src/jexer/layout/BoxLayoutManager.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.layout;
  30
  31 import java.util.ArrayList;
  32
  33 import jexer.TWidget;
  34 import jexer.event.TResizeEvent;
  35
  36 /**
  37  * BoxLayoutManager repositions child widgets based on the order they are
  38  * added to the parent widget and desired orientation.
  39  */
  40 public class BoxLayoutManager implements LayoutManager {
  41
  42     // ------------------------------------------------------------------------
  43     // Variables --------------------------------------------------------------
  44     // ------------------------------------------------------------------------
  45
  46     /**
  47      * If true, orient vertically.  If false, orient horizontally.
  48      */
  49     private boolean vertical = true;
  50
  51     /**
  52      * Current width.
  53      */
  54     private int width = 0;
  55
  56     /**
  57      * Current height.
  58      */
  59     private int height = 0;
  60
  61     /**
  62      * Widgets being managed.
  63      */
  64     private ArrayList<TWidget> children = new ArrayList<TWidget>();
  65
  66     // ------------------------------------------------------------------------
  67     // Constructors -----------------------------------------------------------
  68     // ------------------------------------------------------------------------
  69
  70     /**
  71      * Public constructor.
  72      *
  73      * @param width the width of the parent widget
  74      * @param height the height of the parent widget
  75      * @param vertical if true, arrange widgets vertically
  76      */
  77     public BoxLayoutManager(final int width, final int height,
  78         final boolean vertical) {
  79
  80         this.width = width;
  81         this.height = height;
  82         this.vertical = vertical;
  83     }
  84
  85     // ------------------------------------------------------------------------
  86     // LayoutManager ----------------------------------------------------------
  87     // ------------------------------------------------------------------------
  88
  89     /**
  90      * Process the parent widget's resize event, and resize/reposition child
  91      * widgets.
  92      *
  93      * @param resize resize event
  94      */
  95     public void onResize(final TResizeEvent resize) {
  96         if (resize.getType() == TResizeEvent.Type.WIDGET) {
  97             width = resize.getWidth();
  98             height = resize.getHeight();
  99             layoutChildren();
 100         }
 101     }
 102
 103     /**
 104      * Add a child widget to manage.
 105      *
 106      * @param child the widget to manage
 107      */
 108     public void add(final TWidget child) {
 109         children.add(child);
 110         layoutChildren();
 111     }
 112
 113     /**
 114      * Remove a child widget from those managed by this LayoutManager.
 115      *
 116      * @param child the widget to remove
 117      */
 118     public void remove(final TWidget child) {
 119         children.remove(child);
 120         layoutChildren();
 121     }
 122
 123     /**
 124      * Reset a child widget's original/preferred size.
 125      *
 126      * @param child the widget to manage
 127      */
 128     public void resetSize(final TWidget child) {
 129         // NOP
 130     }
 131
 132     // ------------------------------------------------------------------------
 133     // BoxLayoutManager -------------------------------------------------------
 134     // ------------------------------------------------------------------------
 135
 136     /**
 137      * Resize/reposition child widgets based on horizontal/vertical
 138      * arrangement.
 139      */
 140     private void layoutChildren() {
 141         if (children.size() == 0) {
 142             return;
 143         }
 144         if (vertical) {
 145             int widgetHeight = Math.max(1, height / children.size());
 146             int leftoverHeight = height % children.size();
 147             for (int i = 0; i < children.size() - 1; i++) {
 148                 TWidget child = children.get(i);
 149                 child.setDimensions(child.getX(), i * widgetHeight,
 150                     width, widgetHeight);
 151             }
 152             TWidget child = children.get(children.size() - 1);
 153             child.setDimensions(child.getX(),
 154                 (children.size() - 1) * widgetHeight, width,
 155                 widgetHeight + leftoverHeight);
 156         } else {
 157             int widgetWidth = Math.max(1, width / children.size());
 158             int leftoverWidth = width % children.size();
 159             for (int i = 0; i < children.size() - 1; i++) {
 160                 TWidget child = children.get(i);
 161                 child.setDimensions(i * widgetWidth, child.getY(),
 162                     widgetWidth, height);
 163             }
 164             TWidget child = children.get(children.size() - 1);
 165             child.setDimensions((children.size() - 1) * widgetWidth,
 166                 child.getY(), widgetWidth + leftoverWidth, height);
 167         }
 168     }
 169
 170 }