I am creating an application that has a built-in Webview with other elements nested in a ScrollView. I noticed that in ICS, testing on a Galaxy Nexus device, WebView does not seem to be shared with the rest of the display elements when the page is deleted, which causes the WebView to look floating due to a few ms backlog from drawing. This does not happen in versions of Android 2.x (not tested on 3.x). Here's a video with a floating effect http://www.youtube.com/watch?v=avfBoWmooM4 (you can clearly see if you set full-screen mode to 1080p)
Can anyone suggest why this might happen, or fix it?
I set up 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;
}
}
}