Refine page navigation with touch events

Open navigation menu with double tab.
Use GestureDetector.
Hide app bar.

Author: devgrapher

OCEBook/app/src/main/java/com/devgrapher/ocebook/HiddenRendererFragment.java

@@ -98,18 +98,7 @@ public void onDetach() {
         mListener = null;
     }
 
-    /**
-     * This interface must be implemented by activities that contain this
-     * fragment to allow an interaction in this fragment to be communicated
-     * to the activity and potentially other fragments contained in that
-     * activity.
-     * <p>
-     * See the Android Training lesson <a href=
-     * "http://developer.android.com/training/basics/fragments/communicating.html"
-     * >Communicating with Other Fragments</a> for more information.
-     */
     public interface OnFragmentInteractionListener {
-        // TODO: Update argument type and name
         void onBrowsePageInProgress(int currentSpine, int totalSpine, int pageCount);
     }
 

OCEBook/app/src/main/java/com/devgrapher/ocebook/ReaderActivity.java

@@ -13,6 +13,7 @@
 import android.support.v7.app.ActionBarDrawerToggle;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
+import android.view.Gravity;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.TextView;
@@ -217,6 +218,12 @@ public void onPageChanged(int pageIndex, int spineIndex) {
         }
     }
 
+    @Override
+    public void onOpenMenu() {
+        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
+        drawer.openDrawer(GravityCompat.START);
+    }
+
     @Override
     public void onBrowsePageInProgress(int spineIndex, int totalSpine, int pageCount) {
         int percent = (int) ((spineIndex + 1) / (float) totalSpine * 100);

OCEBook/app/src/main/java/com/devgrapher/ocebook/WebViewFragment.java

@@ -7,23 +7,21 @@
 import android.app.Fragment;
 import android.util.Log;
 import android.view.LayoutInflater;
-import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 import android.webkit.WebChromeClient;
 import android.webkit.WebResourceRequest;
 import android.webkit.WebResourceResponse;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
-import android.widget.TextView;
 
 import com.devgrapher.ocebook.readium.ObjectHolder;
 import com.devgrapher.ocebook.readium.ReadiumContext;
 import com.devgrapher.ocebook.model.OpenPageRequest;
 import com.devgrapher.ocebook.model.Page;
 import com.devgrapher.ocebook.model.PaginationInfo;
 import com.devgrapher.ocebook.model.ViewerSettings;
-import com.devgrapher.ocebook.util.MotionHandler;
+import com.devgrapher.ocebook.util.WebViewMotionHandler;
 
 import org.readium.sdk.android.Container;
 import org.readium.sdk.android.Package;
@@ -32,7 +30,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;
-import java.util.Locale;
 
 
 /**
@@ -114,17 +111,23 @@ private void initWebView() {
         mWebView.getSettings().setAllowUniversalAccessFromFileURLs(true);
         mWebView.setWebViewClient(new ReadiumWebViewClient());
         mWebView.setWebChromeClient(new WebChromeClient());
-        mWebView.setOnTouchListener(new MotionHandler(new MotionHandler.OnMotionListener() {
-            @Override
-            public void onMoveNextPage() {
-                mReadiumCtx.getApi().openPageRight();
-            }
+        mWebView.setOnTouchListener(
+                new WebViewMotionHandler(getContext(), new WebViewMotionHandler.OnMotionListener() {
+                    @Override
+                    public void onMoveNextPage() {
+                        mReadiumCtx.getApi().openPageRight();
+                    }
 
-            @Override
-            public void onMovePreviousPage() {
-                mReadiumCtx.getApi().openPageLeft();
-            }
-        }));
+                    @Override
+                    public void onMovePreviousPage() {
+                        mReadiumCtx.getApi().openPageLeft();
+                    }
+
+                    @Override
+                    public void onOpenMenu() {
+                        mListener.onOpenMenu();
+                    }
+                }));
     }
 
     private void initReadium() {
@@ -221,6 +224,7 @@ public void onDestroy() {
     public interface OnFragmentInteractionListener {
         void onPackageOpen(ReadiumContext readiumContext);
         void onPageChanged(int pageIndex, int spineIndex);
+        void onOpenMenu();
     }
 
     public final class ReadiumWebViewClient extends WebViewClient {

OCEBook/app/src/main/java/com/devgrapher/ocebook/util/MotionHandler.java

@@ -0,0 +1,80 @@
+package com.devgrapher.ocebook.util;
+
+import android.content.Context;
+import android.util.Log;
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+import android.view.View;
+
+/**
+ * Hide implementations of motion handling.
+ * This only provides motions that we desired through OnMotionListener.
+ */
+
+public class WebViewMotionHandler implements View.OnTouchListener {
+
+    private static final String TAG = WebViewMotionHandler.class.toString();
+
+    private final OnMotionListener mMotionListener;
+    private final GestureDetector mGestureDetector;
+
+    private View mView;
+
+    public interface OnMotionListener {
+        void onMoveNextPage();
+        void onMovePreviousPage();
+        void onOpenMenu();
+    }
+
+    public WebViewMotionHandler(Context context, OnMotionListener listener) {
+        mMotionListener = listener;
+        mGestureDetector = new GestureDetector(context, new GestureListener());
+    }
+
+    @Override
+    public boolean onTouch(View v, MotionEvent event) {
+        mView = v;
+        return mGestureDetector.onTouchEvent(event);
+    }
+
+    private class GestureListener extends GestureDetector.SimpleOnGestureListener {
+        @Override
+        public boolean onDoubleTap(MotionEvent e) {
+            Log.d(TAG, "Double Tap");
+            // Only accept 1/3 potion in the middle.
+            if (e.getX() > mView.getWidth() / 3 &&
+                    e.getX() < mView.getWidth() * 2/3) {
+                mMotionListener.onOpenMenu();
+            } else {
+                // deal it as if double move page.
+                onSingleTapConfirmed(e);
+                onSingleTapConfirmed(e);
+            }
+            return true;
+        }
+
+        @Override
+        public boolean onSingleTapConfirmed(MotionEvent e) {
+            if (e.getX() < mView.getWidth() / 2) {
+                Log.d(TAG, "Touch left");
+                mMotionListener.onMovePreviousPage();
+            } else {
+                Log.d(TAG, "Touch right");
+                mMotionListener.onMoveNextPage();
+            }
+            return true;
+        }
+
+        @Override
+        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
+            if (e1.getX() < mView.getWidth() / 2) {
+                Log.d(TAG, "Fling left");
+                mMotionListener.onMovePreviousPage();
+            } else {
+                Log.d(TAG, "Fling right");
+                mMotionListener.onMoveNextPage();
+            }
+            return true;
+        }
+    }
+}

OCEBook/app/src/main/java/com/devgrapher/ocebook/util/WebViewMotionHandler.java

@@ -10,6 +10,7 @@
     <android.support.design.widget.AppBarLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
+        android:visibility="gone"
         android:theme="@style/AppTheme.AppBarOverlay">
 
         <android.support.v7.widget.Toolbar