Dr. Hikmat A. M. AbdelJaber

Transcription

1 Dr. Hikmat A. M. AbdelJaber

2 Portion of the Java class hierarchy that include basic graphics classes and Java 2D API classes and interfaces. java.lang.object Java.awt.Color Java.awt.Component Java.awt.Container Javax.swing.JComponent Java.awt.Font Contains paintcomponent() used to draw graphics on a component Java.awt.FontMetrics for obtaining font information.

3 Java.awt.Graphics Java.awt.Graphics2D for drawing strings, lines,.. Java.awt.Polygon creating polygons Java.awt.BasicStroke specify the drawing characteristics of lines Java.awt.GradientPaint Java.awt.TexturePaint specify the characteristics for filling shapes with colors & patterns Interfaces Java.awt.paint Java.awt.shape Java.awt.stroke

4 Java.awt.geom.GeneralPath Java.awt.geom.Line2D Java.awt.geom.RectangularShape Several java shapes Java.awt.geom.Arc2D Java.awt.geom.Ellipse2D Java.awt.geom.Rectangle2D Java.awt.geom.RoundRectangle2D

5 Coordinate system of Java is composed of pairs (xcoordinate, y-coordinate) to specify where the texts and shapes should be displayed and they are measured in pixels. Graphics Context and Graphics Objects Graphics context: enables drawing on the screen. Graphics object: manages a graphics context and draws pixels on the screen that represent texts and other shapes Ex. public void paintcomponent( Graphics g ) in JComponent class Graphics object to manage graphics context.

6 The method paintcomponent( ) is called when: 1. The application container executes and displays the component. (add Panel on Frame) 2. The component is covered & uncovered by another window. 3. The method repaint() is called. The graphics/drawing capabilities are platformindependent (different drawing capabilities on different platforms-portability).

7 Color constants RED, GREEN, ORANGE, Color methods Color( int r, int g, int b ) Color( float r, float g, float b ) getred() getgreen() getblue() getcolor() setcolor(color c) Sets the current drawing color Show the program final & static Returns a value b/w representing the red content Returns a value b/w representing the green content Returns a value b/w representing the blue content Where a color object represent the current drawing color fillrect() is Graphics method used to draw a filled Rect showstring() is Graphics method used to draw a string

8 import java.awt.*; import java.awt.event.actionevent; import java.awt.event.actionlistener; import javax.swing.*; First Program ColorJPanel.java public class ColorJPanel extends JPanel private JButton button = new JButton("Change color"); private Color color = Color.WHITE; public ColorJPanel() setlayout(new BorderLayout()); add(button, BorderLayout.SOUTH); button.addactionlistener(new ActionListener() public void actionperformed(actionevent e) color = JColorChooser.showDialog(ColorJPanel.this,"Change color",color); setbackground(color); } // end actionperformed method }); } // end constructor

9 public void paintcomponent(graphics g) super.paintcomponent(g); setbackground(color); g.setcolor(new Color(255,0,0)); // set drawing Red color using integers g.fillrect(15, 25, 100, 20); g.drawstring("current RGB: " + g.getcolor(), 130, 40); g.setcolor(new Color(0.5f, 0.75f, 0.0f)); // set drawing Green color using floats g.fillrect(15, 75, 100, 20); g.drawstring("current RGB: " + g.getcolor(), 130, 90); g.setcolor(color.magenta); // set drawing Magenta color using Color object g.fillrect(15, 125, 100, 20); g.drawstring("rgb values:" + color.getred()+", "+color.getgreen()+", "+color.getblue(), 130, 140); } } // end class

10 import java.swing.jframe; public class ShowColors public static void main(string[] args) JFrame frame = new JFrame("Using colors"); frame.setdefaultcloseoperation(jframe.exit_on_close); Second Program ShowColors.java } } ColorJPanel colorjpanel = new ColorJPanel(); frame.add(colorjpanel); frame.setsize(450, 250); frame.setvisible(true);

11 Output

12 Some of Font constants and methods: PLAIN BOLD ITALIC Font(String name, int style, int size) int getstyle(): font style can be used in combination. int getsize(): is measured in points String getname(): monospaced, SansSerief, Serif, etc. String getfamily(): returns the font s family name.

13 boolean isplain() boolean isbold() boolean isitalic() Font getfont() void setfont( Font f ) Graphics methods for manipulating fonts Font objects are immutable Show the program

14 import java.awt.*; import javax.swing.*; public class FontJPanel extends JPanel public void paintcomponent( Graphics g) super.paintcomponent(g); this.setbackground(color.white); g.setfont(new Font("Serif", Font.BOLD, 12)); g.drawstring("serif 12 point bold", 20, 50); g.setfont(new Font("Monospaced", Font.ITALIC, 24)); g.drawstring("monospaced 24 point italic", 20, 70); g.setfont(new Font("SansSerif", Font.PLAIN, 14)); g.drawstring("sansserif 14 point plain", 20, 90);

15 g.setcolor(color.red); g.setfont(new Font("Serif", Font.BOLD+Font.ITALIC, 18)); g.drawstring(g.getfont().getname()+" "+g.getfont().getsize()+" point bold italic", 20, 110); } // end paintcomponent method public static void main( String[] args) JFrame frame = new JFrame("Using Fonts"); frame.setdefaultcloseoperation(jframe.exit_on_close); FontJPanel fontjpanel = new FontJPanel(); frame.add(fontjpanel); frame.setsize(420, 170); frame.setvisible(true); } // end main } // end class

16 Output

17 Some Graphics methods: drawline( x1, y1, x2, y2 ) drawrect( x, y, width, height ) fillrect( x, y, width, height ) clearrect(x, y, width, height) Used to remove a portion of an image drawroundrect(x, y, width, height, arcwidth, archeight) fillroundrect( x, y, width, height, arcwidth, archeight )

18 Notes: 1. If width, height, arcwidth and archeight have the same values, the result is a circle. 2. If width and height have the same values and arcwidth and archeight are 0, the result is square. draw3drect( x, y, width, height, boolean b ) fill3drect( x, y, width, height, boolean b ) original color Raised darker color lowered false (Lowered) darker color original color true (Raised)

19 drawoval( x, y, width, height ) filloval( x, y, width, height ) Show the program.

20 import java.awt.*; import javax.swing.*; First Program LinesRecOvalJPanel.java public class LinesRecOvalJPanel extends JPanel public void paintcomponent( Graphics g ) super.paintcomponent(g); g.setcolor(color.red); g.drawline(5, 30, 380, 30); g.setcolor(color.blue); g.drawrect(5, 40, 90, 55); g.fillrect(100, 40, 90, 55); g.clearrect(130, 50, 30, 30); g.setcolor(color.cyan); g.fillroundrect(195, 40, 90, 55, 50, 50); g.drawroundrect(290, 40, 90, 55, 20, 20);

21 // if the values for width and height are the same and the values of // arcwidth and archeight are 0, then the result is Square g.setcolor(color.red); g.fillroundrect(400, 40, 55, 55, 0, 0); // if the values for width, height, arcwidth and archeightare // have the same values, then the result is Circle g.setcolor(color.yellow); g.fillroundrect(470, 40, 55, 55, 55, 55); g.setcolor(color.orange); g.draw3drect(5, 100, 90, 55, true); g.fill3drect(100, 100, 90, 55, true); g.setcolor(color.magenta); g.drawoval(195, 100, 90, 55); g.filloval(290, 100, 90, 55); } // end paintcomponent method } // end class

22 import java.awt.*; import javax.swing.jframe; Second Program LinesRecOvalTest.java public class LinesRecOvalTest public static void main( String[] args) JFrame frame = new JFrame("Drawing lines, rectangles and ovals"); frame.setdefaultcloseoperation(jframe.exit_on_close); LinesRecOvalJPanel linesrecovaljpanel = new LinesRecOvalJPanel(); linesrecovaljpanel.setbackground(color.white); frame.add(linesrecovaljpanel); Toolkit kit = Toolkit.getDefaultToolkit(); frame.setlocation(kit.getscreensize().width/4, kit.getscreensize().height/4); frame.setsize(kit.getscreensize().width/2, kit.getscreensize().height/2); frame.setvisible(true); } // end main } // end class

23 Output