Disable ViewPager when photo viewer zoomed in

Work around common limitation with GestureImageView when using with
ViewPager.

Requires some modifications to GestureImageView outlined at
jasonpolites/gesture-imageview#30

res/layout/photoviewer.xml

@@ -5,7 +5,7 @@
     android:layout_width="fill_parent"
     android:layout_height="fill_parent">
 
-    <android.support.v4.view.ViewPager
+    <com.bourke.glimmr.common.ViewPagerDisable
         android:id="@+id/pager"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content" />

src/com/bourke/glimmr/activities/PhotoViewerActivity.java

@@ -7,12 +7,11 @@
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentStatePagerAdapter;
-import android.support.v4.view.ViewPager;
+import com.bourke.glimmr.common.ViewPagerDisable;
 
 import android.util.Log;
 
 import com.bourke.glimmr.common.Constants;
-import com.bourke.glimmr.event.Events.IOverlayVisbilityListener;
 import com.bourke.glimmr.fragments.viewer.PhotoViewerFragment;
 import com.bourke.glimmr.R;
 
@@ -26,6 +25,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import com.googlecode.flickrjandroid.people.User;
+import android.support.v4.view.ViewPager;
 
 /**
  * Activity for viewing photos.
@@ -34,14 +34,15 @@
  * a startIndex in a zoomable ImageView.
  */
 public class PhotoViewerActivity extends BaseActivity
-        implements ViewPager.OnPageChangeListener, IOverlayVisbilityListener {
+        implements ViewPager.OnPageChangeListener,
+                   PhotoViewerFragment.IPhotoViewerCallbacks {
 
     private static final String TAG = "Glimmr/PhotoViewerActivity";
 
     private List<Photo> mPhotos = new ArrayList<Photo>();
 
     private PhotoViewerPagerAdapter mAdapter;
-    private ViewPager mPager;
+    private ViewPagerDisable mPager;
     private List<WeakReference<Fragment>> mFragList =
         new ArrayList<WeakReference<Fragment>>();
 
@@ -72,7 +73,7 @@ private void handleIntent(Intent intent) {
             }
             mAdapter =
                 new PhotoViewerPagerAdapter(getSupportFragmentManager());
-            mPager = (ViewPager) findViewById(R.id.pager);
+            mPager = (ViewPagerDisable) findViewById(R.id.pager);
             mPager.setAdapter(mAdapter);
             /* Don't show the PageIndicator if there's a lot of items */
             if (mPhotos.size() <= Constants.LINE_PAGE_INDICATOR_LIMIT) {
@@ -128,6 +129,11 @@ public void onVisibilityChanged() {
         }
     }
 
+    @Override
+    public void onZoomed(boolean isZoomed) {
+        mPager.setPagingEnabled(!isZoomed);
+    }
+
     class PhotoViewerPagerAdapter extends FragmentStatePagerAdapter {
         public PhotoViewerPagerAdapter(FragmentManager fm) {
             super(fm);

src/com/bourke/glimmr/common/ViewPagerDisable.java

@@ -0,0 +1,42 @@
+package com.bourke.glimmr.common;
+
+import android.content.Context;
+
+import android.support.v4.view.ViewPager;
+
+import android.util.AttributeSet;
+
+import android.view.MotionEvent;
+
+/**
+ * Extend ViewPager to allow the paging to be disabled/mEnabled.
+ */
+public class ViewPagerDisable extends ViewPager {
+
+    private boolean mEnabled;
+
+    public ViewPagerDisable(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mEnabled = true;
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        if (mEnabled) {
+            return super.onTouchEvent(event);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent event) {
+        if (mEnabled) {
+            return super.onInterceptTouchEvent(event);
+        }
+        return false;
+    }
+
+    public void setPagingEnabled(boolean enabled) {
+        mEnabled = enabled;
+    }
+}

src/com/bourke/glimmr/event/Events.java

@@ -60,8 +60,4 @@ public interface IPhotoInfoReadyListener {
     public interface ICommentAddedListener {
         void onCommentAdded(String commentId);
     }
-
-    public interface IOverlayVisbilityListener {
-        void onVisibilityChanged();
-    }
 }

src/com/bourke/glimmr/fragments/viewer/PhotoViewerFragment.java

@@ -1,6 +1,8 @@
 package com.bourke.glimmr.fragments.viewer;
 
+import com.bourke.glimmr.activities.PhotoViewerActivity;
 import com.actionbarsherlock.widget.ShareActionProvider;
+import com.polites.android.GestureImageView;
 import android.content.Intent;
 
 import android.os.Bundle;
@@ -23,7 +25,6 @@
 import com.bourke.glimmr.activities.ExifInfoDialogActivity;
 import com.bourke.glimmr.common.Constants;
 import com.bourke.glimmr.event.Events.IFavoriteReadyListener;
-import com.bourke.glimmr.event.Events.IOverlayVisbilityListener;
 import com.bourke.glimmr.event.Events.IPhotoInfoReadyListener;
 import com.bourke.glimmr.fragments.base.BaseFragment;
 import com.bourke.glimmr.fragments.viewer.PhotoViewerFragment;
@@ -34,6 +35,7 @@
 import com.googlecode.flickrjandroid.photos.Photo;
 
 import java.util.concurrent.atomic.AtomicBoolean;
+import android.view.MotionEvent;
 
 public final class PhotoViewerFragment extends BaseFragment
         implements IPhotoInfoReadyListener, IFavoriteReadyListener {
@@ -46,15 +48,15 @@ public final class PhotoViewerFragment extends BaseFragment
     private MenuItem mFavoriteButton;
     private LoadPhotoInfoTask mTask;
     private AtomicBoolean mIsFavoriting = new AtomicBoolean(false);
-    private IOverlayVisbilityListener mVisibilityListener;
+    private IPhotoViewerCallbacks mListener;
 
     public static PhotoViewerFragment newInstance(Photo photo,
-            IOverlayVisbilityListener visiblityListener) {
+            IPhotoViewerCallbacks listener) {
         if (Constants.DEBUG)
             Log.d("Glimmr/PhotoViewerFragment", "newInstance");
         PhotoViewerFragment photoFragment = new PhotoViewerFragment();
         photoFragment.mBasePhoto = photo;
-        photoFragment.mVisibilityListener = visiblityListener;
+        photoFragment.mListener = listener;
         return photoFragment;
     }
 
@@ -71,16 +73,28 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container,
         mLayout = (RelativeLayout) inflater.inflate(
                 R.layout.photoviewer_fragment, container, false);
         mAq = new AQuery(mActivity, mLayout);
-        mAq.id(R.id.image).clicked(
-                new View.OnClickListener() {
-                    @Override
-                    public void onClick(View v) {
-                        /* Set our own visiblity and update others */
-                        setOverlayVisibility(mActionBar.isShowing());
-                        mVisibilityListener.onVisibilityChanged();
-                    }
-                });
+
+        mAq.id(R.id.image).clicked(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                /* Set our own visiblity and update others */
+                setOverlayVisibility(mActionBar.isShowing());
+                mListener.onVisibilityChanged();
+            }
+        });
+
+        final GestureImageView i =
+            (GestureImageView) mLayout.findViewById(R.id.image);
+        i.setOnTouchListener(new View.OnTouchListener() {
+            @Override
+            public boolean onTouch(View v, MotionEvent event) {
+                mListener.onZoomed(i.isZoomed());
+                return false;
+            }
+        });
+
         refreshOverlayVisibility();
+
         return mLayout;
     }
 
@@ -320,4 +334,9 @@ public void refreshOverlayVisibility() {
     protected String getLogTag() {
         return TAG;
     }
+
+    public interface IPhotoViewerCallbacks {
+        void onVisibilityChanged();
+        void onZoomed(boolean isZoomed);
+    }
 }