Polished demo app a bit.

Author: Rolf Smit

demo/src/main/java/org/neotech/app/retainabletasksdemo/Main.java

@@ -17,39 +17,47 @@
 
 public class Main extends AppCompatActivity implements View.OnClickListener, Task.AdvancedCallback, OnAlertDialogClickListener {
 
-    private static final String TASK_SIMPLE = "Demo-task";
+    private static final String TASK_PROGRESS = "Demo-task";
+    private static final String DIALOG_PROGRESS = "progress-dialog";
 
     private ProgressDialog progressDialog;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
-        setSupportActionBar(toolbar);
+        setSupportActionBar((Toolbar) findViewById(R.id.toolbar));
 
-        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
-        fab.setOnClickListener(this);
+        findViewById(R.id.fab).setOnClickListener(this);
+
+        findViewById(R.id.button_no_ui_task).setOnClickListener(this);
+        findViewById(R.id.button_progress_task).setOnClickListener(this);
     }
 
     @Override
     protected void onStart() {
         super.onStart();
-        progressDialog = ProgressDialog.getExistingInstance(getSupportFragmentManager(), "progress-dialog");
-        getTaskHandler().attachListener(TASK_SIMPLE, this);
+        progressDialog = ProgressDialog.getExistingInstance(getSupportFragmentManager(), DIALOG_PROGRESS);
+        getTaskHandler().attachListener(TASK_PROGRESS, this);
     }
 
     @Override
     public void onClick(View v) {
-        if(getTaskHandler().isRunning(TASK_SIMPLE)){
-            Toast.makeText(this, "Task already running", Toast.LENGTH_SHORT).show();
-        }
+        final int id = v.getId();
+        if(id == R.id.fab){
+            //TODO info
+        } else if(id == R.id.button_progress_task) {
+            if (getTaskHandler().isRunning(TASK_PROGRESS)) {
+                Toast.makeText(this, "Task already running.", Toast.LENGTH_SHORT).show();
+            }
+            SimpleTask task = new SimpleTask(TASK_PROGRESS);
+            getTaskHandler().execute(task, this);
+
+        } else if(id == R.id.button_no_ui_task){
+            TaskWithoutCallback task = new TaskWithoutCallback(this);
+            TaskExecutor.execute(task);
 
-        SimpleTask task = new SimpleTask(TASK_SIMPLE);
-        getTaskHandler().execute(task, this);
-
-        TaskWithoutCallback callback = new TaskWithoutCallback(this);
-        TaskExecutor.execute(callback);
+        }
     }
 
     public TaskHandler getTaskHandler(){
@@ -58,19 +66,19 @@ public TaskHandler getTaskHandler(){
 
     @Override
     public void onPreExecute(Task<?, ?> task) {
-        progressDialog = ProgressDialog.showIfNotShowing(getSupportFragmentManager(), "progress-dialog");
+        progressDialog = ProgressDialog.showIfNotShowing(getSupportFragmentManager(), DIALOG_PROGRESS);
     }
 
     @Override
     public void onPostExecute(Task<?, ?> task) {
         progressDialog.dismiss();
-        Snackbar.make(findViewById(android.R.id.content), "Task finished.", Snackbar.LENGTH_LONG).show();
+        Snackbar.make(findViewById(android.R.id.content), "'Progress task' finished.", Snackbar.LENGTH_LONG).show();
     }
 
     @Override
     public void onCanceled(Task<?, ?> task) {
         progressDialog.dismiss();
-        Snackbar.make(findViewById(android.R.id.content), "Task canceled.", Snackbar.LENGTH_LONG).show();
+        Snackbar.make(findViewById(android.R.id.content), "'Progress task' canceled.", Snackbar.LENGTH_LONG).show();
     }
 
     @Override
@@ -80,6 +88,6 @@ public void onProgressUpdate(Task<?, ?> task, Object progress) {
 
     @Override
     public void onDialogFragmentClick(DialogFragment fragment, int which) {
-        getTaskHandler().cancel(TASK_SIMPLE);
+        getTaskHandler().cancel(TASK_PROGRESS);
     }
 }

demo/src/main/java/org/neotech/app/retainabletasksdemo/tasks/TaskWithoutCallback.java

@@ -9,7 +9,7 @@
 /**
  * Created by Rolf on 29-2-2016.
  */
-public class TaskWithoutCallback extends Task<Void, String> {
+public class TaskWithoutCallback extends Task<Void, Void> {
 
     private final Context context;
 
@@ -19,13 +19,18 @@ public TaskWithoutCallback(Context context) {
     }
 
     @Override
-    protected String doInBackground() {
-        SystemClock.sleep(5000);
-        return "Result";
+    protected Void doInBackground() {
+        SystemClock.sleep(4000);
+        return null;
+    }
+
+    @Override
+    protected void onPreExecute() {
+        Toast.makeText(context, "'Task without UI callback' started.", Toast.LENGTH_SHORT).show();
     }
 
     @Override
     protected void onPostExecute() {
-        Toast.makeText(context, "Task finished, result: " + getResult(), Toast.LENGTH_SHORT).show();
+        Toast.makeText(context, "'Task without UI callback' finished.", Toast.LENGTH_SHORT).show();
     }
 }

demo/src/main/res/drawable-hdpi/ic_info_outline.png

@@ -29,6 +29,6 @@
         android:layout_height="wrap_content"
         android:layout_gravity="bottom|end"
         android:layout_margin="@dimen/fab_margin"
-        android:src="@android:drawable/ic_dialog_email" />
+        android:src="@drawable/ic_info_outline" />
 
 </android.support.design.widget.CoordinatorLayout>

demo/src/main/res/drawable-mdpi/ic_info_outline.png

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
@@ -12,8 +12,23 @@
     tools:context="org.neotech.app.retainabletasksdemo.Main"
     tools:showIn="@layout/activity_main">
 
-    <TextView
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:text="Hello World!" />
-</RelativeLayout>
+    <LinearLayout
+        android:orientation="vertical"
+        android:gravity="center_horizontal"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <Button
+            android:id="@+id/button_no_ui_task"
+            android:layout_height="wrap_content"
+            android:layout_width="wrap_content"
+            android:text="Task without UI callback" />
+
+        <Button
+            android:id="@+id/button_progress_task"
+            android:layout_height="wrap_content"
+            android:layout_width="wrap_content"
+            android:text="Progress Task" />
+
+    </LinearLayout>
+</ScrollView>