Java graphics - JavaTech: An Introduction to Scientific and Technical Computing with Java - page 178

gives the current color in use by the graphics context object. To obtain the back-
ground and foreground colors for a component, use

Color bg = getBackground ();
Color fg = getForeground ();

6.7 Drawing with the Graphics class
Here we illustrate drawing operations using the methods available in the Graph-
ics class. The Graphics2D class offers more capabilities, which we discuss
briefly in Section 6.8. Drawing typically begins with an invocation of the set-
Color (Color c) method in Graphics that tells the graphics context what
color to use when it draws a line or primitive shape like a rectangle or when
it fills a primitive shape with a solid color. The methods in the Graphics
class for drawing and filling include the following (all parameters are int
types):
drawLine (x1, y1, x2, y2) - draws a line between points (x1,y1) and
(x2,y2).
drawRect (x, y, width, height) and fillRect (x, y, width,
height) - draws (fills) a rectangle, (x,y) are the coordinates of the top-left corner,
the bottom-right corner will be at (x+width,y+height) .
drawOval (x, y, width, height)

and

fillOval (x, y, width,

height) - draws (fills) an oval bounded by

the rectangle specified by these

parameters.
draw3DRect (x, y, width, height) and fill3DRect (x, y, width,
height) - draws (fills) a rectangle with shaded sides that provide a 3-D appearance.
drawRoundRect (x, y, width, height) and fill3DRect (x, y,
width, height) - draws (fills) a rectangle with rounded corners.
drawPolyline (int[] x, int[] y, int n) - draws lines connecting the n
points given by the x and y arrays.
drawPolygon (int[] x, int[] y, int n) - draws lines connecting the
points given by the x and y arrays. Connects the last point to the first if they are not
already the same point.

Note that Graphics does not provide a method to set the width of a line. The line
is always one pixel wide and continuous (i.e. no dot-dash options). Nevertheless,
these methods are simple and often convenient to use and can be used along with
the Graphics2D methods.

Figure 6.6
Example
DrawApplet
uses drawing
methods in the
Graphics class.

6.7.1 Drawing demo
The applet DrawApplet shown in Figure 6.6 illustrates some of the drawing
methods from the Graphics class. The applet first creates a JPanel subclass