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.List;
  32
  33 import jexer.bits.CellAttributes;
  34 import jexer.bits.GraphicsChars;
  35 import jexer.event.TKeypressEvent;
  36 import jexer.event.TMouseEvent;
  37 import static jexer.TKeypress.*;
  38
  39 /**
  40  * TComboBox implements a combobox containing a drop-down list and edit
  41  * field.  Alt-Down can be used to show the drop-down.
  42  */
  43 public class TComboBox extends TWidget {
  44
  45     // ------------------------------------------------------------------------
  46     // Variables --------------------------------------------------------------
  47     // ------------------------------------------------------------------------
  48
  49     /**
  50      * The list of items in the drop-down.
  51      */
  52     private TList list;
  53
  54     /**
  55      * The edit field containing the value to return.
  56      */
  57     private TField field;
  58
  59     /**
  60      * The action to perform when the user selects an item (clicks or enter).
  61      */
  62     private TAction updateAction = null;
  63
  64     /**
  65      * If true, the field cannot be updated to a value not on the list.
  66      */
  67     private boolean limitToListValue = true;
  68
  69     /**
  70      * The maximum height of the values drop-down when it is visible.
  71      */
  72     private int maxValuesHeight = 3;
  73
  74     // ------------------------------------------------------------------------
  75     // Constructors -----------------------------------------------------------
  76     // ------------------------------------------------------------------------
  77
  78     /**
  79      * Public constructor.
  80      *
  81      * @param parent parent widget
  82      * @param x column relative to parent
  83      * @param y row relative to parent
  84      * @param width visible combobox width, including the down-arrow
  85      * @param values the possible values for the box, shown in the drop-down
  86      * @param valuesIndex the initial index in values, or -1 for no default
  87      * value
  88      * @param maxValuesHeight the maximum height of the values drop-down when
  89      * it is visible
  90      * @param updateAction action to call when a new value is selected from
  91      * the list or enter is pressed in the edit field
  92      */
  93     public TComboBox(final TWidget parent, final int x, final int y,
  94         final int width, final List<String> values, final int valuesIndex,
  95         final int maxValuesHeight, final TAction updateAction) {
  96
  97         // Set parent and window
  98         super(parent, x, y, width, 1);
  99
 100         assert (values != null);
 101
 102         this.updateAction = updateAction;
 103         this.maxValuesHeight = maxValuesHeight;
 104
 105         field = addField(0, 0, width - 3, false, "", updateAction, null);
 106         if ((valuesIndex >= 0) && (valuesIndex < values.size())) {
 107             field.setText(values.get(valuesIndex));
 108         }
 109
 110         list = addList(values, 0, 1, width,
 111             Math.max(3, Math.min(values.size() + 1, maxValuesHeight)),
 112             new TAction() {
 113                 public void DO() {
 114                     field.setText(list.getSelected());
 115                     list.setEnabled(false);
 116                     list.setVisible(false);
 117                     TComboBox.super.setHeight(1);
 118                     if (TComboBox.this.limitToListValue == false) {
 119                         TComboBox.this.activate(field);
 120                     }
 121                     if (updateAction != null) {
 122                         updateAction.DO(TComboBox.this);
 123                     }
 124                 }
 125             }
 126         );
 127         if (valuesIndex >= 0) {
 128             list.setSelectedIndex(valuesIndex);
 129         }
 130
 131         list.setEnabled(false);
 132         list.setVisible(false);
 133         super.setHeight(1);
 134         if (limitToListValue) {
 135             field.setEnabled(false);
 136         } else {
 137             activate(field);
 138         }
 139     }
 140
 141     // ------------------------------------------------------------------------
 142     // Event handlers ---------------------------------------------------------
 143     // ------------------------------------------------------------------------
 144
 145     /**
 146      * Returns true if the mouse is currently on the down arrow.
 147      *
 148      * @param mouse mouse event
 149      * @return true if the mouse is currently on the down arrow
 150      */
 151     private boolean mouseOnArrow(final TMouseEvent mouse) {
 152         if ((mouse.getY() == 0)
 153             && (mouse.getX() >= getWidth() - 3)
 154             && (mouse.getX() <= getWidth() - 1)
 155         ) {
 156             return true;
 157         }
 158         return false;
 159     }
 160
 161     /**
 162      * Handle mouse down clicks.
 163      *
 164      * @param mouse mouse button down event
 165      */
 166     @Override
 167     public void onMouseDown(final TMouseEvent mouse) {
 168         if ((mouseOnArrow(mouse)) && (mouse.isMouse1())) {
 169             // Make the list visible or not.
 170             if (list.isActive()) {
 171                 hideList();
 172             } else {
 173                 showList();
 174             }
 175         }
 176
 177         // Pass to parent for the things we don't care about.
 178         super.onMouseDown(mouse);
 179     }
 180
 181     /**
 182      * Handle keystrokes.
 183      *
 184      * @param keypress keystroke event
 185      */
 186     @Override
 187     public void onKeypress(final TKeypressEvent keypress) {
 188         if (keypress.equals(kbEsc)) {
 189             if (list.isActive()) {
 190                 hideList();
 191                 return;
 192             }
 193         }
 194
 195         if (keypress.equals(kbAltDown)) {
 196             showList();
 197             return;
 198         }
 199
 200         if (keypress.equals(kbTab)
 201             || (keypress.equals(kbShiftTab))
 202             || (keypress.equals(kbBackTab))
 203         ) {
 204             if (list.isActive()) {
 205                 hideList();
 206                 return;
 207             }
 208         }
 209
 210         // Pass to parent for the things we don't care about.
 211         super.onKeypress(keypress);
 212     }
 213
 214     // ------------------------------------------------------------------------
 215     // TWidget ----------------------------------------------------------------
 216     // ------------------------------------------------------------------------
 217
 218     /**
 219      * Override TWidget's width: we need to set child widget widths.
 220      *
 221      * @param width new widget width
 222      */
 223     @Override
 224     public void setWidth(final int width) {
 225         if (field != null) {
 226             field.setWidth(width - 3);
 227         }
 228         if (list != null) {
 229             list.setWidth(width);
 230         }
 231         super.setWidth(width);
 232     }
 233
 234     /**
 235      * Override TWidget's height: we can only set height at construction
 236      * time.
 237      *
 238      * @param height new widget height (ignored)
 239      */
 240     @Override
 241     public void setHeight(final int height) {
 242         // Do nothing
 243     }
 244
 245     /**
 246      * Draw the combobox down arrow.
 247      */
 248     @Override
 249     public void draw() {
 250         CellAttributes comboBoxColor;
 251
 252         if (!isAbsoluteActive()) {
 253             // We lost focus, turn off the list.
 254             if (list.isActive()) {
 255                 hideList();
 256             }
 257         }
 258
 259         if (isAbsoluteActive()) {
 260             comboBoxColor = getTheme().getColor("tcombobox.active");
 261         } else {
 262             comboBoxColor = getTheme().getColor("tcombobox.inactive");
 263         }
 264
 265         putCharXY(getWidth() - 3, 0, GraphicsChars.DOWNARROWLEFT,
 266             comboBoxColor);
 267         putCharXY(getWidth() - 2, 0, GraphicsChars.DOWNARROW,
 268             comboBoxColor);
 269         putCharXY(getWidth() - 1, 0, GraphicsChars.DOWNARROWRIGHT,
 270             comboBoxColor);
 271     }
 272
 273     // ------------------------------------------------------------------------
 274     // TComboBox --------------------------------------------------------------
 275     // ------------------------------------------------------------------------
 276
 277     /**
 278      * Hide the drop-down list.
 279      */
 280     public void hideList() {
 281         list.setEnabled(false);
 282         list.setVisible(false);
 283         super.setHeight(1);
 284         if (limitToListValue == false) {
 285             activate(field);
 286         }
 287     }
 288
 289     /**
 290      * Show the drop-down list.
 291      */
 292     public void showList() {
 293         list.setEnabled(true);
 294         list.setVisible(true);
 295         super.setHeight(list.getHeight() + 1);
 296         activate(list);
 297     }
 298
 299     /**
 300      * Get combobox text value.
 301      *
 302      * @return text in the edit field
 303      */
 304     public String getText() {
 305         return field.getText();
 306     }
 307
 308     /**
 309      * Set combobox text value.
 310      *
 311      * @param text the new text in the edit field
 312      */
 313     public void setText(final String text) {
 314         setText(text, true);
 315     }
 316
 317     /**
 318      * Set combobox text value.
 319      *
 320      * @param text the new text in the edit field
 321      * @param caseSensitive if true, perform a case-sensitive search for the
 322      * list item
 323      */
 324     public void setText(final String text, final boolean caseSensitive) {
 325         field.setText(text);
 326         for (int i = 0; i < list.getMaxSelectedIndex(); i++) {
 327             if (caseSensitive == true) {
 328                 if (list.getListItem(i).equals(text)) {
 329                     list.setSelectedIndex(i);
 330                     return;
 331                 }
 332             } else {
 333                 if (list.getListItem(i).toLowerCase().equals(text.toLowerCase())) {
 334                     list.setSelectedIndex(i);
 335                     return;
 336                 }
 337             }
 338         }
 339         list.setSelectedIndex(-1);
 340     }
 341
 342     /**
 343      * Set combobox text to one of the list values.
 344      *
 345      * @param index the index in the list
 346      */
 347     public void setIndex(final int index) {
 348         list.setSelectedIndex(index);
 349         field.setText(list.getSelected());
 350     }
 351
 352     /**
 353      * Get a copy of the list of strings to display.
 354      *
 355      * @return the list of strings
 356      */
 357     public final List<String> getList() {
 358         return list.getList();
 359     }
 360
 361     /**
 362      * Set the new list of strings to display.
 363      *
 364      * @param list new list of strings
 365      */
 366     public final void setList(final List<String> list) {
 367         this.list.setList(list);
 368         this.list.setHeight(Math.max(3, Math.min(list.size() + 1,
 369                     maxValuesHeight)));
 370         field.setText("");
 371     }
 372
 373 }