Bitmapfun Sample: Minor updates/fixes.

Change-Id: I71dce2fdbe41ff67cc0aac9456d72d9aa7cb8318

samples/training/bitmapfun/BitmapFun/build.gradle

@@ -14,7 +14,7 @@ repositories {
 
 android {
     compileSdkVersion 19
-    buildToolsVersion "18.1.1"
+    buildToolsVersion "19.0.0"
 
     defaultConfig {
         minSdkVersion 7
@@ -23,5 +23,5 @@ android {
 }
 
 dependencies {
-    compile 'com.android.support:support-v4:18.0.0'
+    compile 'com.android.support:support-v4:19.0.+'
 }

samples/training/bitmapfun/BitmapFun/src/main/java/com/example/android/bitmapfun/ui/ImageDetailActivity.java

@@ -18,6 +18,7 @@ package com.example.android.bitmapfun.ui;
 
 import android.annotation.TargetApi;
 import android.app.ActionBar;
+import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentActivity;
@@ -48,7 +49,7 @@ public class ImageDetailActivity extends FragmentActivity implements OnClickList
     private ImageFetcher mImageFetcher;
     private ViewPager mPager;
 
-    @TargetApi(11)
+    @TargetApi(VERSION_CODES.HONEYCOMB)
     @Override
     public void onCreate(Bundle savedInstanceState) {
         if (BuildConfig.DEBUG) {
@@ -199,7 +200,7 @@ public class ImageDetailActivity extends FragmentActivity implements OnClickList
      * Set on the ImageView in the ViewPager children fragments, to enable/disable low profile mode
      * when the ImageView is touched.
      */
-    @TargetApi(11)
+    @TargetApi(VERSION_CODES.HONEYCOMB)
     @Override
     public void onClick(View v) {
         final int vis = mPager.getSystemUiVisibility();

samples/training/bitmapfun/BitmapFun/src/main/java/com/example/android/bitmapfun/ui/ImageGridFragment.java

@@ -20,6 +20,7 @@ import android.annotation.TargetApi;
 import android.app.ActivityOptions;
 import android.content.Context;
 import android.content.Intent;
+import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.util.Log;
@@ -134,6 +135,13 @@ public class ImageGridFragment extends Fragment implements AdapterView.OnItemCli
                                 if (BuildConfig.DEBUG) {
                                     Log.d(TAG, "onCreateView - numColumns set to " + numColumns);
                                 }
+                                if (Utils.hasJellyBean()) {
+                                    mGridView.getViewTreeObserver()
+                                            .removeOnGlobalLayoutListener(this);
+                                } else {
+                                    mGridView.getViewTreeObserver()
+                                            .removeGlobalOnLayoutListener(this);
+                                }
                             }
                         }
                     }
@@ -163,7 +171,7 @@ public class ImageGridFragment extends Fragment implements AdapterView.OnItemCli
         mImageFetcher.closeCache();
     }
 
-    @TargetApi(16)
+    @TargetApi(VERSION_CODES.JELLY_BEAN)
     @Override
     public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
         final Intent i = new Intent(getActivity(), ImageDetailActivity.class);
@@ -226,6 +234,11 @@ public class ImageGridFragment extends Fragment implements AdapterView.OnItemCli
 
         @Override
         public int getCount() {
+            // If columns have yet to be determined, return no items
+            if (getNumColumns() == 0) {
+                return 0;
+            }
+
             // Size + number of columns for top empty row
             return Images.imageThumbUrls.length + mNumColumns;
         }

samples/training/bitmapfun/BitmapFun/src/main/java/com/example/android/bitmapfun/util/ImageCache.java

@@ -23,6 +23,7 @@ import android.graphics.Bitmap.CompressFormat;
 import android.graphics.Bitmap.Config;
 import android.graphics.BitmapFactory;
 import android.graphics.drawable.BitmapDrawable;
+import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import android.os.Environment;
 import android.os.StatFs;
@@ -354,24 +355,26 @@ public class ImageCache {
         Bitmap bitmap = null;
 
         if (mReusableBitmaps != null && !mReusableBitmaps.isEmpty()) {
-            final Iterator<SoftReference<Bitmap>> iterator = mReusableBitmaps.iterator();
+            synchronized (mReusableBitmaps) {
-            Bitmap item;
+                final Iterator<SoftReference<Bitmap>> iterator = mReusableBitmaps.iterator();
+                Bitmap item;
 
-            while (iterator.hasNext()) {
+                while (iterator.hasNext()) {
-                item = iterator.next().get();
+                    item = iterator.next().get();
 
-                if (null != item && item.isMutable()) {
+                    if (null != item && item.isMutable()) {
-                    // Check to see it the item can be used for inBitmap
+                        // Check to see it the item can be used for inBitmap
-                    if (canUseForInBitmap(item, options)) {
+                        if (canUseForInBitmap(item, options)) {
-                        bitmap = item;
+                            bitmap = item;
 
-                        // Remove from reusable set so it can't be used again
+                            // Remove from reusable set so it can't be used again
+                            iterator.remove();
+                            break;
+                        }
+                    } else {
+                        // Remove from the set if the reference has been cleared.
                         iterator.remove();
-                        break;
                     }
-                } else {
-                    // Remove from the set if the reference has been cleared.
-                    iterator.remove();
                 }
             }
         }
@@ -503,6 +506,7 @@ public class ImageCache {
      * @return true if <code>candidate</code> can be used for inBitmap re-use with
      *      <code>targetOptions</code>
      */
+    @TargetApi(VERSION_CODES.KITKAT)
     private static boolean canUseForInBitmap(
             Bitmap candidate, BitmapFactory.Options targetOptions) {
 
@@ -594,7 +598,7 @@ public class ImageCache {
      * @param value
      * @return size in bytes
      */
-    @TargetApi(12)
+    @TargetApi(VERSION_CODES.KITKAT)
     public static int getBitmapSize(BitmapDrawable value) {
         Bitmap bitmap = value.getBitmap();
 
@@ -618,7 +622,7 @@ public class ImageCache {
      * @return True if external storage is removable (like an SD card), false
      *         otherwise.
      */
-    @TargetApi(9)
+    @TargetApi(VERSION_CODES.GINGERBREAD)
     public static boolean isExternalStorageRemovable() {
         if (Utils.hasGingerbread()) {
             return Environment.isExternalStorageRemovable();
@@ -632,7 +636,7 @@ public class ImageCache {
      * @param context The context to use
      * @return The external cache dir
      */
-    @TargetApi(8)
+    @TargetApi(VERSION_CODES.FROYO)
     public static File getExternalCacheDir(Context context) {
         if (Utils.hasFroyo()) {
             return context.getExternalCacheDir();
@@ -649,7 +653,7 @@ public class ImageCache {
      * @param path The path to check
      * @return The space available in bytes
      */
-    @TargetApi(9)
+    @TargetApi(VERSION_CODES.GINGERBREAD)
     public static long getUsableSpace(File path) {
         if (Utils.hasGingerbread()) {
             return path.getUsableSpace();

samples/training/bitmapfun/BitmapFun/src/main/java/com/example/android/bitmapfun/util/Utils.java

@@ -16,20 +16,22 @@
 
 package com.example.android.bitmapfun.util;
 
-import com.example.android.bitmapfun.ui.ImageDetailActivity;
-import com.example.android.bitmapfun.ui.ImageGridActivity;
-
 import android.annotation.TargetApi;
 import android.os.Build;
+import android.os.Build.VERSION_CODES;
 import android.os.StrictMode;
 
+import com.example.android.bitmapfun.ui.ImageDetailActivity;
+import com.example.android.bitmapfun.ui.ImageGridActivity;
+
 /**
  * Class containing some static utility methods.
  */
 public class Utils {
     private Utils() {};
 
-    @TargetApi(11)
+
+    @TargetApi(VERSION_CODES.HONEYCOMB)
     public static void enableStrictMode() {
         if (Utils.hasGingerbread()) {
             StrictMode.ThreadPolicy.Builder threadPolicyBuilder =