Lec 18 Writing Methods that Draw Graphics

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Lec 18
Writing Methods that Draw Graphics
Agenda
• More Applet stuff
– Methods that draw things on screen
• (house, car, tree, etc)
• use of "this" again
– Higher level groupings (block, neighborhood)
Methods as Building blocks
• Want to draw more complex pictures?
– a scene of houses and cars, or a farm scene
• Make a method called drawHouse
– like a stamp we can use to make many copies
– we just say what to draw and where to draw it
Methods can call other methods
• Suppose you want a row of houses (a block)
• drawBlock method can invoke house method
public void drawBlock(Graphics g, int x, int y){
int k=0;
while (k<6){
this.drawHouse(g, x + k*60, y);
this.drawTree(g, x+k*60+50, y);
k++;
}
}
Lab18BarnyardApplet
• Make a drawCow method, a drawBarn
method, drawDuck, drawPig, etc and plant
many copies all over yard.
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