Image-forming apparatus and method for controlling the same

An image-forming apparatus comprising:

• a printing unit which prints an image on a paper medium or a non-paper medium in accordance with image data;
• a paper-medium supplier which supplies the paper medium to the printing unit;
• a non-paper-medium supplier which supplies the non-paper medium to the printing unit and which can be detachably attached to a main body of the image-forming apparatus;
• a first monitor which detects whether or not the non-paper-medium supplier is attached to the main body;
• a first reading unit which reads image data from an original;
• a first image-forming unit which performs an image-forming process by transmitting the image data read by the first reading unit to the printing unit and causing the printing unit to print an image in accordance with the image data read by the first reading unit;
• a second image-forming unit which performs an image-forming process by receiving image data from an external information processing terminal which is connected to the image-forming apparatus, transmitting the received image data to the printing unit, and causing the printing unit to print an image in accordance with the received image data;
• and
• a controller which stops the image-forming process performed by the first image-forming unit when the first image-forming unit is commanded to perform the image-forming process and when the first monitor determines that the non-paper-medium supplier is attached to the main body.