Android™ Requires Chilkat v11.7.0+

QR Code with a Text Caption

See more QR Code Examples

Demonstrates printing a line of text under a QR code, such as the order number or the address the code holds, so that a person can read it too. render.text turns the caption on and gives its value, which is printable ASCII and is drawn in a built-in font that needs no font files. The caption can go above or below the symbol, be aligned left, center or right, and be scaled. Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    CkJsonObject json = new CkJsonObject();
    json.UpdateString("payload.text","https://www.chilkatsoft.com/order/12345");
    json.UpdateInt("render.moduleSize",6);

    //  The caption.  It need not be the same as the text in the QR code.
    json.UpdateBool("render.text.enabled",true);
    json.UpdateString("render.text.value","ORDER 12345");
    //  position is "below" (the default) or "above".  alignment is "center" (the default), "left" or "right".
    json.UpdateString("render.text.position","below");
    //  Each dot of the caption's font is drawn this many pixels wide.
    json.UpdateInt("render.text.scale",3);

    json.UpdateString("output.path","qa_output/qr_caption.png");
    json.UpdateBool("output.overwrite",true);
    json.UpdateString("output.return","none");

    CkFormats fmt = new CkFormats();
    CkJsonObject jsonOut = new CkJsonObject();
    success = fmt.QrCode("generate",json,jsonOut);
    if (success == false) {
        Log.i(TAG, fmt.lastErrorText());
        return;
        }

    Log.i(TAG, "caption: " + jsonOut.stringOf("measurements[0].text"));
    Log.i(TAG, "caption scale: " + String.valueOf(jsonOut.IntOf("measurements[0].textScale")));
    Log.i(TAG, "height added for the caption: " + String.valueOf(jsonOut.IntOf("measurements[0].textBandPx")) + " pixels");
    Log.i(TAG, "image: " + String.valueOf(jsonOut.IntOf("measurements[0].canvasWidth")) + " x " + String.valueOf(jsonOut.IntOf("measurements[0].canvasHeight")) + " pixels");

    //  The image written to qa_output/qr_caption.png:

    //  

    //  Sample output:

    //  caption: ORDER 12345
    //  caption scale: 3
    //  height added for the caption: 21 pixels
    //  image: 222 x 243 pixels

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}