Bug 703744: Make ReaderView usable from outside of package.

Author: artifex-tor

lib/src/main/java/com/artifex/mupdf/viewer/DocumentActivity.java

@@ -634,7 +634,8 @@ public void onDestroy()
 	{
 		if (mDocView != null) {
 			mDocView.applyToChildren(new ReaderView.ViewMapper() {
-				void applyToView(View view) {
+				@Override
+				public void applyToView(View view) {
 					((PageView)view).releaseBitmaps();
 				}
 			});

lib/src/main/java/com/artifex/mupdf/viewer/ReaderView.java

@@ -69,8 +69,8 @@ public class ReaderView
 
 	protected Stack<Integer> mHistory;
 
-	static abstract class ViewMapper {
-		abstract void applyToView(View view);
+	public interface ViewMapper {
+		void applyToView(View view);
 	}
 
 	public ReaderView(Context context) {
@@ -125,6 +125,10 @@ public void pushHistory() {
 		mHistory.push(mCurrent);
 	}
 
+	public void clearHistory() {
+		mHistory.clear();
+	}
+
 	public int getDisplayedViewIndex() {
 		return mCurrent;
 	}