1 /*

     2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  *

     8  *   - Redistributions of source code must retain the above copyright

     9  *     notice, this list of conditions and the following disclaimer.

    10  *

    11  *   - Redistributions in binary form must reproduce the above copyright

    12  *     notice, this list of conditions and the following disclaimer in the

    13  *     documentation and/or other materials provided with the distribution.

    14  *

    15  *   - Neither the name of Oracle nor the names of its

    16  *     contributors may be used to endorse or promote products derived

    17  *     from this software without specific prior written permission.

    18  *

    19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

    20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

    21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

    23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

    24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

    25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

    26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

    27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

    28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

    29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    30  */

    31 

    32 /*

    33  * This source code is provided to illustrate the usage of a given feature

    34  * or technique and has been deliberately simplified. Additional steps

    35  * required for a production-quality application, such as security checks,

    36  * input validation and proper error handling, might not be present in

    37  * this sample code.

    38  */

    39 

    40 

    41 

    42 import java.awt.*;

    43 import java.awt.event.*;

    44 import java.applet.*;

    45 

    46 

    47 /**

    48  * An interactive test of the Graphics.drawArc and Graphics.fillArc

    49  * routines. Can be run either as a standalone application by

    50  * typing "java ArcTest" or as an applet in the AppletViewer.

    51  */

    52 @SuppressWarnings("serial")

    53 public class ArcTest extends Applet {

    54 

    55     ArcControls controls;   // The controls for marking and filling arcs

    56     ArcCanvas canvas;       // The drawing area to display arcs

    57 

    58     @Override

    59     public void init() {

    60         setLayout(new BorderLayout());

    61         canvas = new ArcCanvas();

    62         add("Center", canvas);

    63         add("South", controls = new ArcControls(canvas));

    64     }

    65 

    66     @Override

    67     public void destroy() {

    68         remove(controls);

    69         remove(canvas);

    70     }

    71 

    72     @Override

    73     public void start() {

    74         controls.setEnabled(true);

    75     }

    76 

    77     @Override

    78     public void stop() {

    79         controls.setEnabled(false);

    80     }

    81 

    82     @Override

    83     public void processEvent(AWTEvent e) {

    84         if (e.getID() == Event.WINDOW_DESTROY) {

    85             System.exit(0);

    86         }

    87     }

    88 

    89     public static void main(String args[]) {

    90         Frame f = new Frame("ArcTest");

    91         ArcTest arcTest = new ArcTest();

    92 

    93         arcTest.init();

    94         arcTest.start();

    95 

    96         f.add("Center", arcTest);

    97         f.setSize(300, 300);

    98         f.setVisible(true);

    99     }

   100 

   101     @Override

   102     public String getAppletInfo() {

   103         return "An interactive test of the Graphics.drawArc and \nGraphics."

   104                 + "fillArc routines. Can be run \neither as a standalone "

   105                 + "application by typing 'java ArcTest' \nor as an applet in "

   106                 + "the AppletViewer.";

   107     }

   108 }

   109 

   110 

   111 @SuppressWarnings("serial")

   112 class ArcCanvas extends Canvas {

   113 

   114     int startAngle = 0;

   115     int extent = 45;

   116     boolean filled = false;

   117     Font font = new java.awt.Font("SansSerif", Font.PLAIN, 12);

   118 

   119     @Override

   120     public void paint(Graphics g) {

   121         Rectangle r = getBounds();

   122         int hlines = r.height / 10;

   123         int vlines = r.width / 10;

   124 

   125         g.setColor(Color.pink);

   126         for (int i = 1; i <= hlines; i++) {

   127             g.drawLine(0, i * 10, r.width, i * 10);

   128         }

   129         for (int i = 1; i <= vlines; i++) {

   130             g.drawLine(i * 10, 0, i * 10, r.height);

   131         }

   132 

   133         g.setColor(Color.red);

   134         if (filled) {

   135             g.fillArc(0, 0, r.width - 1, r.height - 1, startAngle, extent);

   136         } else {

   137             g.drawArc(0, 0, r.width - 1, r.height - 1, startAngle, extent);

   138         }

   139 

   140         g.setColor(Color.black);

   141         g.setFont(font);

   142         g.drawLine(0, r.height / 2, r.width, r.height / 2);

   143         g.drawLine(r.width / 2, 0, r.width / 2, r.height);

   144         g.drawLine(0, 0, r.width, r.height);

   145         g.drawLine(r.width, 0, 0, r.height);

   146         int sx = 10;

   147         int sy = r.height - 28;

   148         g.drawString("Start = " + startAngle, sx, sy);

   149         g.drawString("Extent = " + extent, sx, sy + 14);

   150     }

   151 

   152     public void redraw(boolean filled, int start, int extent) {

   153         this.filled = filled;

   154         this.startAngle = start;

   155         this.extent = extent;

   156         repaint();

   157     }

   158 }

   159 

   160 

   161 @SuppressWarnings("serial")

   162 class ArcControls extends Panel

   163         implements ActionListener {

   164 

   165     TextField startTF;

   166     TextField extentTF;

   167     ArcCanvas canvas;

   168 

   169     @SuppressWarnings("LeakingThisInConstructor")

   170     public ArcControls(ArcCanvas canvas) {

   171         Button b = null;

   172 

   173         this.canvas = canvas;

   174         add(startTF = new IntegerTextField("0", 4));

   175         add(extentTF = new IntegerTextField("45", 4));

   176         b = new Button("Fill");

   177         b.addActionListener(this);

   178         add(b);

   179         b = new Button("Draw");

   180         b.addActionListener(this);

   181         add(b);

   182     }

   183 

   184     @Override

   185     public void actionPerformed(ActionEvent ev) {

   186         String label = ev.getActionCommand();

   187 

   188         int start, extent;

   189         try {

   190             start = Integer.parseInt(startTF.getText().trim());

   191         } catch (NumberFormatException ignored) {

   192             start = 0;

   193         }

   194         try {

   195             extent = Integer.parseInt(extentTF.getText().trim());

   196         } catch (NumberFormatException ignored) {

   197             extent = 0;

   198         }

   199 

   200         canvas.redraw(label.equals("Fill"), start, extent);

   201     }

   202 }

   203 

   204 

   205 @SuppressWarnings("serial")

   206 class IntegerTextField extends TextField {

   207 

   208     String oldText = null;

   209 

   210     public IntegerTextField(String text, int columns) {

   211         super(text, columns);

   212         enableEvents(AWTEvent.KEY_EVENT_MASK | AWTEvent.TEXT_EVENT_MASK);

   213         oldText = getText();

   214     }

   215 

   216     // Consume non-digit KeyTyped events

   217     // Note that processTextEvent kind of eliminates the need for this

   218     // function, but this is neater, since ideally, it would prevent

   219     // the text from appearing at all.  Sigh.  See bugid 4100317/4114565.

   220     //

   221     @Override

   222     protected void processEvent(AWTEvent evt) {

   223         int id = evt.getID();

   224         if (id != KeyEvent.KEY_TYPED) {

   225             super.processEvent(evt);

   226             return;

   227         }

   228 

   229         KeyEvent kevt = (KeyEvent) evt;

   230         char c = kevt.getKeyChar();

   231 

   232         // Digits, backspace, and delete are okay

   233         // Note that the minus sign is allowed, but not the decimal

   234         if (Character.isDigit(c) || (c == '\b') || (c == '\u007f') || (c

   235                 == '\u002d')) {

   236             super.processEvent(evt);

   237             return;

   238         }

   239 

   240         Toolkit.getDefaultToolkit().beep();

   241         kevt.consume();

   242     }

   243 

   244     // Should consume TextEvents for non-integer Strings

   245     // Store away the text in the tf for every TextEvent

   246     // so we can revert to it on a TextEvent (paste, or

   247     // legal key in the wrong location) with bad text

   248     //

   249     @Override

   250     protected void processTextEvent(TextEvent te) {

   251         // The empty string is okay, too

   252         String newText = getText();

   253         if (newText.equals("") || textIsInteger(newText)) {

   254             oldText = newText;

   255             super.processTextEvent(te);

   256             return;

   257         }

   258 

   259         Toolkit.getDefaultToolkit().beep();

   260         setText(oldText);

   261     }

   262 

   263     // Returns true for Integers (zero and negative

   264     // values are allowed).

   265     // Note that the empty string is not allowed.

   266     //

   267     private boolean textIsInteger(String textToCheck) {

   268 

   269         try {

   270             Integer.parseInt(textToCheck, 10);

   271             return true;

   272         } catch (NumberFormatException ignored) {

   273             return false;

   274         }

   275     }

   276 }