Java Reference
In-Depth Information
The angles are numbered with zero degrees, as shown in Display 18.14. In the first
figure, the start angle is zero degrees. The counterclockwise direction is positive. So a
start angle of 90 degrees would start at the top of the oval. A start angle of 90 degrees
would start at the bottom of the oval. For example, the smile on the happy face in Dis-
play 18.13 has a start angle of 180 degrees, so it starts on the left end of the invisible oval.
The last argument is also 180, so the arc is made visible through a counterclockwise
direction of 180 degrees, or halfway around the oval in the counterclockwise direction.
TIP:
Self-Test Exercises
10. Give an invocation of a method to draw a horizontal line from point (30, 40) to
point (100, 60). The calling object of type Graphics is named g .
11. Give an invocation of a method to draw a horizontal line of length 100 starting at
position (30, 40) and extending to the right. The calling object of type Graphics is
named g .
12. Give an invocation of a method that draws a vertical line of length 100 starting
at position (30, 40) and extending downward. Use graphicsObject (of type
Graphic ) as the calling object.
13. Give an invocation of a method to draw a solid rectangle of width 100 and
height 50 with the upper-left corner at position (20, 30). The calling object of
type Graphics is named graphicsObject .
14. Give an invocation of a method to draw a solid rectangle of width 100 and
height 50 with the upper-right corner at position (200, 300). The calling object
of type Graphics is named g .
15. Give an invocation of a method to draw a circle of diameter 100 with the center
at position (300, 400). The calling object of type Graphics is named g .
16. Give an invocation of a method to draw a circle of radius 100 with the center at
position (300, 400). The calling object of type Graphics is named g .
Rounded Rectangles
A rounded rectangle is a rectangle whose corners have been replaced by arcs so that
the corners are rounded. For example, suppose g is of type Graphics and consider
what would be drawn by the following:
rounded
rectangle
g.drawRoundRect(x, y, width, height, arcWidth, arcHeight)
The arguments x , y , width , and height determine a regular rectangle in the usual way.
The upper-left corner is at the point ( x , y ). The rectangle has the specified width and
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