I wanted to end this brief series talking about HTML5 video and rotation. There are some gotchas that it's important to be aware of in these areas that I've come across over the past few years.
In some versions of Android the audio of video that was playing in a Web View will continue to play in the background even after exiting the Fragment or Activity that is hosting the web view. This appears to be a bug where onPause isn't being called on the web view in those versions of Android.
Handling this isn't simply a matter or calling onPause explicitly on the Web View if your app is targeting devices running Gingerbread or below. This is because those versions of Android don't have a public onPause method on the Web View.
The easiest way to handle this in a platform version independent way is to call the Web View's onPause method via reflection.
Playing Arbitrary HTML5 Videos
Playing HTML5 Video Using A Native Video Player
While it is possible to create a custom WebChromeClient to intercept HTML5 video and play it using a native video player I would not recommend this. There are several problems with this approach that are very difficult to overcome.
- Some pages dynamically load videos on the page which means you have to be monitoring the DOM for changes.
Depending on how you handle rotation in your Activities and Fragments you may be accidentally reloading web pages on rotation. This happens when the call to loadUrl is made during the Activity or Fragment setup, since the rotation workflow causes the Activity or Fragment to be recreated.
This can be made even worse when the user had navigated several links deep into a web page. When the app is rotated and the Url is reloaded the user will find themselves back on the initial web page and not where they expect.
Handling rotation with a WebView can be done by:
- Only calling loadUrl when creating the WebView when the saved instance state in null.
- Call the WebView's saveState method in your Activity's onSaveInstanceState method.
- Call the WebView's restoreState method in your Activity's onRestoreInstanceState method.
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