Java Reference
In-Depth Information
p1.setLocation(p1.x, p1.y - height1);
p2.setLocation(p2.x, p2.y - height2);
g2D.draw(new Line2D.Float(p1, p2));
g2D.drawString("Lines and rectangles", 60, 250); // Draw some text
}
Directory "Sketcher 2 drawing lines and rectangles"
If you type this code in correctly and recompile the
SketcherView
class, the Sketcher window looks like
the one shown in
Figure 19-9
.
How It Works
After casting the graphics context object that is passed to the
paint()
method to type
Graphics2D
, you
set the drawing color to red. All subsequent drawing that you do is in red until you change the color with
another call to
setPaint()
. You define a
Point2D.Float
object to represent the position of the first
rectangle, and you define variables to hold the width and height of the rectangle. You use these to create
the rectangle by passing them as arguments to the constructor that you saw earlier in this chapter and
display the rectangle by passing the
rect
object to the
draw()
method for the graphics context,
g2D
. The
second rectangle is defined by essentially the same process, except that this time you create the
Rect-
angle2D.Float
object in the argument expression for the
draw()
method.
Note that you have to cast the values returned by the
getX()
and
getY()
members of the
Point2D
object,
as they are returned as type
double
. It is generally more convenient to reference the
x
and
y
fields dir-
ectly as you do in the rest of the code.
You change the drawing color to blue so that you can see quite clearly the lines you are drawing. You
use the
setLocation()
method for the point objects to move the point on each rectangle to successive
corners and draw a line at each position. The caption also appears in blue because that is the color in
effect when you call the
drawString()
method to output the text string.
