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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

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
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.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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