| 1 | /* |
| 2 | * Jexer - Java Text User Interface |
| 3 | * |
| 4 | * The MIT License (MIT) |
| 5 | * |
| 6 | * Copyright (C) 2016 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.bits.CellAttributes; |
| 32 | import jexer.bits.GraphicsChars; |
| 33 | import jexer.event.TMouseEvent; |
| 34 | |
| 35 | /** |
| 36 | * THScroller implements a simple horizontal scroll bar. |
| 37 | */ |
| 38 | public final class THScroller extends TWidget { |
| 39 | |
| 40 | /** |
| 41 | * Value that corresponds to being on the left edge of the scroll bar. |
| 42 | */ |
| 43 | private int leftValue = 0; |
| 44 | |
| 45 | /** |
| 46 | * Get the value that corresponds to being on the left edge of the scroll |
| 47 | * bar. |
| 48 | * |
| 49 | * @return the scroll value |
| 50 | */ |
| 51 | public int getLeftValue() { |
| 52 | return leftValue; |
| 53 | } |
| 54 | |
| 55 | /** |
| 56 | * Set the value that corresponds to being on the left edge of the |
| 57 | * scroll bar. |
| 58 | * |
| 59 | * @param leftValue the new scroll value |
| 60 | */ |
| 61 | public void setLeftValue(final int leftValue) { |
| 62 | this.leftValue = leftValue; |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Value that corresponds to being on the right edge of the scroll bar. |
| 67 | */ |
| 68 | private int rightValue = 100; |
| 69 | |
| 70 | /** |
| 71 | * Get the value that corresponds to being on the right edge of the |
| 72 | * scroll bar. |
| 73 | * |
| 74 | * @return the scroll value |
| 75 | */ |
| 76 | public int getRightValue() { |
| 77 | return rightValue; |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * Set the value that corresponds to being on the right edge of the |
| 82 | * scroll bar. |
| 83 | * |
| 84 | * @param rightValue the new scroll value |
| 85 | */ |
| 86 | public void setRightValue(final int rightValue) { |
| 87 | this.rightValue = rightValue; |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Current value of the scroll. |
| 92 | */ |
| 93 | private int value = 0; |
| 94 | |
| 95 | /** |
| 96 | * Get current value of the scroll. |
| 97 | * |
| 98 | * @return the scroll value |
| 99 | */ |
| 100 | public int getValue() { |
| 101 | return value; |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * Set current value of the scroll. |
| 106 | * |
| 107 | * @param value the new scroll value |
| 108 | */ |
| 109 | public void setValue(final int value) { |
| 110 | this.value = value; |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * The increment for clicking on an arrow. |
| 115 | */ |
| 116 | private int smallChange = 1; |
| 117 | |
| 118 | /** |
| 119 | * Set the increment for clicking on an arrow. |
| 120 | * |
| 121 | * @param smallChange the new increment value |
| 122 | */ |
| 123 | public void setSmallChange(final int smallChange) { |
| 124 | this.smallChange = smallChange; |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * The increment for clicking in the bar between the box and an arrow. |
| 129 | */ |
| 130 | private int bigChange = 20; |
| 131 | |
| 132 | /** |
| 133 | * Set the increment for clicking in the bar between the box and an |
| 134 | * arrow. |
| 135 | * |
| 136 | * @param bigChange the new increment value |
| 137 | */ |
| 138 | public void setBigChange(final int bigChange) { |
| 139 | this.bigChange = bigChange; |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * When true, the user is dragging the scroll box. |
| 144 | */ |
| 145 | private boolean inScroll = false; |
| 146 | |
| 147 | /** |
| 148 | * Public constructor. |
| 149 | * |
| 150 | * @param parent parent widget |
| 151 | * @param x column relative to parent |
| 152 | * @param y row relative to parent |
| 153 | * @param width height of scroll bar |
| 154 | */ |
| 155 | public THScroller(final TWidget parent, final int x, final int y, |
| 156 | final int width) { |
| 157 | |
| 158 | // Set parent and window |
| 159 | super(parent, x, y, width, 1); |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * Compute the position of the scroll box (a.k.a. grip, thumb). |
| 164 | * |
| 165 | * @return Y position of the box, between 1 and width - 2 |
| 166 | */ |
| 167 | private int boxPosition() { |
| 168 | return (getWidth() - 3) * (value - leftValue) / (rightValue - leftValue) + 1; |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * Draw a horizontal scroll bar. |
| 173 | */ |
| 174 | @Override |
| 175 | public void draw() { |
| 176 | CellAttributes arrowColor = getTheme().getColor("tscroller.arrows"); |
| 177 | CellAttributes barColor = getTheme().getColor("tscroller.bar"); |
| 178 | getScreen().putCharXY(0, 0, GraphicsChars.CP437[0x11], arrowColor); |
| 179 | getScreen().putCharXY(getWidth() - 1, 0, GraphicsChars.CP437[0x10], |
| 180 | arrowColor); |
| 181 | |
| 182 | // Place the box |
| 183 | if (rightValue > leftValue) { |
| 184 | getScreen().hLineXY(1, 0, getWidth() - 2, GraphicsChars.CP437[0xB1], |
| 185 | barColor); |
| 186 | getScreen().putCharXY(boxPosition(), 0, GraphicsChars.BOX, |
| 187 | arrowColor); |
| 188 | } else { |
| 189 | getScreen().hLineXY(1, 0, getWidth() - 2, GraphicsChars.HATCH, |
| 190 | barColor); |
| 191 | } |
| 192 | |
| 193 | } |
| 194 | |
| 195 | /** |
| 196 | * Perform a small step change left. |
| 197 | */ |
| 198 | public void decrement() { |
| 199 | if (leftValue == rightValue) { |
| 200 | return; |
| 201 | } |
| 202 | value -= smallChange; |
| 203 | if (value < leftValue) { |
| 204 | value = leftValue; |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Perform a small step change right. |
| 210 | */ |
| 211 | public void increment() { |
| 212 | if (leftValue == rightValue) { |
| 213 | return; |
| 214 | } |
| 215 | value += smallChange; |
| 216 | if (value > rightValue) { |
| 217 | value = rightValue; |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | /** |
| 222 | * Handle mouse button releases. |
| 223 | * |
| 224 | * @param mouse mouse button release event |
| 225 | */ |
| 226 | @Override |
| 227 | public void onMouseUp(final TMouseEvent mouse) { |
| 228 | |
| 229 | if (inScroll) { |
| 230 | inScroll = false; |
| 231 | return; |
| 232 | } |
| 233 | |
| 234 | if (rightValue == leftValue) { |
| 235 | return; |
| 236 | } |
| 237 | |
| 238 | if ((mouse.getX() == 0) |
| 239 | && (mouse.getY() == 0) |
| 240 | ) { |
| 241 | // Clicked on the left arrow |
| 242 | decrement(); |
| 243 | return; |
| 244 | } |
| 245 | |
| 246 | if ((mouse.getY() == 0) |
| 247 | && (mouse.getX() == getWidth() - 1) |
| 248 | ) { |
| 249 | // Clicked on the right arrow |
| 250 | increment(); |
| 251 | return; |
| 252 | } |
| 253 | |
| 254 | if ((mouse.getY() == 0) |
| 255 | && (mouse.getX() > 0) |
| 256 | && (mouse.getX() < boxPosition()) |
| 257 | ) { |
| 258 | // Clicked between the left arrow and the box |
| 259 | value -= bigChange; |
| 260 | if (value < leftValue) { |
| 261 | value = leftValue; |
| 262 | } |
| 263 | return; |
| 264 | } |
| 265 | |
| 266 | if ((mouse.getY() == 0) |
| 267 | && (mouse.getX() > boxPosition()) |
| 268 | && (mouse.getX() < getWidth() - 1) |
| 269 | ) { |
| 270 | // Clicked between the box and the right arrow |
| 271 | value += bigChange; |
| 272 | if (value > rightValue) { |
| 273 | value = rightValue; |
| 274 | } |
| 275 | return; |
| 276 | } |
| 277 | } |
| 278 | |
| 279 | /** |
| 280 | * Handle mouse movement events. |
| 281 | * |
| 282 | * @param mouse mouse motion event |
| 283 | */ |
| 284 | @Override |
| 285 | public void onMouseMotion(final TMouseEvent mouse) { |
| 286 | |
| 287 | if (rightValue == leftValue) { |
| 288 | inScroll = false; |
| 289 | return; |
| 290 | } |
| 291 | |
| 292 | if ((mouse.isMouse1()) |
| 293 | && (inScroll) |
| 294 | && (mouse.getX() > 0) |
| 295 | && (mouse.getX() < getWidth() - 1) |
| 296 | ) { |
| 297 | // Recompute value based on new box position |
| 298 | value = (rightValue - leftValue) |
| 299 | * (mouse.getX()) / (getWidth() - 3) + leftValue; |
| 300 | return; |
| 301 | } |
| 302 | inScroll = false; |
| 303 | } |
| 304 | |
| 305 | /** |
| 306 | * Handle mouse button press events. |
| 307 | * |
| 308 | * @param mouse mouse button press event |
| 309 | */ |
| 310 | @Override |
| 311 | public void onMouseDown(final TMouseEvent mouse) { |
| 312 | if (rightValue == leftValue) { |
| 313 | inScroll = false; |
| 314 | return; |
| 315 | } |
| 316 | |
| 317 | if ((mouse.getY() == 0) |
| 318 | && (mouse.getX() == boxPosition()) |
| 319 | ) { |
| 320 | inScroll = true; |
| 321 | return; |
| 322 | } |
| 323 | |
| 324 | } |
| 325 | |
| 326 | } |