src/jexer/menu/TMenuItem.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2017 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.event.TKeypressEvent;
  37 import jexer.event.TMouseEvent;
  38 import jexer.event.TMenuEvent;
  39 import static jexer.TKeypress.*;
  40
  41 /**
  42  * TMenuItem implements a menu item.
  43  */
  44 public class TMenuItem extends TWidget {
  45
  46     /**
  47      * Label for this menu item.
  48      */
  49     private String label;
  50
  51     /**
  52      * Menu ID.  IDs less than 1024 are reserved for common system
  53      * functions.  Existing ones are defined in TMenu, i.e. TMenu.MID_EXIT.
  54      */
  55     private int id = TMenu.MID_UNUSED;
  56
  57     /**
  58      * Get the menu item ID.
  59      *
  60      * @return the id
  61      */
  62     public final int getId() {
  63         return id;
  64     }
  65
  66     /**
  67      * When true, this item can be checked or unchecked.
  68      */
  69     private boolean checkable = false;
  70
  71     /**
  72      * Set checkable flag.
  73      *
  74      * @param checkable if true, this menu item can be checked/unchecked
  75      */
  76     public final void setCheckable(final boolean checkable) {
  77         this.checkable = checkable;
  78     }
  79
  80     /**
  81      * When true, this item is checked.
  82      */
  83     private boolean checked = false;
  84
  85     /**
  86      * Global shortcut key.
  87      */
  88     private TKeypress key;
  89
  90     /**
  91      * The title string.  Use '&' to specify a mnemonic, i.e. "&File" will
  92      * highlight the 'F' and allow 'f' or 'F' to select it.
  93      */
  94     private MnemonicString mnemonic;
  95
  96     /**
  97      * Get the mnemonic string for this menu item.
  98      *
  99      * @return mnemonic string
 100      */
 101     public final MnemonicString getMnemonic() {
 102         return mnemonic;
 103     }
 104
 105     /**
 106      * Get a global accelerator key for this menu item.
 107      *
 108      * @return global keyboard accelerator, or null if no key is associated
 109      * with this item
 110      */
 111     public final TKeypress getKey() {
 112         return key;
 113     }
 114
 115     /**
 116      * Set a global accelerator key for this menu item.
 117      *
 118      * @param key global keyboard accelerator
 119      */
 120     public final void setKey(final TKeypress key) {
 121         this.key = key;
 122
 123         if (key != null) {
 124             int newWidth = (label.length() + 4 + key.toString().length() + 2);
 125             if (newWidth > getWidth()) {
 126                 setWidth(newWidth);
 127             }
 128         }
 129     }
 130
 131     /**
 132      * Package private constructor.
 133      *
 134      * @param parent parent widget
 135      * @param id menu id
 136      * @param x column relative to parent
 137      * @param y row relative to parent
 138      * @param label menu item title
 139      */
 140     TMenuItem(final TMenu parent, final int id, final int x, final int y,
 141         final String label) {
 142
 143         // Set parent and window
 144         super(parent);
 145
 146         mnemonic = new MnemonicString(label);
 147
 148         setX(x);
 149         setY(y);
 150         setHeight(1);
 151         this.label = mnemonic.getRawLabel();
 152         setWidth(label.length() + 4);
 153         this.id = id;
 154
 155         // Default state for some known menu items
 156         switch (id) {
 157
 158         case TMenu.MID_CUT:
 159             setEnabled(false);
 160             break;
 161         case TMenu.MID_COPY:
 162             setEnabled(false);
 163             break;
 164         case TMenu.MID_PASTE:
 165             setEnabled(false);
 166             break;
 167         case TMenu.MID_CLEAR:
 168             setEnabled(false);
 169             break;
 170
 171         case TMenu.MID_TILE:
 172             break;
 173         case TMenu.MID_CASCADE:
 174             break;
 175         case TMenu.MID_CLOSE_ALL:
 176             break;
 177         case TMenu.MID_WINDOW_MOVE:
 178             break;
 179         case TMenu.MID_WINDOW_ZOOM:
 180             break;
 181         case TMenu.MID_WINDOW_NEXT:
 182             break;
 183         case TMenu.MID_WINDOW_PREVIOUS:
 184             break;
 185         case TMenu.MID_WINDOW_CLOSE:
 186             break;
 187         default:
 188             break;
 189         }
 190
 191     }
 192
 193     /**
 194      * Returns true if the mouse is currently on the menu item.
 195      *
 196      * @param mouse mouse event
 197      * @return if true then the mouse is currently on this item
 198      */
 199     private boolean mouseOnMenuItem(final TMouseEvent mouse) {
 200         if ((mouse.getY() == 0)
 201             && (mouse.getX() >= 0)
 202             && (mouse.getX() < getWidth())
 203         ) {
 204             return true;
 205         }
 206         return false;
 207     }
 208
 209     /**
 210      * Draw a menu item with label.
 211      */
 212     @Override
 213     public void draw() {
 214         CellAttributes background = getTheme().getColor("tmenu");
 215         CellAttributes menuColor;
 216         CellAttributes menuMnemonicColor;
 217         if (isAbsoluteActive()) {
 218             menuColor = getTheme().getColor("tmenu.highlighted");
 219             menuMnemonicColor = getTheme().getColor("tmenu.mnemonic.highlighted");
 220         } else {
 221             if (isEnabled()) {
 222                 menuColor = getTheme().getColor("tmenu");
 223                 menuMnemonicColor = getTheme().getColor("tmenu.mnemonic");
 224             } else {
 225                 menuColor = getTheme().getColor("tmenu.disabled");
 226                 menuMnemonicColor = getTheme().getColor("tmenu.disabled");
 227             }
 228         }
 229
 230         char cVSide = GraphicsChars.WINDOW_SIDE;
 231         getScreen().vLineXY(0, 0, 1, cVSide, background);
 232         getScreen().vLineXY(getWidth() - 1, 0, 1, cVSide, background);
 233
 234         getScreen().hLineXY(1, 0, getWidth() - 2, ' ', menuColor);
 235         getScreen().putStringXY(2, 0, mnemonic.getRawLabel(), menuColor);
 236         if (key != null) {
 237             String keyLabel = key.toString();
 238             getScreen().putStringXY((getWidth() - keyLabel.length() - 2), 0,
 239                 keyLabel, menuColor);
 240         }
 241         if (mnemonic.getShortcutIdx() >= 0) {
 242             getScreen().putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 243                 mnemonic.getShortcut(), menuMnemonicColor);
 244         }
 245         if (checked) {
 246             assert (checkable);
 247             getScreen().putCharXY(1, 0, GraphicsChars.CHECK, menuColor);
 248         }
 249
 250     }
 251
 252     /**
 253      * Dispatch event(s) due to selection or click.
 254      */
 255     public void dispatch() {
 256         assert (isEnabled());
 257
 258         getApplication().postMenuEvent(new TMenuEvent(id));
 259         if (checkable) {
 260             checked = !checked;
 261         }
 262     }
 263
 264     /**
 265      * Handle mouse button releases.
 266      *
 267      * @param mouse mouse button release event
 268      */
 269     @Override
 270     public void onMouseUp(final TMouseEvent mouse) {
 271         if ((mouseOnMenuItem(mouse)) && (mouse.isMouse1())) {
 272             dispatch();
 273             return;
 274         }
 275     }
 276
 277     /**
 278      * Handle keystrokes.
 279      *
 280      * @param keypress keystroke event
 281      */
 282     @Override
 283     public void onKeypress(final TKeypressEvent keypress) {
 284         if (keypress.equals(kbEnter)) {
 285             dispatch();
 286             return;
 287         }
 288
 289         // Pass to parent for the things we don't care about.
 290         super.onKeypress(keypress);
 291     }
 292 }