Fix visual enablement and context menu messages for disabled tasks

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/util/nodeselection/NodeSelection.java

@@ -177,6 +177,10 @@ public static NodeSelection empty() {
         return EMPTY;
     }
 
+    public static NodeSelection single(Object object) {
+        return new NodeSelection(ImmutableList.of(object));
+    }
+
     /**
      * Creates a new instance reflecting the given {@link IStructuredSelection} instance.
      *

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/view/task/CreateRunConfigurationAction.java

@@ -40,7 +40,7 @@ public boolean isVisibleFor(NodeSelection selection) {
 
     @Override
     public boolean isEnabledFor(NodeSelection selection) {
-        return (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnabledFor(selection) ||
+        return (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(selection).asBoolean() ||
                 TaskViewActionStateRules.projectScopedTaskExecutionActionsEnabledFor(selection)) && isValidSelection(selection);
     }
 

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/view/task/OpenRunConfigurationAction.java

@@ -40,7 +40,7 @@ public boolean isVisibleFor(NodeSelection selection) {
 
     @Override
     public boolean isEnabledFor(NodeSelection selection) {
-        return (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnabledFor(selection) ||
+        return (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(selection).asBoolean() ||
                 TaskViewActionStateRules.projectScopedTaskExecutionActionsEnabledFor(selection)) && isValidSelection(selection);
     }
 

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/view/task/RunTasksAction.java

@@ -16,6 +16,7 @@
 import org.eclipse.buildship.ui.util.nodeselection.NodeSelection;
 import org.eclipse.buildship.ui.util.nodeselection.SelectionSpecificAction;
 import org.eclipse.buildship.ui.view.CommandBackedAction;
+import org.eclipse.buildship.ui.view.task.TaskViewActionStateRules.TaskScopedActionEnablement;
 
 /**
  * Runs the selected Gradle tasks.
@@ -38,20 +39,30 @@ public boolean isVisibleFor(NodeSelection selection) {
 
     @Override
     public boolean isEnabledFor(NodeSelection selection) {
-        return TaskViewActionStateRules.taskScopedTaskExecutionActionsEnabledFor(selection);
+        return TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(selection).asBoolean();
     }
 
     @Override
     public void setEnabledFor(NodeSelection selection) {
-        boolean isEnabled = isEnabledFor(selection);
+        TaskScopedActionEnablement enablement = TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(selection);
+
+        boolean isEnabled = enablement.asBoolean();
         setEnabled(isEnabled);
-        if (isEnabled) {
-            setText(TaskViewMessages.Action_RunTasks_Text);
-            setImageDescriptor(PluginImages.RUN_TASKS.withState(PluginImage.ImageState.ENABLED).getImageDescriptor());
-        } else {
-            setText(TaskViewMessages.Action_RunTasks_Text_Disabled);
-            setImageDescriptor(PluginImages.RUN_TASKS.withState(PluginImage.ImageState.DISABLED).getImageDescriptor());
+        setImageDescriptor(PluginImages.RUN_TASKS.withState(isEnabled ? PluginImages.ImageState.ENABLED : PluginImage.ImageState.DISABLED).getImageDescriptor());
+
+        switch (enablement) {
+            case ENABLED:
+                setText(TaskViewMessages.Action_RunTasks_Text);
+                break;
+            case DISABLED_INCLUDED_BUILD:
+                setText(TaskViewMessages.Action_RunTasks_Text_Disabled_Included);
+                break;
+            case DISABLED_NO_ROOT_PROJECT:
+                setText(TaskViewMessages.Action_RunTasks_Text_Disabled_NonStandard_layout);
+                break;
+            default:
+                setText(TaskViewMessages.Action_RunTasks_Text_Disabled_Other);
+                break;
         }
     }
-
 }

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/view/task/TaskNameLabelProvider.java

@@ -26,6 +26,7 @@
 import org.eclipse.buildship.ui.PluginImage;
 import org.eclipse.buildship.ui.PluginImage.ImageState;
 import org.eclipse.buildship.ui.PluginImages;
+import org.eclipse.buildship.ui.util.nodeselection.NodeSelection;
 
 /**
  * Styled label provider for the task name column in the TaskView.
@@ -138,6 +139,6 @@ private Image getTaskSelectorImage(TaskSelectorNode taskSelector) {
     }
 
     private ImageState getImageState(TaskNode taskNode) {
-        return taskNode.getParentProjectNode().isIncludedProject() ? ImageState.DISABLED : ImageState.ENABLED;
+        return TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(NodeSelection.single(taskNode)).asBoolean() ? ImageState.ENABLED: ImageState.DISABLED;
     }
 }

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/view/task/TaskNodeSelectionUtils.java

@@ -43,7 +43,7 @@ private TaskNodeSelectionUtils() {
      * @return {@code true} if the the selection can be mapped to a run configuration
      */
     public static boolean isValidRunConfiguration(NodeSelection selection) {
-        return TaskViewActionStateRules.taskScopedTaskExecutionActionsEnabledFor(selection) ||
+        return TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(selection).asBoolean() ||
                 TaskViewActionStateRules.projectScopedTaskExecutionActionsEnabledFor(selection);
     }
 
@@ -72,7 +72,7 @@ public static GradleRunConfigurationAttributes getRunConfigurationAttributes(Nod
         Preconditions.checkNotNull(selection);
         List<String> tasks = getTaskPathStrings(selection);
 
-        if (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnabledFor(selection)) {
+        if (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(selection).asBoolean()) {
             TaskNode taskNode = selection.getFirstElement(TaskNode.class);
             return getRunConfigurationAttributes(taskNode.getParentProjectNode(), tasks);
         } else if (TaskViewActionStateRules.projectScopedTaskExecutionActionsEnabledFor(selection)) {
@@ -117,7 +117,7 @@ private static String gradleUserHomeExpression(File gradleUserHome) {
     }
 
     private static ImmutableList<String> getTaskPathStrings(NodeSelection selection) {
-        if (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnabledFor(selection)) {
+        if (TaskViewActionStateRules.taskScopedTaskExecutionActionsEnablement(selection).asBoolean()) {
             // running the set of project tasks and task selectors
             ImmutableList.Builder<String> taskStrings = ImmutableList.builder();
             for (TaskNode node : selection.toList(TaskNode.class)) {

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/view/task/TaskViewActionStateRules.java

@@ -55,35 +55,40 @@ public static boolean taskScopedTaskExecutionActionsVisibleFor(NodeSelection nod
      * Determines whether the actions related to task execution should be enabled or disabled.
      *
      * @param nodeSelection the node selection based on which to make the decision
-     * @return {@code true} if actions related to task execution should be enabled
+     * @return a classification whether and why the action should be disabled or enabled
      */
-    public static boolean taskScopedTaskExecutionActionsEnabledFor(NodeSelection nodeSelection) {
+    public static TaskScopedActionEnablement taskScopedTaskExecutionActionsEnablement(NodeSelection nodeSelection) {
         // short-circuit in case the selection is empty
         if (nodeSelection.isEmpty()) {
-            return false;
+            return TaskScopedActionEnablement.DISABLED_DEFAULT;
         }
 
         // execution is enabled only if no tasks from included builds are selected and each task is from the same project
         List<?> elements = nodeSelection.toList();
         List<TaskNode> taskNodes = FluentIterable.from(elements).filter(TaskNode.class).toList();
-        if (elements.size() != taskNodes.size() || hasMultipleOrIncludedParentProject(taskNodes)) {
-            return false;
+        if (elements.size() != taskNodes.size()) {
+            return TaskScopedActionEnablement.DISABLED_DEFAULT;
+        }
+
+        if (hasMultipleOrIncludedParentProject(taskNodes)) {
+            return TaskScopedActionEnablement.DISABLED_INCLUDED_BUILD;
         }
 
         // if project tasks are selected only then the execution should be permitted
         List<ProjectTaskNode> projectNodes = FluentIterable.from(elements).filter(ProjectTaskNode.class).toList();
         if (projectNodes.size() == taskNodes.size()) {
-            return true;
+            return TaskScopedActionEnablement.ENABLED;
         }
 
         // if task selectors are selected only then the execution should be permitted if the root project can be found
         List<TaskSelectorNode> taskSelectorNodes = FluentIterable.from(elements).filter(TaskSelectorNode.class).toList();
         if (taskSelectorNodes.size() == taskNodes.size()) {
-            return canFindRootProjects(taskSelectorNodes);
+            boolean hasRootProjects = canFindRootProjects(taskSelectorNodes);
+            return hasRootProjects ? TaskScopedActionEnablement.ENABLED : TaskScopedActionEnablement.DISABLED_NO_ROOT_PROJECT;
         }
 
         // as a default disable the execution
-        return  false;
+        return  TaskScopedActionEnablement.DISABLED_DEFAULT;
     }
 
     private static boolean hasMultipleOrIncludedParentProject(List<TaskNode> nodes) {
@@ -148,4 +153,14 @@ public static boolean projectScopedTaskExecutionActionsEnabledFor(NodeSelection
         return nodeSelection.hasAllNodesOfType(ProjectNode.class) && nodeSelection.isSingleSelection() && !nodeSelection.getFirstElement(ProjectNode.class).isIncludedProject();
     }
 
+    /**
+     * Possible statuses that {@link #taskScopedTaskExecutionActionsEnablement(NodeSelection)} can return.
+     */
+    public enum TaskScopedActionEnablement {
+        ENABLED, DISABLED_DEFAULT, DISABLED_INCLUDED_BUILD, DISABLED_NO_ROOT_PROJECT;
+
+        public boolean asBoolean() {
+            return this == ENABLED;
+        }
+    }
 }

org.eclipse.buildship.ui/src/main/java/org/eclipse/buildship/ui/view/task/TaskViewMessages.java

@@ -29,7 +29,9 @@ public final class TaskViewMessages extends NLS {
     // context menu entries
 
     public static String Action_RunTasks_Text;
-    public static String Action_RunTasks_Text_Disabled;
+    public static String Action_RunTasks_Text_Disabled_Included;
+    public static String Action_RunTasks_Text_Disabled_NonStandard_layout;
+    public static String Action_RunTasks_Text_Disabled_Other;
     public static String Action_RunDefaultTasks_Text;
     public static String Action_CreateRunConfiguration_Text;
     public static String Action_OpenRunConfiguration_Text;

org.eclipse.buildship.ui/src/main/resources/org/eclipse/buildship/ui/view/task/TaskViewMessages.properties

@@ -16,7 +16,9 @@ Tree_Column_Name_Text=Name
 Tree_Column_Description_Text=Description
 
 Action_RunTasks_Text=Run Gradle Tasks
-Action_RunTasks_Text_Disabled=Cannot run tasks for included builds
+Action_RunTasks_Text_Disabled_Included=Cannot run tasks for included builds
+Action_RunTasks_Text_Disabled_NonStandard_layout=Cannot run task selectors in non-standard project layouts
+Action_RunTasks_Text_Disabled_Other=Cannot run tasks
 Action_RunDefaultTasks_Text=Run Default Gradle Tasks
 Action_CreateRunConfiguration_Text=Create Gradle Run Configuration...
 Action_OpenRunConfiguration_Text=Open Gradle Run Configuration...