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      * Set checkable flag.
  66      *
  67      * @param checkable if true, this menu item can be checked/unchecked
  68      */
  69     public final void setCheckable(final boolean checkable) {
  70         this.checkable = checkable;
  71     }
  72
  73     /**
  74      * When true, this item is checked.
  75      */
  76     private boolean checked = false;
  77
  78     /**
  79      * Global shortcut key.
  80      */
  81     private TKeypress key;
  82
  83     /**
  84      * When true, a global accelerator can be used to select this item.
  85      */
  86     private boolean hasKey = false;
  87
  88     /**
  89      * The title string.  Use '&' to specify a mnemonic, i.e. "&File" will
  90      * highlight the 'F' and allow 'f' or 'F' to select it.
  91      */
  92     private MnemonicString mnemonic;
  93
  94     /**
  95      * Get the mnemonic string for this menu item.
  96      *
  97      * @return mnemonic string
  98      */
  99     public final MnemonicString getMnemonic() {
 100         return mnemonic;
 101     }
 102
 103     /**
 104      * Set a global accelerator key for this menu item.
 105      *
 106      * @param key global keyboard accelerator
 107      */
 108     public final void setKey(final TKeypress key) {
 109         hasKey = true;
 110         this.key = key;
 111
 112         int newWidth = (label.length() + 4 + key.toString().length() + 2);
 113         if (newWidth > getWidth()) {
 114             setWidth(newWidth);
 115         }
 116     }
 117
 118     /**
 119      * Package private constructor.
 120      *
 121      * @param parent parent widget
 122      * @param id menu id
 123      * @param x column relative to parent
 124      * @param y row relative to parent
 125      * @param label menu item title
 126      */
 127     TMenuItem(final TMenu parent, final int id, final int x, final int y,
 128         final String label) {
 129
 130         // Set parent and window
 131         super(parent);
 132
 133         mnemonic = new MnemonicString(label);
 134
 135         setX(x);
 136         setY(y);
 137         setHeight(1);
 138         this.label = mnemonic.getRawLabel();
 139         setWidth(label.length() + 4);
 140         this.id = id;
 141
 142         // Default state for some known menu items
 143         switch (id) {
 144
 145         case TMenu.MID_CUT:
 146             setEnabled(false);
 147             break;
 148         case TMenu.MID_COPY:
 149             setEnabled(false);
 150             break;
 151         case TMenu.MID_PASTE:
 152             setEnabled(false);
 153             break;
 154         case TMenu.MID_CLEAR:
 155             setEnabled(false);
 156             break;
 157
 158         case TMenu.MID_TILE:
 159             break;
 160         case TMenu.MID_CASCADE:
 161             break;
 162         case TMenu.MID_CLOSE_ALL:
 163             break;
 164         case TMenu.MID_WINDOW_MOVE:
 165             break;
 166         case TMenu.MID_WINDOW_ZOOM:
 167             break;
 168         case TMenu.MID_WINDOW_NEXT:
 169             break;
 170         case TMenu.MID_WINDOW_PREVIOUS:
 171             break;
 172         case TMenu.MID_WINDOW_CLOSE:
 173             break;
 174         default:
 175             break;
 176         }
 177
 178     }
 179
 180     /**
 181      * Returns true if the mouse is currently on the menu item.
 182      *
 183      * @param mouse mouse event
 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      * Draw a menu item with label.
 197      */
 198     @Override
 199     public void draw() {
 200         CellAttributes background = getTheme().getColor("tmenu");
 201         CellAttributes menuColor;
 202         CellAttributes menuMnemonicColor;
 203         if (getAbsoluteActive()) {
 204             menuColor = getTheme().getColor("tmenu.highlighted");
 205             menuMnemonicColor = getTheme().getColor("tmenu.mnemonic.highlighted");
 206         } else {
 207             if (getEnabled()) {
 208                 menuColor = getTheme().getColor("tmenu");
 209                 menuMnemonicColor = getTheme().getColor("tmenu.mnemonic");
 210             } else {
 211                 menuColor = getTheme().getColor("tmenu.disabled");
 212                 menuMnemonicColor = getTheme().getColor("tmenu.disabled");
 213             }
 214         }
 215
 216         char cVSide = GraphicsChars.WINDOW_SIDE;
 217         getScreen().vLineXY(0, 0, 1, cVSide, background);
 218         getScreen().vLineXY(getWidth() - 1, 0, 1, cVSide, background);
 219
 220         getScreen().hLineXY(1, 0, getWidth() - 2, ' ', menuColor);
 221         getScreen().putStrXY(2, 0, mnemonic.getRawLabel(), menuColor);
 222         if (hasKey) {
 223             String keyLabel = key.toString();
 224             getScreen().putStrXY((getWidth() - keyLabel.length() - 2), 0,
 225                 keyLabel, menuColor);
 226         }
 227         if (mnemonic.getShortcutIdx() >= 0) {
 228             getScreen().putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 229                 mnemonic.getShortcut(), menuMnemonicColor);
 230         }
 231         if (checked) {
 232             assert (checkable);
 233             getScreen().putCharXY(1, 0, GraphicsChars.CHECK, menuColor);
 234         }
 235
 236     }
 237
 238     /**
 239      * Dispatch event(s) due to selection or click.
 240      */
 241     public void dispatch() {
 242         assert (getEnabled());
 243
 244         getApplication().addMenuEvent(new TMenuEvent(id));
 245         if (checkable) {
 246             checked = !checked;
 247         }
 248     }
 249
 250     /**
 251      * Handle mouse button presses.
 252      *
 253      * @param event mouse button press event
 254      */
 255     /* TODO: this was commented out in d-tui, why?
 256     @Override
 257     public void onMouseDown(final TMouseEvent event) {
 258         if ((mouseOnMenuItem(event)) && (event.mouse1)) {
 259             dispatch();
 260             return;
 261         }
 262     }
 263     */
 264
 265     /**
 266      * Handle mouse button releases.
 267      *
 268      * @param mouse mouse button release event
 269      */
 270     @Override
 271     public void onMouseUp(final TMouseEvent mouse) {
 272         if ((mouseOnMenuItem(mouse)) && (mouse.getMouse1())) {
 273             dispatch();
 274             return;
 275         }
 276     }
 277
 278     /**
 279      * Handle keystrokes.
 280      *
 281      * @param keypress keystroke event
 282      */
 283     @Override
 284     public void onKeypress(final TKeypressEvent keypress) {
 285         if (keypress.equals(kbEnter)) {
 286             dispatch();
 287             return;
 288         }
 289
 290         // Pass to parent for the things we don't care about.
 291         super.onKeypress(keypress);
 292     }
 293 }