make activeTask a property

it can now be binded, besides being used in imperative code as it was

REVIEWED-BY:Eike Hein <hein@kde.org>

libtaskmanager/tasksmodel.cpp

@@ -197,6 +197,10 @@ void TasksModel::Private::initModels()
             if (sortMode == SortActivity && roles.contains(AbstractTasksModel::Activities)) {
                 updateActivityTaskCounts();
             }
+
+            if (roles.contains(AbstractTasksModel::IsActive)) {
+                emit q->activeTaskChanged();
+            }
         }
     );
 

libtaskmanager/tasksmodel.h

@@ -88,6 +88,7 @@ class TASKMANAGER_EXPORT TasksModel : public QSortFilterProxyModel, public Abstr
                WRITE setGroupingAppIdBlacklist NOTIFY groupingAppIdBlacklistChanged)
     Q_PROPERTY(QStringList groupingLauncherUrlBlacklist READ groupingLauncherUrlBlacklist
                WRITE setGroupingLauncherUrlBlacklist NOTIFY groupingLauncherUrlBlacklistChanged)
+    Q_PROPERTY(QModelIndex activeTask READ activeTask NOTIFY activeTaskChanged)
 
 public:
     enum SortMode {
@@ -509,6 +510,15 @@ public:
      **/
     void setGroupingLauncherUrlBlacklist(const QStringList &list);
 
+    /**
+     * Finds the first active (AbstractTasksModel::IsActive) task in the model
+     * and returns its QModelIndex, or a null QModelIndex if no active task is
+     * found.
+     *
+     * @returns the model index for the first active task, if any.
+     */
+    QModelIndex activeTask() const;
+
     /**
      * Request adding a launcher with the given URL.
      *
@@ -737,15 +747,6 @@ public:
      */
     Q_INVOKABLE void syncLaunchers();
 
-    /**
-     * Finds the first active (AbstractTasksModel::IsActive) task in the model
-     * and returns its QModelIndex, or a null QModelIndex if no active task is
-     * found.
-     *
-     * @returns the model index for the first active task, if any.
-     */
-    Q_INVOKABLE QModelIndex activeTask() const;
-
     /**
      * Given a row in the model, returns a QModelIndex for it. To get an index
      * for a child in a task group, an optional child row may be passed as well.
@@ -779,6 +780,7 @@ Q_SIGNALS:
     void groupingWindowTasksThresholdChanged() const;
     void groupingAppIdBlacklistChanged() const;
     void groupingLauncherUrlBlacklistChanged() const;
+    void activeTaskChanged() const;
 
 protected:
     bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const override;