src/jexer/TList.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 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 TScrollableWidget {
  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         reflowData();
  93     }
  94
  95     /**
  96      * Maximum width of a single line.
  97      */
  98     private int maxLineWidth;
  99
 100     /**
 101      * The action to perform when the user selects an item (clicks or enter).
 102      */
 103     private TAction enterAction = null;
 104
 105     /**
 106      * The action to perform when the user navigates with keyboard.
 107      */
 108     private TAction moveAction = null;
 109
 110     /**
 111      * Perform user selection action.
 112      */
 113     public void dispatchEnter() {
 114         assert (selectedString >= 0);
 115         assert (selectedString < strings.size());
 116         if (enterAction != null) {
 117             enterAction.DO();
 118         }
 119     }
 120
 121     /**
 122      * Perform list movement action.
 123      */
 124     public void dispatchMove() {
 125         assert (selectedString >= 0);
 126         assert (selectedString < strings.size());
 127         if (moveAction != null) {
 128             moveAction.DO();
 129         }
 130     }
 131
 132     /**
 133      * Resize for a new width/height.
 134      */
 135     @Override
 136     public void reflowData() {
 137
 138         // Reset the lines
 139         selectedString = -1;
 140         maxLineWidth = 0;
 141
 142         for (int i = 0; i < strings.size(); i++) {
 143             String line = strings.get(i);
 144             if (line.length() > maxLineWidth) {
 145                 maxLineWidth = line.length();
 146             }
 147         }
 148
 149         setBottomValue(strings.size() - getHeight() + 1);
 150         if (getBottomValue() < 0) {
 151             setBottomValue(0);
 152         }
 153
 154         setRightValue(maxLineWidth - getWidth() + 1);
 155         if (getRightValue() < 0) {
 156             setRightValue(0);
 157         }
 158     }
 159
 160     /**
 161      * Public constructor.
 162      *
 163      * @param parent parent widget
 164      * @param strings list of strings to show
 165      * @param x column relative to parent
 166      * @param y row relative to parent
 167      * @param width width of text area
 168      * @param height height of text area
 169      */
 170     public TList(final TWidget parent, final List<String> strings, final int x,
 171         final int y, final int width, final int height) {
 172
 173         this(parent, strings, x, y, width, height, null);
 174     }
 175
 176     /**
 177      * Public constructor.
 178      *
 179      * @param parent parent widget
 180      * @param strings list of strings to show.  This is allowed to be null
 181      * and set later with setList() or by subclasses.
 182      * @param x column relative to parent
 183      * @param y row relative to parent
 184      * @param width width of text area
 185      * @param height height of text area
 186      * @param enterAction action to perform when an item is selected
 187      */
 188     public TList(final TWidget parent, final List<String> strings, final int x,
 189         final int y, final int width, final int height,
 190         final TAction enterAction) {
 191
 192         super(parent, x, y, width, height);
 193         this.enterAction = enterAction;
 194         this.strings = new ArrayList<String>();
 195         if (strings != null) {
 196             this.strings.addAll(strings);
 197         }
 198
 199         hScroller = new THScroller(this, 0, getHeight() - 1, getWidth() - 1);
 200         vScroller = new TVScroller(this, getWidth() - 1, 0, getHeight() - 1);
 201         reflowData();
 202     }
 203
 204     /**
 205      * Public constructor.
 206      *
 207      * @param parent parent widget
 208      * @param strings list of strings to show.  This is allowed to be null
 209      * and set later with setList() or by subclasses.
 210      * @param x column relative to parent
 211      * @param y row relative to parent
 212      * @param width width of text area
 213      * @param height height of text area
 214      * @param enterAction action to perform when an item is selected
 215      * @param moveAction action to perform when the user navigates to a new
 216      * item with arrow/page keys
 217      */
 218     public TList(final TWidget parent, final List<String> strings, final int x,
 219         final int y, final int width, final int height,
 220         final TAction enterAction, final TAction moveAction) {
 221
 222         super(parent, x, y, width, height);
 223         this.enterAction = enterAction;
 224         this.moveAction = moveAction;
 225         this.strings = new ArrayList<String>();
 226         if (strings != null) {
 227             this.strings.addAll(strings);
 228         }
 229
 230         hScroller = new THScroller(this, 0, getHeight() - 1, getWidth() - 1);
 231         vScroller = new TVScroller(this, getWidth() - 1, 0, getHeight() - 1);
 232         reflowData();
 233     }
 234
 235     /**
 236      * Draw the files list.
 237      */
 238     @Override
 239     public void draw() {
 240         CellAttributes color = null;
 241         int begin = getVerticalValue();
 242         int topY = 0;
 243         for (int i = begin; i < strings.size(); i++) {
 244             String line = strings.get(i);
 245             if (getHorizontalValue() < line.length()) {
 246                 line = line.substring(getHorizontalValue());
 247             } else {
 248                 line = "";
 249             }
 250             if (i == selectedString) {
 251                 color = getTheme().getColor("tlist.selected");
 252             } else if (isAbsoluteActive()) {
 253                 color = getTheme().getColor("tlist");
 254             } else {
 255                 color = getTheme().getColor("tlist.inactive");
 256             }
 257             String formatString = "%-" + Integer.toString(getWidth() - 1) + "s";
 258             getScreen().putStringXY(0, topY, String.format(formatString, line),
 259                     color);
 260             topY++;
 261             if (topY >= getHeight() - 1) {
 262                 break;
 263             }
 264         }
 265
 266         if (isAbsoluteActive()) {
 267             color = getTheme().getColor("tlist");
 268         } else {
 269             color = getTheme().getColor("tlist.inactive");
 270         }
 271
 272         // Pad the rest with blank lines
 273         for (int i = topY; i < getHeight() - 1; i++) {
 274             getScreen().hLineXY(0, i, getWidth() - 1, ' ', color);
 275         }
 276     }
 277
 278     /**
 279      * Handle mouse press events.
 280      *
 281      * @param mouse mouse button press event
 282      */
 283     @Override
 284     public void onMouseDown(final TMouseEvent mouse) {
 285         if (mouse.isMouseWheelUp()) {
 286             verticalDecrement();
 287             return;
 288         }
 289         if (mouse.isMouseWheelDown()) {
 290             verticalIncrement();
 291             return;
 292         }
 293
 294         if ((mouse.getX() < getWidth() - 1)
 295             && (mouse.getY() < getHeight() - 1)) {
 296             if (getVerticalValue() + mouse.getY() < strings.size()) {
 297                 selectedString = getVerticalValue() + mouse.getY();
 298                 dispatchEnter();
 299             }
 300             return;
 301         }
 302
 303         // Pass to children
 304         super.onMouseDown(mouse);
 305     }
 306
 307     /**
 308      * Handle keystrokes.
 309      *
 310      * @param keypress keystroke event
 311      */
 312     @Override
 313     public void onKeypress(final TKeypressEvent keypress) {
 314         if (keypress.equals(kbLeft)) {
 315             horizontalDecrement();
 316         } else if (keypress.equals(kbRight)) {
 317             horizontalIncrement();
 318         } else if (keypress.equals(kbUp)) {
 319             if (strings.size() > 0) {
 320                 if (selectedString >= 0) {
 321                     if (selectedString > 0) {
 322                         if (selectedString - getVerticalValue() == 0) {
 323                             verticalDecrement();
 324                         }
 325                         selectedString--;
 326                     }
 327                 } else {
 328                     selectedString = strings.size() - 1;
 329                 }
 330             }
 331             if (selectedString >= 0) {
 332                 dispatchMove();
 333             }
 334         } else if (keypress.equals(kbDown)) {
 335             if (strings.size() > 0) {
 336                 if (selectedString >= 0) {
 337                     if (selectedString < strings.size() - 1) {
 338                         selectedString++;
 339                         if (selectedString - getVerticalValue() == getHeight() - 1) {
 340                             verticalIncrement();
 341                         }
 342                     }
 343                 } else {
 344                     selectedString = 0;
 345                 }
 346             }
 347             if (selectedString >= 0) {
 348                 dispatchMove();
 349             }
 350         } else if (keypress.equals(kbPgUp)) {
 351             bigVerticalDecrement();
 352             if (selectedString >= 0) {
 353                 selectedString -= getHeight() - 1;
 354                 if (selectedString < 0) {
 355                     selectedString = 0;
 356                 }
 357             }
 358             if (selectedString >= 0) {
 359                 dispatchMove();
 360             }
 361         } else if (keypress.equals(kbPgDn)) {
 362             bigVerticalIncrement();
 363             if (selectedString >= 0) {
 364                 selectedString += getHeight() - 1;
 365                 if (selectedString > strings.size() - 1) {
 366                     selectedString = strings.size() - 1;
 367                 }
 368             }
 369             if (selectedString >= 0) {
 370                 dispatchMove();
 371             }
 372         } else if (keypress.equals(kbHome)) {
 373             toTop();
 374             if (strings.size() > 0) {
 375                 selectedString = 0;
 376             }
 377             if (selectedString >= 0) {
 378                 dispatchMove();
 379             }
 380         } else if (keypress.equals(kbEnd)) {
 381             toBottom();
 382             if (strings.size() > 0) {
 383                 selectedString = strings.size() - 1;
 384             }
 385             if (selectedString >= 0) {
 386                 dispatchMove();
 387             }
 388         } else if (keypress.equals(kbTab)) {
 389             getParent().switchWidget(true);
 390         } else if (keypress.equals(kbShiftTab) || keypress.equals(kbBackTab)) {
 391             getParent().switchWidget(false);
 392         } else if (keypress.equals(kbEnter)) {
 393             if (selectedString >= 0) {
 394                 dispatchEnter();
 395             }
 396         } else {
 397             // Pass other keys (tab etc.) on
 398             super.onKeypress(keypress);
 399         }
 400     }
 401
 402 }