set pixel in frame

[Tian Zhang]

hi there!

i have a class that extends JFrame, i was wondering if it is possible to set (draw) individual pixels within the frame, i.e. something that looks like:

setColor(int x, int y, Color c)

at the moment i'm considering (which is probably inefficient):

Graphics g = myClass.getGraphics();
g.drawLine(x, y, x, y);

thanks,
tian.

[Campbell Ritchie]

I haven't tried drawing a line like that for some time, but as far as I can remember, you don't even try it on a JFrame.
You add a JPanel to the JFrame, and put such drawing into the paintComponent(Graphics g) method.
Two warnings

You have to put super.paintComponent(); as the first line of your method.

There is also a paintComponents() method, so don't get confused with it.

Then you get a Graphics object in the method, which makes it easy to write g.drawLine(x1, y1, x2, y2);
[ September 19, 2006: Message edited by: Campbell Ritchie ]

[Tian Zhang]

thanks for your reply!

i currently have what you suggested in my code - but ommitted them from the code listing for simplicity. is there a method in the Graphics class to paint individual pixels, or will i need to paint lines with length 1?

tian

[Nathan Pruett]

Nope - no method in the graphics class to draw a pixel - you have to draw a line of length 1.

[Tian Zhang]

thanks,

i had feared as much. perhaps the overhead of drawing length 1 lines isnt as bad as i thought.


tian

[Campbell Ritchie]

Lines of length 0, surely?

[Tian Zhang]

hi there!

the code will be something like:

drawLine(x, y, x, y);

which will draw pixel at (x, y) so i guess it is length zero (length:=sqrt((x1 - x2)^2 + (y1 - y2)^2) - as defined by the eucledian metric).

tian
[ September 21, 2006: Message edited by: Tian Zhang ]