WebView doesn't load my HTML the second time?

I've created a small Activity which is capable of loading two different HTML strings in a webview. When I run the Activity it starts by loading the String from the page_1 variable. So far so good. The page shows as expected. I've added an onFling listener which should make the activity load the content of the page_2 variable. The problem is that even though the onFling is called and the loadUrl is called the webview isn't updated?

My activity looks like this:

import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.webkit.WebView;

public class Test extends Activity {
private GestureDetector mGestureDetector;
private WebView mWebView;
private int mPageIndex;

private static final String page_1 = "<html><body>Hello page 1</body></html>";
private static final String page_2 = "<html><body>Hello page 2</body></html>";

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.test);
  mWebView = (WebView) findViewById(R.id.webview);
  mWebView.loadData(page_1, "text/html", "utf-8");
  setupGestureDetection();
  mPageIndex = 0;
}

private void setupGestureDetection() {
  mGestureDetector = new GestureDetector(new MyGestureDetector());
  mWebView.setOnTouchListener(new OnTouchListener() {
    public boolean onTouch(View v, MotionEvent event) {
      return mGestureDetector.onTouchEvent(event);
    }
  });
}

class MyGestureDetector extends GestureDetector.SimpleOnGestureListener {
  private static final int SWIPE_DISTANCE_THRESHOLD = 120;
  private static final int SWIPE_VELOCITY_THRESHOLD = 200;

  private boolean isHorizontalSwipe(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
    if (Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
      if (Math.abs(e1.getX() - e2.getX()) > SWIPE_DISTANCE_THRESHOLD) {
        return true;
      }
    }
    return false;
}

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
  if (isHorizontalSwipe(e1, e2, velocityX, velocityY)) {
    if (e1.getX() > e2.getX()) {
      // Right to left
      if (++mPageIndex % 2 == 0) {
        mWebView.loadData(page_1, "text/html", "utf-8");
      } else {
        mWebView.loadData(page_2, "text/html", "utf-8");
      }
      return true;
    }
  }
  return false;
}
}
}

My layout looks like this:

<?xml version="1.0" encoding="utf-8"?>
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/webview"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" />

I hope someone can help me! :-)

Best regards

Stig Andersen

Solution

First, try to avoid WebView#loadData(String, String, String) like the plague - it's a buggy p.o.s. Use WebView#loadDataWithBaseURL(String, String, String, String, String) instead.

Further, this will fix your problem. Counter-intuitive I know, but hey, it's the Android way.

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        if (isHorizontalSwipe(e1, e2, velocityX, velocityY)) {
            if (e1.getX() > e2.getX()) {
                // Right to left
                if (++mPageIndex % 2 == 0) {
                    mWebView.loadDataWithBaseURL(null, page_1, null, "utf-8", null);
                } else {
                    mWebView.loadDataWithBaseURL(null, page_2, null, "utf-8", null);
                }
                // Seriously. You must return false for the loadDataWithBaseURL to work. Not kidding. So you could skip this return.
                return false;
            }
        }
        return false;
    }