<< Chapter < Page Chapter >> Page >

The new code

The only code in Listing 4 that is new to this module is the call to the setClip method.

The setClip method is defined in the Graphics class and inherited into the Graphics2D class.

(Among other things, that means that it wasn't necessary for me to cast the Graphics object to type Graphics2D in Listing 4 .)

The setClip method

There are a couple of overloaded versions of the setClip method. The one used in Listing 4 requires an incoming parameter of the interface type Shape .

The Shape interface

Briefly, Sun tells us that the Shape interface "provides definitions for objects that represent some form of geometric shape."

There are several dozen classes that implement the Shape interface, one of which is the class named Ellipse2D.Double . Therefore, the object of that type that is instantiated in Listing 4 satisfies the type requirement for being passed to the setClip method.

Behavior of the setClip method

With regard to the behavior of the setClip method, Sun tells us that the method

"Sets the current clipping area to an arbitrary clip shape."

What is the significance of the clipping area?

The closest answer that I can find for that question is the following statement in Sun's description of the Graphics class:

"All rendering operations modify only pixels which lie within the area bounded by the current clip, which is specified by a Shape in user space and is controlled by the program using the Graphics object."

In other words...

The clipping area is analogous to the current clip . In this case, the position and shape of the current clip is the position and shape ofthe ellipse.

When the image is later drawn on the red Picture object, only those pixels within the ellipse are modified to show the image. Theremaining pixels retain their original color, which was set to red early in Listing 4 .

End of discussion

That concludes my explanation of this program. You will find the methods that I didn't discuss in Listing 5 near the end of the module.

Run the program

I encourage you to copy the code from Listing 5 . Compile the code and execute it. Experiment with the code, making changes, andobserving the results of your changes. Make certain that you can explain why your changes behave as they do.

Click Prob04a.jpg to download the required input image file.


In this module, you learned how to use shapes to clip images during the drawing process.

What's next?

In the next module, you will learn how to merge pictures.

While not a requirement of the course, you can select the following link to view an optional online video lecture on the material in this module.


This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Java OOP: Clipping Images
  • File: Java3028.htm
  • Published: 08/06/12

Financial : Although the Connexions site makes it possible for you to download a PDF file for thismodule at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, you should beaware that some of the HTML elements in this module may not translate well into PDF.

I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version of the module.

In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. Ineither receive compensation for those sales nor do I know who does receive compensation. If you purchase such a book, please beaware that it is a copy of a module that is freely available on cnx.org and that it was made and published withoutmy prior knowledge.

Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Object-oriented programming (oop) with java' conversation and receive update notifications?