2 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
3 * Copyright (C) $$Year-Rel$$ The Jalview Authors
5 * This file is part of Jalview.
7 * Jalview is free software: you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation, either version 3
10 * of the License, or (at your option) any later version.
12 * Jalview is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR
15 * PURPOSE. See the GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with Jalview. If not, see <http://www.gnu.org/licenses/>.
19 * The Jalview Authors are detailed in the 'AUTHORS' file.
22 * author: Lauren Michelle Lui
27 import java.util.Locale;
29 import java.awt.Color;
30 import java.util.HashMap;
32 import java.util.Random;
34 public class ColorUtils
36 private static final int MAX_CACHE_SIZE = 1729;
39 * a cache for colours generated from text strings
41 static Map<String, Color> myColours = new HashMap<>();
44 * Generates a random color, will mix with input color. Code taken from
45 * http://stackoverflow
46 * .com/questions/43044/algorithm-to-randomly-generate-an-aesthetically
47 * -pleasing-color-palette
50 * @return Random color in RGB
52 public static final Color generateRandomColor(Color mix)
54 Random random = new Random();
55 int red = random.nextInt(256);
56 int green = random.nextInt(256);
57 int blue = random.nextInt(256);
62 red = (red + mix.getRed()) / 2;
63 green = (green + mix.getGreen()) / 2;
64 blue = (blue + mix.getBlue()) / 2;
67 Color color = new Color(red, green, blue);
74 * @return random color
76 public static final Color getARandomColor()
79 Color col = new Color((int) (Math.random() * 255),
80 (int) (Math.random() * 255), (int) (Math.random() * 255));
85 * Convert to Tk colour code format
90 * ://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/colortool.html#
93 public static final String toTkCode(Color colour)
95 String colstring = "#" + ((colour.getRed() < 16) ? "0" : "")
96 + Integer.toHexString(colour.getRed())
97 + ((colour.getGreen() < 16) ? "0" : "")
98 + Integer.toHexString(colour.getGreen())
99 + ((colour.getBlue() < 16) ? "0" : "")
100 + Integer.toHexString(colour.getBlue());
105 * Returns a colour three shades darker. Note you can't guarantee that
106 * brighterThan reverses this, as darkerThan may result in black.
111 public static Color darkerThan(Color col)
113 return col == null ? null : col.darker().darker().darker();
117 * Returns a colour three shades brighter. Note you can't guarantee that
118 * darkerThan reverses this, as brighterThan may result in white.
123 public static Color brighterThan(Color col)
125 return col == null ? null : col.brighter().brighter().brighter();
129 * Returns a color between minColour and maxColour; the RGB values are in
130 * proportion to where 'value' lies between minValue and maxValue
139 public static Color getGraduatedColour(float value, float minValue,
140 Color minColour, float maxValue, Color maxColour)
142 if (minValue == maxValue)
146 if (value < minValue)
150 if (value > maxValue)
156 * prop = proportion of the way value is from minValue to maxValue
158 float prop = (value - minValue) / (maxValue - minValue);
159 float r = minColour.getRed()
160 + prop * (maxColour.getRed() - minColour.getRed());
161 float g = minColour.getGreen()
162 + prop * (maxColour.getGreen() - minColour.getGreen());
163 float b = minColour.getBlue()
164 + prop * (maxColour.getBlue() - minColour.getBlue());
165 return new Color(r / 255, g / 255, b / 255);
169 * 'Fades' the given colour towards white by the specified proportion. A
170 * factor of 1 or more results in White, a factor of 0 leaves the colour
171 * unchanged, and a factor between 0 and 1 results in a proportionate change
172 * of RGB values towards (255, 255, 255).
174 * A negative bleachFactor can be specified to darken the colour towards Black
178 * @param bleachFactor
181 public static Color bleachColour(Color colour, float bleachFactor)
183 if (bleachFactor >= 1f)
187 if (bleachFactor <= -1f)
191 if (bleachFactor == 0f)
196 int red = colour.getRed();
197 int green = colour.getGreen();
198 int blue = colour.getBlue();
200 if (bleachFactor > 0)
202 red += (255 - red) * bleachFactor;
203 green += (255 - green) * bleachFactor;
204 blue += (255 - blue) * bleachFactor;
205 return new Color(red, green, blue);
209 float factor = 1 + bleachFactor;
213 return new Color(red, green, blue);
218 * Parses a string into a Color, where the accepted formats are
220 * <li>an AWT colour name e.g. white</li>
221 * <li>a hex colour value (without prefix) e.g. ff0000</li>
222 * <li>an rgb triple e.g. 100,50,150</li>
226 * @return the parsed colour, or null if parsing fails
228 public static Color parseColourString(String colour)
234 colour = colour.trim();
239 int value = Integer.parseInt(colour, 16);
240 col = new Color(value);
241 } catch (NumberFormatException ex)
247 col = ColorUtils.getAWTColorFromName(colour);
254 String[] tokens = colour.split(",");
255 if (tokens.length == 3)
257 int r = Integer.parseInt(tokens[0].trim());
258 int g = Integer.parseInt(tokens[1].trim());
259 int b = Integer.parseInt(tokens[2].trim());
260 col = new Color(r, g, b);
262 } catch (Exception ex)
264 // non-numeric token or out of 0-255 range
272 * Constructs a colour from a text string. The hashcode of the whole string is
273 * scaled to the range 0-135. This is added to RGB values made from the
274 * hashcode of each third of the string, and scaled to the range 20-229.
279 public static Color createColourFromName(String name)
285 if (myColours.containsKey(name))
287 return myColours.get(name);
289 int lsize = name.length();
293 int rgbOffset = Math.abs(name.hashCode() % 10) * 15; // 0-135
298 int r = Math.abs(name.substring(start, end).hashCode() + rgbOffset)
308 * green: second third
310 int g = Math.abs(name.substring(start, end).hashCode() + rgbOffset)
316 int b = Math.abs(name.substring(end).hashCode() + rgbOffset) % 210 + 20;
318 Color color = new Color(r, g, b);
320 if (myColours.size() < MAX_CACHE_SIZE)
322 myColours.put(name, color);
329 * Returns the Color constant for a given colour name e.g. "pink", or null if
330 * the name is not recognised
335 public static Color getAWTColorFromName(String name)
342 name = name.toLowerCase(Locale.ROOT);
344 // or make a static map; or use reflection on the field name
357 col = Color.darkGray;
366 col = Color.lightGray;