Java Course Lec11

Java 11. java.awt20 2003 : ( Sun ) ( Sun ) < [email protected]>Copyright 2003 Sun , , .

java.awt ....

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11. java.awt...................................................................................................11. .......................................................................................................................... 2 2. ............................................................................................................................2 2.1. HTML .................................................................................................3 2.2. ............................................................................................ 5 2.3. .................................................................................................... 5 2.4. .................................................................................................5 2.5. ..........................................................................6 2.6. ............................................................................................................7 2.7. .....................................................7 2.8. Graphics......................................................................... 7 2.9. ......................................................................................................................... 8 2.9.1. Color..................................................................................... 9 2.10. ................................................................................................................. 9 2.10.1. .......................................................................... 10 2.10.2. : FontMetrics............................................. 11 2.10.3. FontMetrics....................................................................... 11 2.10.4. ...............................................................................12 3. ............................................................................................................. 12 4. .................................................................................................. 13 5. ................................................................................................23 6. ................................................................................................................................ 26 7. ...............................................................................................................................27 8. ....................................................................................................... 28 8.1. "" Java............................................................................. 32 8.2. "" ...................... 33 9. .................................................................................................................... 34 10. .................................................................................................35

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11. java.awt .1. ......................................................................................................................... 2 2. ........................................................................................................................... 22.1. HTML .......................................................................................................3 2.2. ..................................................................................................5 2.3. .......................................................................................................... 5 2.4. .......................................................................................................5 2.5. ................................................................................6 2.6. ................................................................................................................. 7 2.7. ...........................................................7 2.8. Graphics............................................................................... 7 2.9. ............................................................................................................................... 8 2.9.1. Color........................................................................................... 9 2.10. .......................................................................................................................9 2.10.1. ................................................................................ 10 2.10.2. : FontMetrics................................................... 11 2.10.3. FontMetrics.............................................................................11 2.10.4. .....................................................................................12

3. ............................................................................................................ 12 4. ................................................................................................. 13 5. ............................................................................................... 23 6. ............................................................................................................................... 26 7. .............................................................................................................................. 27 8. ...................................................................................................... 288.1. "" Java................................................................................... 32 8.2. "" ............................ 33

9. ................................................................................................................... 34 10. ................................................................................................ 35

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1. , , , , , . . , - , . , , "" - . Java Abstraction Window Toolkit (AWT) . AWT .

2. (applets) - , Internet, , , HTML. , . HelloWorld, :import java.awt.*; import java.applet.*; public class HelloWorldApplet extends Applet { public void paint(Graphics g) { g.drawString("Hello World!", 20, 20); } }

, java.applet java.awt. paint, Applet. , Graphics. . drawString, Graphics, (20,20) "Hello World". , , html-.

Java


HTML

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html-, appletviewer . .

2.1. HTML HTML-, appletviewer. appletviewer , . : [< PARAM NAME = AttributeNamel VALUE = AttributeValuel >] [< PARAM NAME = AttributeName2 VALUE = AttributeValue2 >] [HTML-, Java]

CODE = appletClassFile CODE - , , . codebase, , , CODEBASE. Java 1.1 OBJECT.

OBJECT = appletClassSerialFile , , . init(), start(). CODE, OBJECT, .

WIDTH = pixels HEIGHT = pixels WIDTH HEIGHT - , .

ARCHIVE = jarFiles jar- ( ), Web-. Java


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, , , . JAR, TAR Unix:c:\> jar cf soundmap.jar *.class image.gif sound.wav

, jar- . (Lotus JavaBeans, Borland JBuilder) jar-. CODEBASE = codebaseURL CODEBASE - , URL , , ( CODE). , HTML-. CODEBASE , HTML-. ALT = alternateAppletText ALT - , , ( , ) , , . , HTML-, , . NAME = appletInstanceName NAME - , . , . , MyApplet Applet "Duke", : MyApplet a = getAppletContext().getApplet("Duke"); , , , . ALIGN = alignment ALIGN - , . , IMG, - LEFT, RIGHT, TOP, TEXTTOP, MIDDLE, ABSMIDDLE, BASELINE, BOTTOM, ABSBOTTOM. VSPACE = pixels HSPACE = pixels (VSPACE), (HSPACE). , IMG. PARAM NAME = appletAttribute1 VALUE = value1 HTML- . , getParameter(), . Java


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2.2. getParameter(String) getParameter String, . - , - . getParameter :

, :String String String String FontName = getParameter("fontName"); FontSize = Integer.parseInt(getParameter("fontSize")); Leading = Float.valueOf(getParameter("leading")); PaidUp = Boolean.valueOf(getParameter("accountEnabled"));

2.3. getDocumentBase getCodeBase , , . Java , HTML-, ( - getDocumentBase), , class- ( - getCodeBase). AppletContext showDocument AppletContext , . showDocument , .

2.4. : . , , :System.out.println("Hello there, welcome to Java");

, , . Netscape Java Options, "Show Java Console".

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showStatus pletviewer Java. .

2.5. , Applet, , . init init . . start start init. , . , init - , start HTML-, , . , , WWW-, , start. paint paint . AWT , , , . , , , paint. update update Applet , paint. paint , update - , , . , update. update, paint, AWT, update. stop stop , HTML-, . stop . , . , , start. destroy destroy , (, Netscape) , . , .

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2.6. HelloWorldApplet. paint, . Applet , . , update . update repaint. repaint repaint . , , update. , , update . AWT, update . , repaint(time) - , . repaint(time) repaint, ( repaint). repaint(x, y, w, h) , , . repaint(time, x, , w, h) - .

2.7. , , . size, Dimension. Dimension, width height:Dimension d = size(); System.out.println(d. width + "," + d.height);

2.8. Graphics Graphics . , . drawRect, drawOval, fillRect fillOval : int x, int y, int width int height. , width height . drawLinedrawline(int x1, int 1, int 2, int 2) Java


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(1,1) (2,2). 1 . . drawArc fillArc drawArc fillArc :drawArc(int x, int , int width, int height, int startAngle, int sweepAngle)

(fillArc ) , (x,y,width, height), startAngle sweepAngle. 3 , (, 90 12 , 180 - 9 , ). drawPolygon fillPolygon :drawPolygon(int[], int[], int) fillPolygon(int[], int[], int)

drawPolygon ( ), , , - . drawPolygon . , , . Java Graphics.

2.9. AWT , . , , Java , . , - , , , . Color.black - - black, white, red, green, blue, cyan, yellow, magenta, orange, pink, gray, darkGray lightGray. . Color(int, int, int) 0 255 , . Color(int) - , , . 16-23, - 8-15, - 0-7. Java


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Color(float, float, float) , Color(float, float, float), float ( 0.0 1.0) , .

2.9.1. Color HSBtoRGB(float, float, float) RGBtoHSB(int, int, int, float[]) HSBtoRGB , , (HSB), RGB, Color(int). RGBtoHSB , , float HSB, . HSB (Hue-Saturation-Brightness, --) Red-Green-Blue . ( 0.0 1.0, , , , , , , , ). ( 0.0 1.0) - , . - 0.0 1.0, , - . getRed(), getGreen(), getBlue() . getRGB() , , red = Oxff & (getRGB() >> 16); green = Oxff & (getRGB() >> 8); blue = Oxff & getRGB();

Graphics: setPaintMode() setXORMode(Color) paint - , . XOR , XOR ( ) ( ).

2.10. AWT Java


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. , Java ./* * * * */ import java.applet.*; import java.awt.*; public class WhatFontsAreHere extends Applet { public void init() { String fontList[]; // : // Toolkit.getDefaultToolkit().getFontList() fontList = GraphicsEnvironment.getLocalGraphicsEnvironment(). getAvailableFontFamilyNames(); for (int i=0; i < fontList.length; i++) { System.out.println(i + ": " + fontList[i]); } } }

drawString drawString(String, x, ). . (,) , , . , , , FontMetrics.

2.10.1. Font , :Font StrongFont = new Font("Helvetica", Font.BOLD|Font.ITALIC, 24);

: Dialog, Helvetica, TimesRoman, Courier Symbol. . - Font.PLAIN, Font.BOLD Font.ITALIC, , . . getFamily getName

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getFamily . getName . getSize , . getStyle , . Font: - PLAIN, BOLD ITALIC. isBold, isItalic, isPlain true , - (bold), (italic) (plain), .

2.10.2. : FontMetrics Java , FontMetrics . - , : (height) - . (baseline) - , ( (descent)). (ascent) - . (descent) - .

2.10.3. FontMetrics FontMetrics: stringWidth . bytesWidth, charsWidth . getAscent, getDescent, getHeight , . . - g . .. getMaxAscent getMaxDescent .

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2.10.4. FontMetrics , , , ./* * * * */ import java.applet.*; import java.awt.*; public class HelloWorld extends Applet { final Font f = new Font("Helvetica", Font.BOLD, 18); public void paint(Graphics g) { Dimension d = this.size(); g.setColor(Color.white); g.fillRect(0,0,d.width,d.height); g.setColor(Color.black); g.setFont(f); drawCenteredString("Hello World!", d.width, d.height, g); g.drawRect(0,0,d.width-1,d.height-1); } public void drawCenteredString(String s, int w, int h, Graphics g) { FontMetrics fm = g.getFontMetrics(); int x = (w - fm.stringWidth(s)) / 2; int y = (fm.getAscent() + (h - (fm.getAscent() + fm.getDescent()))/2); g.drawString(s, x, y); } }

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3. , Graphics Fonts AWT, . Component - , - , , , / , , ,

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, ( 100 ). Component. Container Container - Component, , , . Container LayoutManager, . Panel Panel - Container. , . Panel , . add Panel . , - , setLocation, setSize setBounds Component. Panel - Applet. , Applet, paint update Panel. , Panel, AWT, Panel .

4. Canvas Canvas , . Canvas . , , "" - , . Canvas GrayCanvas, . , ./* */ import java.awt.*; import java.applet.*; class GrayCanvas extends Canvas { Color gray; public GrayCanvas(float g) {

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gray = new Color(g, g, g); } public void paint(Graphics g) { Dimension size = size(); g.setColor(gray); g.fillRect(0, 0, size.width, size.height); g.setColor(Color.black); g.drawRect(0, 0, size.width-1, size.height-1); } } public class PanelDemo extends Applet { static final int n = 4; public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { float g = (i * n + j) / (float) (n * n); Canvas = new GrayCanvas(g); add(c); c.setSize(width / n, height / n); c.setLocation(i * width / n, j * height / n); } } } }

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Canvas , size, Dimension. , Canvas resize move. , . setLayout(null). Label Label , , String - , . , , Component. Java


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getFont/setFont getForeground/setForeground. setText. Label LEFT, RIGHT CENTER. , , - ./* */ import java.awt.*; import java.applet.*; public class LabelDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); Label left = new Label("Left", Label.LEFT); Label right = new Label("Right", Label.RIGHT); Label center = new Label("Center", Label.CENTER); add(left); add(right); add(center); left.setBounds(0, 0, width, height / 3); right.setBounds(0, height / 3, width, height / 3); center.setBounds(0, 2 * height / 3, width, height / 3); } }

, Label, reshape. , - 1/3 . , :

Button - , Label ( ). , , . , ./* */ import java.awt.*; Java


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import java.applet.*; public class ButtonDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); Button yes = new Button("Yes"); Button no = new Button("No"); Button maybe = new Button("Undecided"); add(yes); add(no); add(maybe); yes.setBounds(0, 0, width, height / 3); no.setBounds(0, height / 3, width, height / 3); maybe.setBounds(0, 2 * height / 3, width, height / 3); } }

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Checkbox Checkbox . Checkbox , . getState setState. Checkbox, ./* */ import java.awt.*; import java.applet.*; public class CheckboxDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); Checkbox win95 = new Checkbox("Windows 95/98", null, true); Checkbox Solaris = new Checkbox("Solaris 2.5"); Checkbox mac = new Checkbox("MacOS 7.5"); Java


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add(win95); add(solaris); add(mac); win95.setBounds(0, 0, width, height / 3); Solaris.setBounds(0, height / 3, width, height / 3); mac.setBounds(0, 2 * height / 3, width, height / 3); } }

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CheckboxGroup Checkbox ( null) Checkbox. CheckboxGroup, Checkbox, ( ). , , Checkbox - getCheckboxGroup setCheckboxGroup. getCurrent setCurrent Checkbox. , , ./* */ import java.awt.*; import java.applet.*; public class CheckboxGroupDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); CheckboxGroup g = new CheckboxGroup(); Checkbox win95 = new Checkbox("Windows 95/98", g, true); Checkbox solaris = new Checkbox("Solaris 2.5", g, false); Checkbox mac = new Checkbox("MacOS 7.5", g, false); add(win95); add(solaris); add(mac); win95.setBounds(0, 0, width, height / 3); solaris.setBounds(0, height / 3, width, height / 3); Java


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mac.setBounds(0, 2 * height / 3, width, height / 3); } }

- , , :

Choice Choice () ( ComboBox Windows). Choice , , , , . - , , . , Choice. countItems . , , select, ( ), , . , getSelectedItem getSelectedIndex , , - . , Choice./* */ import java.awt.*; import java.applet.*; public class ChoiceDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); Choice os = new Choice(); Choice browser = new Choice(); os.addItem("Windows 95/98"); os.addItem("Solaris 2.5"); os.addItem("MacOS 7.5"); browser.addItem("Netscape Navigator 3.0"); browser.addItem("Netscape Communicator 4.5"); browser.addItem("Internet Explorer 3.0"); browser.addItem("Mosaic 3.0"); browser.addItem("Lynx 2.4"); browser.select("Netscape Communicator 4.5"); add(os); Java


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add(browser); os.setBounds(0, 0, width, height / 2); browser.setBounds(0, height / 2, width, height / 2); } }

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List List ( ListBox Windows). , , ./* */ import java.awt.*; import java.applet.*; public class ListDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); List os = new List(0, true); List browser = new List(0, false); os.addItem("Windows 95/98"); os.addItem("Solaris 2.5"); os.addItem("MacOS 7.5"); browser.addItem("Netscape Navigator 3.0"); browser.addItem("Netscape Communicator 4.5"); browser.addItem("lnternet Explorer 4.0"); browser.addItem("Mosaic 3.0"); browser.addItem("Lynx 2.4"); browser.select(1); add(os); add(browser); os.setBounds(0, 0, width, height / 2); browser.setBounds(0, height / 2, width, height / 2); } }

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, , :

Scrollbar Scrollbar ( ) . , , . , , , . , , . Scrollbar - VERTICAL HORIZONTAL. , , , . getValue setValue. , getMinimum getMaximum, . , , ./* */ import java.awt.*; import java.applet.*; public class ScrollbarDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer. parseInt(getParameter("height")); Scrollbar hs = new Scrollbar(Scrollbar.HORIZONTAL, 50, width / 10, 0, 100); Scrollbar vs = new Scrollbar(Scrollbar.VERTICAL, 50, height / 2, 0, 100); add(hs); add(vs); int thickness = 16; hs.setBounds(0, height - thickness, width - thickness, thickness); vs.setBounds(width - thickness, 0, thickness, height - thickness); } }

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, , :

TextField TextField . . "" TextField setEditable, isEditable , . getText setText. select , , . selectAll. setEchoChar , . , TextField , echoCharIsSet, , -, getEchoChar. , ./* */ import java.awt.*; import java.applet.*; public class TextFieldDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); Label namep = new Label("Name : ", Label.RIGHT); Label passp = new Label("Password : ", Label.RIGHT); TextField name = new TextField(8); TextField pass = new TextField(8); pass.setEchoChar('*'); add(namep); add(name); add(passp); add(pass); int space = 25; int w1 = width / 3; namep.setBounds(0, (height - space) / 2, w1, space); name.setBounds(w1, (height - space) / 2, w1, space); passp.setBounds(0, (height + space) / 2, w1, space); pass.setBounds(w1, (height + space) / 2, w1, space);

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} }

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TextArea . AWT , TextArea. TextArea String . , , . , TextArea: appendText String ; insertText ; rplaceText - , , -. , TextArea ./* */ import java.awt.*; import java.applet.*; public class TextAreaDemo extends Applet { public void init() { setLayout(null); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); String val = "Java, whose original name\n"+ "was Oak, was developed as a part\n"+ "of the Green project at Sun.\n"; System.out.println(val); TextArea text = new TextArea(val, 80, 40); add(text); text.setBounds(0, 0, width, height); } }

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5. Layout , , "". setLayout(null). . AWT (layout managers). LayoutManager , LayoutManager, , String. , Panel, . Panel, minimumLayoutSize preferredLayoutSize. , , preferredSize minimumSize. , . , . Java - , . FlowLayout FlowLayout , , , . , . , , . FlowLayout. , , LEFT, RIGHT CENTER . - CENTER, - 5 . , Panel Label. Panel FlowLayout RIGHT./* */ import java.awt.*; import java.applet.*; import java.util.*; public class FlowLayoutDemo extends Applet { public void init() {

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setLayout(new FlowLayout(FlowLayout.RIGHT, 10, 3)); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); String val = "Data is not information " + "is not knowledge is not wisdom."; StringTokenizer st = new StringTokenizer(val); while (st.hasMoreTokens()) { add(new Button(st.nextToken())); } } }

( 200 250 ) , , Label , :

BorderLayout BorderLayout , , , , . -: String.North, String.South, String.East String.West , a Center - . BorderLayout ./* */ import java.awt.*; import java.applet.*; import java.util.*; public class BorderLayoutDemo extends Applet { public void init() { setLayout(new BorderLayout()); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); add("North", new Button("This is across the top")); add("South", new Label("The footer message might go here")); add("East", new Button("Left")); add("West", new Button("Right")); String msg = "The origins of Java go back to 1990,\n"+ "when the World Wide Web was\n"+ Java


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"barely a glimmer in a British\n"+ "programmer's eye.\n\n"+ "-- The Java Saga, by David Bank"; add("Center", new TextArea(msg)); } }

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GridLayout GridLayout . . , GridLayout 44, 15 16 , . , , , - ""./* */ import java.awt.*; import java.applet.*; public class GridLayoutDemo extends Applet { static final int n = 4; public void init() { setLayout(new GridLayout(n, n)); setFont(new Font("Helvetica", Font.BOLD, 24)); int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { int k = i * n + j; if (k > 0) add(new Button("" + k)); } } } }

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- :

, ( , "" Windows), AWT- , Windows . Insets Insets , Panel , , . , Panel, Insets , Insets , , , .public Insets insets() { return new Insets(10, 10, 10, 10); }

CardLayout CardLayout . , , . , . , , .

6. Window Window Panel , . Window, Frame. Frame Frame - , . Frame , . / Frame, show hide. , Frame TextArea./* Java


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*/ import java.awt.*; import java.applet.*; public class FrameDemo extends Applet { public void init() { int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); Frame f = new Frame("Demo Frame"); f.setSize(width, height); f.setLayout(new FlowLayout(FlowLayout.LEFT)); f.add(new Label(" ...")); f.add(new Label(" , ")); f.add(new Label(" , - .")); f.add(new Label("- (George Gilder), Forbes ASAP")); f.show(); } }

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7. . MenuBar Menu. , , - MenuItem. Menu - MenuItem, Menu , . , ./* */ import java.awt.*; import java.applet. *; Java


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public class MenuDemo extends Applet { public void init() { int width = Integer.parseInt(getParameter("width")); int height = Integer.parseInt(getParameter("height")); Frame f = new Frame("Demo Frame"); f.setSize(width, height); MenuBar mbar = new MenuBar(); f.setMenuBar(mbar); Menu file = new Menu("File"); file.add(new MenuItem("New... ")); file.add(new MenuItem("0pen...")); file.add(new MenuItem("Close")); file.add(new MenuItem("-")); file.add(new MenuItem("Quit...")); mbar.add(file); Menu edit = new Menu("Edit"); edit.add(new MenuItem("Cut")); edit.add(new MenuItem("Copy")); edit.add(new Menultem("Paste")); edit.add(new MenuItem("-")); Menu sub = new Menu("Special"); sub.add(new MenuItem("First")); sub.add(new MenuItem("Second")); sub.add(new MenuItem("Third")); edit.add(sub); edit.add(new CheckBoxMenuItem("Debug")); edit.add(new CheckBoxMenuItem("Testing")); mbar.add(edit); f.show(); } }

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8. AWT , , (callback). GUI- , Java


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( , ..). C++, ( , ). Java ( ). , . GUI-, . , GUI- , . Java AWT, JavaBeans API. Java. java.util.EventObject. AWT, , java.awt.AWTEvent. AWT (, MouseEvent tionEvent) java.awt.event. , getSource(), AWT , getID(). , , . , FocusEvent : FocusEvent.FOCUS_GAINED FocusEvent.FOCUS_LOST. , . , MouseEvent getX(), getY() getClickCount (). , , getModifiers() getWhen(). Java . , . , ( ), , , , , . ( , ), , . ( EventObject). , . , . , ActionEvent ActionListener. java.awt.event (, MouseEvent : MouseListener MouseMotionListener). java.util.EventListener. , -, . . , , MouseEvent, , , Java


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. . , , , . , . 6 java.awt.event , , , . 1. , Java ActionEvent AdjustmentEvent ComponentEvent ActionListener AdjustmentListener ComponentListener actionPerformed() adjustmentValueChanged() componentHidden() componentMoved() componentResized() componentShown() componentAdded() componentRemoved() focusGained() focusLost () itemStateChanged() keyPressed() keyReleased() keyTyped() mouseClicked() mouseEntered() mouseExited() mousePressed() mouseReleased() mouseDragged() mouseMoved() textValueChanged() windowActivated() windowClosed() windowClosing() windowDeactivated() windowDeiconified() windowlconified() windowOpened()

ContainerEvent FocusEvent ItemEvent KeyEvent

ContainerListener FocusListener ItemListener KeyListener

MouseEvent

MouseListener

MouseMotionEvent TextEvent WindowEvent

MouseMotionListener TextListener WindowListener

, , java.awt.event -, . , -, . , , , . , , , Listener Adapter: MouseAdapter, WindowAdapter .. -, , . Java


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. AWT - . : X, addXListener () removeXListener() . Java , . , . , API Button , ActionEvent. 7 AWT , . 2. AWT Java1.1 Button CheckBox CheckBoxMenuItem Choice Component ActionEvent ItemEvent ItemEvent ItemEvent ComponentEvent FocusEvent KeyEvent MouseEvent , , , , , , , ,

Container List

ContainerEvent ActionEvent ItemEvent

MenuItem Scrollbar TextComponent TextField Window

ActionEvent AdjustmentEvent TextEvent ActionEvent WindowEvent

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8.1. "" Java , Java. MouseListener MouseMotionListener, addMouseListener() addMouseMotionListener()./* * */ import java.applet.*; import java.awt.*; import java.awt.event.*; public class Scribble2 extends Applet implements MouseListener, MouseMotionListener { private int last_x, last_y; public void init() { // , // MouseListener MouseMotionListener // , . // , // . this.addMouseListener(this) ; this.addMouseMotionListener(this); } // MouseListener. // . public void mousePressed(MouseEvent e) { last_x = e.getX(); last_y = e.getY(); } // MouseMotionListener. // . public void mouseDragged(MouseEvent e) { Graphics g = this.getGraphics(); int x = e.getX(), y = e.getY(); g.drawLine(last_x, last_y, x, y); last_x = x; last_y = y; } // , MouseListener. public void mouseReleased(MouseEvent e) {;} public void mouseClicked(MouseEvent e) {;} public void mouseEntered(MouseEvent e) {;} public void mouseExited(MouseEvent e) {;}

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// MouseMotionListener. public void mouseMoved(MouseEvent e) {;} }

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8.2. "" Java , Java: . , , . . , - Clear. ActionListener, ./* * */ import java.applet.*; import java.awt.*; import java.awt.event.*; public class Scribble3 extends Applet { int last_x, last_y; public void init() { // , MouseListener. this.addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent e) { last_x = e.getX(); last_y = e.getY(); } }); // , MouseMotionListener. this.addMouseMotionListener(new MouseMotionAdapter() { public void mouseDragged(MouseEvent e) { Graphics g = getGraphics(); int x = e.getX(), y= e.getY(); g.setColor(Color.black); g.drawLine(last_x, last_y, x, y); last_x = x; last_y = y; }

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}); // Clear. Button b = new Button("Clear"); // , // , . b.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { // Graphics g = getGraphics(); g.setColor(getBackground()); g.fillRect(0, 0, getSize().width, getSize().height); } }); // . this.add(b); } }

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, 3 : Scribble3$1,2,3.

9. (GUI) Java, AWT. , , HTML-. -, , . , , . -, , , main. , Java Graphics, , . AWT, Component . Container, . Component Java


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( . controls), Container . (Layout managers). Container Window, . Dialog Frame. Dialog FileDialog. MenuComponent . , , , , . 11 GUI-.

10. 11-1. Applet? a.) java.awt.Panel 11-2. init ? start? a.) init . start , . 11-3. paint, update, repaint? a.) paint , update (background) , paint repaint , update 11-4. Color, ? a.) new Color(0,0,255). Color.blue 11-5. Java ? a.) , ( ), (, , ). 11-6. FontMetrics? a.) , , , Java


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. .

FontMetrics , , . 11-7. -, 1010. a.) public class SquareComponent extends Canvas {public void paint(Graphics g) { g.drawRect(getWidth()-5, getHeight()-5, 10, 10); } }

11-8. AWT (check-box)? - (radio-button)? a.) Checkbox:Checkbox chbox = new Checkbox();

- Checkbox CheckboxGroup:CheckboxGroup group = new CheckboxGroup(); Checkbox rb1 = new Checkbox(" 1",group, true); Checkbox rb2 = new Checkbox(" 2",group, false);

11-9. List Choice? a.) List , Choise . List ( multiselect), Choice . 11-10. ? ? a.) . , , , . : constraints, ..) (

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11-11. Dialog Frame? a.) , Frame , Dialog Frame. Dialog . Frame . Dialog . 11-12. , , ? a.) . -, Listener-, . , addListener, . 11-13. , ? a.) , addListener .

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Java Course Lec11