One of the most interesting parts of BlackBerry's PlayBook tablet is its forthcoming support for Android apps.

Explaining more about the process were RIM's Rajeev Mohindra and Kamen Vitanov.

In a talk entitled 'Getting started with Android Player', Mohindra explained that in most cases to-date, the cost of porting from Android to PlayBook's QNX should be small.

"65 percent of apps convert to Android without any changes to source code," he said.

Changes, changes

Of course, there are plenty of differences between Android and the PlayBook Android Player, which supports Android 2.3.3 and API level 10. These include issues such as the PlayBook only supports 4 independent touch points, whereas Android can support up to 13.

Another example is RIM has had to 'fake' an SD card on the PlayBook for Android apps that require this.

More prosaically, a PlayBook app icon is 86 pixels square, while for Android it's 72 pixels square.

Keep it safe

In terms of operation, Android apps are kept insulated from the rest of the PlayBook system, running in a secure sandbox.

They launch just like any other native apps, although running multiple Android apps on PlayBook will just be rendered in one window, whereas running multiple instants of native PlayBook apps are displayed in multiple windows.

The Player window includes a touch Back button and display the icons for all Android apps running in a navigation bar at the bottom of the screen. This can be switched off if you want to run your app full screen.

Missing tricks

Getting into more detail about the porting process, Mohindra warned, "It's not a case of just taking your Android app and it will run".

"We support most Android's APIs but not all of them."

For example, the Android PlayBook player doesn't support native Android code, Google libraries such as Google Maps or Android Market, phone features, camera APIs (although you can take and use photos), and SIP and VOIP stacks aren't supported, nor Bluetooth.

RIM's tools enables developers to check for any incompatibilities.

Best of the situation

"Because the Android Player sits on top of QNX that means it's pretty secure," said Mohindra.

"It also means we can leverage the hardware acceleration features, but it's a lot harder than just making the Android open source run on top of some hardware."

Of course, the current beta release of the Android Player is a work in progress, with Mohindra saying RIM had been prioritising what features it can support for launch.

"It's a large project. It's taken a lot to get here," he confessed, although remarking that when Google open sources its Ice Cream Sandwich OS, RIM would consider how it could support it.