src/jexer/TTreeView.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 jexer.event.TKeypressEvent;
  32 import jexer.event.TMouseEvent;
  33 import static jexer.TKeypress.*;
  34
  35 /**
  36  * TTreeView implements a simple tree view.
  37  */
  38 public class TTreeView extends TScrollableWidget {
  39
  40     /**
  41      * Root of the tree.
  42      */
  43     private TTreeItem treeRoot;
  44
  45     /**
  46      * Get the root of the tree.
  47      *
  48      * @return the root of the tree
  49      */
  50     public final TTreeItem getTreeRoot() {
  51         return treeRoot;
  52     }
  53
  54     /**
  55      * Set the root of the tree.
  56      *
  57      * @param treeRoot the new root of the tree
  58      */
  59     public final void setTreeRoot(final TTreeItem treeRoot) {
  60         this.treeRoot = treeRoot;
  61     }
  62
  63     /**
  64      * Maximum width of a single line.
  65      */
  66     private int maxLineWidth;
  67
  68     /**
  69      * Only one of my children can be selected.
  70      */
  71     private TTreeItem selectedItem = null;
  72
  73     /**
  74      * If true, move the window to put the selected item in view.  This
  75      * normally only happens once after setting treeRoot.
  76      */
  77     private boolean centerWindow = false;
  78
  79     /**
  80      * The action to perform when the user selects an item.
  81      */
  82     private TAction action = null;
  83
  84     /**
  85      * Set treeRoot.
  86      *
  87      * @param treeRoot ultimate root of tree
  88      * @param centerWindow if true, move the window to put the root in view
  89      */
  90     public void setTreeRoot(final TTreeItem treeRoot,
  91         final boolean centerWindow) {
  92
  93         this.treeRoot = treeRoot;
  94         this.centerWindow = centerWindow;
  95     }
  96
  97     /**
  98      * Public constructor.
  99      *
 100      * @param parent parent widget
 101      * @param x column relative to parent
 102      * @param y row relative to parent
 103      * @param width width of tree view
 104      * @param height height of tree view
 105      */
 106     public TTreeView(final TWidget parent, final int x, final int y,
 107         final int width, final int height) {
 108
 109         this(parent, x, y, width, height, null);
 110     }
 111
 112     /**
 113      * Public constructor.
 114      *
 115      * @param parent parent widget
 116      * @param x column relative to parent
 117      * @param y row relative to parent
 118      * @param width width of tree view
 119      * @param height height of tree view
 120      * @param action action to perform when an item is selected
 121      */
 122     public TTreeView(final TWidget parent, final int x, final int y,
 123         final int width, final int height, final TAction action) {
 124
 125         super(parent, x, y, width, height);
 126         this.action = action;
 127
 128         vScroller = new TVScroller(this, getWidth() - 1, 0, getHeight() - 1);
 129         hScroller = new THScroller(this, 0, getHeight() - 1, getWidth() - 1);
 130     }
 131
 132     /**
 133      * Get the tree view item that was selected.
 134      *
 135      * @return the selected item, or null if no item is selected
 136      */
 137     public final TTreeItem getSelected() {
 138         return selectedItem;
 139     }
 140
 141     /**
 142      * Set the new selected tree view item.
 143      *
 144      * @param item new item that became selected
 145      */
 146     public void setSelected(final TTreeItem item) {
 147         if (item != null) {
 148             item.setSelected(true);
 149         }
 150         if ((selectedItem != null) && (selectedItem != item)) {
 151             selectedItem.setSelected(false);
 152         }
 153         selectedItem = item;
 154     }
 155
 156     /**
 157      * Perform user selection action.
 158      */
 159     public void dispatch() {
 160         if (action != null) {
 161             action.DO();
 162         }
 163     }
 164
 165     /**
 166      * Resize text and scrollbars for a new width/height.
 167      */
 168     @Override
 169     public void reflowData() {
 170         int selectedRow = 0;
 171         boolean foundSelectedRow = false;
 172
 173         if (treeRoot == null) {
 174             return;
 175         }
 176
 177         // Make each child invisible/inactive to start, expandTree() will
 178         // reactivate the visible ones.
 179         for (TWidget widget: getChildren()) {
 180             if (widget instanceof TTreeItem) {
 181                 TTreeItem item = (TTreeItem) widget;
 182                 item.setInvisible(true);
 183                 item.setEnabled(false);
 184                 item.keyboardPrevious = null;
 185                 item.keyboardNext = null;
 186             }
 187         }
 188
 189         // Expand the tree into a linear list
 190         getChildren().clear();
 191         getChildren().addAll(treeRoot.expandTree("", true));
 192
 193         // Locate the selected row and maximum line width
 194         for (TWidget widget: getChildren()) {
 195             TTreeItem item = (TTreeItem) widget;
 196
 197             if (item == selectedItem) {
 198                 foundSelectedRow = true;
 199             }
 200             if (!foundSelectedRow) {
 201                 selectedRow++;
 202             }
 203
 204             int lineWidth = item.getText().length()
 205                 + item.getPrefix().length() + 4;
 206             if (lineWidth > maxLineWidth) {
 207                 maxLineWidth = lineWidth;
 208             }
 209         }
 210
 211         if ((centerWindow) && (foundSelectedRow)) {
 212             if ((selectedRow < getVerticalValue())
 213                 || (selectedRow > getVerticalValue() + getHeight() - 2)
 214             ) {
 215                 setVerticalValue(selectedRow);
 216                 centerWindow = false;
 217             }
 218         }
 219         updatePositions();
 220
 221         // Rescale the scroll bars
 222         setBottomValue(getChildren().size() - getHeight() + 1);
 223         if (getBottomValue() < 0) {
 224             setBottomValue(0);
 225         }
 226         if (getVerticalValue() > getBottomValue()) {
 227             setVerticalValue(getBottomValue());
 228         }
 229         setRightValue(maxLineWidth - getWidth() + 3);
 230         if (getRightValue() < 0) {
 231             setRightValue(0);
 232         }
 233         if (getHorizontalValue() > getRightValue()) {
 234             setHorizontalValue(getRightValue());
 235         }
 236         getChildren().add(hScroller);
 237         getChildren().add(vScroller);
 238     }
 239
 240     /**
 241      * Update the Y positions of all the children items.
 242      */
 243     private void updatePositions() {
 244         if (treeRoot == null) {
 245             return;
 246         }
 247
 248         int begin = getVerticalValue();
 249         int topY = 0;
 250
 251         // As we walk the list we also adjust next/previous pointers,
 252         // resulting in a doubly-linked list but only of the expanded items.
 253         TTreeItem p = null;
 254
 255         for (int i = 0; i < getChildren().size(); i++) {
 256             if (!(getChildren().get(i) instanceof TTreeItem)) {
 257                 // Skip the scrollbars
 258                 continue;
 259             }
 260             TTreeItem item = (TTreeItem) getChildren().get(i);
 261
 262             if (p != null) {
 263                 item.keyboardPrevious = p;
 264                 p.keyboardNext = item;
 265             }
 266             p = item;
 267
 268             if (i < begin) {
 269                 // Render invisible
 270                 item.setEnabled(false);
 271                 item.setInvisible(true);
 272                 continue;
 273             }
 274
 275             if (topY >= getHeight() - 1) {
 276                 // Render invisible
 277                 item.setEnabled(false);
 278                 item.setInvisible(true);
 279                 continue;
 280             }
 281
 282             item.setY(topY);
 283             item.setEnabled(true);
 284             item.setInvisible(false);
 285             item.setWidth(getWidth() - 1);
 286             topY++;
 287         }
 288
 289     }
 290
 291     /**
 292      * Handle mouse press events.
 293      *
 294      * @param mouse mouse button press event
 295      */
 296     @Override
 297     public void onMouseDown(final TMouseEvent mouse) {
 298         if (mouse.isMouseWheelUp()) {
 299             verticalDecrement();
 300         } else if (mouse.isMouseWheelDown()) {
 301             verticalIncrement();
 302         } else {
 303             // Pass to children
 304             super.onMouseDown(mouse);
 305         }
 306
 307         // Update the screen after the scrollbars have moved
 308         reflowData();
 309     }
 310
 311     /**
 312      * Handle mouse release events.
 313      *
 314      * @param mouse mouse button release event
 315      */
 316     @Override
 317     public void onMouseUp(final TMouseEvent mouse) {
 318         // Pass to children
 319         super.onMouseDown(mouse);
 320
 321         // Update the screen after any thing has expanded/contracted
 322         reflowData();
 323     }
 324
 325     /**
 326      * Handle keystrokes.
 327      *
 328      * @param keypress keystroke event
 329      */
 330     @Override
 331     public void onKeypress(final TKeypressEvent keypress) {
 332         if (keypress.equals(kbShiftLeft)
 333             || keypress.equals(kbCtrlLeft)
 334             || keypress.equals(kbAltLeft)
 335         ) {
 336             horizontalDecrement();
 337         } else if (keypress.equals(kbShiftRight)
 338             || keypress.equals(kbCtrlRight)
 339             || keypress.equals(kbAltRight)
 340         ) {
 341             horizontalIncrement();
 342         } else if (keypress.equals(kbShiftUp)
 343             || keypress.equals(kbCtrlUp)
 344             || keypress.equals(kbAltUp)
 345         ) {
 346             verticalDecrement();
 347         } else if (keypress.equals(kbShiftDown)
 348             || keypress.equals(kbCtrlDown)
 349             || keypress.equals(kbAltDown)
 350         ) {
 351             verticalIncrement();
 352         } else if (keypress.equals(kbShiftPgUp)
 353             || keypress.equals(kbCtrlPgUp)
 354             || keypress.equals(kbAltPgUp)
 355         ) {
 356             bigVerticalDecrement();
 357         } else if (keypress.equals(kbShiftPgDn)
 358             || keypress.equals(kbCtrlPgDn)
 359             || keypress.equals(kbAltPgDn)
 360         ) {
 361             bigVerticalIncrement();
 362         } else if (keypress.equals(kbHome)) {
 363             toTop();
 364         } else if (keypress.equals(kbEnd)) {
 365             toBottom();
 366         } else if (keypress.equals(kbEnter)) {
 367             if (selectedItem != null) {
 368                 dispatch();
 369             }
 370         } else if (keypress.equals(kbUp)) {
 371             // Select the previous item
 372             if (selectedItem != null) {
 373                 TTreeItem oldItem = selectedItem;
 374                 if (selectedItem.keyboardPrevious != null) {
 375                     setSelected(selectedItem.keyboardPrevious);
 376                     if (oldItem.getY() == 0) {
 377                         verticalDecrement();
 378                     }
 379                 }
 380             }
 381         } else if (keypress.equals(kbDown)) {
 382             // Select the next item
 383             if (selectedItem != null) {
 384                 TTreeItem oldItem = selectedItem;
 385                 if (selectedItem.keyboardNext != null) {
 386                     setSelected(selectedItem.keyboardNext);
 387                     if (oldItem.getY() == getHeight() - 2) {
 388                         verticalIncrement();
 389                     }
 390                 }
 391             }
 392         } else if (keypress.equals(kbTab)) {
 393             getParent().switchWidget(true);
 394             return;
 395         } else if (keypress.equals(kbShiftTab)
 396                 || keypress.equals(kbBackTab)) {
 397             getParent().switchWidget(false);
 398             return;
 399         } else if (selectedItem != null) {
 400             // Give the TTreeItem a chance to handle arrow keys
 401             selectedItem.onKeypress(keypress);
 402         } else {
 403             // Pass other keys (tab etc.) on to TWidget's handler.
 404             super.onKeypress(keypress);
 405             return;
 406         }
 407
 408         // Update the screen after any thing has expanded/contracted
 409         reflowData();
 410     }
 411
 412 }