Example usage for android.graphics Canvas drawOval

Introduction

In this page you can find the example usage for android.graphics Canvas drawOval.

Prototype

public void drawOval(float left, float top, float right, float bottom, @NonNull Paint paint) 

Source Link

Document

Draw the specified oval using the specified paint.

Usage

From source file:Main.java

/**
 * Given an input bitmap, scales it to the given width/height and makes it round.
 *
 * @param input {@link Bitmap} to scale and crop
 * @param targetWidth desired output width
 * @param targetHeight desired output height
 * @return output bitmap scaled to the target width/height and cropped to an oval. The
 *         cropping algorithm will try to fit as much of the input into the output as possible,
 *         while preserving the target width/height ratio.
 *//*from   w  w w  .  ja  va2  s .com*/
public static Bitmap getRoundedBitmap(Bitmap input, int targetWidth, int targetHeight) {
    if (input == null) {
        return null;
    }
    final Bitmap.Config inputConfig = input.getConfig();
    final Bitmap result = Bitmap.createBitmap(targetWidth, targetHeight,
            inputConfig != null ? inputConfig : Bitmap.Config.ARGB_8888);
    final Canvas canvas = new Canvas(result);
    final Paint paint = new Paint();
    canvas.drawARGB(0, 0, 0, 0);
    paint.setAntiAlias(true);
    canvas.drawOval(0, 0, targetWidth, targetHeight, paint);

    // Specifies that only pixels present in the destination (i.e. the drawn oval) should
    // be overwritten with pixels from the input bitmap.
    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

    final int inputWidth = input.getWidth();
    final int inputHeight = input.getHeight();

    // Choose the largest scale factor that will fit inside the dimensions of the
    // input bitmap.
    final float scaleBy = Math.min((float) inputWidth / targetWidth, (float) inputHeight / targetHeight);

    final int xCropAmountHalved = (int) (scaleBy * targetWidth / 2);
    final int yCropAmountHalved = (int) (scaleBy * targetHeight / 2);

    final Rect src = new Rect(inputWidth / 2 - xCropAmountHalved, inputHeight / 2 - yCropAmountHalved,
            inputWidth / 2 + xCropAmountHalved, inputHeight / 2 + yCropAmountHalved);

    final RectF dst = new RectF(0, 0, targetWidth, targetHeight);
    canvas.drawBitmap(input, src, dst, paint);
    return result;
}

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