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.bits.StringUtils;
  36 import jexer.event.TKeypressEvent;
  37 import jexer.event.TMouseEvent;
  38 import static jexer.TKeypress.kbEnter;
  39 import static jexer.TKeypress.kbSpace;
  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 class TButton extends TWidget {
  48
  49     // ------------------------------------------------------------------------
  50     // Variables --------------------------------------------------------------
  51     // ------------------------------------------------------------------------
  52
  53     /**
  54      * The shortcut and button text.
  55      */
  56     private MnemonicString mnemonic;
  57
  58     /**
  59      * Remember mouse state.
  60      */
  61     private TMouseEvent mouse;
  62
  63     /**
  64      * True when the button is being pressed and held down.
  65      */
  66     private boolean inButtonPress = false;
  67
  68     /**
  69      * The action to perform when the button is clicked.
  70      */
  71     private TAction action;
  72
  73     /**
  74      * The background color used for the button "shadow", or null for "no
  75      * shadow".
  76      */
  77     private CellAttributes shadowColor;
  78
  79     // ------------------------------------------------------------------------
  80     // Constructors -----------------------------------------------------------
  81     // ------------------------------------------------------------------------
  82
  83     /**
  84      * Private constructor.
  85      *
  86      * @param parent parent widget
  87      * @param text label on the button
  88      * @param x column relative to parent
  89      * @param y row relative to parent
  90      */
  91     private TButton(final TWidget parent, final String text,
  92         final int x, final int y) {
  93
  94         // Set parent and window
  95         super(parent);
  96
  97         mnemonic = new MnemonicString(text);
  98
  99         setX(x);
 100         setY(y);
 101         super.setHeight(2);
 102         super.setWidth(StringUtils.width(mnemonic.getRawLabel()) + 3);
 103
 104         shadowColor = new CellAttributes();
 105         shadowColor.setTo(getWindow().getBackground());
 106         shadowColor.setForeColor(Color.BLACK);
 107         shadowColor.setBold(false);
 108
 109         // Since we set dimensions after TWidget's constructor, we need to
 110         // update the layout manager.
 111         if (getParent().getLayoutManager() != null) {
 112             getParent().getLayoutManager().remove(this);
 113             getParent().getLayoutManager().add(this);
 114         }
 115     }
 116
 117     /**
 118      * Public constructor.
 119      *
 120      * @param parent parent widget
 121      * @param text label on the button
 122      * @param x column relative to parent
 123      * @param y row relative to parent
 124      * @param action to call when button is pressed
 125      */
 126     public TButton(final TWidget parent, final String text,
 127         final int x, final int y, final TAction action) {
 128
 129         this(parent, text, x, y);
 130         this.action = action;
 131     }
 132
 133     /**
 134      * The action to call when the button is pressed.
 135      **/
 136     public TAction getAction() {
 137                 return action;
 138         }
 139
 140     /**
 141      * The action to call when the button is pressed.
 142      **/
 143     public void setAction(TAction action) {
 144                 this.action = action;
 145         }
 146
 147     // ------------------------------------------------------------------------
 148     // Event handlers ---------------------------------------------------------
 149     // ------------------------------------------------------------------------
 150
 151     /**
 152      * Returns true if the mouse is currently on the button.
 153      *
 154      * @return if true the mouse is currently on the button
 155      */
 156     private boolean mouseOnButton() {
 157         int rightEdge = getWidth() - 1;
 158         if (inButtonPress) {
 159             rightEdge++;
 160         }
 161         if ((mouse != null)
 162             && (mouse.getY() == 0)
 163             && (mouse.getX() >= 0)
 164             && (mouse.getX() < rightEdge)
 165         ) {
 166             return true;
 167         }
 168         return false;
 169     }
 170
 171     /**
 172      * Handle mouse button presses.
 173      *
 174      * @param mouse mouse button event
 175      */
 176     @Override
 177     public void onMouseDown(final TMouseEvent mouse) {
 178         this.mouse = mouse;
 179
 180         if ((mouseOnButton()) && (mouse.isMouse1())) {
 181             // Begin button press
 182             inButtonPress = true;
 183         }
 184     }
 185
 186     /**
 187      * Handle mouse button releases.
 188      *
 189      * @param mouse mouse button release event
 190      */
 191     @Override
 192     public void onMouseUp(final TMouseEvent mouse) {
 193         this.mouse = mouse;
 194
 195         if (inButtonPress && mouse.isMouse1()) {
 196             // Dispatch the event
 197             dispatch();
 198         }
 199
 200     }
 201
 202     /**
 203      * Handle mouse movements.
 204      *
 205      * @param mouse mouse motion event
 206      */
 207     @Override
 208     public void onMouseMotion(final TMouseEvent mouse) {
 209         this.mouse = mouse;
 210
 211         if (!mouseOnButton()) {
 212             inButtonPress = false;
 213         }
 214     }
 215
 216     /**
 217      * Handle keystrokes.
 218      *
 219      * @param keypress keystroke event
 220      */
 221     @Override
 222     public void onKeypress(final TKeypressEvent keypress) {
 223         if (keypress.equals(kbEnter)
 224             || keypress.equals(kbSpace)
 225         ) {
 226             // Dispatch
 227             dispatch();
 228             return;
 229         }
 230
 231         // Pass to parent for the things we don't care about.
 232         super.onKeypress(keypress);
 233     }
 234
 235     // ------------------------------------------------------------------------
 236     // TWidget ----------------------------------------------------------------
 237     // ------------------------------------------------------------------------
 238
 239     /**
 240      * Override TWidget's width: we can only set width at construction time.
 241      *
 242      * @param width new widget width (ignored)
 243      */
 244     @Override
 245     public void setWidth(final int width) {
 246         // Do nothing
 247     }
 248
 249     /**
 250      * Override TWidget's height: we can only set height at construction
 251      * time.
 252      *
 253      * @param height new widget height (ignored)
 254      */
 255     @Override
 256     public void setHeight(final int height) {
 257         // Do nothing
 258     }
 259
 260     /**
 261      * Draw a button with a shadow.
 262      */
 263     @Override
 264     public void draw() {
 265         CellAttributes buttonColor;
 266         CellAttributes menuMnemonicColor;
 267
 268         if (!isEnabled()) {
 269             buttonColor = getTheme().getColor("tbutton.disabled");
 270             menuMnemonicColor = getTheme().getColor("tbutton.disabled");
 271         } else if (isAbsoluteActive()) {
 272             buttonColor = getTheme().getColor("tbutton.active");
 273             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic.highlighted");
 274         } else {
 275             buttonColor = getTheme().getColor("tbutton.inactive");
 276             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic");
 277         }
 278
 279         if (inButtonPress) {
 280             putCharXY(1, 0, ' ', buttonColor);
 281             putStringXY(2, 0, mnemonic.getRawLabel(), buttonColor);
 282             putCharXY(getWidth() - 1, 0, ' ', buttonColor);
 283         } else {
 284             putCharXY(0, 0, ' ', buttonColor);
 285             putStringXY(1, 0, mnemonic.getRawLabel(), buttonColor);
 286             putCharXY(getWidth() - 2, 0, ' ', buttonColor);
 287
 288             if (shadowColor != null) {
 289                 putCharXY(getWidth() - 1, 0,
 290                     GraphicsChars.CP437[0xDC], shadowColor);
 291                 hLineXY(1, 1, getWidth() - 1,
 292                     GraphicsChars.CP437[0xDF], shadowColor);
 293             }
 294         }
 295         if (mnemonic.getScreenShortcutIdx() >= 0) {
 296             if (inButtonPress) {
 297                 putCharXY(2 + mnemonic.getScreenShortcutIdx(), 0,
 298                     mnemonic.getShortcut(), menuMnemonicColor);
 299             } else {
 300                 putCharXY(1 + mnemonic.getScreenShortcutIdx(), 0,
 301                     mnemonic.getShortcut(), menuMnemonicColor);
 302             }
 303         }
 304     }
 305
 306     // ------------------------------------------------------------------------
 307     // TButton ----------------------------------------------------------------
 308     // ------------------------------------------------------------------------
 309
 310     /**
 311      * Get the mnemonic string for this button.
 312      *
 313      * @return mnemonic string
 314      */
 315     public MnemonicString getMnemonic() {
 316         return mnemonic;
 317     }
 318
 319     /**
 320      * Act as though the button was pressed.  This is useful for other UI
 321      * elements to get the same action as if the user clicked the button.
 322      */
 323     public void dispatch() {
 324         if (action != null) {
 325             action.DO(this);
 326             inButtonPress = false;
 327         }
 328     }
 329
 330     /**
 331      * Set the background color used for the button "shadow".  If null, no
 332      * shadow will be drawn.
 333      *
 334      * @param color the new background color, or null for no shadow
 335      */
 336     public void setShadowColor(final CellAttributes color) {
 337         if (color != null) {
 338             shadowColor = new CellAttributes();
 339             shadowColor.setTo(color);
 340             shadowColor.setForeColor(Color.BLACK);
 341             shadowColor.setBold(false);
 342         } else {
 343             shadowColor = null;
 344         }
 345     }
 346
 347 }