1 / 15

Spring 2009 Programming Fundamentals I Java Programming

Spring 2009 Programming Fundamentals I Java Programming. XuanTung Hoang tung_hx@icu.ac.kr. Lecture No. 18. Java GUI. Introduction Java Graphics. GUI in a nutshell. Other topics: Drawing Capabilities. Drawing on a panel. Sometimes it is necessary to paint on a GUI component

vida
Download Presentation

Spring 2009 Programming Fundamentals I Java Programming

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Spring 2009 Programming Fundamentals IJava Programming XuanTung Hoang tung_hx@icu.ac.kr Lecture No. 18

  2. Java GUI Introduction Java Graphics

  3. GUI in a nutshell Other topics: Drawing Capabilities

  4. Drawing on a panel • Sometimes it is necessary to paint on a GUI component • For example: Paint on a JPanel, paint on a JButton, … • How to paint on a GUI component? • Create a subclass of the component (inheritance) • Override paintComponent(Graphics g)method • The argument g is the object that provide drawing capabilities • Use the object g to paint • Frequently used methods: getClipBounds(), setColor(), getColor(), clearRect(), drawRect(), fillRect(), drawLine(), drawOval()

  5. Example: Drawing on a Panel • Create our own panel class by extending JPanel • Override paintComponent() method and put our drawing code there • Create our own frame and use our panel class as a Swing component

  6. Our own panel class

  7. Graphics class: • Class that represents “graphic contexts” • The area that paintComponent() will draw on • Control font styles/line patterns/fill patterns/colors • Provide drawing support methods

  8. Rectangle class • Getting drawing area from Graphics object Rectangle r specifies drawing area of Graphics object g in current drawing context coordinate system

  9. Drawing using Graphics object

  10. Put our drawing panel into a frame and show the frame • NOTE: setLayout before adding drawing panel

  11. Output

  12. We can add more GUI components to control drawing How ?

  13. Example: Make a snake that runs • We will make a snake that runs across a panel • Solution: • A snake = a horizontal line = a point (x, y) (the head) , a length, and a direction • We use a timer, after each timer event we change position of the head and repaint the snake on a panel (0, 0) dir (x, y) LEFT = 0 RIGHT = 1 length DOWN = 2 UP= 3 (MAXX, MAXY)

  14. Render and image on a panel • Import java.awt.image.* • Import javax.imageio.* • Create a BufferedImage object using static method read of ImageIO class • BufferedImage img = ImageIO.read(new FileInputStream(“Image.jpg” )); • Draw the image with drawImage() method of class Graphics • g.drawImage(img, x, y, width, height, null);

  15. Example: Display cards on Panel

More Related