Android multitouch in supported devices

let's say I'd like to have an image view in my app with zoom is it possible to add multito开发者_Go百科uch event listeners on phones that do support multi touch (API 7+), while on older phones show zoom buttons?

Can this be done in a single version of the app or do I need multiple app versions and multiple APKs?

You don't need multiple APK in this case.

You can check availability of the multitouch in the code:

if (Integer.parseInt(Build.VERSION.SDK) >= 7) {
    PackageManager pm = context.getPackageManager();
    boolean hasMultitouch = 
        pm.hasSystemFeature(PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH);
    if (hasMultitouch) {
        // set multitouch event listeners
    } else {
        // set zoom buttons
    }
} else {
    // set zoom buttons
}

You can get PackageManager from your activity (service) without using context: PackageManager pm = getPackageManager();

There are three types of multitouch you can check.

• FEATURE_TOUCHSCREEN_MULTITOUCH - basic two-finger gesture detection.
• FEATURE_TOUCHSCREEN_MULTITOUCH_DISTINCT - tracking two or more fingers fully independently.
• FEATURE_TOUCHSCREEN_MULTITOUCH_JAZZHAND - tracking a full hand of fingers fully independently - that is, 5 or more simultaneous independent pointers.

Upd: you must check API version before multitouch availability check. FEATURE_TOUCHSCREEN_MULTITOUCH available only from API 7. I've updated the code sample.

you can check out your api level at the start up of your app and set the correct listeners and buttons on this information.

may be this site is usefull for you

example:

    if(Integer.parseInt(Build.VERSION.SDK) >= 7)
    {
        //add multi touch listeners
    }
    else
    {
        // add zoom buttons
    }