When utilizing a WebView to display simple formatted text (no remote content loading), some devices like the Nexus 4 or Galaxy Nexus have a very notable delay between onPageFinished() and actually displaying the text. If the WebView is used in a dynamic vertical layout with it's height set to wrap_content, all elements below will visibly jump down and hence create a very bad user experience.
For example:
public class WebViewActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_web_view);
WebView webview = (WebView) findViewById(R.id.webview);
webview.loadData("<html><head></head><body>WebView rendering is slow on some devices like the Nexus 4!</body></html>", "text/html", "utf-8");
}
}
With R.layout.activity_web_view being
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent" android:layout_height="match_parent"
android:orientation="vertical"
android:background="#AAA" >
<WebView android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/webview"/>
<TextView android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:layout_margin="5dp"
android:text="Elements below the WebView are jumping down when rendering is completed."/>
</LinearLayout>
A demo project with this code can be found at https://github.com/rodja/webview-slow-rendering-demo
How can I best work around this issue? Speed up tips I found on StackOverflow seems not to help. Is hiding the whole LayoutGroup until rendering is done the only option?
