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      * When true, this item can be checked or unchecked.
  61      */
  62     private boolean checkable = false;
  63
  64     /**
  65      * When true, this item is checked.
  66      */
  67     private boolean checked = false;
  68
  69     /**
  70      * Global shortcut key.
  71      */
  72     private TKeypress key;
  73
  74     /**
  75      * When true, a global accelerator can be used to select this item.
  76      */
  77     private boolean hasKey = false;
  78
  79     /**
  80      * The title string.  Use '&' to specify a mnemonic, i.e. "&File" will
  81      * highlight the 'F' and allow 'f' or 'F' to select it.
  82      */
  83     private MnemonicString mnemonic;
  84
  85     /**
  86      * Get the mnemonic string for this menu item.
  87      *
  88      * @return mnemonic string
  89      */
  90     public final MnemonicString getMnemonic() {
  91         return mnemonic;
  92     }
  93
  94     /**
  95      * Set a global accelerator key for this menu item.
  96      *
  97      * @param key global keyboard accelerator
  98      */
  99     public final void setKey(final TKeypress key) {
 100         hasKey = true;
 101         this.key = key;
 102
 103         int newWidth = (label.length() + 4 + key.toString().length() + 2);
 104         if (newWidth > getWidth()) {
 105             setWidth(newWidth);
 106         }
 107     }
 108
 109     /**
 110      * Package private constructor.
 111      *
 112      * @param parent parent widget
 113      * @param id menu id
 114      * @param x column relative to parent
 115      * @param y row relative to parent
 116      * @param label menu item title
 117      */
 118     TMenuItem(final TMenu parent, final int id, final int x, final int y,
 119         final String label) {
 120
 121         // Set parent and window
 122         super(parent);
 123
 124         mnemonic = new MnemonicString(label);
 125
 126         setX(x);
 127         setY(y);
 128         setHeight(1);
 129         this.label = mnemonic.getRawLabel();
 130         setWidth(label.length() + 4);
 131         this.id = id;
 132
 133         // Default state for some known menu items
 134         switch (id) {
 135
 136         case TMenu.MID_CUT:
 137             setEnabled(false);
 138             break;
 139         case TMenu.MID_COPY:
 140             setEnabled(false);
 141             break;
 142         case TMenu.MID_PASTE:
 143             setEnabled(false);
 144             break;
 145         case TMenu.MID_CLEAR:
 146             setEnabled(false);
 147             break;
 148
 149         case TMenu.MID_TILE:
 150             break;
 151         case TMenu.MID_CASCADE:
 152             break;
 153         case TMenu.MID_CLOSE_ALL:
 154             break;
 155         case TMenu.MID_WINDOW_MOVE:
 156             break;
 157         case TMenu.MID_WINDOW_ZOOM:
 158             break;
 159         case TMenu.MID_WINDOW_NEXT:
 160             break;
 161         case TMenu.MID_WINDOW_PREVIOUS:
 162             break;
 163         case TMenu.MID_WINDOW_CLOSE:
 164             break;
 165         default:
 166             break;
 167         }
 168
 169     }
 170
 171     /**
 172      * Returns true if the mouse is currently on the menu item.
 173      *
 174      * @param mouse mouse event
 175      */
 176     private boolean mouseOnMenuItem(final TMouseEvent mouse) {
 177         if ((mouse.getY() == 0)
 178             && (mouse.getX() >= 0)
 179             && (mouse.getX() < getWidth())
 180         ) {
 181             return true;
 182         }
 183         return false;
 184     }
 185
 186     /**
 187      * Draw a menu item with label.
 188      */
 189     @Override
 190     public void draw() {
 191         CellAttributes background = getTheme().getColor("tmenu");
 192         CellAttributes menuColor;
 193         CellAttributes menuMnemonicColor;
 194         if (getAbsoluteActive()) {
 195             menuColor = getTheme().getColor("tmenu.highlighted");
 196             menuMnemonicColor = getTheme().getColor("tmenu.mnemonic.highlighted");
 197         } else {
 198             if (getEnabled()) {
 199                 menuColor = getTheme().getColor("tmenu");
 200                 menuMnemonicColor = getTheme().getColor("tmenu.mnemonic");
 201             } else {
 202                 menuColor = getTheme().getColor("tmenu.disabled");
 203                 menuMnemonicColor = getTheme().getColor("tmenu.disabled");
 204             }
 205         }
 206
 207         char cVSide = GraphicsChars.WINDOW_SIDE;
 208         getScreen().vLineXY(0, 0, 1, cVSide, background);
 209         getScreen().vLineXY(getWidth() - 1, 0, 1, cVSide, background);
 210
 211         getScreen().hLineXY(1, 0, getWidth() - 2, ' ', menuColor);
 212         getScreen().putStrXY(2, 0, mnemonic.getRawLabel(), menuColor);
 213         if (hasKey) {
 214             String keyLabel = key.toString();
 215             getScreen().putStrXY((getWidth() - keyLabel.length() - 2), 0,
 216                 keyLabel, menuColor);
 217         }
 218         if (mnemonic.getShortcutIdx() >= 0) {
 219             getScreen().putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 220                 mnemonic.getShortcut(), menuMnemonicColor);
 221         }
 222         if (checked) {
 223             assert (checkable);
 224             getScreen().putCharXY(1, 0, GraphicsChars.CHECK, menuColor);
 225         }
 226
 227     }
 228
 229     /**
 230      * Dispatch event(s) due to selection or click.
 231      */
 232     public void dispatch() {
 233         assert (getEnabled());
 234
 235         getApplication().addMenuEvent(new TMenuEvent(id));
 236         if (checkable) {
 237             checked = !checked;
 238         }
 239     }
 240
 241     /**
 242      * Handle mouse button presses.
 243      *
 244      * @param event mouse button press event
 245      */
 246     /* TODO: this was commented out in d-tui, why?
 247     @Override
 248     public void onMouseDown(final TMouseEvent event) {
 249         if ((mouseOnMenuItem(event)) && (event.mouse1)) {
 250             dispatch();
 251             return;
 252         }
 253     }
 254     */
 255
 256     /**
 257      * Handle mouse button releases.
 258      *
 259      * @param mouse mouse button release event
 260      */
 261     @Override
 262     public void onMouseUp(final TMouseEvent mouse) {
 263         if ((mouseOnMenuItem(mouse)) && (mouse.getMouse1())) {
 264             dispatch();
 265             return;
 266         }
 267     }
 268
 269     /**
 270      * Handle keystrokes.
 271      *
 272      * @param keypress keystroke event
 273      */
 274     @Override
 275     public void onKeypress(final TKeypressEvent keypress) {
 276         if (keypress.equals(kbEnter)) {
 277             dispatch();
 278             return;
 279         }
 280
 281         // Pass to parent for the things we don't care about.
 282         super.onKeypress(keypress);
 283     }
 284 }