TaskAttribute taskAttribute) throws CoreException {
+			super(manager, taskAttribute);
+			setControl(new Shell());
+		}
+
+		@Override
+		public void createControl(Composite parent, FormToolkit toolkit) {
+			// ignore
+		}
+
+		@Override
+		public boolean isRequired() {
+			return super.isRequired();
+		}
+
+		@Override
+		public void refresh() {
+			// ignore
+		}
+
+		@Override
+		public Label getLabelControl() {
+			return new Label(new Shell(), SWT.NONE);
+		}
+
+		@Override
+		protected boolean shouldAutoRefresh() {
+			return true;
+		}
+	}
+
+	private TaskRepository repository;
+
+	private TaskData taskData;
+
+	private TaskDataModel manager;
+
+	@Override
+	protected void setUp() throws Exception {
+		repository = new TaskRepository(MockRepositoryConnector.CONNECTOR_KIND, MockRepositoryConnector.REPOSITORY_URL);
+		TasksUiPlugin.getRepositoryManager().addRepository(repository);
+
+		taskData = new TaskData(new TaskAttributeMapper(repository), MockRepositoryConnector.CONNECTOR_KIND,
+				MockRepositoryConnector.REPOSITORY_URL, "1");
+
+		manager = createManager();
+	}
+
+	public void testDetermineNotRequired() throws Exception {
+		TaskAttribute attribute = new TaskAttribute(taskData.getRoot(), "not.required.field");
+		MockAttributeEditor editor = new MockAttributeEditor(manager, attribute);
+		assertFalse(editor.isRequired());
+		attribute.setValue("");
+		assertFalse(editor.isRequired());
+		attribute.setValue("abc");
+		assertFalse(editor.isRequired());
+	}
+
+	public void testDetermineRequired() throws Exception {
+		TaskAttribute attribute = new TaskAttribute(taskData.getRoot(), "a.required.field");
+		attribute.getMetaData().setRequired(true);
+		MockAttributeEditor editor = new MockAttributeEditor(manager, attribute);
+		assertTrue(editor.isRequired());
+		attribute.setValue("");
+		assertTrue(editor.isRequired());
+		attribute.setValue("abc");
+		assertFalse(editor.isRequired());
+	}
+
+	public void testDecorateRequired() throws Exception {
+		final StringBuilder eventLog = new StringBuilder();
+		TaskAttribute attribute = new TaskAttribute(taskData.getRoot(), "a.required.field");
+		MockAttributeEditor editor = new MockAttributeEditor(manager, attribute) {
+			@Override
+			protected void decorateRequired() {
+				eventLog.append("decorateRequired");
+			}
+
+		};
+
+		assertEquals("", eventLog.toString());
+		Color someColor = WorkbenchUtil.getShell().getDisplay().getSystemColor(SWT.COLOR_CYAN);
+		editor.decorate(someColor);
+		assertEquals("", eventLog.toString());
+
+		attribute.getMetaData().setRequired(true);
+		editor.decorate(someColor);
+		assertEquals("decorateRequired", eventLog.toString());
+		eventLog.setLength(0);
+
+		attribute.getMetaData().setRequired(false);
+		editor.decorate(someColor);
+		assertEquals("", eventLog.toString());
+	}
+
+	public void testDecorateRequiredOnChange() throws Exception {
+		final StringBuilder eventLog = new StringBuilder();
+		TaskAttribute attribute = new TaskAttribute(taskData.getRoot(), "a.required.field");
+		MockAttributeEditor editor = new MockAttributeEditor(manager, attribute) {
+
+			@Override
+			protected void decorateRequired() {
+				eventLog.append("decorateRequired");
+			}
+
+			@Override
+			public boolean isRequired() {
+				eventLog.append("asked");
+				return super.isRequired();
+			}
+
+		};
+
+		assertEquals("", eventLog.toString());
+		Color someColor = WorkbenchUtil.getShell().getDisplay().getSystemColor(SWT.COLOR_CYAN);
+
+		attribute.getMetaData().setRequired(true);
+		editor.decorate(someColor);
+		assertEquals("askeddecorateRequired", eventLog.toString());
+		eventLog.setLength(0);
+
+		attribute.setValue("someValue");
+		manager.attributeChanged(attribute);
+
+		assertEquals("asked", eventLog.toString());
+	}
+
+	public void testDecorateRequiredReal() throws Exception {
+		TaskAttribute attribute = new TaskAttribute(taskData.getRoot(), "a.required.field");
+		MockAttributeEditor editor = new MockAttributeEditor(manager, attribute);
+
+		Color someColor = WorkbenchUtil.getShell().getDisplay().getSystemColor(SWT.COLOR_CYAN);
+
+		attribute.getMetaData().setRequired(true);
+		editor.decorate(someColor);
+
+		attribute.getMetaData().setRequired(false);
+		manager.attributeChanged(attribute);
+	}
+
+	public void testNoDecorateWithoutLabel() throws Exception {
+		TaskAttribute attribute = new TaskAttribute(taskData.getRoot(), "a.required.field");
+		MockAttributeEditor editor = new MockAttributeEditor(manager, attribute) {
+			@Override
+			public Label getLabelControl() {
+				return null;
+			}
+		};
+
+		Color someColor = WorkbenchUtil.getShell().getDisplay().getSystemColor(SWT.COLOR_CYAN);
+
+		attribute.getMetaData().setRequired(true);
+		editor.decorate(someColor);
+
+		attribute.getMetaData().setRequired(false);
+		manager.attributeChanged(attribute);
+	}
+
+	private TaskDataModel createManager() throws Exception {
+		MockTask task = new MockTask("taskId");
+		TaskDataState state = new TaskDataState("kind", "url", "taskId");
+		state.setEditsData(taskData);
+		state.setLocalTaskData(taskData);
+		TaskDataModel manager = new TaskDataModel(repository, task, state);
+		return manager;
+	}
+
+}
diff --git a/org.eclipse.mylyn.tasks.ui/icons/ovr16/overlay-required.gif b/org.eclipse.mylyn.tasks.ui/icons/ovr16/overlay-required.gif
new file mode 100644
index 000000000..1b17af928
--- /dev/null
+++ b/org.eclipse.mylyn.tasks.ui/icons/ovr16/overlay-required.gif
diff --git a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/Messages.java b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/Messages.java
index 49597de80..5cf42dbf3 100644
--- a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/Messages.java
+++ b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/Messages.java
@@ -25,6 +25,8 @@ public class Messages extends NLS {
 		NLS.initializeMessages(BUNDLE_NAME, Messages.class);
 	}
 
+	public static String AbstractAttributeEditor_AttributeIsRequired;
+
 	public static String AbstractReplyToCommentAction_Reply;
 
 	public static String AttachmentSizeFormatter_0_bytes;
diff --git a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/messages.properties b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/messages.properties
index cb12598c9..0586ac69e 100644
--- a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/messages.properties
+++ b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/messages.properties
@@ -8,6 +8,7 @@
 # Contributors:
 #      Tasktop Technologies - initial API and implementation
 ###############################################################################
+AbstractAttributeEditor_AttributeIsRequired=This attribute is required
 AbstractReplyToCommentAction_Reply=Reply
 
 AttachmentSizeFormatter_0_bytes=0 bytes
diff --git a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/tasks/ui/editors/AbstractAttributeEditor.java b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/tasks/ui/editors/AbstractAttributeEditor.java
index 38291ebdd..f68a8a97a 100644
--- a/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/tasks/ui/editors/AbstractAttributeEditor.java
+++ b/org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/tasks/ui/editors/AbstractAttributeEditor.java
@@ -11,16 +11,22 @@
 
 package org.eclipse.mylyn.tasks.ui.editors;
 
+import org.apache.commons.lang.StringUtils;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.jface.action.LegacyActionTools;
+import org.eclipse.jface.fieldassist.ControlDecoration;
+import org.eclipse.jface.fieldassist.FieldDecorationRegistry;
+import org.eclipse.mylyn.internal.tasks.ui.editors.Messages;
 import org.eclipse.mylyn.tasks.core.data.TaskAttribute;
 import org.eclipse.mylyn.tasks.core.data.TaskAttributeMapper;
 import org.eclipse.mylyn.tasks.core.data.TaskDataModel;
 import org.eclipse.mylyn.tasks.core.data.TaskDataModelEvent;
 import org.eclipse.mylyn.tasks.core.data.TaskDataModelListener;
+import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Label;
@@ -66,10 +72,13 @@ public abstract class AbstractAttributeEditor {
 	private final TaskDataModelListener modelListener = new TaskDataModelListener() {
 		@Override
 		public void attributeChanged(TaskDataModelEvent event) {
-			if (shouldAutoRefresh() && getTaskAttribute().equals(event.getTaskAttribute())) {
+			if (getTaskAttribute().equals(event.getTaskAttribute())) {
 				try {
-					refreshInProgress = true;
-					refresh();
+					if (shouldAutoRefresh()) {
+						refreshInProgress = true;
+						refresh();
+					}
+					updateRequiredDecoration();
 				} catch (UnsupportedOperationException e) {
 				} finally {
 					refreshInProgress = false;
@@ -84,6 +93,8 @@ public abstract class AbstractAttributeEditor {
 		}
 	};
 
+	private ControlDecoration decoration;
+
 	/**
 	 * @since 3.0
 	 */
@@ -233,10 +244,47 @@ public abstract class AbstractAttributeEditor {
 			if (manager.hasOutgoingChanges(getTaskAttribute())) {
 				decorateOutgoing(color);
 			}
+			updateRequiredDecoration();
+		}
+	}
+
+	private void updateRequiredDecoration() {
+		if (getLabelControl() != null && isRequired()) {
+			decorateRequired();
+		} else if (decoration != null) {
+			decoration.hide();
+			decoration.dispose();
 		}
 	}
 
 	/**
+	 * @since 3.11
+	 */
+	protected void decorateRequired() {
+		decoration = new ControlDecoration(getLabelControl(), SWT.TOP | SWT.RIGHT);
+		decoration.setDescriptionText(Messages.AbstractAttributeEditor_AttributeIsRequired);
+		decoration.setMarginWidth(0);
+		Image image = FieldDecorationRegistry.getDefault()
+				.getFieldDecoration(FieldDecorationRegistry.DEC_ERROR)
+				.getImage();
+		decoration.setImage(image);
+		getLabelControl().addDisposeListener(new DisposeListener() {
+			public void widgetDisposed(DisposeEvent e) {
+				decoration.dispose();
+			}
+		});
+	}
+
+	/**
+	 * @since 3.11
+	 */
+	protected boolean isRequired() {
+		boolean isRequired = getTaskAttribute().getMetaData().isRequired();
+		boolean hasValue = !StringUtils.isEmpty(getTaskAttribute().getValue());
+		return isRequired && !hasValue;
+	}
+
+	/**
 	 * @since 3.0
 	 */
 	protected void decorateOutgoing(Color color) {