Android: rotate a bitmap

Android.Bitmap.Rotate

public Bitmap rotateBitmap(Bitmap original, float degrees) {
    int width = original.getWidth();
    int height = original.getHeight();

    Matrix matrix = new Matrix();
    matrix.preRotate(degrees);

    Bitmap rotatedBitmap = Bitmap.createBitmap(original, 0, 0, width, height, matrix, true);
    Canvas canvas = new Canvas(rotatedBitmap);
    canvas.drawBitmap(original, 5.0f, 0.0f, null);

    return rotatedBitmap;
}

nice code

Extension for Kotlin

fun Bitmap.rotate(degrees: Float): Bitmap {
    val matrix = Matrix().apply { postRotate(degrees) }
    return Bitmap.createBitmap(this, 0, 0, width, height, matrix, true)
}

And usage:

bitmap.rotate(90)

awsome, thanx for kotlin ext too!!

Bitmap.createBitmap is java call and might be null. And I think we can use Number for parameter and infix for readability

infix fun Bitmap.rotate(degrees: Number): Bitmap? {
    return Bitmap.createBitmap(
        this,
        0,
        0,
        width,
        height,
        Matrix().apply { postRotate(degrees.toFloat()) },
        true
    )
}

Usage

bitmap rotate 90

great !

To understand, this piece of code will rotate my photo to the right position or I choose how much and where it will rotate. Thank you.

Thank you, nice code !