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.kbEnter;
  38 import static jexer.TKeypress.kbSpace;
  39
  40 /**
  41  * TButton implements a simple button.  To make the button do something, pass
  42  * a TAction class to its constructor.
  43  *
  44  * @see TAction#DO()
  45  */
  46 public class TButton extends TWidget {
  47
  48     // ------------------------------------------------------------------------
  49     // Variables --------------------------------------------------------------
  50     // ------------------------------------------------------------------------
  51
  52     /**
  53      * The shortcut and button text.
  54      */
  55     private MnemonicString mnemonic;
  56
  57     /**
  58      * Remember mouse state.
  59      */
  60     private TMouseEvent mouse;
  61
  62     /**
  63      * True when the button is being pressed and held down.
  64      */
  65     private boolean inButtonPress = false;
  66
  67     /**
  68      * The action to perform when the button is clicked.
  69      */
  70     private TAction action;
  71
  72     /**
  73      * The background color used for the button "shadow", or null for "no
  74      * shadow".
  75      */
  76     private CellAttributes shadowColor;
  77
  78     // ------------------------------------------------------------------------
  79     // Constructors -----------------------------------------------------------
  80     // ------------------------------------------------------------------------
  81
  82     /**
  83      * Private constructor.
  84      *
  85      * @param parent parent widget
  86      * @param text label on the button
  87      * @param x column relative to parent
  88      * @param y row relative to parent
  89      */
  90     private TButton(final TWidget parent, final String text,
  91         final int x, final int y) {
  92
  93         // Set parent and window
  94         super(parent);
  95
  96         mnemonic = new MnemonicString(text);
  97
  98         setX(x);
  99         setY(y);
 100         setHeight(2);
 101         setWidth(mnemonic.getRawLabel().length() + 3);
 102
 103         shadowColor = new CellAttributes();
 104         shadowColor.setTo(getWindow().getBackground());
 105         shadowColor.setForeColor(Color.BLACK);
 106         shadowColor.setBold(false);
 107     }
 108
 109     /**
 110      * Public constructor.
 111      *
 112      * @param parent parent widget
 113      * @param text label on the button
 114      * @param x column relative to parent
 115      * @param y row relative to parent
 116      * @param action to call when button is pressed
 117      */
 118     public TButton(final TWidget parent, final String text,
 119         final int x, final int y, final TAction action) {
 120
 121         this(parent, text, x, y);
 122         this.action = action;
 123     }
 124
 125     // ------------------------------------------------------------------------
 126     // Event handlers ---------------------------------------------------------
 127     // ------------------------------------------------------------------------
 128
 129     /**
 130      * Returns true if the mouse is currently on the button.
 131      *
 132      * @return if true the mouse is currently on the button
 133      */
 134     private boolean mouseOnButton() {
 135         int rightEdge = getWidth() - 1;
 136         if (inButtonPress) {
 137             rightEdge++;
 138         }
 139         if ((mouse != null)
 140             && (mouse.getY() == 0)
 141             && (mouse.getX() >= 0)
 142             && (mouse.getX() < rightEdge)
 143         ) {
 144             return true;
 145         }
 146         return false;
 147     }
 148
 149     /**
 150      * Handle mouse button presses.
 151      *
 152      * @param mouse mouse button event
 153      */
 154     @Override
 155     public void onMouseDown(final TMouseEvent mouse) {
 156         this.mouse = mouse;
 157
 158         if ((mouseOnButton()) && (mouse.isMouse1())) {
 159             // Begin button press
 160             inButtonPress = true;
 161         }
 162     }
 163
 164     /**
 165      * Handle mouse button releases.
 166      *
 167      * @param mouse mouse button release event
 168      */
 169     @Override
 170     public void onMouseUp(final TMouseEvent mouse) {
 171         this.mouse = mouse;
 172
 173         if (inButtonPress && mouse.isMouse1()) {
 174             // Dispatch the event
 175             dispatch();
 176         }
 177
 178     }
 179
 180     /**
 181      * Handle mouse movements.
 182      *
 183      * @param mouse mouse motion event
 184      */
 185     @Override
 186     public void onMouseMotion(final TMouseEvent mouse) {
 187         this.mouse = mouse;
 188
 189         if (!mouseOnButton()) {
 190             inButtonPress = false;
 191         }
 192     }
 193
 194     /**
 195      * Handle keystrokes.
 196      *
 197      * @param keypress keystroke event
 198      */
 199     @Override
 200     public void onKeypress(final TKeypressEvent keypress) {
 201         if (keypress.equals(kbEnter)
 202             || keypress.equals(kbSpace)
 203         ) {
 204             // Dispatch
 205             dispatch();
 206             return;
 207         }
 208
 209         // Pass to parent for the things we don't care about.
 210         super.onKeypress(keypress);
 211     }
 212
 213     // ------------------------------------------------------------------------
 214     // TWidget ----------------------------------------------------------------
 215     // ------------------------------------------------------------------------
 216
 217     /**
 218      * Draw a button with a shadow.
 219      */
 220     @Override
 221     public void draw() {
 222         CellAttributes buttonColor;
 223         CellAttributes menuMnemonicColor;
 224
 225         if (!isEnabled()) {
 226             buttonColor = getTheme().getColor("tbutton.disabled");
 227             menuMnemonicColor = getTheme().getColor("tbutton.disabled");
 228         } else if (isAbsoluteActive()) {
 229             buttonColor = getTheme().getColor("tbutton.active");
 230             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic.highlighted");
 231         } else {
 232             buttonColor = getTheme().getColor("tbutton.inactive");
 233             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic");
 234         }
 235
 236         if (inButtonPress) {
 237             putCharXY(1, 0, ' ', buttonColor);
 238             putStringXY(2, 0, mnemonic.getRawLabel(), buttonColor);
 239             putCharXY(getWidth() - 1, 0, ' ', buttonColor);
 240         } else {
 241             putCharXY(0, 0, ' ', buttonColor);
 242             putStringXY(1, 0, mnemonic.getRawLabel(), buttonColor);
 243             putCharXY(getWidth() - 2, 0, ' ', buttonColor);
 244
 245             if (shadowColor != null) {
 246                 putCharXY(getWidth() - 1, 0,
 247                     GraphicsChars.CP437[0xDC], shadowColor);
 248                 hLineXY(1, 1, getWidth() - 1,
 249                     GraphicsChars.CP437[0xDF], shadowColor);
 250             }
 251         }
 252         if (mnemonic.getShortcutIdx() >= 0) {
 253             if (inButtonPress) {
 254                 putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 255                     mnemonic.getShortcut(), menuMnemonicColor);
 256             } else {
 257                 putCharXY(1 + mnemonic.getShortcutIdx(), 0,
 258                     mnemonic.getShortcut(), menuMnemonicColor);
 259             }
 260         }
 261     }
 262
 263     // ------------------------------------------------------------------------
 264     // TButton ----------------------------------------------------------------
 265     // ------------------------------------------------------------------------
 266
 267     /**
 268      * Get the mnemonic string for this button.
 269      *
 270      * @return mnemonic string
 271      */
 272     public MnemonicString getMnemonic() {
 273         return mnemonic;
 274     }
 275
 276     /**
 277      * Act as though the button was pressed.  This is useful for other UI
 278      * elements to get the same action as if the user clicked the button.
 279      */
 280     public void dispatch() {
 281         if (action != null) {
 282             action.DO();
 283             inButtonPress = false;
 284         }
 285     }
 286
 287     /**
 288      * Set the background color used for the button "shadow".  If null, no
 289      * shadow will be drawn.
 290      *
 291      * @param color the new background color, or null for no shadow
 292      */
 293     public void setShadowColor(final CellAttributes color) {
 294         if (color != null) {
 295             shadowColor = new CellAttributes();
 296             shadowColor.setTo(color);
 297             shadowColor.setForeColor(Color.BLACK);
 298             shadowColor.setBold(false);
 299         } else {
 300             shadowColor = null;
 301         }
 302     }
 303
 304 }