Improve performance of detail page by cancelling useless async tasks

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/BarCard.java

@@ -54,9 +54,6 @@ public class BarCard extends HabitCard
     @BindView(R.id.title)
     TextView title;
 
-    @Nullable
-    private TaskRunner taskRunner;
-
     private int bucketSize;
 
     public BarCard(Context context)
@@ -85,29 +82,13 @@ public class BarCard extends HabitCard
         refreshData();
     }
 
-    @Override
-    protected void refreshData()
-    {
-        if (taskRunner == null) return;
-        taskRunner.execute(new RefreshTask(getHabit()));
-    }
-
     private void init()
     {
         inflate(getContext(), R.layout.show_habit_bar, this);
         ButterKnife.bind(this);
-
         boolSpinner.setSelection(1);
         numericalSpinner.setSelection(2);
         bucketSize = 7;
-
-        Context appContext = getContext().getApplicationContext();
-        if (appContext instanceof HabitsApplication)
-        {
-            HabitsApplication app = (HabitsApplication) appContext;
-            taskRunner = app.getComponent().getTaskRunner();
-        }
-
         if (isInEditMode()) initEditMode();
     }
 
@@ -119,11 +100,17 @@ public class BarCard extends HabitCard
         chart.populateWithRandomData();
     }
 
-    private class RefreshTask implements Task
+    @Override
+    protected Task createRefreshTask()
+    {
+        return new RefreshTask(getHabit());
+    }
+
+    private class RefreshTask extends CancelableTask
     {
         private final Habit habit;
 
-        public RefreshTask(Habit habit)
+        RefreshTask(Habit habit)
         {
             this.habit = habit;
         }
@@ -131,6 +118,7 @@ public class BarCard extends HabitCard
         @Override
         public void doInBackground()
         {
+            if (isCanceled()) return;
             List<Checkmark> checkmarks;
             if (bucketSize == 1) checkmarks = habit.getCheckmarks().getAll();
             else checkmarks = habit.getCheckmarks().groupBy(getTruncateField(bucketSize));

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/FrequencyCard.java

@@ -43,9 +43,6 @@ public class FrequencyCard extends HabitCard
     @BindView(R.id.frequencyChart)
     FrequencyChart chart;
 
-    @Nullable
-    private TaskRunner taskRunner;
-
     public FrequencyCard(Context context)
     {
         super(context);
@@ -59,24 +56,15 @@ public class FrequencyCard extends HabitCard
     }
 
     @Override
-    protected void refreshData()
+    protected Task createRefreshTask()
     {
-        if(taskRunner == null) return;
+        return new RefreshTask();
-        taskRunner.execute(new RefreshTask());
     }
 
     private void init()
     {
         inflate(getContext(), R.layout.show_habit_frequency, this);
         ButterKnife.bind(this);
-
-        Context appContext = getContext().getApplicationContext();
-        if(appContext instanceof HabitsApplication)
-        {
-            HabitsApplication app = (HabitsApplication) appContext;
-            taskRunner = app.getComponent().getTaskRunner();
-        }
-
         if (isInEditMode()) initEditMode();
     }
 
@@ -88,11 +76,12 @@ public class FrequencyCard extends HabitCard
         chart.populateWithRandomData();
     }
 
-    private class RefreshTask implements Task
+    private class RefreshTask  extends CancelableTask
     {
         @Override
         public void doInBackground()
         {
+            if (isCanceled()) return;
             RepetitionList reps = getHabit().getRepetitions();
             HashMap<Timestamp, Integer[]> frequency = reps.getWeekdayFrequency();
             chart.setFrequency(frequency);

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/HabitCard.java

@@ -24,8 +24,10 @@ import android.support.annotation.*;
 import android.util.*;
 import android.widget.*;
 
+import org.isoron.uhabits.*;
 import org.isoron.uhabits.core.models.*;
 import org.isoron.uhabits.core.models.memory.*;
+import org.isoron.uhabits.core.tasks.*;
 
 public abstract class HabitCard extends LinearLayout
     implements ModelObservable.Listener
@@ -33,6 +35,12 @@ public abstract class HabitCard extends LinearLayout
     @NonNull
     private Habit habit;
 
+    @Nullable
+    private TaskRunner taskRunner;
+
+    @Nullable
+    private Task currentRefreshTask;
+
     public HabitCard(Context context)
     {
         super(context);
@@ -82,7 +90,15 @@ public abstract class HabitCard extends LinearLayout
         super.onDetachedFromWindow();
     }
 
-    protected abstract void refreshData();
+    protected void refreshData()
+    {
+        if(taskRunner == null) return;
+        if(currentRefreshTask != null) currentRefreshTask.cancel();
+        currentRefreshTask = createRefreshTask();
+        taskRunner.execute(currentRefreshTask);
+    }
+
+    protected abstract Task createRefreshTask();
 
     private void attachTo(Habit habit)
     {
@@ -99,5 +115,11 @@ public abstract class HabitCard extends LinearLayout
     private void init()
     {
         if(!isInEditMode()) habit = new MemoryModelFactory().buildHabit();
+        Context appContext = getContext().getApplicationContext();
+        if(appContext instanceof HabitsApplication)
+        {
+            HabitsApplication app = (HabitsApplication) appContext;
+            taskRunner = app.getComponent().getTaskRunner();
+        }
     }
 }

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/HistoryCard.java

@@ -44,9 +44,6 @@ public class HistoryCard extends HabitCard
     @NonNull
     private Controller controller;
 
-    @Nullable
-    private TaskRunner taskRunner;
-
     public HistoryCard(Context context)
     {
         super(context);
@@ -70,25 +67,10 @@ public class HistoryCard extends HabitCard
         this.controller = controller;
     }
 
-    @Override
-    protected void refreshData()
-    {
-        if(taskRunner == null) return;
-        taskRunner.execute(new RefreshTask(getHabit()));
-    }
-
     private void init()
     {
         inflate(getContext(), R.layout.show_habit_history, this);
         ButterKnife.bind(this);
-
-        Context appContext = getContext().getApplicationContext();
-        if (appContext instanceof HabitsApplication)
-        {
-            HabitsApplication app = (HabitsApplication) appContext;
-            taskRunner = app.getComponent().getTaskRunner();
-        }
-
         controller = new Controller() {};
         if (isInEditMode()) initEditMode();
     }
@@ -101,20 +83,30 @@ public class HistoryCard extends HabitCard
         chart.populateWithRandomData();
     }
 
+    @Override
+    protected Task createRefreshTask()
+    {
+        return new RefreshTask(getHabit());
+    }
+
     public interface Controller
     {
         default void onEditHistoryButtonClick() {}
     }
 
-    private class RefreshTask implements Task
+    private class RefreshTask  extends CancelableTask
     {
         private final Habit habit;
 
-        public RefreshTask(Habit habit) {this.habit = habit;}
+        private RefreshTask(Habit habit)
+        {
+            this.habit = habit;
+        }
 
         @Override
         public void doInBackground()
         {
+            if (isCanceled()) return;
             int checkmarks[] = habit.getCheckmarks().getAllValues();
             chart.setCheckmarks(checkmarks);
         }

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/OverviewCard.java

@@ -60,9 +60,6 @@ public class OverviewCard extends HabitCard
 
     private int color;
 
-    @Nullable
-    private TaskRunner taskRunner;
-
     public OverviewCard(Context context)
     {
         super(context);
@@ -75,13 +72,6 @@ public class OverviewCard extends HabitCard
         init();
     }
 
-    @Override
-    protected void refreshData()
-    {
-        if(taskRunner == null) return;
-        taskRunner.execute(new RefreshTask());
-    }
-
     private String formatPercentageDiff(float percentageDiff)
     {
         return String.format("%s%.0f%%", (percentageDiff >= 0 ? "+" : "\u2212"),
@@ -90,17 +80,9 @@ public class OverviewCard extends HabitCard
 
     private void init()
     {
-        Context appContext = getContext().getApplicationContext();
-        if (appContext instanceof HabitsApplication)
-        {
-            HabitsApplication app = (HabitsApplication) appContext;
-            taskRunner = app.getComponent().getTaskRunner();
-        }
-
         inflate(getContext(), R.layout.show_habit_overview, this);
         ButterKnife.bind(this);
         cache = new Cache();
-
         if (isInEditMode()) initEditMode();
     }
 
@@ -146,20 +128,27 @@ public class OverviewCard extends HabitCard
 
     private class Cache
     {
-        public float todayScore;
+        float todayScore;
 
-        public float lastMonthScore;
+        float lastMonthScore;
 
-        public float lastYearScore;
+        float lastYearScore;
 
-        public long totalCount;
+        long totalCount;
     }
 
-    private class RefreshTask implements Task
+    @Override
+    protected Task createRefreshTask()
+    {
+        return new RefreshTask();
+    }
+
+    private class RefreshTask  extends CancelableTask
     {
         @Override
         public void doInBackground()
         {
+            if (isCanceled()) return;
             Habit habit = getHabit();
 
             ScoreList scores = habit.getScores();
@@ -177,6 +166,7 @@ public class OverviewCard extends HabitCard
         @Override
         public void onPostExecute()
         {
+            if (isCanceled()) return;
             refreshScore();
         }
 

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/ScoreCard.java

@@ -52,9 +52,6 @@ public class ScoreCard extends HabitCard
 
     private int bucketSize;
 
-    @Nullable
-    private TaskRunner taskRunner;
-
     @Nullable
     private Preferences prefs;
 
@@ -94,13 +91,6 @@ public class ScoreCard extends HabitCard
         refreshData();
     }
 
-    @Override
-    protected void refreshData()
-    {
-        if(taskRunner == null) return;
-        taskRunner.execute(new RefreshTask());
-    }
-
     private int getDefaultSpinnerPosition()
     {
         if(prefs == null) return 0;
@@ -113,7 +103,6 @@ public class ScoreCard extends HabitCard
         if (appContext instanceof HabitsApplication)
         {
             HabitsApplication app = (HabitsApplication) appContext;
-            taskRunner = app.getComponent().getTaskRunner();
             prefs = app.getComponent().getPreferences();
         }
 
@@ -140,11 +129,18 @@ public class ScoreCard extends HabitCard
         bucketSize = BUCKET_SIZES[position];
     }
 
-    private class RefreshTask implements Task
+    @Override
+    protected Task createRefreshTask()
+    {
+        return new RefreshTask();
+    }
+
+    private class RefreshTask  extends CancelableTask
     {
         @Override
         public void doInBackground()
         {
+            if (isCanceled()) return;
             List<Score> scores;
             ScoreList scoreList = getHabit().getScores();
 

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/StreakCard.java

@@ -45,9 +45,6 @@ public class StreakCard extends HabitCard
     @BindView(R.id.streakChart)
     StreakChart streakChart;
 
-    @Nullable
-    private TaskRunner taskRunner;
-
     public StreakCard(Context context)
     {
         super(context);
@@ -60,22 +57,8 @@ public class StreakCard extends HabitCard
         init();
     }
 
-    @Override
-    protected void refreshData()
-    {
-        if(taskRunner == null) return;
-        taskRunner.execute(new RefreshTask());
-    }
-
     private void init()
     {
-        Context appContext = getContext().getApplicationContext();
-        if (appContext instanceof HabitsApplication)
-        {
-            HabitsApplication app = (HabitsApplication) appContext;
-            taskRunner = app.getComponent().getTaskRunner();
-        }
-
         inflate(getContext(), R.layout.show_habit_streak, this);
         ButterKnife.bind(this);
         setOrientation(VERTICAL);
@@ -90,13 +73,20 @@ public class StreakCard extends HabitCard
         streakChart.populateWithRandomData();
     }
 
-    private class RefreshTask implements Task
+    @Override
+    protected Task createRefreshTask()
     {
-        public List<Streak> bestStreaks;
+        return new RefreshTask();
+    }
+
+    private class RefreshTask extends CancelableTask
+    {
+        List<Streak> bestStreaks;
 
         @Override
         public void doInBackground()
         {
+            if (isCanceled()) return;
             StreakList streaks = getHabit().getStreaks();
             bestStreaks = streaks.getBest(NUM_STREAKS);
         }
@@ -104,6 +94,7 @@ public class StreakCard extends HabitCard
         @Override
         public void onPostExecute()
         {
+            if (isCanceled()) return;
             streakChart.setStreaks(bestStreaks);
         }
 

android/uhabits-android/src/main/java/org/isoron/uhabits/activities/habits/show/views/SubtitleCard.java

@@ -27,6 +27,7 @@ import android.widget.*;
 
 import org.isoron.uhabits.R;
 import org.isoron.uhabits.core.models.*;
+import org.isoron.uhabits.core.tasks.*;
 import org.isoron.uhabits.utils.*;
 
 import butterknife.*;
@@ -111,4 +112,10 @@ public class SubtitleCard extends HabitCard
             AndroidDateUtils.formatTime(getContext(), reminder.getHour(),
                 reminder.getMinute()));
     }
+
+    @Override
+    protected Task createRefreshTask() {
+        // Never called
+        throw new IllegalStateException();
+    }
 }

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

@@ -87,6 +87,7 @@ public class AndroidTaskRunner implements TaskRunner
     private class CustomAsyncTask extends AsyncTask<Void, Integer, Void>
     {
         private final Task task;
+        private boolean isCancelled = false;
 
         public CustomAsyncTask(Task task)
         {
@@ -106,6 +107,7 @@ public class AndroidTaskRunner implements TaskRunner
         @Override
         protected Void doInBackground(Void... params)
         {
+            if(isCancelled) return null;
             task.doInBackground();
             return null;
         }
@@ -113,6 +115,7 @@ public class AndroidTaskRunner implements TaskRunner
         @Override
         protected void onPostExecute(Void aVoid)
         {
+            if(isCancelled) return;
             task.onPostExecute();
             activeTasks.remove(this);
             taskToAsyncTask.remove(task);
@@ -122,6 +125,8 @@ public class AndroidTaskRunner implements TaskRunner
         @Override
         protected void onPreExecute()
         {
+            isCancelled = task.isCanceled();
+            if(isCancelled) return;
             for (Listener l : listeners) l.onTaskStarted(task);
             activeTasks.add(this);
             taskToAsyncTask.put(task, this);

android/uhabits-core/src/main/java/org/isoron/uhabits/core/tasks/CancelableTask.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2016 Álinson Santos Xavier <isoron@gmail.com>
+ *
+ * This file is part of Loop Habit Tracker.
+ *
+ * Loop Habit Tracker is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * Loop Habit Tracker is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * 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 abstract class CancelableTask implements Task
+{
+    private boolean isCanceled = false;
+
+    @Override
+    public synchronized void cancel()
+    {
+        isCanceled = true;
+    }
+
+    @Override
+    public synchronized boolean isCanceled()
+    {
+        return isCanceled;
+    }
+}

android/uhabits-core/src/main/java/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.java

@@ -35,10 +35,13 @@ public class SingleThreadTaskRunner implements TaskRunner
     public void execute(Task task)
     {
         for(Listener l : listeners) l.onTaskStarted(task);
+        if(!task.isCanceled())
+        {
             task.onAttached(this);
             task.onPreExecute();
             task.doInBackground();
             task.onPostExecute();
+        }
         for(Listener l : listeners) l.onTaskFinished(task);
     }
 

android/uhabits-core/src/main/java/org/isoron/uhabits/core/tasks/Task.java

@@ -25,6 +25,11 @@ public interface Task
 {
     default void cancel() {}
 
+    default boolean isCanceled()
+    {
+        return false;
+    }
+
     void doInBackground();
 
     default void onAttached(@NonNull TaskRunner runner) {}