src/jexer/TButton.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2017 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 final class TButton extends TWidget {
  46
  47     /**
  48      * The shortcut and button text.
  49      */
  50     private MnemonicString mnemonic;
  51
  52     /**
  53      * Get the mnemonic string for this button.
  54      *
  55      * @return mnemonic string
  56      */
  57     public MnemonicString getMnemonic() {
  58         return mnemonic;
  59     }
  60
  61     /**
  62      * Remember mouse state.
  63      */
  64     private TMouseEvent mouse;
  65
  66     /**
  67      * True when the button is being pressed and held down.
  68      */
  69     private boolean inButtonPress = false;
  70
  71     /**
  72      * The action to perform when the button is clicked.
  73      */
  74     private TAction action;
  75
  76     /**
  77      * The time at which dispatch() was called.
  78      */
  79     private long dispatchTime;
  80
  81     /**
  82      * How long to animate dispatch of the event in millis.
  83      */
  84     private static final long DISPATCH_TIME = 75;
  85
  86     /**
  87      * Act as though the button was pressed.  This is useful for other UI
  88      * elements to get the same action as if the user clicked the button.
  89      */
  90     public void dispatch() {
  91         if (action != null) {
  92             long now = System.currentTimeMillis();
  93             if (now - dispatchTime > DISPATCH_TIME) {
  94                 action.DO();
  95                 dispatchTime = now;
  96             }
  97         }
  98     }
  99
 100     /**
 101      * Private constructor.
 102      *
 103      * @param parent parent widget
 104      * @param text label on the button
 105      * @param x column relative to parent
 106      * @param y row relative to parent
 107      */
 108     private TButton(final TWidget parent, final String text,
 109         final int x, final int y) {
 110
 111         // Set parent and window
 112         super(parent);
 113
 114         mnemonic = new MnemonicString(text);
 115
 116         setX(x);
 117         setY(y);
 118         setHeight(2);
 119         setWidth(mnemonic.getRawLabel().length() + 3);
 120     }
 121
 122     /**
 123      * Public constructor.
 124      *
 125      * @param parent parent widget
 126      * @param text label on the button
 127      * @param x column relative to parent
 128      * @param y row relative to parent
 129      * @param action to call when button is pressed
 130      */
 131     public TButton(final TWidget parent, final String text,
 132         final int x, final int y, final TAction action) {
 133
 134         this(parent, text, x, y);
 135         this.action = action;
 136     }
 137
 138     /**
 139      * Returns true if the mouse is currently on the button.
 140      *
 141      * @return if true the mouse is currently on the button
 142      */
 143     private boolean mouseOnButton() {
 144         int rightEdge = getWidth() - 1;
 145         if (inButtonPress) {
 146             rightEdge++;
 147         }
 148         if ((mouse != null)
 149             && (mouse.getY() == 0)
 150             && (mouse.getX() >= 0)
 151             && (mouse.getX() < rightEdge)
 152         ) {
 153             return true;
 154         }
 155         return false;
 156     }
 157
 158     /**
 159      * Draw a button with a shadow.
 160      */
 161     @Override
 162     public void draw() {
 163         CellAttributes buttonColor;
 164         CellAttributes menuMnemonicColor;
 165         CellAttributes shadowColor = new CellAttributes();
 166         shadowColor.setTo(getWindow().getBackground());
 167         shadowColor.setForeColor(Color.BLACK);
 168         shadowColor.setBold(false);
 169
 170         long now = System.currentTimeMillis();
 171         boolean inDispatch = false;
 172         if (now - dispatchTime < DISPATCH_TIME) {
 173             inDispatch = true;
 174         }
 175
 176         if (!isEnabled()) {
 177             buttonColor = getTheme().getColor("tbutton.disabled");
 178             menuMnemonicColor = getTheme().getColor("tbutton.disabled");
 179         } else if (isAbsoluteActive()) {
 180             buttonColor = getTheme().getColor("tbutton.active");
 181             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic.highlighted");
 182         } else {
 183             buttonColor = getTheme().getColor("tbutton.inactive");
 184             menuMnemonicColor = getTheme().getColor("tbutton.mnemonic");
 185         }
 186
 187         if (inButtonPress || inDispatch) {
 188             getScreen().putCharXY(1, 0, ' ', buttonColor);
 189             getScreen().putStringXY(2, 0, mnemonic.getRawLabel(), buttonColor);
 190             getScreen().putCharXY(getWidth() - 1, 0, ' ', buttonColor);
 191         } else {
 192             getScreen().putCharXY(0, 0, ' ', buttonColor);
 193             getScreen().putStringXY(1, 0, mnemonic.getRawLabel(), buttonColor);
 194             getScreen().putCharXY(getWidth() - 2, 0, ' ', buttonColor);
 195
 196             getScreen().putCharXY(getWidth() - 1, 0,
 197                 GraphicsChars.CP437[0xDC], shadowColor);
 198             getScreen().hLineXY(1, 1, getWidth() - 1,
 199                 GraphicsChars.CP437[0xDF], shadowColor);
 200         }
 201         if (mnemonic.getShortcutIdx() >= 0) {
 202             if (inButtonPress || inDispatch) {
 203                 getScreen().putCharXY(2 + mnemonic.getShortcutIdx(), 0,
 204                     mnemonic.getShortcut(), menuMnemonicColor);
 205             } else {
 206                 getScreen().putCharXY(1 + mnemonic.getShortcutIdx(), 0,
 207                     mnemonic.getShortcut(), menuMnemonicColor);
 208             }
 209
 210         }
 211     }
 212
 213     /**
 214      * Handle mouse button presses.
 215      *
 216      * @param mouse mouse button event
 217      */
 218     @Override
 219     public void onMouseDown(final TMouseEvent mouse) {
 220         this.mouse = mouse;
 221
 222         if ((mouseOnButton()) && (mouse.isMouse1())) {
 223             // Begin button press
 224             inButtonPress = true;
 225         }
 226     }
 227
 228     /**
 229      * Handle mouse button releases.
 230      *
 231      * @param mouse mouse button release event
 232      */
 233     @Override
 234     public void onMouseUp(final TMouseEvent mouse) {
 235         this.mouse = mouse;
 236
 237         if (inButtonPress && mouse.isMouse1()) {
 238             inButtonPress = false;
 239             // Dispatch the event
 240             dispatch();
 241         }
 242
 243     }
 244
 245     /**
 246      * Handle mouse movements.
 247      *
 248      * @param mouse mouse motion event
 249      */
 250     @Override
 251     public void onMouseMotion(final TMouseEvent mouse) {
 252         this.mouse = mouse;
 253
 254         if (!mouseOnButton()) {
 255             inButtonPress = false;
 256         }
 257     }
 258
 259     /**
 260      * Handle keystrokes.
 261      *
 262      * @param keypress keystroke event
 263      */
 264     @Override
 265     public void onKeypress(final TKeypressEvent keypress) {
 266         if (keypress.equals(kbEnter)
 267             || keypress.equals(kbSpace)
 268         ) {
 269             // Dispatch
 270             dispatch();
 271             return;
 272         }
 273
 274         // Pass to parent for the things we don't care about.
 275         super.onKeypress(keypress);
 276     }
 277
 278 }