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After setting the drawing mode to honor transparency and setting the background color to red, the code in Listing 11 causes the three images of the spider along the top of Figure 2 to be displayed each time the render method is called. (Recall that the names of the drawing mode constants appear to be reversed between opaque and transparent.)

The call to the draw method in Listing 11 displays the spider image in the upper-left corner of Figure 2 .

The first call to the drawFlash method calls one of three overloaded versions of the drawFlash method. This version of the method draws a white silhouette of the spider at a location specified by theparameters, 133,0.

The second call to the drawFlash method draws a silhouette of the spider at a location of 266,0, with a width of 131 pixels, a height of128 pixels and a blue color.

Note that none of the code in Listing 11 depends on the logic that is executed in the update method. Therefore, the three images appear to be static despite the fact thatthey are being redrawn about 60 times per second.

The large flashing spider

The call to the drawFlash method in Listing 12 produces the large flashing spider at the bottom of Figure 2 and Figure 3 .

Listing 12 . The large flashing spider.
//Cause an enlarged version of the spider to flash // between white and blue silhouette at a rate// of 1/flashInterval. spider.drawFlash(0f,0f,262f,256f,silohetteColor);}//end render }//end class Slick0160b

This is the same version of the drawFlash method that was called to produce the blue spider in the upper-right corner of Figure 2 . However, in this case, the third and fourth parameters specify that the spider should be drawn with a width of 262pixels and a height of 256 pixels.

More importantly, rather than passing a constant color as the last parameter, Listing 12 passes the reference to the Color object stored in the variable named silohetteColor . Recall that the color represented by that object is periodically switched between white andblue in the update method of Listing 10 . This causes the color of the spider to switch between white and blue.

The end of the program

Listing 12 signals the end of the render method and the end of the class named Slick0160b .

Run the programs

I encourage you to copy the code from Listing 13 and Listing 14 . Compile the code and execute it,making changes, and observing the results of your changes. Make certain that you can explain why your changes behave as they do.


In this module, you learned about using the draw , drawCentered , and drawFlash methods of the Image class.

What's next?

In the next module, you will learn how to use the following methods of the Input class to get user input:

  • isKeyDown
  • isMouseButtonDown
  • getMouseX
  • getMouseY


This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Slick0160: Using the draw and drawFlash methods
  • File: Slick0160.htm
  • Published: 02/05/13
  • Revised: 09/03/15

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 doesreceive compensation. If you purchase such a book, please be aware that it is a copy of a module that is freelyavailable on cnx.org and that it was made and published without my 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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