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| 2 | import javax.swing.JSlider; |
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| 3 | /* |
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| 4 | The MIT License |
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| 5 | |
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| 6 | Copyright (c) 2010 Ernest Yu. All rights reserved. |
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| 7 | |
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| 8 | Permission is hereby granted, free of charge, to any person obtaining a copy |
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| 9 | of this software and associated documentation files (the "Software"), to deal |
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| 10 | in the Software without restriction, including without limitation the rights |
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| 11 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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| 12 | copies of the Software, and to permit persons to whom the Software is |
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| 13 | furnished to do so, subject to the following conditions: |
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| 14 | |
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| 15 | The above copyright notice and this permission notice shall be included in |
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| 16 | all copies or substantial portions of the Software. |
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| 17 | |
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| 18 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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| 19 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 20 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
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| 21 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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| 22 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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| 23 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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| 24 | THE SOFTWARE. |
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| 25 | */ |
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| 26 | |
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| 27 | /** |
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| 28 | * An extension of JSlider to select a range of values using two thumb controls. |
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| 29 | * The thumb controls are used to select the lower and upper value of a range |
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| 30 | * with predetermined minimum and maximum values. |
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| 31 | * |
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| 32 | * <p>Note that RangeSlider makes use of the default BoundedRangeModel, which |
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| 33 | * supports an inner range defined by a value and an extent. The upper value |
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| 34 | * returned by RangeSlider is simply the lower value plus the extent.</p> |
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| 35 | */ |
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| 36 | public class RangeSlider extends JSlider { |
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| 37 | |
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| 38 | /** |
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| 39 | * Constructs a RangeSlider with default minimum and maximum values of 0 |
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| 40 | * and 100. |
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| 41 | */ |
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| 42 | public RangeSlider() { |
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| 43 | initSlider(); |
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| 44 | } |
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| 45 | |
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| 46 | /** |
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| 47 | * Constructs a RangeSlider with the specified default minimum and maximum |
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| 48 | * values. |
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| 49 | */ |
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| 50 | public RangeSlider(int min, int max) { |
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| 51 | super(min, max); |
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| 52 | initSlider(); |
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| 53 | } |
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| 54 | |
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| 55 | /** |
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| 56 | * Initializes the slider by setting default properties. |
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| 57 | */ |
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| 58 | private void initSlider() { |
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| 59 | setOrientation(HORIZONTAL); |
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| 60 | } |
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| 61 | |
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| 62 | /** |
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| 63 | * Overrides the superclass method to install the UI delegate to draw two |
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| 64 | * thumbs. |
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| 65 | */ |
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| 66 | @Override |
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| 67 | public void updateUI() { |
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| 68 | setUI(new RangeSliderUI(this)); |
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| 69 | // Update UI for slider labels. This must be called after updating the |
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| 70 | // UI of the slider. Refer to JSlider.updateUI(). |
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| 71 | updateLabelUIs(); |
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| 72 | } |
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| 73 | |
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| 74 | /** |
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| 75 | * Returns the lower value in the range. |
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| 76 | */ |
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| 77 | @Override |
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| 78 | public int getValue() { |
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| 79 | return super.getValue(); |
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| 80 | } |
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| 81 | |
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| 82 | /** |
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| 83 | * Sets the lower value in the range. |
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| 84 | */ |
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| 85 | @Override |
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| 86 | public void setValue(int value) { |
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| 87 | int oldValue = getValue(); |
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| 88 | if (oldValue == value) { |
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| 89 | return; |
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| 90 | } |
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| 91 | |
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| 92 | // Compute new value and extent to maintain upper value. |
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| 93 | int oldExtent = getExtent(); |
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| 94 | int newValue = Math.min(Math.max(getMinimum(), value), oldValue + oldExtent); |
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| 95 | int newExtent = oldExtent + oldValue - newValue; |
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| 96 | |
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| 97 | // Set new value and extent, and fire a single change event. |
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| 98 | getModel().setRangeProperties(newValue, newExtent, getMinimum(), |
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| 99 | getMaximum(), getValueIsAdjusting()); |
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| 100 | } |
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| 101 | |
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| 102 | /** |
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| 103 | * Returns the upper value in the range. |
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| 104 | */ |
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| 105 | public int getUpperValue() { |
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| 106 | return getValue() + getExtent(); |
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| 107 | } |
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| 108 | |
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| 109 | /** |
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| 110 | * Sets the upper value in the range. |
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| 111 | */ |
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| 112 | public void setUpperValue(int value) { |
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| 113 | // Compute new extent. |
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| 114 | int lowerValue = getValue(); |
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| 115 | int newExtent = Math.min(Math.max(0, value - lowerValue), getMaximum() - lowerValue); |
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| 116 | |
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| 117 | // Set extent to set upper value. |
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| 118 | setExtent(newExtent); |
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| 119 | } |
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| 120 | } |
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