src/jexer/TButton.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2019 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;
  30
  31 import jexer.bits.CellAttributes;
  32 import jexer.bits.Color;
  33 import jexer.bits.GraphicsChars;
  34 import jexer.bits.MnemonicString;
  35 import jexer.event.TKeypressEvent;
  36 import jexer.event.TMouseEvent;
  37 import static jexer.TKeypress.*;
  38
  39 /**
  40  * TButton implements a simple button.  To make the button do something, pass
  41  * a TAction class to its constructor.
  42  *
  43  * @see TAction#DO()
  44  */
  45 public class TButton extends TWidget {
  46
  47     // ------------------------------------------------------------------------
  48     // Variables --------------------------------------------------------------
  49     // ------------------------------------------------------------------------
  50
  51     /**
  52      * The shortcut and button text.
  53      */
  54     private MnemonicString mnemonic;
  55
  56     /**
  57      * Remember mouse state.
  58      */
  59     private TMouseEvent mouse;
  60
  61     /**
  62      * True when the button is being pressed and held down.
  63      */
  64     private boolean inButtonPress = false;
  65
  66     /**
  67      * The action to perform when the button is clicked.
  68      */
  69     private TAction action;
  70
  71     /**
  72      * The background color used for the button "shadow", or NULL for "no shadow".
  73      */
  74     private CellAttributes shadowColor;
  75
  76     // ------------------------------------------------------------------------
  77     // Constructors -----------------------------------------------------------
  78     // ------------------------------------------------------------------------
  79
  80     /**
  81      * Private constructor.
  82      *
  83      * @param parent parent widget
  84      * @param text label on the button
  85      * @param x column relative to parent
  86      * @param y row relative to parent
  87      */
  88     private TButton(final TWidget parent, final String text,
  89         final int x, final int y) {
  90
  91         // Set parent and window
  92         super(parent);
  93
  94         mnemonic = new MnemonicString(text);
  95
  96         setX(x);
  97         setY(y);
  98         setHeight(2);
  99         setWidth(mnemonic.getRawLabel().length() + 3);
 100
 101         shadowColor = new CellAttributes();
 102         shadowColor.setTo(getWindow().getBackground());
 103         shadowColor.setForeColor(Color.BLACK);
 104         shadowColor.setBold(false);
 105     }
 106
 107     /**
 108      * Public constructor.
 109      *
 110      * @param parent parent widget
 111      * @param text label on the button
 112      * @param x column relative to parent
 113      * @param y row relative to parent
 114      * @param action to call when button is pressed
 115      */
 116     public TButton(final TWidget parent, final String text,
 117         final int x, final int y, final TAction action) {
 118
 119         this(parent, text, x, y);
 120         this.action = action;
 121     }
 122
 123     // ------------------------------------------------------------------------
 124     // Event handlers ---------------------------------------------------------
 125     // ------------------------------------------------------------------------
 126
 127     /**
 128      * Returns true if the mouse is currently on the button.
 129      *
 130      * @return if true the mouse is currently on the button
 131      */
 132     private boolean mouseOnButton() {
 133         int rightEdge = getWidth() - 1;
 134         if (inButtonPress) {
 135             rightEdge++;
 136         }
 137         if ((mouse != null)
 138             && (mouse.getY() == 0)
 139             && (mouse.getX() >= 0)
 140             && (mouse.getX() < rightEdge)
 141         ) {
 142             return true;
 143         }
 144         return false;
 145     }
 146
 147     /**
 148      * Handle mouse button presses.
 149      *
 150      * @param mouse mouse button event
 151      */
 152     @Override
 153     public void onMouseDown(final TMouseEvent mouse) {
 154         this.mouse = mouse;
 155
 156         if ((mouseOnButton()) && (mouse.isMouse1())) {
 157             // Begin button press
 158             inButtonPress = true;
 159         }
 160     }
 161
 162     /**
 163      * Handle mouse button releases.
 164      *
 165      * @param mouse mouse button release event
 166      */
 167     @Override
 168     public void onMouseUp(final TMouseEvent mouse) {
 169         this.mouse = mouse;
 170
 171         if (inButtonPress && mouse.isMouse1()) {
 172             // Dispatch the event
 173             dispatch();
 174         }
 175
 176     }
 177
 178     /**
 179      * Handle mouse movements.
 180      *
 181      * @param mouse mouse motion event
 182      */
 183     @Override
 184     public void onMouseMotion(final TMouseEvent mouse) {
 185         this.mouse = mouse;
 186
 187         if (!mouseOnButton()) {
 188             inButtonPress = false;
 189         }
 190     }
 191
 192     /**
 193      * Handle keystrokes.
 194      *
 195      * @param keypress keystroke event
 196      */
 197     @Override
 198     public void onKeypress(final TKeypressEvent keypress) {
 199         if (keypress.equals(kbEnter)
 200             || keypress.equals(kbSpace)
 201         ) {
 202             // Dispatch
 203             dispatch();
 204             return;
 205         }
 206
 207         // Pass to parent for the things we don't care about.
 208         super.onKeypress(keypress);
 209     }
 210
 211     // ------------------------------------------------------------------------
 212     // TWidget ----------------------------------------------------------------
 213     // ------------------------------------------------------------------------
 214
 215     /**
 216      * Draw a button with a shadow.
 217      */
 218     @Override
 219     public void draw() {
 220         CellAttributes buttonColor;
 221         CellAttributes menuMnemonicColor;
 222
 223         if (!isEnabled()) {
 224             buttonColor = getTheme().getColor("tbutton.disabled");
 225             menuMnemonicColor = getTheme().getColor("tbutton.disabled");
 226         } else if (isAbsoluteActive()) {
 227             buttonColor = getTheme().getColor("tbutton.active");
 228             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic.highlighted");
 229         } else {
 230             buttonColor = getTheme().getColor("tbutton.inactive");
 231             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic");
 232         }
 233
 234         if (inButtonPress) {
 235                 putCharXY(1, 0, ' ', buttonColor);
 236                 putStringXY(2, 0, mnemonic.getRawLabel(), buttonColor);
 237             putCharXY(getWidth() - 1, 0, ' ', buttonColor);
 238         } else {
 239             putCharXY(0, 0, ' ', buttonColor);
 240             putStringXY(1, 0, mnemonic.getRawLabel(), buttonColor);
 241             putCharXY(getWidth() - 2, 0, ' ', buttonColor);
 242
 243             if (shadowColor != null) {
 244                     putCharXY(getWidth() - 1, 0,
 245                         GraphicsChars.CP437[0xDC], shadowColor);
 246                     hLineXY(1, 1, getWidth() - 1,
 247                         GraphicsChars.CP437[0xDF], shadowColor);
 248             }
 249         }
 250         if (mnemonic.getShortcutIdx() >= 0) {
 251             if (inButtonPress) {
 252                 putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 253                     mnemonic.getShortcut(), menuMnemonicColor);
 254             } else {
 255                 putCharXY(1 + mnemonic.getShortcutIdx(), 0,
 256                     mnemonic.getShortcut(), menuMnemonicColor);
 257             }
 258         }
 259     }
 260
 261     // ------------------------------------------------------------------------
 262     // TButton ----------------------------------------------------------------
 263     // ------------------------------------------------------------------------
 264
 265     /**
 266      * Get the mnemonic string for this button.
 267      *
 268      * @return mnemonic string
 269      */
 270     public MnemonicString getMnemonic() {
 271         return mnemonic;
 272     }
 273
 274     /**
 275      * Act as though the button was pressed.  This is useful for other UI
 276      * elements to get the same action as if the user clicked the button.
 277      */
 278     public void dispatch() {
 279         if (action != null) {
 280             action.DO();
 281             inButtonPress = false;
 282         }
 283     }
 284
 285     /**
 286      * Set the background color used for the button "shadow".
 287      * <p>
 288      * Can be NULL for "no shadow".
 289      *
 290      * @param color the new background color, or NULL if none
 291      */
 292     public void setShadowColor(final CellAttributes color) {
 293         if (color != null) {
 294                 shadowColor = new CellAttributes();
 295                 shadowColor.setTo(color);
 296                 shadowColor.setForeColor(Color.BLACK);
 297                 shadowColor.setBold(false);
 298         } else {
 299                 shadowColor = null;
 300         }
 301     }
 302
 303 }