src/jexer/layout/StretchLayoutManager.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.awt.Rectangle;
  32 import java.util.HashMap;
  33
  34 import jexer.TWidget;
  35 import jexer.event.TResizeEvent;
  36
  37 /**
  38  * StretchLayoutManager repositions child widgets based on their coordinates
  39  * when added and the current widget size.
  40  */
  41 public class StretchLayoutManager implements LayoutManager {
  42
  43     // ------------------------------------------------------------------------
  44     // Variables --------------------------------------------------------------
  45     // ------------------------------------------------------------------------
  46
  47     /**
  48      * Current width.
  49      */
  50     private int width = 0;
  51
  52     /**
  53      * Current height.
  54      */
  55     private int height = 0;
  56
  57     /**
  58      * Original width.
  59      */
  60     private int originalWidth = 0;
  61
  62     /**
  63      * Original height.
  64      */
  65     private int originalHeight = 0;
  66
  67     /**
  68      * Map of widget to original dimensions.
  69      */
  70     private HashMap<TWidget, Rectangle> children = new HashMap<TWidget, Rectangle>();
  71
  72     // ------------------------------------------------------------------------
  73     // Constructors -----------------------------------------------------------
  74     // ------------------------------------------------------------------------
  75
  76     /**
  77      * Public constructor.
  78      *
  79      * @param width the width of the parent widget
  80      * @param height the height of the parent widget
  81      */
  82     public StretchLayoutManager(final int width, final int height) {
  83         originalWidth = width;
  84         originalHeight = height;
  85         this.width = width;
  86         this.height = height;
  87     }
  88
  89     // ------------------------------------------------------------------------
  90     // LayoutManager ----------------------------------------------------------
  91     // ------------------------------------------------------------------------
  92
  93     /**
  94      * Process the parent widget's resize event, and resize/reposition child
  95      * widgets.
  96      *
  97      * @param resize resize event
  98      */
  99     public void onResize(final TResizeEvent resize) {
 100         if (resize.getType() == TResizeEvent.Type.WIDGET) {
 101             width = resize.getWidth();
 102             height = resize.getHeight();
 103             layoutChildren();
 104         }
 105     }
 106
 107     /**
 108      * Add a child widget to manage.
 109      *
 110      * @param child the widget to manage
 111      */
 112     public void add(final TWidget child) {
 113         Rectangle rect = new Rectangle(child.getX(), child.getY(),
 114             child.getWidth(), child.getHeight());
 115         children.put(child, rect);
 116         layoutChildren();
 117     }
 118
 119     /**
 120      * Remove a child widget from those managed by this LayoutManager.
 121      *
 122      * @param child the widget to remove
 123      */
 124     public void remove(final TWidget child) {
 125         children.remove(child);
 126         layoutChildren();
 127     }
 128
 129     /**
 130      * Reset a child widget's original/preferred size.
 131      *
 132      * @param child the widget to manage
 133      */
 134     public void resetSize(final TWidget child) {
 135         // For this layout, adding is the same as replacing.
 136         add(child);
 137     }
 138
 139     // ------------------------------------------------------------------------
 140     // StretchLayoutManager ---------------------------------------------------
 141     // ------------------------------------------------------------------------
 142
 143     /**
 144      * Resize/reposition child widgets based on difference between current
 145      * dimensions and the original dimensions.
 146      */
 147     private void layoutChildren() {
 148         double widthRatio = (double) width / originalWidth;
 149         if (Math.abs(widthRatio) > Double.MAX_VALUE) {
 150             widthRatio = 1;
 151         }
 152         double heightRatio = (double) height / originalHeight;
 153         if (Math.abs(heightRatio) > Double.MAX_VALUE) {
 154             heightRatio = 1;
 155         }
 156         for (TWidget child: children.keySet()) {
 157             Rectangle rect = children.get(child);
 158             child.setDimensions((int) (rect.getX() * widthRatio),
 159                 (int) (rect.getY() * heightRatio),
 160                 (int) (rect.getWidth() * widthRatio),
 161                 (int) (rect.getHeight() * heightRatio));
 162         }
 163     }
 164
 165 }