Qassim babyDroid Qassim babyDroid - 9 months ago 63
Android Question

Restore webview scroll position?

I want to save the state of my

webView
with its page scroll position when user leaves the app and restore them when user opens the app again. So that, user can continue reading the restored webview content scrolled down to the restored position.

Here are methods I'm using:

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_book);
webView = (WebView)this.findViewById(R.id.webView);
if (savedInstanceState != null) {
int positionY = Math.round(scrollPos);
webView.scrollTo(0, positionY);
} esle {
//do something
}


Function that calculates the position:

private int calculateProgression(WebView content) {
int positionTopView = content.getTop();
int contentHeight = content.getContentHeight();
int currentScrollPosition = content.getScrollY();
int percentWebview = (currentScrollPosition - positionTopView) / contentHeight;
return percentWebview;
}


save/restore functions:

@Override
protected void onSaveInstanceState(Bundle outState) {
outState.putInt("position", calculateProgression(webView));
super.onSaveInstanceState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
scrollPos = savedInstanceState.getFloat("position");
}

Answer Source

You could save the position in the SharedPreferences in the OnDestroy method and retrieve it in the OnCreate method.

EDIT: As stated here, OnPause should be the place to store data, not OnDestroy.