src/jexer/TList.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2016 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 java.util.ArrayList;
  32 import java.util.List;
  33
  34 import jexer.bits.CellAttributes;
  35 import jexer.event.TKeypressEvent;
  36 import jexer.event.TMouseEvent;
  37 import static jexer.TKeypress.*;
  38
  39 /**
  40  * TList shows a list of strings, and lets the user select one.
  41  */
  42 public class TList extends TWidget {
  43
  44     /**
  45      * The list of strings to display.
  46      */
  47     private List<String> strings;
  48
  49     /**
  50      * Selected string.
  51      */
  52     private int selectedString = -1;
  53
  54     /**
  55      * Get the selection index.
  56      *
  57      * @return -1 if nothing is selected, otherwise the index into the list
  58      */
  59     public final int getSelectedIndex() {
  60         return selectedString;
  61     }
  62
  63     /**
  64      * Set the selected string index.
  65      *
  66      * @param index -1 to unselect, otherwise the index into the list
  67      */
  68     public final void setSelectedIndex(final int index) {
  69         selectedString = index;
  70     }
  71
  72     /**
  73      * Get the selected string.
  74      *
  75      * @return the selected string, or null of nothing is selected yet
  76      */
  77     public final String getSelected() {
  78         if ((selectedString >= 0) && (selectedString <= strings.size() - 1)) {
  79             return strings.get(selectedString);
  80         }
  81         return null;
  82     }
  83
  84     /**
  85      * Set the new list of strings to display.
  86      *
  87      * @param list new list of strings
  88      */
  89     public final void setList(final List<String> list) {
  90         strings.clear();
  91         strings.addAll(list);
  92         reflow();
  93     }
  94
  95     /**
  96      * Vertical scrollbar.
  97      */
  98     private TVScroller vScroller;
  99
 100     /**
 101      * Get the vertical scrollbar.  This is used by subclasses.
 102      *
 103      * @return the vertical scrollbar
 104      */
 105     public final TVScroller getVScroller() {
 106         return vScroller;
 107     }
 108
 109     /**
 110      * Horizontal scrollbar.
 111      */
 112     private THScroller hScroller;
 113
 114     /**
 115      * Get the horizontal scrollbar.  This is used by subclasses.
 116      *
 117      * @return the horizontal scrollbar
 118      */
 119     public final THScroller getHScroller() {
 120         return hScroller;
 121     }
 122
 123     /**
 124      * Maximum width of a single line.
 125      */
 126     private int maxLineWidth;
 127
 128     /**
 129      * The action to perform when the user selects an item (clicks or enter).
 130      */
 131     private TAction enterAction = null;
 132
 133     /**
 134      * The action to perform when the user navigates with keyboard.
 135      */
 136     private TAction moveAction = null;
 137
 138     /**
 139      * Perform user selection action.
 140      */
 141     public void dispatchEnter() {
 142         assert (selectedString >= 0);
 143         assert (selectedString < strings.size());
 144         if (enterAction != null) {
 145             enterAction.DO();
 146         }
 147     }
 148
 149     /**
 150      * Perform list movement action.
 151      */
 152     public void dispatchMove() {
 153         assert (selectedString >= 0);
 154         assert (selectedString < strings.size());
 155         if (moveAction != null) {
 156             moveAction.DO();
 157         }
 158     }
 159
 160     /**
 161      * Resize for a new width/height.
 162      */
 163     public void reflow() {
 164
 165         // Reset the lines
 166         selectedString = -1;
 167         maxLineWidth = 0;
 168
 169         for (int i = 0; i < strings.size(); i++) {
 170             String line = strings.get(i);
 171             if (line.length() > maxLineWidth) {
 172                 maxLineWidth = line.length();
 173             }
 174         }
 175
 176         // Start at the top
 177         if (vScroller == null) {
 178             vScroller = new TVScroller(this, getWidth() - 1, 0,
 179                 getHeight() - 1);
 180         } else {
 181             vScroller.setX(getWidth() - 1);
 182             vScroller.setHeight(getHeight() - 1);
 183         }
 184         vScroller.setBottomValue(strings.size() - getHeight() + 1);
 185         vScroller.setTopValue(0);
 186         vScroller.setValue(0);
 187         if (vScroller.getBottomValue() < 0) {
 188             vScroller.setBottomValue(0);
 189         }
 190         vScroller.setBigChange(getHeight() - 1);
 191
 192         // Start at the left
 193         if (hScroller == null) {
 194             hScroller = new THScroller(this, 0, getHeight() - 1,
 195                 getWidth() - 1);
 196         } else {
 197             hScroller.setY(getHeight() - 1);
 198             hScroller.setWidth(getWidth() - 1);
 199         }
 200         hScroller.setRightValue(maxLineWidth - getWidth() + 1);
 201         hScroller.setLeftValue(0);
 202         hScroller.setValue(0);
 203         if (hScroller.getRightValue() < 0) {
 204             hScroller.setRightValue(0);
 205         }
 206         hScroller.setBigChange(getWidth() - 1);
 207     }
 208
 209     /**
 210      * Public constructor.
 211      *
 212      * @param parent parent widget
 213      * @param strings list of strings to show
 214      * @param x column relative to parent
 215      * @param y row relative to parent
 216      * @param width width of text area
 217      * @param height height of text area
 218      */
 219     public TList(final TWidget parent, final List<String> strings, final int x,
 220         final int y, final int width, final int height) {
 221
 222         this(parent, strings, x, y, width, height, null);
 223     }
 224
 225     /**
 226      * Public constructor.
 227      *
 228      * @param parent parent widget
 229      * @param strings list of strings to show.  This is allowed to be null
 230      * and set later with setList() or by subclasses.
 231      * @param x column relative to parent
 232      * @param y row relative to parent
 233      * @param width width of text area
 234      * @param height height of text area
 235      * @param enterAction action to perform when an item is selected
 236      */
 237     public TList(final TWidget parent, final List<String> strings, final int x,
 238         final int y, final int width, final int height,
 239         final TAction enterAction) {
 240
 241         super(parent, x, y, width, height);
 242         this.enterAction = enterAction;
 243         this.strings = new ArrayList<String>();
 244         if (strings != null) {
 245             this.strings.addAll(strings);
 246         }
 247         reflow();
 248     }
 249
 250     /**
 251      * Public constructor.
 252      *
 253      * @param parent parent widget
 254      * @param strings list of strings to show.  This is allowed to be null
 255      * and set later with setList() or by subclasses.
 256      * @param x column relative to parent
 257      * @param y row relative to parent
 258      * @param width width of text area
 259      * @param height height of text area
 260      * @param enterAction action to perform when an item is selected
 261      * @param moveAction action to perform when the user navigates to a new
 262      * item with arrow/page keys
 263      */
 264     public TList(final TWidget parent, final List<String> strings, final int x,
 265         final int y, final int width, final int height,
 266         final TAction enterAction, final TAction moveAction) {
 267
 268         super(parent, x, y, width, height);
 269         this.enterAction = enterAction;
 270         this.moveAction = moveAction;
 271         this.strings = new ArrayList<String>();
 272         if (strings != null) {
 273             this.strings.addAll(strings);
 274         }
 275         reflow();
 276     }
 277
 278     /**
 279      * Draw the files list.
 280      */
 281     @Override
 282     public void draw() {
 283         CellAttributes color = null;
 284         int begin = vScroller.getValue();
 285         int topY = 0;
 286         for (int i = begin; i < strings.size(); i++) {
 287             String line = strings.get(i);
 288             if (hScroller.getValue() < line.length()) {
 289                 line = line.substring(hScroller.getValue());
 290             } else {
 291                 line = "";
 292             }
 293             if (i == selectedString) {
 294                 color = getTheme().getColor("tlist.selected");
 295             } else if (isAbsoluteActive()) {
 296                 color = getTheme().getColor("tlist");
 297             } else {
 298                 color = getTheme().getColor("tlist.inactive");
 299             }
 300             String formatString = "%-" + Integer.toString(getWidth() - 1) + "s";
 301             getScreen().putStringXY(0, topY, String.format(formatString, line),
 302                     color);
 303             topY++;
 304             if (topY >= getHeight() - 1) {
 305                 break;
 306             }
 307         }
 308
 309         if (isAbsoluteActive()) {
 310             color = getTheme().getColor("tlist");
 311         } else {
 312             color = getTheme().getColor("tlist.inactive");
 313         }
 314
 315         // Pad the rest with blank lines
 316         for (int i = topY; i < getHeight() - 1; i++) {
 317             getScreen().hLineXY(0, i, getWidth() - 1, ' ', color);
 318         }
 319     }
 320
 321     /**
 322      * Handle mouse press events.
 323      *
 324      * @param mouse mouse button press event
 325      */
 326     @Override
 327     public void onMouseDown(final TMouseEvent mouse) {
 328         if (mouse.isMouseWheelUp()) {
 329             vScroller.decrement();
 330             return;
 331         }
 332         if (mouse.isMouseWheelDown()) {
 333             vScroller.increment();
 334             return;
 335         }
 336
 337         if ((mouse.getX() < getWidth() - 1)
 338             && (mouse.getY() < getHeight() - 1)) {
 339             if (vScroller.getValue() + mouse.getY() < strings.size()) {
 340                 selectedString = vScroller.getValue() + mouse.getY();
 341             }
 342             dispatchEnter();
 343             return;
 344         }
 345
 346         // Pass to children
 347         super.onMouseDown(mouse);
 348     }
 349
 350     /**
 351      * Handle keystrokes.
 352      *
 353      * @param keypress keystroke event
 354      */
 355     @Override
 356     public void onKeypress(final TKeypressEvent keypress) {
 357         if (keypress.equals(kbLeft)) {
 358             hScroller.decrement();
 359         } else if (keypress.equals(kbRight)) {
 360             hScroller.increment();
 361         } else if (keypress.equals(kbUp)) {
 362             if (strings.size() > 0) {
 363                 if (selectedString >= 0) {
 364                     if (selectedString > 0) {
 365                         if (selectedString - vScroller.getValue() == 0) {
 366                             vScroller.decrement();
 367                         }
 368                         selectedString--;
 369                     }
 370                 } else {
 371                     selectedString = strings.size() - 1;
 372                 }
 373             }
 374             if (selectedString >= 0) {
 375                 dispatchMove();
 376             }
 377         } else if (keypress.equals(kbDown)) {
 378             if (strings.size() > 0) {
 379                 if (selectedString >= 0) {
 380                     if (selectedString < strings.size() - 1) {
 381                         selectedString++;
 382                         if (selectedString - vScroller.getValue() == getHeight() - 1) {
 383                             vScroller.increment();
 384                         }
 385                     }
 386                 } else {
 387                     selectedString = 0;
 388                 }
 389             }
 390             if (selectedString >= 0) {
 391                 dispatchMove();
 392             }
 393         } else if (keypress.equals(kbPgUp)) {
 394             vScroller.bigDecrement();
 395             if (selectedString >= 0) {
 396                 selectedString -= getHeight() - 1;
 397                 if (selectedString < 0) {
 398                     selectedString = 0;
 399                 }
 400             }
 401             if (selectedString >= 0) {
 402                 dispatchMove();
 403             }
 404         } else if (keypress.equals(kbPgDn)) {
 405             vScroller.bigIncrement();
 406             if (selectedString >= 0) {
 407                 selectedString += getHeight() - 1;
 408                 if (selectedString > strings.size() - 1) {
 409                     selectedString = strings.size() - 1;
 410                 }
 411             }
 412             if (selectedString >= 0) {
 413                 dispatchMove();
 414             }
 415         } else if (keypress.equals(kbHome)) {
 416             vScroller.toTop();
 417             if (strings.size() > 0) {
 418                 selectedString = 0;
 419             }
 420             if (selectedString >= 0) {
 421                 dispatchMove();
 422             }
 423         } else if (keypress.equals(kbEnd)) {
 424             vScroller.toBottom();
 425             if (strings.size() > 0) {
 426                 selectedString = strings.size() - 1;
 427             }
 428             if (selectedString >= 0) {
 429                 dispatchMove();
 430             }
 431         } else if (keypress.equals(kbTab)) {
 432             getParent().switchWidget(true);
 433         } else if (keypress.equals(kbShiftTab) || keypress.equals(kbBackTab)) {
 434             getParent().switchWidget(false);
 435         } else if (keypress.equals(kbEnter)) {
 436             if (selectedString >= 0) {
 437                 dispatchEnter();
 438             }
 439         } else {
 440             // Pass other keys (tab etc.) on
 441             super.onKeypress(keypress);
 442         }
 443     }
 444
 445 }