menu/TMenuItem.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2019 Kevin Lamonte
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24  * DEALINGS IN THE SOFTWARE.
  25  *
  26  * @author Kevin Lamonte [kevin.lamonte@gmail.com]
  27  * @version 1
  28  */
  29 package jexer.menu;
  30
  31 import jexer.TKeypress;
  32 import jexer.TWidget;
  33 import jexer.bits.CellAttributes;
  34 import jexer.bits.GraphicsChars;
  35 import jexer.bits.MnemonicString;
  36 import jexer.bits.StringUtils;
  37 import jexer.event.TKeypressEvent;
  38 import jexer.event.TMouseEvent;
  39 import jexer.event.TMenuEvent;
  40 import static jexer.TKeypress.*;
  41
  42 /**
  43  * TMenuItem implements a menu item.
  44  */
  45 public class TMenuItem extends TWidget {
  46
  47     // ------------------------------------------------------------------------
  48     // Variables --------------------------------------------------------------
  49     // ------------------------------------------------------------------------
  50
  51     /**
  52      * Label for this menu item.
  53      */
  54     private String label;
  55
  56     /**
  57      * Menu ID.  IDs less than 1024 are reserved for common system
  58      * functions.  Existing ones are defined in TMenu, i.e. TMenu.MID_EXIT.
  59      */
  60     private int id = TMenu.MID_UNUSED;
  61
  62     /**
  63      * When true, this item can be checked or unchecked.
  64      */
  65     private boolean checkable = false;
  66
  67     /**
  68      * When true, this item is checked.
  69      */
  70     private boolean checked = false;
  71
  72     /**
  73      * Global shortcut key.
  74      */
  75     private TKeypress key;
  76
  77     /**
  78      * The title string.  Use '&' to specify a mnemonic, i.e. "&File" will
  79      * highlight the 'F' and allow 'f' or 'F' to select it.
  80      */
  81     private MnemonicString mnemonic;
  82
  83     /**
  84      * An optional 2-cell-wide picture/icon for this item.
  85      */
  86     private int icon = -1;
  87
  88     // ------------------------------------------------------------------------
  89     // Constructors -----------------------------------------------------------
  90     // ------------------------------------------------------------------------
  91
  92     /**
  93      * Package private constructor.
  94      *
  95      * @param parent parent widget
  96      * @param id menu id
  97      * @param x column relative to parent
  98      * @param y row relative to parent
  99      * @param label menu item title
 100      */
 101     TMenuItem(final TMenu parent, final int id, final int x, final int y,
 102         final String label) {
 103
 104         this(parent, id, x, y, label, -1);
 105     }
 106
 107     /**
 108      * Package private constructor.
 109      *
 110      * @param parent parent widget
 111      * @param id menu id
 112      * @param x column relative to parent
 113      * @param y row relative to parent
 114      * @param label menu item title
 115      * @param icon icon picture/emoji
 116      */
 117     TMenuItem(final TMenu parent, final int id, final int x, final int y,
 118         final String label, final int icon) {
 119
 120         // Set parent and window
 121         super(parent);
 122
 123         mnemonic = new MnemonicString(label);
 124
 125         setX(x);
 126         setY(y);
 127         setHeight(1);
 128         this.label = mnemonic.getRawLabel();
 129         if (parent.useIcons) {
 130             setWidth(StringUtils.width(label) + 6);
 131         } else {
 132             setWidth(StringUtils.width(label) + 4);
 133         }
 134         this.id = id;
 135         this.icon = icon;
 136
 137         // Default state for some known menu items
 138         switch (id) {
 139
 140         case TMenu.MID_CUT:
 141             setEnabled(false);
 142             break;
 143         case TMenu.MID_COPY:
 144             setEnabled(false);
 145             break;
 146         case TMenu.MID_PASTE:
 147             setEnabled(false);
 148             break;
 149         case TMenu.MID_CLEAR:
 150             setEnabled(false);
 151             break;
 152
 153         case TMenu.MID_TILE:
 154             break;
 155         case TMenu.MID_CASCADE:
 156             break;
 157         case TMenu.MID_CLOSE_ALL:
 158             break;
 159         case TMenu.MID_WINDOW_MOVE:
 160             break;
 161         case TMenu.MID_WINDOW_ZOOM:
 162             break;
 163         case TMenu.MID_WINDOW_NEXT:
 164             break;
 165         case TMenu.MID_WINDOW_PREVIOUS:
 166             break;
 167         case TMenu.MID_WINDOW_CLOSE:
 168             break;
 169         default:
 170             break;
 171         }
 172
 173     }
 174
 175     // ------------------------------------------------------------------------
 176     // Event handlers ---------------------------------------------------------
 177     // ------------------------------------------------------------------------
 178
 179     /**
 180      * Returns true if the mouse is currently on the menu item.
 181      *
 182      * @param mouse mouse event
 183      * @return if true then the mouse is currently on this item
 184      */
 185     private boolean mouseOnMenuItem(final TMouseEvent mouse) {
 186         if ((mouse.getY() == 0)
 187             && (mouse.getX() >= 0)
 188             && (mouse.getX() < getWidth())
 189         ) {
 190             return true;
 191         }
 192         return false;
 193     }
 194
 195     /**
 196      * Handle mouse button releases.
 197      *
 198      * @param mouse mouse button release event
 199      */
 200     @Override
 201     public void onMouseUp(final TMouseEvent mouse) {
 202         if ((mouseOnMenuItem(mouse)) && (mouse.isMouse1())) {
 203             dispatch();
 204             return;
 205         }
 206     }
 207
 208     /**
 209      * Handle keystrokes.
 210      *
 211      * @param keypress keystroke event
 212      */
 213     @Override
 214     public void onKeypress(final TKeypressEvent keypress) {
 215         if (keypress.equals(kbEnter)) {
 216             dispatch();
 217             return;
 218         }
 219
 220         // Pass to parent for the things we don't care about.
 221         super.onKeypress(keypress);
 222     }
 223
 224     // ------------------------------------------------------------------------
 225     // TWidget ----------------------------------------------------------------
 226     // ------------------------------------------------------------------------
 227
 228     /**
 229      * Draw a menu item with label.
 230      */
 231     @Override
 232     public void draw() {
 233         CellAttributes background = getTheme().getColor("tmenu");
 234         CellAttributes menuColor;
 235         CellAttributes menuMnemonicColor;
 236         if (isAbsoluteActive()) {
 237             menuColor = getTheme().getColor("tmenu.highlighted");
 238             menuMnemonicColor = getTheme().getColor("tmenu.mnemonic.highlighted");
 239         } else {
 240             if (isEnabled()) {
 241                 menuColor = getTheme().getColor("tmenu");
 242                 menuMnemonicColor = getTheme().getColor("tmenu.mnemonic");
 243             } else {
 244                 menuColor = getTheme().getColor("tmenu.disabled");
 245                 menuMnemonicColor = getTheme().getColor("tmenu.disabled");
 246             }
 247         }
 248
 249         boolean useIcons = ((TMenu) getParent()).useIcons;
 250
 251         char cVSide = GraphicsChars.WINDOW_SIDE;
 252         vLineXY(0, 0, 1, cVSide, background);
 253         vLineXY(getWidth() - 1, 0, 1, cVSide, background);
 254
 255         hLineXY(1, 0, getWidth() - 2, ' ', menuColor);
 256         putStringXY(2 + (useIcons ? 2 : 0), 0, mnemonic.getRawLabel(),
 257             menuColor);
 258         if (key != null) {
 259             String keyLabel = key.toString();
 260             putStringXY((getWidth() - StringUtils.width(keyLabel) - 2), 0,
 261                 keyLabel, menuColor);
 262         }
 263         if (mnemonic.getScreenShortcutIdx() >= 0) {
 264             putCharXY(2 + (useIcons ? 2 : 0) + mnemonic.getScreenShortcutIdx(),
 265                 0, mnemonic.getShortcut(), menuMnemonicColor);
 266         }
 267         if (checked) {
 268             assert (checkable);
 269             putCharXY(1, 0, GraphicsChars.CHECK, menuColor);
 270         }
 271         if ((useIcons == true) && (icon != -1)) {
 272             putCharXY(2, 0, icon, menuColor);
 273         }
 274     }
 275
 276     // ------------------------------------------------------------------------
 277     // TMenuItem --------------------------------------------------------------
 278     // ------------------------------------------------------------------------
 279
 280     /**
 281      * Get the menu item ID.
 282      *
 283      * @return the id
 284      */
 285     public final int getId() {
 286         return id;
 287     }
 288
 289     /**
 290      * Set checkable flag.
 291      *
 292      * @param checkable if true, this menu item can be checked/unchecked
 293      */
 294     public final void setCheckable(final boolean checkable) {
 295         this.checkable = checkable;
 296     }
 297
 298     /**
 299      * Get checkable flag.
 300      *
 301      * @return true if this menu item is both checkable and checked
 302      */
 303     public final boolean getChecked() {
 304         return ((checkable == true) && (checked == true));
 305     }
 306
 307     /**
 308      * Set checked flag.  Note that setting checked on an item checkable will
 309      * do nothing.
 310      *
 311      * @param checked if true, and if this menu item is checkable, then
 312      * getChecked() will return true
 313      */
 314     public final void setChecked(final boolean checked) {
 315         if (checkable) {
 316             this.checked = checked;
 317         } else {
 318             this.checked = false;
 319         }
 320     }
 321
 322     /**
 323      * Get the mnemonic string for this menu item.
 324      *
 325      * @return mnemonic string
 326      */
 327     public final MnemonicString getMnemonic() {
 328         return mnemonic;
 329     }
 330
 331     /**
 332      * Get a global accelerator key for this menu item.
 333      *
 334      * @return global keyboard accelerator, or null if no key is associated
 335      * with this item
 336      */
 337     public final TKeypress getKey() {
 338         return key;
 339     }
 340
 341     /**
 342      * Set a global accelerator key for this menu item.
 343      *
 344      * @param key global keyboard accelerator
 345      */
 346     public final void setKey(final TKeypress key) {
 347         this.key = key;
 348
 349         if (key != null) {
 350             int newWidth = (StringUtils.width(label) + 4 +
 351                 StringUtils.width(key.toString()) + 2);
 352             if (((TMenu) getParent()).useIcons) {
 353                 newWidth += 2;
 354             }
 355             if (newWidth > getWidth()) {
 356                 setWidth(newWidth);
 357             }
 358         }
 359     }
 360
 361     /**
 362      * Get a picture/emoji icon for this menu item.
 363      *
 364      * @return the codepoint, or -1 if no icon is specified for this menu
 365      * item
 366      */
 367     public final int getIcon() {
 368         return icon;
 369     }
 370
 371     /**
 372      * Set a picture/emoji icon for this menu item.
 373      *
 374      * @param icon a codepoint, or -1 to unset the icon
 375      */
 376     public final void setIcon(final int icon) {
 377         this.icon = icon;
 378     }
 379
 380     /**
 381      * Dispatch event(s) due to selection or click.
 382      */
 383     public void dispatch() {
 384         assert (isEnabled());
 385
 386         getApplication().postMenuEvent(new TMenuEvent(id));
 387         if (checkable) {
 388             checked = !checked;
 389         }
 390     }
 391
 392 }