Drawing Shapes in Java

  Java provides a standard set of methods for drawing typical geometric shapes, such as rectangles, ovals, and polygons. It also has a method for drawing 3D rectangles (rectangles with shading to make them look 3D), but because the line widths are so narrow, it's almost impossible to see the 3D effect under normal circumstances. The syntax for the various shape-drawing methods follow.

drawRect(int x, int y, int width, int height)

This draws a traditional rectangle.

x: Upper-left corner
y: Upper-left corner
width: Width of the rectangle
height: Height of the rectangle

drawRoundRect(int x, int y, int width, int height, int r_width, int r_height)

This draws a rectangle with rounded corners. You define the amount of curvature by setting the width and height of the rectangle that contains the curved corner

x: Upper-left corner
y: Upper-left corner
width: Width of the rectangle
height: Height of the rectangle
r_width: Width of the rectangle that defines the roundness of the corner
rectangle: Defines the roundness of the corner
r_height: Height of the rectangle that defines the roundness of the corner

draw3DRect(int x, int y, int width, int height, boolean flag)

This draws a rectangle with a 3D shadow. Because the lines are so thin, you can't really see the shadow.

x: Upper-left corner
y: Upper-left corner
width: Width of rectangle
height: Height of rectangle
flag: If TRUE, the rectangle is raised; if FALSE, the rectangle is indented

drawPolygon(int x[], int y[], int n_points)

This takes two lists-one with x and one with y coordinates-and draws a line between successive points. The polygon will not close automatically. If you want a closed polygon, you must make sure that the first and last points have the same coordinates.

x: An array of integers with the x coordinates of the polygon's vertices
y: An array of integers with the y coordinates of the polygon's vertices
n_points: Number of vertices in the polygon

drawOval(int x, int y, int width, int height)

This draws an oval. If width and height have the same value, you get a circle.

x: Upper-left corner of the rectangle that contains the oval (see Figure 17.15)
y: Upper-left corner of the rectangle that contains the oval
width: Width of the rectangle that contains the oval
height: Height of the rectangle that contains the oval