控制台程序。
为了显示各个应用程序参数的状态，并且将各个参数显示在各自的面板中，在应用程序窗口的底部添加状态栏是常见且非常方便的方式。
定义状态栏时没有Swing类可用，所以必须自己建立StatusBar类。在理想情况下，应为一般目地的状态栏设计类，然后再针对Sketcher进行定制。但由于篇幅显示，这里采用简单方法说明如何设计专用语Sketcher的类。
1 // Class defining a status bar 2 import javax.swing.*; 3 import java.awt.*; 4 import javax.swing.border.BevelBorder; 5 import static Constants.SketcherConstants.*; 6 7 @SuppressWarnings("serial") 8 class StatusBar extends JPanel { 9 // Constructor 10 public StatusBar() { 11 setLayout(new FlowLayout(FlowLayout.LEFT, 10, 3)); 12 setBackground(Color.LIGHT_GRAY); 13 setBorder(BorderFactory.createLineBorder(Color.DARK_GRAY)); 14 setColorPane(DEFAULT_ELEMENT_COLOR); 15 setTypePane(DEFAULT_ELEMENT_TYPE); 16 add(colorPane); // Add color pane to status bar 17 add(typePane); // Add type pane to status bar 18 } 19 20 // Set color pane contents 21 public void setColorPane(Color color) { 22 String text = null; // Text for the color pane 23 Icon icon = null; // Icon to be displayed 24 if(color.equals(Color.RED)) { 25 text = "RED"; 26 icon = RED16; 27 } else if(color.equals(Color.YELLOW)) { 28 text = "YELLOW"; 29 icon = YELLOW16; 30 } else if(color.equals(Color.GREEN)) { 31 text = "GREEN"; 32 icon = GREEN16; 33 } else if(color.equals(Color.BLUE)) { 34 text = "BLUE"; 35 icon = BLUE16; 36 } else { 37 text = "CUSTOM COLOR"; 38 } 39 colorPane.setIcon(icon); 40 colorPane.setText(text); // Set the pane text 41 } 42 43 // Set type pane label 44 public void setTypePane (int elementType) { 45 String text = null; // Text for the type pane 46 switch(elementType) { 47 case LINE: 48 text = "LINE"; 49 break; 50 case RECTANGLE: 51 text = "RECTANGLE"; 52 break; 53 case CIRCLE: 54 text = "CIRCLE"; 55 break; 56 case CURVE: 57 text = "CURVE"; 58 break; 59 default: 60 assert false; 61 } 62 typePane.setText(text); // Set the pane text 63 } 64 65 // Panes in the status bar 66 private StatusPane colorPane = new StatusPane("BLUE", BLUE16);; 67 private StatusPane typePane = new StatusPane("LINE"); 68 69 // Class defining a status bar pane 70 class StatusPane extends JLabel { 71 // Constructor - text only 72 public StatusPane(String text) { 73 super(text, LEFT); 74 setupPane(); 75 } 76 77 // Constructor - text with an icon 78 public StatusPane(String text, Icon icon) { 79 super(text, icon, LEFT); 80 setupPane(); 81 } 82 83 // Helper method for use by constructors 84 private void setupPane() { 85 setBackground(Color.LIGHT_GRAY); // Set background color 86 setForeground(Color.BLACK); // Set foreground color 87 setFont(paneFont); // Set the fixed font 88 setBorder(BorderFactory.createCompoundBorder( 89 BorderFactory.createBevelBorder(BevelBorder.LOWERED), // Outside border 90 BorderFactory.createEmptyBorder(0,5,0,3))); // Inside border 91 setPreferredSize(new Dimension(80,20)); 92 } 93 94 // Font for pane text 95 private Font paneFont = new Font("Serif", Font.PLAIN, 10); 96 } 97 }
然后，在SketcherFrame类中添加对状态栏的定义：
1 // Frame for the Sketcher application 2 import javax.swing.*; 3 import javax.swing.border.*; 4 import java.awt.event.*; 5 import java.awt.*; 6 7 import static java.awt.event.InputEvent.*; 8 import static java.awt.Color.*; 9 import static Constants.SketcherConstants.*; 10 import static javax.swing.Action.*; 11 12 @SuppressWarnings("serial") 13 public class SketcherFrame extends JFrame { 14 // Constructor 15 public SketcherFrame(String title, Sketcher theApp) { 16 setTitle(title); // Set the window title 17 this.theApp = theApp; // Save app. object reference 18 setJMenuBar(menuBar); // Add the menu bar to the window 19 setDefaultCloseOperation(EXIT_ON_CLOSE); // Default is exit the application 20 21 createFileMenu(); // Create the File menu 22 createElementMenu(); // Create the element menu 23 createColorMenu(); // Create the element menu 24 createToolbar(); 25 toolBar.setRollover(true); 26 getContentPane().add(toolBar, BorderLayout.NORTH); // Add the toolbar 27 getContentPane().add(statusBar, BorderLayout.SOUTH); // Add the statusbar 28 } 29 30 // Create File menu item actions 31 private void createFileMenuActions() { 32 newAction = new FileAction("New", 'N', CTRL_DOWN_MASK); 33 openAction = new FileAction("Open", 'O', CTRL_DOWN_MASK); 34 closeAction = new FileAction("Close"); 35 saveAction = new FileAction("Save", 'S', CTRL_DOWN_MASK); 36 saveAsAction = new FileAction("Save As..."); 37 printAction = new FileAction("Print", 'P', CTRL_DOWN_MASK); 38 exitAction = new FileAction("Exit", 'X', CTRL_DOWN_MASK); 39 40 // Initialize the array 41 FileAction[] actions = {openAction, closeAction, saveAction, saveAsAction, printAction, exitAction}; 42 fileActions = actions; 43 44 // Add toolbar icons 45 newAction.putValue(LARGE_ICON_KEY, NEW24); 46 openAction.putValue(LARGE_ICON_KEY, OPEN24); 47 saveAction.putValue(LARGE_ICON_KEY, SAVE24); 48 saveAsAction.putValue(LARGE_ICON_KEY, SAVEAS24); 49 printAction.putValue(LARGE_ICON_KEY, PRINT24); 50 51 // Add menu item icons 52 newAction.putValue(SMALL_ICON, NEW16); 53 openAction.putValue(SMALL_ICON, OPEN16); 54 saveAction.putValue(SMALL_ICON, SAVE16); 55 saveAsAction.putValue(SMALL_ICON,SAVEAS16); 56 printAction.putValue(SMALL_ICON, PRINT16); 57 58 // Add tooltip text 59 newAction.putValue(SHORT_DESCRIPTION, "Create a new sketch"); 60 openAction.putValue(SHORT_DESCRIPTION, "Read a sketch from a file"); 61 closeAction.putValue(SHORT_DESCRIPTION, "Close the current sketch"); 62 saveAction.putValue(SHORT_DESCRIPTION, "Save the current sketch to file"); 63 saveAsAction.putValue(SHORT_DESCRIPTION, "Save the current sketch to a new file"); 64 printAction.putValue(SHORT_DESCRIPTION, "Print the current sketch"); 65 exitAction.putValue(SHORT_DESCRIPTION, "Exit Sketcher"); 66 } 67 68 // Create the File menu 69 private void createFileMenu() { 70 JMenu fileMenu = new JMenu("File"); // Create File menu 71 fileMenu.setMnemonic('F'); // Create shortcut 72 createFileMenuActions(); // Create Actions for File menu item 73 74 // Construct the file drop-down menu 75 fileMenu.add(newAction); // New Sketch menu item 76 fileMenu.add(openAction); // Open sketch menu item 77 fileMenu.add(closeAction); // Close sketch menu item 78 fileMenu.addSeparator(); // Add separator 79 fileMenu.add(saveAction); // Save sketch to file 80 fileMenu.add(saveAsAction); // Save As menu item 81 fileMenu.addSeparator(); // Add separator 82 fileMenu.add(printAction); // Print sketch menu item 83 fileMenu.addSeparator(); // Add separator 84 fileMenu.add(exitAction); // Print sketch menu item 85 menuBar.add(fileMenu); // Add the file menu 86 } 87 88 // Create Element menu actions 89 private void createElementTypeActions() { 90 lineAction = new TypeAction("Line", LINE, 'L', CTRL_DOWN_MASK); 91 rectangleAction = new TypeAction("Rectangle", RECTANGLE, 'R', CTRL_DOWN_MASK); 92 circleAction = new TypeAction("Circle", CIRCLE,'C', CTRL_DOWN_MASK); 93 curveAction = new TypeAction("Curve", CURVE,'U', CTRL_DOWN_MASK); 94 95 // Initialize the array 96 TypeAction[] actions = {lineAction, rectangleAction, circleAction, curveAction}; 97 typeActions = actions; 98 99 // Add toolbar icons 100 lineAction.putValue(LARGE_ICON_KEY, LINE24); 101 rectangleAction.putValue(LARGE_ICON_KEY, RECTANGLE24); 102 circleAction.putValue(LARGE_ICON_KEY, CIRCLE24); 103 curveAction.putValue(LARGE_ICON_KEY, CURVE24); 104 105 // Add menu item icons 106 lineAction.putValue(SMALL_ICON, LINE16); 107 rectangleAction.putValue(SMALL_ICON, RECTANGLE16); 108 circleAction.putValue(SMALL_ICON, CIRCLE16); 109 curveAction.putValue(SMALL_ICON, CURVE16); 110 111 // Add tooltip text 112 lineAction.putValue(SHORT_DESCRIPTION, "Draw lines"); 113 rectangleAction.putValue(SHORT_DESCRIPTION, "Draw rectangles"); 114 circleAction.putValue(SHORT_DESCRIPTION, "Draw circles"); 115 curveAction.putValue(SHORT_DESCRIPTION, "Draw curves"); 116 } 117 118 // Create the Elements menu 119 private void createElementMenu() { 120 createElementTypeActions(); 121 elementMenu = new JMenu("Elements"); // Create Elements menu 122 elementMenu.setMnemonic('E'); // Create shortcut 123 createRadioButtonDropDown(elementMenu, typeActions, lineAction); 124 menuBar.add(elementMenu); // Add the element menu 125 } 126 127 // Create Color menu actions 128 private void createElementColorActions() { 129 redAction = new ColorAction("Red", RED, 'R', CTRL_DOWN_MASK|ALT_DOWN_MASK); 130 yellowAction = new ColorAction("Yellow", YELLOW, 'Y', CTRL_DOWN_MASK|ALT_DOWN_MASK); 131 greenAction = new ColorAction("Green", GREEN, 'G', CTRL_DOWN_MASK|ALT_DOWN_MASK); 132 blueAction = new ColorAction("Blue", BLUE, 'B', CTRL_DOWN_MASK|ALT_DOWN_MASK); 133 134 // Initialize the array 135 ColorAction[] actions = {redAction, greenAction, blueAction, yellowAction}; 136 colorActions = actions; 137 138 // Add toolbar icons 139 redAction.putValue(LARGE_ICON_KEY, RED24); 140 greenAction.putValue(LARGE_ICON_KEY, GREEN24); 141 blueAction.putValue(LARGE_ICON_KEY, BLUE24); 142 yellowAction.putValue(LARGE_ICON_KEY, YELLOW24); 143 144 // Add menu item icons 145 redAction.putValue(SMALL_ICON, RED16); 146 greenAction.putValue(SMALL_ICON, GREEN16); 147 blueAction.putValue(SMALL_ICON, BLUE16); 148 yellowAction.putValue(SMALL_ICON, YELLOW16); 149 150 // Add tooltip text 151 redAction.putValue(SHORT_DESCRIPTION, "Draw in red"); 152 greenAction.putValue(SHORT_DESCRIPTION, "Draw in green"); 153 blueAction.putValue(SHORT_DESCRIPTION, "Draw in blue"); 154 yellowAction.putValue(SHORT_DESCRIPTION, "Draw in yellow"); 155 } 156 157 // Create the Color menu 158 private void createColorMenu() { 159 createElementColorActions(); 160 colorMenu = new JMenu("Color"); // Create Elements menu 161 colorMenu.setMnemonic('C'); // Create shortcut 162 createRadioButtonDropDown(colorMenu, colorActions, blueAction); 163 menuBar.add(colorMenu); // Add the color menu 164 } 165 166 // Menu creation helper 167 private void createRadioButtonDropDown(JMenu menu, Action[] actions, Action selected) { 168 ButtonGroup group = new ButtonGroup(); 169 JRadioButtonMenuItem item = null; 170 for(Action action : actions) { 171 group.add(menu.add(item = new JRadioButtonMenuItem(action))); 172 if(action == selected) { 173 item.setSelected(true); // This is default selected 174 } 175 } 176 } 177 178 // Create toolbar buttons on the toolbar 179 private void createToolbar() { 180 for(FileAction action: fileActions){ 181 if(action != exitAction && action != closeAction) 182 addToolbarButton(action); // Add the toolbar button 183 } 184 toolBar.addSeparator(); 185 186 // Create Color menu buttons 187 for(ColorAction action:colorActions){ 188 addToolbarButton(action); // Add the toolbar button 189 } 190 191 toolBar.addSeparator(); 192 193 // Create Elements menu buttons 194 for(TypeAction action:typeActions){ 195 addToolbarButton(action); // Add the toolbar button 196 } 197 } 198 199 // Create and add a toolbar button 200 private void addToolbarButton(Action action) { 201 JButton button = new JButton(action); // Create from Action 202 button.setBorder(BorderFactory.createCompoundBorder( // Add button border 203 new EmptyBorder(2,5,5,2), // Outside border 204 BorderFactory.createRaisedBevelBorder())); // Inside border 205 button.setHideActionText(true); // No label on the button 206 toolBar.add(button); // Add the toolbar button 207 } 208 209 // Return the current drawing color 210 public Color getElementColor() { 211 return elementColor; 212 } 213 214 // Return the current element type 215 public int getElementType() { 216 return elementType; 217 } 218 219 // Set radio button menu checks 220 private void setChecks(JMenu menu, Object eventSource) { 221 if(eventSource instanceof JButton){ 222 JButton button = (JButton)eventSource; 223 Action action = button.getAction(); 224 for(int i = 0 ; i<menu.getItemCount() ; ++i) { 225 JMenuItem item = menu.getItem(i); 226 item.setSelected(item.getAction() == action); 227 } 228 } 229 } 230 231 // Inner class defining Action objects for File menu items 232 class FileAction extends AbstractAction { 233 // Create action with a name 234 FileAction(String name) { 235 super(name); 236 } 237 238 // Create action with a name and accelerator 239 FileAction(String name, char ch, int modifiers) { 240 super(name); 241 putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(ch, modifiers)); 242 243 // Now find the character to underline 244 int index = name.toUpperCase().indexOf(ch); 245 if(index != -1) { 246 putValue(DISPLAYED_MNEMONIC_INDEX_KEY, index); 247 } 248 } 249 250 // Event handler 251 public void actionPerformed(ActionEvent e) { 252 // You will add action code here eventually... 253 } 254 } 255 256 // Inner class defining Action objects for Element type menu items 257 class TypeAction extends AbstractAction { 258 // Create action with just a name property 259 TypeAction(String name, int typeID) { 260 super(name); 261 this.typeID = typeID; 262 } 263 264 // Create action with a name and an accelerator 265 private TypeAction(String name,int typeID, char ch, int modifiers) { 266 this(name, typeID); 267 putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(ch, modifiers)); 268 269 // Now find the character to underline 270 int index = name.toUpperCase().indexOf(ch); 271 if(index != -1) { 272 putValue(DISPLAYED_MNEMONIC_INDEX_KEY, index); 273 } 274 } 275 276 public void actionPerformed(ActionEvent e) { 277 elementType = typeID; 278 setChecks(elementMenu, e.getSource()); 279 statusBar.setTypePane(typeID); 280 } 281 282 private int typeID; 283 } 284 285 // Handles color menu items 286 class ColorAction extends AbstractAction { 287 // Create an action with a name and a color 288 public ColorAction(String name, Color color) { 289 super(name); 290 this.color = color; 291 } 292 293 // Create an action with a name, a color, and an accelerator 294 public ColorAction(String name, Color color, char ch, int modifiers) { 295 this(name, color); 296 putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(ch, modifiers)); 297 298 // Now find the character to underline 299 int index = name.toUpperCase().indexOf(ch); 300 if(index != -1) { 301 putValue(DISPLAYED_MNEMONIC_INDEX_KEY, index); 302 } 303 } 304 305 public void actionPerformed(ActionEvent e) { 306 elementColor = color; 307 setChecks(colorMenu, e.getSource()); 308 statusBar.setColorPane(color); 309 } 310 311 private Color color; 312 } 313 314 // File actions 315 private FileAction newAction, openAction, closeAction, saveAction, saveAsAction, printAction, exitAction; 316 private FileAction[] fileActions; // File actions as an array 317 318 // Element type actions 319 private TypeAction lineAction, rectangleAction, circleAction, curveAction; 320 private TypeAction[] typeActions; // Type actions as an array 321 322 // Element color actions 323 private ColorAction redAction, yellowAction,greenAction, blueAction; 324 private ColorAction[] colorActions; // Color actions as an array 325 326 private JMenuBar menuBar = new JMenuBar(); // Window menu bar 327 private JMenu elementMenu; // Elements menu 328 private JMenu colorMenu; // Color menu 329 private StatusBar statusBar = new StatusBar(); // Window status bar 330 331 private Color elementColor = DEFAULT_ELEMENT_COLOR; // Current element color 332 private int elementType = DEFAULT_ELEMENT_TYPE; // Current element type 333 private JToolBar toolBar = new JToolBar(); // Window toolbar 334 private Sketcher theApp; // The application object 335 }
其他与上一例同。