Image cropping activity/widget

Is there an Image cropping Activity in Android? I know that when you save an images as your wallpaper, it pops up an image cropper... and I've looked into the sourcecode for that, but it depends on a LOT of gallery specific stuff. Not very reusable.

Does anyone know how开发者_C百科 this might be done, or are there any third party libraries that can help me out on this one?

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There's a reasonably well-supported Intent for this (worked on my testing on at least a half dozen different Android 2.1+ phones, including SenseUI and Motoblur devices, and I believe it's been around since Android 1.0 or earlier on the G1). This might get you started:

    final Intent intent = new Intent("com.android.camera.action.CROP");
    intent.setData(uriOfImageToCrop);
    intent.putExtra("outputX", 400);
    intent.putExtra("outputY", 400);
    intent.putExtra("aspectX", 1);
    intent.putExtra("aspectY", 1);
    intent.putExtra("scale", true);
    intent.putExtra("noFaceDetection", true);
    intent.putExtra("output", Uri.fromFile(someOutputFile));
    startActivityForResult(intent, SOME_RANDOM_REQUEST_CODE);

Then just handle what you need to do in the onActivityResult() method of your Activity; your output file should have the cropped image in it at that point.

NOTE: This code makes use of an internal API and will not work on all devices. To be safe, though, you may want to have a fallback behavior (autocrop? Don't crop?) if someone has a device that doesn't support this Intent.

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Don't forget one important attribute:

intent.putExtra("scaleUpIfNeeded", true);

This is crucial if the photo youre cropping is smaller than output you want to get. If not provided you will get black frame around your cropped image