Convert Task and TaskRunner

uhabits-android/src/main/java/org/isoron/uhabits/activities/common/views/TaskProgressBar.kt

@@ -40,8 +40,8 @@ class TaskProgressBar(
         isIndeterminate = true
     }
 
-    override fun onTaskStarted(task: Task?) = update()
-    override fun onTaskFinished(task: Task?) = update()
+    override fun onTaskStarted(task: Task) = update()
+    override fun onTaskFinished(task: Task) = update()
 
     override fun onAttachedToWindow() {
         super.onAttachedToWindow()

uhabits-android/src/main/java/org/isoron/uhabits/tasks/AndroidTaskRunner.java

@@ -23,6 +23,8 @@ import android.os.*;
 
 import org.isoron.uhabits.core.*;
 import org.isoron.uhabits.core.tasks.*;
+import org.isoron.uhabits.core.tasks.Task;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
 
@@ -53,18 +55,19 @@ public class AndroidTaskRunner implements TaskRunner
     }
 
     @Override
-    public void addListener(Listener listener)
+    public void addListener(@NotNull Listener listener)
     {
         listeners.add(listener);
     }
 
     @Override
-    public void execute(Task task)
+    public void execute(@NotNull Task task)
     {
         task.onAttached(this);
         new CustomAsyncTask(task).execute();
     }
 
+
     @Override
     public int getActiveTaskCount()
     {
@@ -72,7 +75,7 @@ public class AndroidTaskRunner implements TaskRunner
     }
 
     @Override
-    public void publishProgress(Task task, int progress)
+    public void publishProgress(@NotNull Task task, int progress)
     {
         CustomAsyncTask asyncTask = taskToAsyncTask.get(task);
         if (asyncTask == null) return;
@@ -80,11 +83,12 @@ public class AndroidTaskRunner implements TaskRunner
     }
 
     @Override
-    public void removeListener(Listener listener)
+    public void removeListener(@NotNull Listener listener)
     {
         listeners.remove(listener);
     }
 
+
     private class CustomAsyncTask extends AsyncTask<Void, Integer, Void>
     {
         private final Task task;

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt

@@ -21,6 +21,9 @@ package org.isoron.uhabits.core.tasks
 import java.util.LinkedList
 
 class SingleThreadTaskRunner : TaskRunner {
+    override val activeTaskCount: Int
+        get() = 0
+
     private val listeners: MutableList<TaskRunner.Listener> = LinkedList()
     override fun addListener(listener: TaskRunner.Listener) {
         listeners.add(listener)
@@ -37,10 +40,6 @@ class SingleThreadTaskRunner : TaskRunner {
         for (l in listeners) l.onTaskFinished(task)
     }
 
-    override fun getActiveTaskCount(): Int {
-        return 0
-    }
-
     override fun publishProgress(task: Task, progress: Int) {
         task.onProgressUpdate(progress)
     }

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/Task.kt

@@ -16,27 +16,16 @@
  * You should have received a copy of the GNU General Public License along
  * with this program. If not, see <http://www.gnu.org/licenses/>.
  */
-
-package org.isoron.uhabits.core.tasks;
-
-import androidx.annotation.*;
-
-public interface Task
-{
-    default void cancel() {}
-
-    default boolean isCanceled()
-    {
-        return false;
-    }
-
-    void doInBackground();
-
-    default void onAttached(@NonNull TaskRunner runner) {}
-
-    default void onPostExecute() {}
-
-    default void onPreExecute() {}
-
-    default void onProgressUpdate(int value) {}
+package org.isoron.uhabits.core.tasks
+
+fun interface Task {
+    fun cancel() {}
+    val isCanceled: Boolean
+        get() = false
+
+    fun doInBackground()
+    fun onAttached(runner: TaskRunner) {}
+    fun onPostExecute() {}
+    fun onPreExecute() {}
+    fun onProgressUpdate(value: Int) {}
 }

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/tasks/TaskRunner.kt

@@ -16,25 +16,17 @@
  * You should have received a copy of the GNU General Public License along
  * with this program. If not, see <http://www.gnu.org/licenses/>.
  */
-
-package org.isoron.uhabits.core.tasks;
-
-public interface TaskRunner
-{
-    void addListener(Listener listener);
-
-    void removeListener(Listener listener);
-
-    void execute(Task task);
-
-    void publishProgress(Task task, int progress);
-
-    int getActiveTaskCount();
-
-    interface Listener
-    {
-        void onTaskStarted(Task task);
-
-        void onTaskFinished(Task task);
+package org.isoron.uhabits.core.tasks
+
+interface TaskRunner {
+    fun addListener(listener: Listener)
+    fun removeListener(listener: Listener)
+    fun execute(task: Task)
+    fun publishProgress(task: Task, progress: Int)
+    val activeTaskCount: Int
+
+    interface Listener {
+        fun onTaskStarted(task: Task)
+        fun onTaskFinished(task: Task)
     }
 }

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/ui/screens/habits/list/HabitCardListCache.kt

@@ -136,8 +136,9 @@ class HabitCardListCache @Inject constructor(
     @Synchronized
     fun refreshAllHabits() {
         if (currentFetchTask != null) currentFetchTask!!.cancel()
-        currentFetchTask = RefreshTask()
-        taskRunner.execute(currentFetchTask)
+        val task = RefreshTask()
+        currentFetchTask = task
+        taskRunner.execute(task)
     }
 
     @Synchronized