Scope changes and removal of unnessecary variable

Adds isFullScreen() and setPhotoIndex() protected methods to
PhotoViewActivity in order to allow subclasses access to this
information.

Removes mDataValid from BaseCursorPagerAdapter since it was hiding how
simple the checks actually were (it was just mCursor != null)

A nullcheck has also been added to BaseFragmentPagerAdapter in
instantiateItem. in the long term, BaseCursorPagerAdapter should not be
so fragile, and should not surface nulls, but that change could be quite
involved, so should probably not be rolled into this change.

Change-Id: I4889c5ae2a764660926c70da25b85565f4600188

3 files changed, 22 insertions, 12 deletions

diff --git a/photoviewer/src/com/android/ex/photo/PhotoViewActivity.java b/photoviewer/src/com/android/ex/photo/PhotoViewActivity.java
index 8628331..ff3eb4c 100644
--- a/photoviewer/src/com/android/ex/photo/PhotoViewActivity.java
+++ b/photoviewer/src/com/android/ex/photo/PhotoViewActivity.java
@@ -415,7 +415,7 @@ public class PhotoViewActivity extends Activity implements
     /**
      * Updates the title bar according to the value of {@link #mFullScreen}.
      */
-    private void setFullScreen(boolean fullScreen, boolean setDelayedRunnable) {
+    protected void setFullScreen(boolean fullScreen, boolean setDelayedRunnable) {
         final boolean fullScreenChanged = (fullScreen != mFullScreen);
         mFullScreen = fullScreen;
 
@@ -549,4 +549,12 @@ public class PhotoViewActivity extends Activity implements
             postActionBarHideRunnableWithDelay();
         }
     }
+
+    protected boolean isFullScreen() {
+        return mFullScreen;
+    }
+
+    protected void setPhotoIndex(int index) {
+        mPhotoIndex = index;
+    }
 }
diff --git a/photoviewer/src/com/android/ex/photo/adapters/BaseCursorPagerAdapter.java b/photoviewer/src/com/android/ex/photo/adapters/BaseCursorPagerAdapter.java
index 848d79a..f827690 100644
--- a/photoviewer/src/com/android/ex/photo/adapters/BaseCursorPagerAdapter.java
+++ b/photoviewer/src/com/android/ex/photo/adapters/BaseCursorPagerAdapter.java
@@ -38,7 +38,6 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
     private static final String TAG = "BaseCursorPagerAdapter";
 
     Context mContext;
-    private boolean mDataValid;
     private Cursor mCursor;
     private int mRowIDColumn;
     /** Mapping of row ID to cursor position */
@@ -67,9 +66,11 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
      */
     public abstract Fragment getItem(Context context, Cursor cursor, int position);
 
+    // TODO: This shouldn't just return null - maybe it needs to wait for a cursor to be supplied?
+    //       See b/7103023
     @Override
     public Fragment getItem(int position) {
-        if (mDataValid && moveCursorTo(position)) {
+        if (mCursor != null && moveCursorTo(position)) {
             return getItem(mContext, mCursor, position);
         }
         return null;
@@ -77,7 +78,7 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
 
     @Override
     public int getCount() {
-        if (mDataValid && mCursor != null) {
+        if (mCursor != null) {
             return mCursor.getCount();
         } else {
             return 0;
@@ -86,7 +87,7 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
 
     @Override
     public Object instantiateItem(View container, int position) {
-        if (!mDataValid) {
+        if (mCursor == null) {
             throw new IllegalStateException("this should only be called when the cursor is valid");
         }
 
@@ -127,7 +128,7 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
      * @return true if data is valid
      */
     public boolean isDataValid() {
-        return mDataValid;
+        return mCursor != null;
     }
 
     /**
@@ -141,7 +142,7 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
      * Returns the data item associated with the specified position in the data set.
      */
     public Object getDataItem(int position) {
-        if (mDataValid && moveCursorTo(position)) {
+        if (mCursor != null && moveCursorTo(position)) {
             return mCursor;
         } else {
             return null;
@@ -152,7 +153,7 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
      * Returns the row id associated with the specified position in the list.
      */
     public long getItemId(int position) {
-        if (mDataValid && moveCursorTo(position)) {
+        if (mCursor != null && moveCursorTo(position)) {
             return mCursor.getString(mRowIDColumn).hashCode();
         } else {
             return 0;
@@ -180,10 +181,8 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
         mCursor = newCursor;
         if (newCursor != null) {
             mRowIDColumn = newCursor.getColumnIndex(PhotoContract.PhotoViewColumns.URI);
-            mDataValid = true;
         } else {
             mRowIDColumn = -1;
-            mDataValid = false;
         }
 
         setItemPosition();
@@ -231,7 +230,6 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
     private void init(Context context, Cursor c) {
         boolean cursorPresent = c != null;
         mCursor = c;
-        mDataValid = cursorPresent;
         mContext = context;
         mRowIDColumn = cursorPresent
                 ? mCursor.getColumnIndex(PhotoContract.PhotoViewColumns.URI) : -1;
@@ -242,7 +240,7 @@ public abstract class BaseCursorPagerAdapter extends BaseFragmentPagerAdapter {
      * row id to cursor position.
      */
     private void setItemPosition() {
-        if (!mDataValid || mCursor == null || mCursor.isClosed()) {
+        if (mCursor == null || mCursor.isClosed()) {
             mItemPosition = null;
             return;
         }
diff --git a/photoviewer/src/com/android/ex/photo/adapters/BaseFragmentPagerAdapter.java b/photoviewer/src/com/android/ex/photo/adapters/BaseFragmentPagerAdapter.java
index 9c24575..2065b2a 100644
--- a/photoviewer/src/com/android/ex/photo/adapters/BaseFragmentPagerAdapter.java
+++ b/photoviewer/src/com/android/ex/photo/adapters/BaseFragmentPagerAdapter.java
@@ -86,6 +86,10 @@ public abstract class BaseFragmentPagerAdapter extends PagerAdapter {
             mCurTransaction.attach(fragment);
         } else {
             fragment = getItem(position);
+            if(fragment == null) {
+                if (DEBUG) Log.e(TAG, "NPE workaround for getItem(). See b/7103023");
+                return null;
+            }
             if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment);
             mCurTransaction.add(container.getId(), fragment,
                     makeFragmentName(container.getId(), position));