Provide access to current activities

app/src/main/java/com/commit451/lifeline/sample/CheckIfForegroundService.java

@@ -5,6 +5,7 @@
 import android.content.Intent;
 import android.os.Handler;
 import android.os.Looper;
+import android.util.Log;
 import android.widget.Toast;
 
 import com.commit451.lifeline.Lifeline;
@@ -22,7 +23,7 @@ public static void check(Context context) {
     }
 
     public CheckIfForegroundService() {
-        super("skldfjla");
+        super(CheckIfForegroundService.class.getSimpleName());
     }
 
     @Override
@@ -31,6 +32,8 @@ protected void onHandleIntent(Intent intent) {
             @Override
             public void run() {
                 Toast.makeText(CheckIfForegroundService.this, "In foreground: " + Lifeline.isInForeground(), Toast.LENGTH_SHORT).show();
+                Log.d("TEST", "Current visible activity: " + Lifeline.getCurrentVisibleActivity());
+                Log.d("TEST", "Current created activity: " + Lifeline.getCurrentCreatedActivity());
             }
         });
         try {

app/src/main/java/com/commit451/lifeline/sample/MainActivity.java

@@ -1,7 +1,10 @@
 package com.commit451.lifeline.sample;
 
+import android.support.v7.app.AlertDialog;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
 import android.widget.Toast;
 
 import com.commit451.lifeline.Lifeline;
@@ -12,15 +15,32 @@ public class MainActivity extends AppCompatActivity {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+
+        findViewById(R.id.button_dialog).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                new AlertDialog.Builder(MainActivity.this)
+                        .setTitle("Hi")
+                        .setMessage("Hello there")
+                        .show();
+            }
+        });
         CheckIfForegroundService.check(this);
     }
 
     @Override
     protected void onResume() {
         super.onResume();
+        Log.d("TEST", "onResume");
         long timeSpentOutsideApp = Lifeline.getTimeSpentOutsideApp();
         if (timeSpentOutsideApp > 0) {
             Toast.makeText(MainActivity.this, "time spend outside of app: " + timeSpentOutsideApp + " ms", Toast.LENGTH_SHORT).show();
         }
     }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        Log.d("TEST", "onPause");
+    }
 }

app/src/main/res/layout/activity_main.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout
+<LinearLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
@@ -8,10 +8,17 @@
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
+    android:orientation="vertical"
     tools:context="com.commit451.lifeline.sample.MainActivity">
 
     <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="Hello World!"/>
-</RelativeLayout>
+
+    <Button
+        android:id="@+id/button_dialog"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Show a Dialog"/>
+</LinearLayout>

lifeline/build.gradle

@@ -22,7 +22,9 @@ android {
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
+    compile fileTree(include: ['*.jar'], dir: 'libs')
+    compile 'com.android.support:support-annotations:25.3.0'
+
     testCompile 'junit:junit:4.12'
 }
 

lifeline/src/main/java/com/commit451/lifeline/Lifeline.java

@@ -3,6 +3,9 @@
 import android.app.Activity;
 import android.app.Application;
 import android.os.Bundle;
+import android.support.annotation.Nullable;
+
+import java.lang.ref.WeakReference;
 
 /**
  * Keeps a pulse on your application
@@ -13,6 +16,7 @@ public class Lifeline {
 
     /**
      * Hooks your Application up to this Lifeline
+     *
      * @param application application
      */
     public static void init(Application application) {
@@ -50,6 +54,48 @@ public static long getTimeSpentOutsideApp() {
         return lifecycleHandler.timeSpentOutsideApp;
     }
 
+    /**
+     * Get the currently visible activity. This could be null in certain cases, such as if a
+     * dialog is showing on top of the current activity
+     *
+     * @return the activity that is showing (resumed) or null if none exists
+     */
+    @Nullable
+    public static Activity getCurrentVisibleActivity() {
+        if (lifecycleHandler.currentVisibleActivityRef != null) {
+            return lifecycleHandler.currentVisibleActivityRef.get();
+        }
+        return null;
+    }
+
+    /**
+     * Get the currently created activity. This could be null in certain cases, such as if a
+     * no activities have been created (just services or broadcast receivers in existence)
+     *
+     * @return the latest created activity or null if none exists
+     */
+    @Nullable
+    public static Activity getCurrentCreatedActivity() {
+        if (lifecycleHandler.currentCreatedActivityRef != null) {
+            return lifecycleHandler.currentCreatedActivityRef.get();
+        }
+        return null;
+    }
+
+    /**
+     * Get the currently started activity. This could be null in certain cases, such as if a
+     * no activities have been started (just services or broadcast receivers in existence)
+     *
+     * @return the latest started activity or null if none exists
+     */
+    @Nullable
+    public static Activity getCurrentStartedActivity() {
+        if (lifecycleHandler.currentStartedActivityRef != null) {
+            return lifecycleHandler.currentStartedActivityRef.get();
+        }
+        return null;
+    }
+
     private static void checkInit() {
         if (lifecycleHandler == null) {
             throw new IllegalStateException("You need to first call `init()` on this class before using it");
@@ -69,12 +115,18 @@ private static class TrackedLifecycleCallbacks implements Application.ActivityLi
         private long timeStartedPause;
         private long timeSpentOutsideApp;
 
+        private WeakReference<Activity> currentVisibleActivityRef;
+        private WeakReference<Activity> currentCreatedActivityRef;
+        private WeakReference<Activity> currentStartedActivityRef;
+
         @Override
         public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
+            currentCreatedActivityRef = new WeakReference<>(activity);
         }
 
         @Override
         public void onActivityDestroyed(Activity activity) {
+            currentVisibleActivityRef = null;
         }
 
         @Override
@@ -84,12 +136,14 @@ public void onActivityResumed(Activity activity) {
                 timeSpentOutsideApp = System.currentTimeMillis() - timeStartedPause;
                 timeStartedPause = 0;
             }
+            currentVisibleActivityRef = new WeakReference<>(activity);
         }
 
         @Override
         public void onActivityPaused(Activity activity) {
             paused = paused + 1;
             timeStartedPause = System.currentTimeMillis();
+            currentVisibleActivityRef = null;
         }
 
         @Override
@@ -99,11 +153,13 @@ public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
         @Override
         public void onActivityStarted(Activity activity) {
             ++started;
+            currentStartedActivityRef = new WeakReference<>(activity);
         }
 
         @Override
         public void onActivityStopped(Activity activity) {
             ++stopped;
+            currentStartedActivityRef = null;
         }
     }
 }