Graphics Drawing Canvas canvas new Drawing Canvas Note

Graphics

Drawing. Canvas canvas = new Drawing. Canvas( ); Note: Drawing. Canvas is not a standard API class; it must be downloaded from the class webpage.

made up of pixels

Java’s (wacky) coordinate system x axis (0, 0) (x, y) y axis the larger the y the farther down the pixel is on the Drawing. Canvas

Shapes

Graphics object To draw in Java we must first get a Graphics object from the Drawing. Canvas: import java. awt. Graphics; . . . Graphics g = canvas. get. Graphics();

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) Examples g. draw. Line(50, 25, 180, 220); (x 1, y 1) (x 2, y 2)

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) Examples g. draw. Rect(30, 70, 150, 100); void draw. Rect (int x, int y, int width, int height) width (x, y) height

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) Examples g. fill. Rect(30, 70, 150, 100); void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) width (x, y) height

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) Examples g. draw. Oval(30, 70, 150, 100); void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) void draw. Oval (int x, int y, int width, int height) width (x, y) height

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) Examples g. fill. Oval(30, 70, 150, 100); void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) void draw. Oval (int x, int y, int width, int height) void fill. Oval (int x, int y, int width, int height) width (x, y) height

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) Examples g. draw. Arc(30, 70, 150, 100, 45, 180); void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) void draw. Oval (int x, int y, int width, int height) void fill. Oval (int x, int y, int width, int height) void draw. Arc (int x, int y, int width, int height, int start. Angle, int arc. Angle) width (x, y) arc. Angle start. Angle height

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) Examples g. draw. String(“I love java!”, 100, 50); void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) void draw. Oval (int x, int y, int width, int height) void fill. Oval (int x, int y, int width, int height) void draw. Arc (int x, int y, int width, int height, int start. Angle, int arc. Angle) void draw. String (String s, int x, int y) (x, y)

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) void draw. Oval (int x, int y, int width, int height) Examples import java. awt. Polygon; … Polygon p = new Polygon(); p. add. Point(100, 80); p. add. Point(250, 80); p. add. Point(200, 150); p. add. Point(50, 150); g. fill. Polygon(p); void fill. Oval (int x, int y, int width, int height) void draw. Arc (int x, int y, int width, int height, int start. Angle, int arc. Angle) void draw. String (String s, int x, int y) void draw. Polygon (Polygon p) (x 1, y 1) (x 4, y 4) (x 2, y 2) (x 3, y 3)

red green blue RGB values 0. . 255

Java predefined colors java. awt. Color. black (0, 0, 0) Color. red (255, 0, 0 ) Color. green (0, 255, 0) Color. blue (0, 0, 255) Color. magenta (255, 0, 255) Color. yellow (255, 0) Color. cyan (0, 255) Color. white (255, 255) Color. light. Gray Color. gray Color. dark. Gray Color. orange Color. pink

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) void draw. Oval (int x, int y, int width, int height) void fill. Oval (int x, int y, int width, int height) void draw. Arc (int x, int y, int width, int height, int start. Angle, int arc. Angle) void draw. String s, int x, int y) void set. Color (Color c) g. set. Color(Color. red); g. fill. Rect(30, 70, 150, 100);

Graphics methods void draw. Line (int x 1, int y 1, int x 2, int y 2) void draw. Rect (int x, int y, int width, int height) void fill. Rect (int x, int y, int width, int height) void draw. Oval (int x, int y, int width, int height) void fill. Oval (int x, int y, int width, int height) void draw. Arc (int x, int y, int width, int height, int start. Angle, int arc. Angle) void draw. String s, int x, int y) void setcolor (Color c) Drawing. Canvas method void set. Background (Color c) Examples canvas. set. Background(Color. yellow); g. set. Color(Color. red); g. fill. Rect(30, 70, 150, 100);

How do we access the Graphics object?

import java. awt. Graphics ; import java. awt. Color ; class Drawing. Example { public static void main (String[] args) { instantiate Drawing. Canvas object Drawing. Canvas canvas = new Drawing. Canvas( ); Graphics g = canvas. get. Graphics( ); get Graphics object for drawing g. draw. Line(10, 50, 25, 100); } } call drawing methods Let’s try it… download Drawing. Canvas. java