Improved AndroidPlatformStrategy & Factory, to avoid memory leak of Context

assignments/week-5-assignment-4/W5-A4-Android/src/edu/vuum/mocca/AndroidPlatformStrategy.java

@@ -3,8 +3,6 @@
 import java.lang.ref.WeakReference;
 import java.util.concurrent.CountDownLatch;
 
-import android.app.Activity;
-import android.widget.TextView;
 import android.util.Log;
 
 /**
@@ -16,24 +14,14 @@
  *        "Concrete Strategy" in the Strategy pattern.
  */
 public class AndroidPlatformStrategy extends PlatformStrategy
-{	
-    /** TextViewVariable. */
-    private TextView mTextViewOutput;
-
+{   
     /** Activity variable finds gui widgets by view. */
-    private WeakReference<Activity> mActivity;
+    private WeakReference<OutputTextViewActivity> mActivity;
 
-    public AndroidPlatformStrategy(Object output,
-                                   final Object activityParam)
+    public AndroidPlatformStrategy(final OutputTextViewActivity activityParam)
     {
-        /**
-         * A textview output which displays calculations and
-         * expression trees.
-         */
-        mTextViewOutput = (TextView) output;
-
-        /** The current activity window (succinct or verbose). */
-        mActivity = new WeakReference<Activity>((Activity) activityParam);
+          /** The current activity window (succinct or verbose). */
+        mActivity = new WeakReference<OutputTextViewActivity>(activityParam);
     }
 
     /**
@@ -61,7 +49,7 @@ public void print(final String outputString)
 
     /** Indicate that a game thread has finished running. */
     public void done()
-    {	
+    {   
         // TODO - You fill in here.
     }
 
@@ -79,4 +67,4 @@ public void errorLog(String javaFile, String errorMessage)
     {
        Log.e(javaFile, errorMessage);
     }
-}
+}

assignments/week-5-assignment-4/W5-A4-Android/src/edu/vuum/mocca/Main.java

@@ -20,8 +20,7 @@ public static void main(String[] args)
          * ConsolePlatform.
          */
         PlatformStrategy.instance
-            (new PlatformStrategyFactory(System.out,
-                                         null).makePlatformStrategy());
+            (new PlatformStrategyFactory(System.out).makePlatformStrategy());
 
         /** Initializes the Options singleton. */
         Options.instance().parseArgs(args);

assignments/week-5-assignment-4/W5-A4-Android/src/edu/vuum/mocca/OutputTextViewActivity.java

@@ -0,0 +1,12 @@
+package edu.vuum.mocca;
+
+import android.app.Activity;
+import android.widget.TextView;
+
+/**
+ * Abstract class, that defines the the getOutputTextView() method. 
+ */
+public abstract class OutputTextViewActivity extends Activity {
+
+    abstract TextView getOutputTextView();
+}

assignments/week-5-assignment-4/W5-A4-Android/src/edu/vuum/mocca/PingPongActivity.java

@@ -1,6 +1,5 @@
 package edu.vuum.mocca;
 
-import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
@@ -11,7 +10,7 @@
  * 
  * @brief Initial start up screen for the android GUI.
  */
-public class PingPongActivity extends Activity {
+public class PingPongActivity extends OutputTextViewActivity {
     /** TextView that PingPong will be "played" upon */
     private TextView mAndroidPingPongOutput;
 
@@ -28,19 +27,16 @@ protected void onCreate(Bundle savedInstanceState) {
 
         // Sets the content view to the xml file, activity_ping_pong.
         setContentView(R.layout.activity_ping_pong);
-        mAndroidPingPongOutput =
-            (TextView) findViewById(R.id.pingpong_output);
+        mAndroidPingPongOutput = (TextView) findViewById(R.id.pingpong_output);
         mPlayButton = (Button) findViewById(R.id.play_button);
 
         // Initializes the Platform singleton with the appropriate
         // Platform strategy, which in this case will be the
         // AndroidPlatform.
-        PlatformStrategy.instance
-            (new PlatformStrategyFactory
-             (mAndroidPingPongOutput,
-              this).makePlatformStrategy());
+        PlatformStrategy.instance(new PlatformStrategyFactory(this)
+                .makePlatformStrategy());
 
-        // Initializes the Options singleton. 
+        // Initializes the Options singleton.
         Options.instance().parseArgs(null);
     }
 
@@ -49,11 +45,10 @@ public void playButtonClicked(View view) {
         if (mGameState == PLAY) {
             // Use a factory method to create the appropriate type of
             // OutputStrategy.
-            PlayPingPong pingPong =
-                new PlayPingPong(PlatformStrategy.instance(),
-                                 Options.instance().maxIterations(),
-                                 Options.instance().maxTurns(),
-                                 Options.instance().syncMechanism());
+            PlayPingPong pingPong = new PlayPingPong(
+                    PlatformStrategy.instance(), Options.instance()
+                            .maxIterations(), Options.instance().maxTurns(),
+                    Options.instance().syncMechanism());
 
             // Play ping-pong with the designated number of
             // iterations.
@@ -73,4 +68,12 @@ public void playButtonClicked(View view) {
             mGameState = RESET;
         }
     }
+
+    /**
+     * grant access of the Output TextView to the AndroidPlatformStrategy
+     */
+    @Override
+    TextView getOutputTextView() {
+        return mAndroidPingPongOutput;
+    }
 }

assignments/week-5-assignment-4/W5-A4-Android/src/edu/vuum/mocca/PlatformStrategyFactory.java

@@ -2,106 +2,98 @@
 
 import java.util.HashMap;
 
+import android.app.Activity;
+
 /**
  * @class PlatformStrategyFactory
  * 
  * @brief This class is a factory that is responsible for building the
  *        designated @a PlatformStrategy implementation at runtime.
  */
-public class PlatformStrategyFactory 
-{
-    /** 
-     * This interface uses the Strategy pattern to create @a
-     * PlatformStrategy implementations at runtime.
+public class PlatformStrategyFactory {
+    /**
+     * This interface uses the Strategy pattern to create @a PlatformStrategy
+     * implementations at runtime.
      */
-    private static interface IPlatformStrategyFactoryStrategy 
-    {
+    private static interface IPlatformStrategyFactoryStrategy {
         public PlatformStrategy execute();
     }
-	
+
     /**
      * Enumeration distinguishing platforms Android from plain ol' Java.
      */
     public enum PlatformType {
-    	ANDROID,
-    	PLAIN_JAVA
+        ANDROID, PLAIN_JAVA
     }
-    
+
     /**
-     * HashMap used to map strings containing the Java platform names
-     * and dispatch the execute() method of the associated @a PlatformStrategy
+     * HashMap used to map strings containing the Java platform names and
+     * dispatch the execute() method of the associated @a PlatformStrategy
      * implementation.
      */
-    private HashMap<PlatformType, IPlatformStrategyFactoryStrategy> mPlatformStrategyMap = 
-        new HashMap<PlatformType, IPlatformStrategyFactoryStrategy>();
-
-    /** 
-     * Ctor that stores the objects that perform output for a
-     * particular platform, such as ConsolePlatformStrategy or the
-     * AndroidPlatformStrategy.
+    private HashMap<PlatformType, IPlatformStrategyFactoryStrategy> mPlatformStrategyMap = new HashMap<PlatformType, IPlatformStrategyFactoryStrategy>();
+
+    /**
+     * Ctor that stores the objects that perform output for a particular
+     * platform, such as ConsolePlatformStrategy or the AndroidPlatformStrategy.
      */
-    public PlatformStrategyFactory(final Object output,
-                                   final Object activity) 
-    {
-    	/** 
-         * The "The Android Project" string maps to a command object
-         * that creates an @a AndroidPlatformStrategy implementation.
+    public PlatformStrategyFactory(final Object output) {
+        /**
+         * The "The Android Project" string maps to a command object that
+         * creates an @a AndroidPlatformStrategy implementation.
          */
         mPlatformStrategyMap.put(PlatformType.ANDROID,
-                                 new IPlatformStrategyFactoryStrategy() 
-                                 {
-                                     /** 
-                                      * Receives the three parameters, input
-                                      * (EditText), output (TextView), activity
-                                      * (activity).
-                                      */
-                                     public PlatformStrategy execute() 
-                                     {
-                                         return new AndroidPlatformStrategy(output,
-                                                                            activity);
-                                     }
-                                 });
-
-    	/** 
-         * The "Sun Microsystems Inc." string maps to a command object
-         * that creates an @a ConsolePlatformStrategy implementation.
+                new IPlatformStrategyFactoryStrategy() {
+                    /**
+                     * Receives the three parameters, input (EditText), output
+                     * (TextView), activity (activity).
+                     * 
+                     * @throws Exception
+                     */
+                    public PlatformStrategy execute() {
+                        if (output instanceof OutputTextViewActivity) {
+                            return new AndroidPlatformStrategy(
+                                    (OutputTextViewActivity) output);
+                        } else {
+                            return new AndroidPlatformStrategy(null);
+                        }
+                    }
+                });
+
+        /**
+         * The "Sun Microsystems Inc." string maps to a command object that
+         * creates an @a ConsolePlatformStrategy implementation.
          */
         mPlatformStrategyMap.put(PlatformType.PLAIN_JAVA,
-                                 new IPlatformStrategyFactoryStrategy() 
-                                 {
-                                     public PlatformStrategy execute() 
-                                     {
-                                         return new ConsolePlatformStrategy(output);
-                                     }
-                                 });
+                new IPlatformStrategyFactoryStrategy() {
+                    public PlatformStrategy execute() {
+                        return new ConsolePlatformStrategy(output);
+                    }
+                });
     }
 
-    /** 
-     * Returns the name of the platform in a string. e.g., Android or
-     * a JVM.
+    /**
+     * Returns the name of the platform in a string. e.g., Android or a JVM.
      */
-    public static String platformName() 
-    {
+    public static String platformName() {
         return System.getProperty("java.specification.vendor");
     }
-
-    /** 
-     * Returns the type of the platformm e.g. Android or
-     * a JVM.
+
+    /**
+     * Returns the type of the platformm e.g. Android or a JVM.
      */
     public static PlatformType platformType() {
-    	if(platformName().indexOf("Android") >= 0) 
+        if (platformName().indexOf("Android") >= 0)
             return PlatformType.ANDROID;
-    	else
+        else
             return PlatformType.PLAIN_JAVA;
     }
 
-    /** 
+    /**
      * Create a new @a PlatformStrategy object based on underlying Java
      * platform.
      */
-    public PlatformStrategy makePlatformStrategy() 
-    {
+    public PlatformStrategy makePlatformStrategy() {
         PlatformType type = platformType();
 
         return mPlatformStrategyMap.get(type).execute();

ex/AcronymApplication/res/layout/acronym_data_row.xml

@@ -9,28 +9,29 @@
     tools:context="edu.vu.isis.serviceparcelableexasync2.MainActivity$PlaceholderFragment" >
 
     <TextView
-        android:id="@+id/name"
+        android:id="@+id/year_added_to_db"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentLeft="true"
         android:layout_alignParentTop="true"
-        android:text="@string/result_string" />
+        android:text="@string/year_string" />
 
     <TextView
         android:id="@+id/db_refs"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentTop="true"
-        android:layout_toLeftOf="@+id/year_added_to_db"
+        android:paddingLeft="5dp"
+        android:layout_toRightOf="@+id/year_added_to_db"
         android:text="@string/refernces_string" />
 
     <TextView
-        android:id="@+id/year_added_to_db"
+        android:id="@+id/name"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentRight="true"
-        android:layout_alignParentTop="true"
-        android:paddingLeft="50dp"
-        android:text="@string/year_string" />
+        android:paddingLeft="5dp"
+        android:layout_toRightOf="@+id/db_refs"
+        android:text="@string/result_string" />
 
 </RelativeLayout>

ex/AcronymApplication/res/values/strings.xml

@@ -4,7 +4,7 @@
     <string name="action_settings">Settings</string>
     <string name="row_result_tv">Result</string>
     <string name="result_string">Result</string>
-    <string name="refernces_string">References</string>
+    <string name="refernces_string">Refs</string>
     <string name="year_string">Year</string>
 
 </resources>