src/jexer/TTreeItem.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * License: LGPLv3 or later
   5  *
   6  * This module is licensed under the GNU Lesser General Public License
   7  * Version 3.  Please see the file "COPYING" in this directory for more
   8  * information about the GNU Lesser General Public License Version 3.
   9  *
  10  *     Copyright (C) 2015  Kevin Lamonte
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public License
  14  * as published by the Free Software Foundation; either version 3 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public
  23  * License along with this program; if not, see
  24  * http://www.gnu.org/licenses/, or write to the Free Software
  25  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  26  * 02110-1301 USA
  27  *
  28  * @author Kevin Lamonte [kevin.lamonte@gmail.com]
  29  * @version 1
  30  */
  31 package jexer;
  32
  33 import java.util.ArrayList;
  34 import java.util.List;
  35
  36 import jexer.bits.CellAttributes;
  37 import jexer.bits.GraphicsChars;
  38 import jexer.event.TKeypressEvent;
  39 import jexer.event.TMouseEvent;
  40 import static jexer.TKeypress.*;
  41
  42 /**
  43  * TTreeItem is a single item in a tree view.
  44  */
  45 public class TTreeItem extends TWidget {
  46
  47     /**
  48      * Hang onto reference to my parent TTreeView so I can call its reflow()
  49      * when I add a child node.
  50      */
  51     private TTreeView view;
  52
  53     /**
  54      * Get the parent TTreeView.
  55      *
  56      * @return the parent TTreeView
  57      */
  58     public final TTreeView getTreeView() {
  59         return view;
  60     }
  61
  62     /**
  63      * Displayable text for this item.
  64      */
  65     private String text;
  66
  67     /**
  68      * Get the displayable text for this item.
  69      *
  70      * @return the displayable text for this item
  71      */
  72     public final String getText() {
  73         return text;
  74     }
  75
  76     /**
  77      * Set the displayable text for this item.
  78      *
  79      * @param text the displayable text for this item
  80      */
  81     public final void setText(final String text) {
  82         this.text = text;
  83     }
  84
  85     /**
  86      * If true, this item is expanded in the tree view.
  87      */
  88     private boolean expanded = true;
  89
  90     /**
  91      * Get expanded value.
  92      *
  93      * @return if true, this item is expanded
  94      */
  95     public final boolean isExpanded() {
  96         return expanded;
  97     }
  98
  99     /**
 100      * Set expanded value.
 101      *
 102      * @param expanded new value
 103      */
 104     public final void setExpanded(final boolean expanded) {
 105         this.expanded = expanded;
 106     }
 107
 108     /**
 109      * If true, this item can be expanded in the tree view.
 110      */
 111     private boolean expandable = false;
 112
 113     /**
 114      * Get expandable value.
 115      *
 116      * @return if true, this item is expandable
 117      */
 118     public final boolean isExpandable() {
 119         return expandable;
 120     }
 121
 122     /**
 123      * Set expandable value.
 124      *
 125      * @param expandable new value
 126      */
 127     public final void setExpandable(final boolean expandable) {
 128         this.expandable = expandable;
 129     }
 130
 131     /**
 132      * The vertical bars and such along the left side.
 133      */
 134     private String prefix = "";
 135
 136     /**
 137      * Get the vertical bars and such along the left side.
 138      *
 139      * @return the vertical bars and such along the left side
 140      */
 141     public final String getPrefix() {
 142         return prefix;
 143     }
 144
 145     /**
 146      * Whether or not this item is last in its parent's list of children.
 147      */
 148     private boolean last = false;
 149
 150     /**
 151      * Tree level.  Note package private access.
 152      */
 153     int level = 0;
 154
 155     /**
 156      * If true, this item will not be drawn.
 157      */
 158     private boolean invisible = false;
 159
 160     /**
 161      * Set invisible value.
 162      *
 163      * @param invisible new value
 164      */
 165     public final void setInvisible(final boolean invisible) {
 166         this.invisible = invisible;
 167     }
 168
 169     /**
 170      * True means selected.
 171      */
 172     private boolean selected = false;
 173
 174     /**
 175      * Get selected value.
 176      *
 177      * @return if true, this item is selected
 178      */
 179     public final boolean isSelected() {
 180         return selected;
 181     }
 182
 183     /**
 184      * Set selected value.
 185      *
 186      * @param selected new value
 187      */
 188     public final void setSelected(final boolean selected) {
 189         this.selected = selected;
 190     }
 191
 192     /**
 193      * True means select-able.
 194      */
 195     private boolean selectable = true;
 196
 197     /**
 198      * Set selectable value.
 199      *
 200      * @param selectable new value
 201      */
 202     public final void setSelectable(final boolean selectable) {
 203         this.selectable = selectable;
 204     }
 205
 206     /**
 207      * Pointer to the previous keyboard-navigable item (kbUp).  Note package
 208      * private access.
 209      */
 210     TTreeItem keyboardPrevious = null;
 211
 212     /**
 213      * Pointer to the next keyboard-navigable item (kbDown).  Note package
 214      * private access.
 215      */
 216     TTreeItem keyboardNext = null;
 217
 218     /**
 219      * Public constructor.
 220      *
 221      * @param view root TTreeView
 222      * @param text text for this item
 223      * @param expanded if true, have it expanded immediately
 224      */
 225     public TTreeItem(final TTreeView view, final String text,
 226         final boolean expanded) {
 227
 228         super(view, 0, 0, view.getWidth() - 3, 1);
 229         this.text = text;
 230         this.expanded = expanded;
 231         this.view = view;
 232
 233         if (view.getTreeRoot() == null) {
 234             view.setTreeRoot(this, true);
 235         }
 236
 237         view.reflow();
 238     }
 239
 240     /**
 241      * Add a child item.
 242      *
 243      * @param text text for this item
 244      * @return the new child item
 245      */
 246     public TTreeItem addChild(final String text) {
 247         return addChild(text, true);
 248     }
 249
 250     /**
 251      * Add a child item.
 252      *
 253      * @param text text for this item
 254      * @param expanded if true, have it expanded immediately
 255      * @return the new child item
 256      */
 257     public TTreeItem addChild(final String text, final boolean expanded) {
 258         TTreeItem item = new TTreeItem(view, text, expanded);
 259         item.level = this.level + 1;
 260         getChildren().add(item);
 261         view.reflow();
 262         return item;
 263     }
 264
 265     /**
 266      * Recursively expand the tree into a linear array of items.
 267      *
 268      * @param prefix vertical bar of parent levels and such that is set on
 269      * each child
 270      * @param last if true, this is the "last" leaf node of a tree
 271      * @return additional items to add to the array
 272      */
 273     public List<TTreeItem> expandTree(final String prefix, final boolean last) {
 274         List<TTreeItem> array = new ArrayList<TTreeItem>();
 275         this.last = last;
 276         this.prefix = prefix;
 277         array.add(this);
 278
 279         if ((getChildren().size() == 0) || !expanded) {
 280             return array;
 281         }
 282
 283         String newPrefix = prefix;
 284         if (level > 0) {
 285             if (last) {
 286                 newPrefix += "  ";
 287             } else {
 288                 newPrefix += GraphicsChars.CP437[0xB3];
 289                 newPrefix += ' ';
 290             }
 291         }
 292         for (int i = 0; i < getChildren().size(); i++) {
 293             TTreeItem item = (TTreeItem) getChildren().get(i);
 294             if (i == getChildren().size() - 1) {
 295                 array.addAll(item.expandTree(newPrefix, true));
 296             } else {
 297                 array.addAll(item.expandTree(newPrefix, false));
 298             }
 299         }
 300         return array;
 301     }
 302
 303     /**
 304      * Get the x spot for the + or - to expand/collapse.
 305      *
 306      * @return column of the expand/collapse button
 307      */
 308     private int getExpanderX() {
 309         if ((level == 0) || (!expandable)) {
 310             return 0;
 311         }
 312         return prefix.length() + 3;
 313     }
 314
 315     /**
 316      * Recursively unselect my or my children.
 317      */
 318     public void unselect() {
 319         if (selected == true) {
 320             selected = false;
 321             view.setSelected(null);
 322         }
 323         for (TWidget widget: getChildren()) {
 324             if (widget instanceof TTreeItem) {
 325                 TTreeItem item = (TTreeItem) widget;
 326                 item.unselect();
 327             }
 328         }
 329     }
 330
 331     /**
 332      * Handle mouse release events.
 333      *
 334      * @param mouse mouse button release event
 335      */
 336     @Override
 337     public void onMouseUp(final TMouseEvent mouse) {
 338         if ((mouse.getX() == (getExpanderX() - view.getHScroller().getValue()))
 339             && (mouse.getY() == 0)
 340         ) {
 341             if (selectable) {
 342                 // Flip expanded flag
 343                 expanded = !expanded;
 344                 if (expanded == false) {
 345                     // Unselect children that became invisible
 346                     unselect();
 347                 }
 348             }
 349             // Let subclasses do something with this
 350             onExpand();
 351         } else if (mouse.getY() == 0) {
 352             view.setSelected(this);
 353             view.dispatch();
 354         }
 355
 356         // Update the screen after any thing has expanded/contracted
 357         view.reflow();
 358     }
 359
 360     /**
 361      * Called when this item is expanded or collapsed.  this.expanded will be
 362      * true if this item was just expanded from a mouse click or keypress.
 363      */
 364     public void onExpand() {
 365         // Default: do nothing.
 366         if (!expandable) {
 367             return;
 368         }
 369     }
 370
 371     /**
 372      * Handle keystrokes.
 373      *
 374      * @param keypress keystroke event
 375      */
 376     @Override
 377     public void onKeypress(final TKeypressEvent keypress) {
 378         if (keypress.equals(kbLeft)
 379             || keypress.equals(kbRight)
 380             || keypress.equals(kbSpace)
 381         ) {
 382             if (selectable) {
 383                 // Flip expanded flag
 384                 expanded = !expanded;
 385                 if (expanded == false) {
 386                     // Unselect children that became invisible
 387                     unselect();
 388                 }
 389                 view.setSelected(this);
 390             }
 391             // Let subclasses do something with this
 392             onExpand();
 393         } else {
 394             // Pass other keys (tab etc.) on to TWidget's handler.
 395             super.onKeypress(keypress);
 396         }
 397     }
 398
 399     /**
 400      * Draw this item to a window.
 401      */
 402     @Override
 403     public void draw() {
 404         if (invisible) {
 405             return;
 406         }
 407
 408         int offset = -view.getHScroller().getValue();
 409
 410         CellAttributes color = getTheme().getColor("ttreeview");
 411         CellAttributes textColor = getTheme().getColor("ttreeview");
 412         CellAttributes expanderColor = getTheme().getColor("ttreeview.expandbutton");
 413         CellAttributes selectedColor = getTheme().getColor("ttreeview.selected");
 414
 415         if (!getParent().isAbsoluteActive()) {
 416             color = getTheme().getColor("ttreeview.inactive");
 417             textColor = getTheme().getColor("ttreeview.inactive");
 418         }
 419
 420         if (!selectable) {
 421             textColor = getTheme().getColor("ttreeview.unreadable");
 422         }
 423
 424         // Blank out the background
 425         getScreen().hLineXY(0, 0, getWidth(), ' ', color);
 426
 427         String line = prefix;
 428         if (level > 0) {
 429             if (last) {
 430                 line += GraphicsChars.CP437[0xC0];
 431             } else {
 432                 line += GraphicsChars.CP437[0xC3];
 433             }
 434             line += GraphicsChars.CP437[0xC4];
 435             if (expandable) {
 436                 line += "[ ] ";
 437             }
 438         }
 439         getScreen().putStringXY(offset, 0, line, color);
 440         if (selected) {
 441             getScreen().putStringXY(offset + line.length(), 0, text,
 442                 selectedColor);
 443         } else {
 444             getScreen().putStringXY(offset + line.length(), 0, text, textColor);
 445         }
 446         if ((level > 0) && (expandable)) {
 447             if (expanded) {
 448                 getScreen().putCharXY(offset + getExpanderX(), 0, '-',
 449                     expanderColor);
 450             } else {
 451                 getScreen().putCharXY(offset + getExpanderX(), 0, '+',
 452                     expanderColor);
 453             }
 454         }
 455     }
 456
 457 }