src/jexer/TButton.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;
  32
  33 import jexer.bits.CellAttributes;
  34 import jexer.bits.Color;
  35 import jexer.bits.GraphicsChars;
  36 import jexer.bits.MnemonicString;
  37 import jexer.event.TKeypressEvent;
  38 import jexer.event.TMouseEvent;
  39 import static jexer.TKeypress.*;
  40
  41 /**
  42  * TButton implements a simple button.  To make the button do something, pass
  43  * a TAction class to its constructor.
  44  *
  45  * @see TAction#DO()
  46  */
  47 public final class TButton extends TWidget {
  48
  49     /**
  50      * The shortcut and button text.
  51      */
  52     private MnemonicString mnemonic;
  53
  54     /**
  55      * Get the mnemonic string for this button.
  56      *
  57      * @return mnemonic string
  58      */
  59     public MnemonicString getMnemonic() {
  60         return mnemonic;
  61     }
  62
  63     /**
  64      * Remember mouse state.
  65      */
  66     private TMouseEvent mouse;
  67
  68     /**
  69      * True when the button is being pressed and held down.
  70      */
  71     private boolean inButtonPress = false;
  72
  73     /**
  74      * The action to perform when the button is clicked.
  75      */
  76     private TAction action;
  77
  78     /**
  79      * Act as though the button was pressed.  This is useful for other UI
  80      * elements to get the same action as if the user clicked the button.
  81      */
  82     public void dispatch() {
  83         if (action != null) {
  84             action.DO();
  85         }
  86     }
  87
  88     /**
  89      * Private constructor.
  90      *
  91      * @param parent parent widget
  92      * @param text label on the button
  93      * @param x column relative to parent
  94      * @param y row relative to parent
  95      */
  96     private TButton(final TWidget parent, final String text,
  97         final int x, final int y) {
  98
  99         // Set parent and window
 100         super(parent);
 101
 102         mnemonic = new MnemonicString(text);
 103
 104         setX(x);
 105         setY(y);
 106         setHeight(2);
 107         setWidth(mnemonic.getRawLabel().length() + 3);
 108     }
 109
 110     /**
 111      * Public constructor.
 112      *
 113      * @param parent parent widget
 114      * @param text label on the button
 115      * @param x column relative to parent
 116      * @param y row relative to parent
 117      * @param action to call when button is pressed
 118      */
 119     public TButton(final TWidget parent, final String text,
 120         final int x, final int y, final TAction action) {
 121
 122         this(parent, text, x, y);
 123         this.action = action;
 124     }
 125
 126     /**
 127      * Returns true if the mouse is currently on the button.
 128      *
 129      * @return if true the mouse is currently on the button
 130      */
 131     private boolean mouseOnButton() {
 132         int rightEdge = getWidth() - 1;
 133         if (inButtonPress) {
 134             rightEdge++;
 135         }
 136         if ((mouse != null)
 137             && (mouse.getY() == 0)
 138             && (mouse.getX() >= 0)
 139             && (mouse.getX() < rightEdge)
 140         ) {
 141             return true;
 142         }
 143         return false;
 144     }
 145
 146     /**
 147      * Draw a button with a shadow.
 148      */
 149     @Override
 150     public void draw() {
 151         CellAttributes buttonColor;
 152         CellAttributes menuMnemonicColor;
 153         CellAttributes shadowColor = new CellAttributes();
 154         shadowColor.setTo(getWindow().getBackground());
 155         shadowColor.setForeColor(Color.BLACK);
 156         shadowColor.setBold(false);
 157
 158         if (!isEnabled()) {
 159             buttonColor = getTheme().getColor("tbutton.disabled");
 160             menuMnemonicColor = getTheme().getColor("tbutton.disabled");
 161         } else if (isAbsoluteActive()) {
 162             buttonColor = getTheme().getColor("tbutton.active");
 163             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic.highlighted");
 164         } else {
 165             buttonColor = getTheme().getColor("tbutton.inactive");
 166             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic");
 167         }
 168
 169         if (inButtonPress) {
 170             getScreen().putCharXY(1, 0, ' ', buttonColor);
 171             getScreen().putStringXY(2, 0, mnemonic.getRawLabel(), buttonColor);
 172             getScreen().putCharXY(getWidth() - 1, 0, ' ', buttonColor);
 173         } else {
 174             getScreen().putCharXY(0, 0, ' ', buttonColor);
 175             getScreen().putStringXY(1, 0, mnemonic.getRawLabel(), buttonColor);
 176             getScreen().putCharXY(getWidth() - 2, 0, ' ', buttonColor);
 177
 178             getScreen().putCharXY(getWidth() - 1, 0,
 179                 GraphicsChars.CP437[0xDC], shadowColor);
 180             getScreen().hLineXY(1, 1, getWidth() - 1,
 181                 GraphicsChars.CP437[0xDF], shadowColor);
 182         }
 183         if (mnemonic.getShortcutIdx() >= 0) {
 184             if (inButtonPress) {
 185                 getScreen().putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 186                     mnemonic.getShortcut(), menuMnemonicColor);
 187             } else {
 188                 getScreen().putCharXY(1 + mnemonic.getShortcutIdx(), 0,
 189                     mnemonic.getShortcut(), menuMnemonicColor);
 190             }
 191
 192         }
 193     }
 194
 195     /**
 196      * Handle mouse button presses.
 197      *
 198      * @param mouse mouse button event
 199      */
 200     @Override
 201     public void onMouseDown(final TMouseEvent mouse) {
 202         this.mouse = mouse;
 203
 204         if ((mouseOnButton()) && (mouse.isMouse1())) {
 205             // Begin button press
 206             inButtonPress = true;
 207         }
 208     }
 209
 210     /**
 211      * Handle mouse button releases.
 212      *
 213      * @param mouse mouse button release event
 214      */
 215     @Override
 216     public void onMouseUp(final TMouseEvent mouse) {
 217         this.mouse = mouse;
 218
 219         if (inButtonPress && mouse.isMouse1()) {
 220             inButtonPress = false;
 221             // Dispatch the event
 222             if (action != null) {
 223                 action.DO();
 224             }
 225         }
 226
 227     }
 228
 229     /**
 230      * Handle mouse movements.
 231      *
 232      * @param mouse mouse motion event
 233      */
 234     @Override
 235     public void onMouseMotion(final TMouseEvent mouse) {
 236         this.mouse = mouse;
 237
 238         if (!mouseOnButton()) {
 239             inButtonPress = false;
 240         }
 241     }
 242
 243     /**
 244      * Handle keystrokes.
 245      *
 246      * @param keypress keystroke event
 247      */
 248     @Override
 249     public void onKeypress(final TKeypressEvent keypress) {
 250         if (keypress.equals(kbEnter)
 251             || keypress.equals(kbSpace)
 252         ) {
 253             // Dispatch
 254             if (action != null) {
 255                 action.DO();
 256             }
 257             return;
 258         }
 259
 260         // Pass to parent for the things we don't care about.
 261         super.onKeypress(keypress);
 262     }
 263
 264 }