How to safely turn WebView zooming on and off as needed

Question

As mentioned in this unanswered question: WebView throws Receiver not registered: android.widget.ZoomButtonsController

By turning the WebView zoom controls on and of

Answer 1

webView.getSettings().setBuiltInZoomControls(true); did not work for me.

dkneller's suggestion did work, however:

    long timeout = ViewConfiguration.getZoomControlsTimeout();
    new Timer().schedule(new TimerTask() {
        @Override
        public void run() {
            webview.destroy();
        }
    }, timeout);

Answer 2

On a Zoom, I found that if one waits for the zoom control to fade out before calling WebView.destroy() a crash no longer occurs. So I've overwritten WebView.destroy() to post a message to a Handler to call WebView.destroy() after a few seconds. From the WebView source we will see the fade-out interval is:

// The time that the Zoom Controls are visible before fading away
private static final long ZOOM_CONTROLS_TIMEOUT =
        ViewConfiguration.getZoomControlsTimeout();

So I used ViewConfiguration.getZoomControlsTimeout() + 1000L as the delay before calling WebView's destroy method. So far no crashes.

Answer 3

If you only want to have pinch zoom working with your webview and you can live without the zoom buttons, you can do this to your webview:

webView.getSettings().setBuiltInZoomControls(true); // will give pinch zoom
webView.getSettings().setDisplayZoomControls(false); // but won't display the zoom buttons

adding

webView.getSettings().setBuiltInZoomControls(true);

in onDestroy / onDestroyView did not help on 3.x.