src/jexer/TComboBox.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 java.util.ArrayList;
  32 import java.util.List;
  33
  34 import jexer.bits.CellAttributes;
  35 import jexer.bits.GraphicsChars;
  36 import jexer.event.TKeypressEvent;
  37 import jexer.event.TMouseEvent;
  38 import jexer.event.TResizeEvent;
  39 import jexer.event.TResizeEvent.Type;
  40 import static jexer.TKeypress.*;
  41
  42 /**
  43  * TComboBox implements a combobox containing a drop-down list and edit
  44  * field.  Alt-Down can be used to show the drop-down.
  45  */
  46 public class TComboBox extends TWidget {
  47
  48     // ------------------------------------------------------------------------
  49     // Variables --------------------------------------------------------------
  50     // ------------------------------------------------------------------------
  51
  52     /**
  53      * The list of items in the drop-down.
  54      */
  55     private TList list;
  56
  57     /**
  58      * The edit field containing the value to return.
  59      */
  60     private TField field;
  61
  62     /**
  63      * The action to perform when the user selects an item (clicks or enter).
  64      */
  65     private TAction updateAction = null;
  66
  67     /**
  68      * If true, the field cannot be updated to a value not on the list.
  69      */
  70     private boolean limitToListValue = true;
  71
  72     /**
  73      * The height of the list of values when it is shown, or -1 to use the
  74      * number of values in the list as the height.
  75      */
  76     private int valuesHeight = -1;
  77
  78     /**
  79      * The values shown by the drop-down list.
  80      */
  81     private List<String> values = new ArrayList<String>();
  82
  83     /**
  84      * When looking for a link between the displayed text and the list
  85      * of values, do a case sensitive search.
  86      */
  87     private boolean caseSensitive = true;
  88
  89     /**
  90      * The maximum height of the values drop-down when it is visible.
  91      */
  92     private int maxValuesHeight = 3;
  93
  94     // ------------------------------------------------------------------------
  95     // Constructors -----------------------------------------------------------
  96     // ------------------------------------------------------------------------
  97
  98     /**
  99      * Public constructor.
 100      *
 101      * @param parent parent widget
 102      * @param x column relative to parent
 103      * @param y row relative to parent
 104      * @param width visible combobox width, including the down-arrow
 105      * @param values the possible values for the box, shown in the drop-down
 106      * @param valuesIndex the initial index in values, or -1 for no default
 107      * value
 108      * @param valuesHeight the height of the values drop-down when it is
 109      * visible, or -1 to use the number of values as the height of the list
 110      * @param updateAction action to call when a new value is selected from
 111      * the list or enter is pressed in the edit field
 112      */
 113     public TComboBox(final TWidget parent, final int x, final int y,
 114         final int width, final List<String> values, final int valuesIndex,
 115         final int valuesHeight, final TAction updateAction) {
 116
 117         // Set parent and window
 118         super(parent, x, y, width, 1);
 119
 120         assert (values != null);
 121
 122         this.updateAction = updateAction;
 123         this.values = values;
 124         this.valuesHeight = valuesHeight;
 125
 126         field = new TField(this, 0, 0, Math.max(0, width - 3), false, "",
 127             updateAction, null);
 128         if (valuesIndex >= 0) {
 129             field.setText(values.get(valuesIndex));
 130         }
 131
 132         setHeight(1);
 133         if (limitToListValue) {
 134             field.setEnabled(false);
 135         } else {
 136             activate(field);
 137         }
 138     }
 139
 140     // ------------------------------------------------------------------------
 141     // Event handlers ---------------------------------------------------------
 142     // ------------------------------------------------------------------------
 143
 144     /**
 145      * Returns true if the mouse is currently on the down arrow.
 146      *
 147      * @param mouse mouse event
 148      * @return true if the mouse is currently on the down arrow
 149      */
 150     private boolean mouseOnArrow(final TMouseEvent mouse) {
 151         if ((mouse.getY() == 0)
 152             && (mouse.getX() >= getWidth() - 3)
 153             && (mouse.getX() <= getWidth() - 1)
 154         ) {
 155             return true;
 156         }
 157         return false;
 158     }
 159
 160     /**
 161      * Handle mouse down clicks.
 162      *
 163      * @param mouse mouse button down event
 164      */
 165     @Override
 166     public void onMouseDown(final TMouseEvent mouse) {
 167         if ((mouseOnArrow(mouse)) && (mouse.isMouse1())) {
 168             // Make the list visible or not.
 169             if (list != null) {
 170                 hideDropdown();
 171             } else {
 172                 displayDropdown();
 173             }
 174         }
 175
 176         // Pass to parent for the things we don't care about.
 177         super.onMouseDown(mouse);
 178     }
 179
 180     /**
 181      * Handle keystrokes.
 182      *
 183      * @param keypress keystroke event
 184      */
 185     @Override
 186     public void onKeypress(final TKeypressEvent keypress) {
 187         if (keypress.equals(kbEsc)) {
 188             if (list != null) {
 189                 hideDropdown();
 190                 return;
 191             }
 192         }
 193
 194         if (keypress.equals(kbAltDown)) {
 195             displayDropdown();
 196             return;
 197         }
 198
 199         if (keypress.equals(kbTab)
 200             || (keypress.equals(kbShiftTab))
 201             || (keypress.equals(kbBackTab))
 202         ) {
 203             if (list != null) {
 204                 hideDropdown();
 205                 return;
 206             }
 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      * Override TWidget's width: we need to set child widget widths.
 219      *
 220      * @param width new widget width
 221      */
 222     @Override
 223     public void setWidth(final int width) {
 224         if (field != null) {
 225             field.setWidth(width - 3);
 226         }
 227         if (list != null) {
 228             list.setWidth(width);
 229         }
 230         super.setWidth(width);
 231     }
 232
 233     /**
 234      * Override TWidget's height: we can only set height at construction
 235      * time.
 236      *
 237      * @param height new widget height (ignored)
 238      */
 239     @Override
 240     public void setHeight(final int height) {
 241         // Do nothing
 242     }
 243
 244     /**
 245      * Draw the combobox down arrow.
 246      */
 247     @Override
 248     public void draw() {
 249         CellAttributes comboBoxColor;
 250
 251         if (!isAbsoluteActive()) {
 252             // We lost focus, turn off the list.
 253             hideDropdown();
 254         }
 255
 256         if (isAbsoluteActive()) {
 257             comboBoxColor = getTheme().getColor("tcombobox.active");
 258         } else {
 259             comboBoxColor = getTheme().getColor("tcombobox.inactive");
 260         }
 261
 262         putCharXY(getWidth() - 3, 0, GraphicsChars.DOWNARROWLEFT,
 263             comboBoxColor);
 264         putCharXY(getWidth() - 2, 0, GraphicsChars.DOWNARROW,
 265             comboBoxColor);
 266         putCharXY(getWidth() - 1, 0, GraphicsChars.DOWNARROWRIGHT,
 267             comboBoxColor);
 268     }
 269
 270     // ------------------------------------------------------------------------
 271     // TComboBox --------------------------------------------------------------
 272     // ------------------------------------------------------------------------
 273
 274     /**
 275      * Hide the drop-down list.
 276      */
 277     public void hideList() {
 278         list.setEnabled(false);
 279         list.setVisible(false);
 280         super.setHeight(1);
 281         if (limitToListValue == false) {
 282             activate(field);
 283         }
 284     }
 285
 286     /**
 287      * Show the drop-down list.
 288      */
 289     public void showList() {
 290         list.setEnabled(true);
 291         list.setVisible(true);
 292         super.setHeight(list.getHeight() + 1);
 293         activate(list);
 294     }
 295
 296     /**
 297      * Get combobox text value.
 298      *
 299      * @return text in the edit field
 300      */
 301     public String getText() {
 302         return field.getText();
 303     }
 304
 305     /**
 306      * Set combobox text value.
 307      *
 308      * @param text the new text in the edit field
 309      */
 310     public void setText(final String text) {
 311         setText(text, true);
 312     }
 313
 314     /**
 315      * Set combobox text value.
 316      *
 317      * @param text the new text in the edit field
 318      * @param caseSensitive if true, perform a case-sensitive search for the
 319      * list item
 320      */
 321     public void setText(final String text, final boolean caseSensitive) {
 322         this.caseSensitive = caseSensitive;
 323         field.setText(text);
 324         if (list != null) {
 325                 displayDropdown();
 326         }
 327     }
 328
 329     /**
 330      * Set combobox text to one of the list values.
 331      *
 332      * @param index the index in the list
 333      */
 334     public void setIndex(final int index) {
 335         list.setSelectedIndex(index);
 336         field.setText(list.getSelected());
 337     }
 338
 339     /**
 340      * Get a copy of the list of strings to display.
 341      *
 342      * @return the list of strings
 343      */
 344     public final List<String> getList() {
 345         return list.getList();
 346     }
 347
 348     /**
 349      * Set the new list of strings to display.
 350      *
 351      * @param list new list of strings
 352      */
 353     public final void setList(final List<String> list) {
 354         this.list.setList(list);
 355         this.list.setHeight(Math.max(3, Math.min(list.size() + 1,
 356                     maxValuesHeight)));
 357         field.setText("");
 358     }
 359
 360     /**
 361      * Make sure the widget displays all its elements correctly according to
 362      * the current size and content.
 363      */
 364     public void reflowData() {
 365         // TODO: why setW/setH/reflow not enough for the scrollbars?
 366         TList list = this.list;
 367         if (list != null) {
 368                 int valuesHeight = this.valuesHeight;
 369                 if (valuesHeight < 0) {
 370                         valuesHeight = values == null ? 0 : values.size() + 1;
 371                 }
 372
 373                 list.onResize(new TResizeEvent(Type.WIDGET, getWidth(),
 374                                 valuesHeight));
 375                 setHeight(valuesHeight + 1);
 376         }
 377
 378         field.onResize(new TResizeEvent(Type.WIDGET, getWidth(),
 379                         field.getHeight()));
 380     }
 381
 382     @Override
 383     public void onResize(TResizeEvent resize) {
 384         super.onResize(resize);
 385         reflowData();
 386     }
 387
 388     /**
 389      * Display the drop-down menu represented by {@link TComboBox#list}.
 390      */
 391     private void displayDropdown() {
 392         if (this.list != null) {
 393                 hideDropdown();
 394         }
 395
 396         int valuesHeight = this.valuesHeight;
 397         if (valuesHeight < 0) {
 398                 valuesHeight = values == null ? 0 : values.size() + 1;
 399         }
 400
 401         TList list = new TList(this, values, 0, 1, getWidth(), valuesHeight,
 402                         new TAction() {
 403                                         @Override
 404                                         public void DO() {
 405                                                 TList list = TComboBox.this.list;
 406                                                 if (list == null) {
 407                                                         return;
 408                                                 }
 409
 410                                                 field.setText(list.getSelected());
 411                                                 hideDropdown();
 412
 413                                                 if (updateAction != null) {
 414                                                         updateAction.DO();
 415                                                 }
 416                                         }
 417                                 }
 418         );
 419
 420         int i = -1;
 421         if (values != null) {
 422                 String current = field.getText();
 423                 for (i = 0 ; i < values.size() ; i++) {
 424                         String value = values.get(i);
 425                         if ((caseSensitive && current.equals(value))
 426                                         || (!caseSensitive && current.equalsIgnoreCase(value))) {
 427                                 break;
 428                         }
 429                 }
 430
 431                 if (i >= values.size()) {
 432                         i = -1;
 433                 }
 434         }
 435         list.setSelectedIndex(i);
 436
 437         list.setEnabled(true);
 438         list.setVisible(true);
 439
 440         this.list = list;
 441
 442         reflowData();
 443         activate(list);
 444     }
 445
 446     /**
 447      * Hide the drop-down menu represented by {@link TComboBox#list}.
 448      */
 449     private void hideDropdown() {
 450         TList list = this.list;
 451
 452         if (list != null) {
 453                 list.setEnabled(false);
 454                 list.setVisible(false);
 455                 removeChild(list);
 456
 457                 setHeight(1);
 458                 if (limitToListValue == false) {
 459                 activate(field);
 460             }
 461
 462                 this.list = null;
 463         }
 464     }
 465 }