I'm making an application which has a Webview inline with other elements, nested in a ScrollView. I've noticed that in ICS, testing on a Galaxy Nexus device, the WebView appears to be disjointed from the rest of the displayed elements when the page is flung, resulting in the WebView appearing to be floating because of a couple of ms worth of lag on drawing. This doesn't happen in 2.x versions of Android (not tested on 3.x). Here's a video of the floating effect http://www.youtube.com/watch?v=avfBoWmooM4 (you can see clearly if you set to fullscreen at 1080p)
Can anyone suggest why this may happen, or a fix?
I've setup a test project, below, to demonstrate:
package com.martynhaigh.floating_web_view;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebView;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TextView;
public class FloatingWebViewTestActivity extends FragmentActivity {
public final int viewId = 0x12345678;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
FrameLayout frame = new FrameLayout(this);
frame.setId(viewId);
setContentView(frame, lp);
FloatingWebViewICSFragment fragment = new FloatingWebViewICSFragment();
getSupportFragmentManager().beginTransaction().add(viewId, fragment).commit();
}
public static class FloatingWebViewICSFragment extends Fragment {
private final String htmlBody = "<html><body><p style=\"font-size:1.5em\">This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. This is a test document. </body></html>";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
TextView textView = new TextView(getActivity().getApplicationContext());
textView.setText("Test Activity");
WebView webView = new WebView(getActivity().getApplicationContext());
webView.loadDataWithBaseURL("file:///android_asset/", htmlBody, "text/html", "UTF-8", "about:blank");
webView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
webView.setScrollContainer(false);
TextView textView2 = new TextView(getActivity().getApplicationContext());
textView2.setText("Test Activity");
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT);
LinearLayout layout = new LinearLayout(getActivity().getApplicationContext());
layout.setLayoutParams(lp);
layout.setOrientation(LinearLayout.VERTICAL);
layout.addView(textView);
layout.addView(webView);
layout.addView(textView2);
ScrollView scrollView = new ScrollView(getActivity().getApplicationContext());
scrollView.setLayoutParams(lp);
scrollView.addView(layout);
return scrollView;
}
}
}