src/jexer/menu/TMenuItem.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * License: LGPLv3 or later
   5  *
   6  * This module is licensed under the GNU Lesser General Public License
   7  * Version 3.  Please see the file "COPYING" in this directory for more
   8  * information about the GNU Lesser General Public License Version 3.
   9  *
  10  *     Copyright (C) 2015  Kevin Lamonte
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public License
  14  * as published by the Free Software Foundation; either version 3 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public
  23  * License along with this program; if not, see
  24  * http://www.gnu.org/licenses/, or write to the Free Software
  25  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  26  * 02110-1301 USA
  27  *
  28  * @author Kevin Lamonte [kevin.lamonte@gmail.com]
  29  * @version 1
  30  */
  31 package jexer.menu;
  32
  33 import jexer.TKeypress;
  34 import jexer.TWidget;
  35 import jexer.bits.CellAttributes;
  36 import jexer.bits.GraphicsChars;
  37 import jexer.bits.MnemonicString;
  38 import jexer.event.TKeypressEvent;
  39 import jexer.event.TMouseEvent;
  40 import jexer.event.TMenuEvent;
  41 import static jexer.TKeypress.*;
  42
  43 /**
  44  * TMenuItem implements a menu item.
  45  */
  46 public class TMenuItem extends TWidget {
  47
  48     /**
  49      * Label for this menu item.
  50      */
  51     private String label;
  52
  53     /**
  54      * Menu ID.  IDs less than 1024 are reserved for common system
  55      * functions.  Existing ones are defined in TMenu, i.e. TMenu.MID_EXIT.
  56      */
  57     private int id = TMenu.MID_UNUSED;
  58
  59     /**
  60      * Get the menu item ID.
  61      *
  62      * @return the id
  63      */
  64     public final int getId() {
  65         return id;
  66     }
  67
  68     /**
  69      * When true, this item can be checked or unchecked.
  70      */
  71     private boolean checkable = false;
  72
  73     /**
  74      * Set checkable flag.
  75      *
  76      * @param checkable if true, this menu item can be checked/unchecked
  77      */
  78     public final void setCheckable(final boolean checkable) {
  79         this.checkable = checkable;
  80     }
  81
  82     /**
  83      * When true, this item is checked.
  84      */
  85     private boolean checked = false;
  86
  87     /**
  88      * Global shortcut key.
  89      */
  90     private TKeypress key;
  91
  92     /**
  93      * The title string.  Use '&' to specify a mnemonic, i.e. "&File" will
  94      * highlight the 'F' and allow 'f' or 'F' to select it.
  95      */
  96     private MnemonicString mnemonic;
  97
  98     /**
  99      * Get the mnemonic string for this menu item.
 100      *
 101      * @return mnemonic string
 102      */
 103     public final MnemonicString getMnemonic() {
 104         return mnemonic;
 105     }
 106
 107     /**
 108      * Get a global accelerator key for this menu item.
 109      *
 110      * @return global keyboard accelerator, or null if no key is associated
 111      * with this item
 112      */
 113     public final TKeypress getKey() {
 114         return key;
 115     }
 116
 117     /**
 118      * Set a global accelerator key for this menu item.
 119      *
 120      * @param key global keyboard accelerator
 121      */
 122     public final void setKey(final TKeypress key) {
 123         this.key = key;
 124
 125         if (key != null) {
 126             int newWidth = (label.length() + 4 + key.toString().length() + 2);
 127             if (newWidth > getWidth()) {
 128                 setWidth(newWidth);
 129             }
 130         }
 131     }
 132
 133     /**
 134      * Package private constructor.
 135      *
 136      * @param parent parent widget
 137      * @param id menu id
 138      * @param x column relative to parent
 139      * @param y row relative to parent
 140      * @param label menu item title
 141      */
 142     TMenuItem(final TMenu parent, final int id, final int x, final int y,
 143         final String label) {
 144
 145         // Set parent and window
 146         super(parent);
 147
 148         mnemonic = new MnemonicString(label);
 149
 150         setX(x);
 151         setY(y);
 152         setHeight(1);
 153         this.label = mnemonic.getRawLabel();
 154         setWidth(label.length() + 4);
 155         this.id = id;
 156
 157         // Default state for some known menu items
 158         switch (id) {
 159
 160         case TMenu.MID_CUT:
 161             setEnabled(false);
 162             break;
 163         case TMenu.MID_COPY:
 164             setEnabled(false);
 165             break;
 166         case TMenu.MID_PASTE:
 167             setEnabled(false);
 168             break;
 169         case TMenu.MID_CLEAR:
 170             setEnabled(false);
 171             break;
 172
 173         case TMenu.MID_TILE:
 174             break;
 175         case TMenu.MID_CASCADE:
 176             break;
 177         case TMenu.MID_CLOSE_ALL:
 178             break;
 179         case TMenu.MID_WINDOW_MOVE:
 180             break;
 181         case TMenu.MID_WINDOW_ZOOM:
 182             break;
 183         case TMenu.MID_WINDOW_NEXT:
 184             break;
 185         case TMenu.MID_WINDOW_PREVIOUS:
 186             break;
 187         case TMenu.MID_WINDOW_CLOSE:
 188             break;
 189         default:
 190             break;
 191         }
 192
 193     }
 194
 195     /**
 196      * Returns true if the mouse is currently on the menu item.
 197      *
 198      * @param mouse mouse event
 199      * @return if true then the mouse is currently on this item
 200      */
 201     private boolean mouseOnMenuItem(final TMouseEvent mouse) {
 202         if ((mouse.getY() == 0)
 203             && (mouse.getX() >= 0)
 204             && (mouse.getX() < getWidth())
 205         ) {
 206             return true;
 207         }
 208         return false;
 209     }
 210
 211     /**
 212      * Draw a menu item with label.
 213      */
 214     @Override
 215     public void draw() {
 216         CellAttributes background = getTheme().getColor("tmenu");
 217         CellAttributes menuColor;
 218         CellAttributes menuMnemonicColor;
 219         if (isAbsoluteActive()) {
 220             menuColor = getTheme().getColor("tmenu.highlighted");
 221             menuMnemonicColor = getTheme().getColor("tmenu.mnemonic.highlighted");
 222         } else {
 223             if (isEnabled()) {
 224                 menuColor = getTheme().getColor("tmenu");
 225                 menuMnemonicColor = getTheme().getColor("tmenu.mnemonic");
 226             } else {
 227                 menuColor = getTheme().getColor("tmenu.disabled");
 228                 menuMnemonicColor = getTheme().getColor("tmenu.disabled");
 229             }
 230         }
 231
 232         char cVSide = GraphicsChars.WINDOW_SIDE;
 233         getScreen().vLineXY(0, 0, 1, cVSide, background);
 234         getScreen().vLineXY(getWidth() - 1, 0, 1, cVSide, background);
 235
 236         getScreen().hLineXY(1, 0, getWidth() - 2, ' ', menuColor);
 237         getScreen().putStringXY(2, 0, mnemonic.getRawLabel(), menuColor);
 238         if (key != null) {
 239             String keyLabel = key.toString();
 240             getScreen().putStringXY((getWidth() - keyLabel.length() - 2), 0,
 241                 keyLabel, menuColor);
 242         }
 243         if (mnemonic.getShortcutIdx() >= 0) {
 244             getScreen().putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 245                 mnemonic.getShortcut(), menuMnemonicColor);
 246         }
 247         if (checked) {
 248             assert (checkable);
 249             getScreen().putCharXY(1, 0, GraphicsChars.CHECK, menuColor);
 250         }
 251
 252     }
 253
 254     /**
 255      * Dispatch event(s) due to selection or click.
 256      */
 257     public void dispatch() {
 258         assert (isEnabled());
 259
 260         getApplication().addMenuEvent(new TMenuEvent(id));
 261         if (checkable) {
 262             checked = !checked;
 263         }
 264     }
 265
 266     /**
 267      * Handle mouse button releases.
 268      *
 269      * @param mouse mouse button release event
 270      */
 271     @Override
 272     public void onMouseUp(final TMouseEvent mouse) {
 273         if ((mouseOnMenuItem(mouse)) && (mouse.isMouse1())) {
 274             dispatch();
 275             return;
 276         }
 277     }
 278
 279     /**
 280      * Handle keystrokes.
 281      *
 282      * @param keypress keystroke event
 283      */
 284     @Override
 285     public void onKeypress(final TKeypressEvent keypress) {
 286         if (keypress.equals(kbEnter)) {
 287             dispatch();
 288             return;
 289         }
 290
 291         // Pass to parent for the things we don't care about.
 292         super.onKeypress(keypress);
 293     }
 294 }