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));
84 * Convert to Tk colour code format
89 * ://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/colortool.html#
92 public static final String toTkCode(Color colour)
94 String colstring = "#" + ((colour.getRed() < 16) ? "0" : "")
95 + Integer.toHexString(colour.getRed())
96 + ((colour.getGreen() < 16) ? "0" : "")
97 + Integer.toHexString(colour.getGreen())
98 + ((colour.getBlue() < 16) ? "0" : "")
99 + Integer.toHexString(colour.getBlue());
104 * Returns a colour three shades darker. Note you can't guarantee that
105 * brighterThan reverses this, as darkerThan may result in black.
110 public static Color darkerThan(Color col)
112 return col == null ? null : col.darker().darker().darker();
116 * Returns a colour three shades brighter. Note you can't guarantee that
117 * darkerThan reverses this, as brighterThan may result in white.
122 public static Color brighterThan(Color col)
124 return col == null ? null : col.brighter().brighter().brighter();
128 * Returns a color between minColour and maxColour; the RGB values are in
129 * proportion to where 'value' lies between minValue and maxValue
138 public static Color getGraduatedColour(float value, float minValue,
139 Color minColour, float maxValue, Color maxColour)
141 if (minValue == maxValue)
145 if (value < minValue)
149 if (value > maxValue)
155 * prop = proportion of the way value is from minValue to maxValue
157 float prop = (value - minValue) / (maxValue - minValue);
158 float r = minColour.getRed()
159 + prop * (maxColour.getRed() - minColour.getRed());
160 float g = minColour.getGreen()
161 + prop * (maxColour.getGreen() - minColour.getGreen());
162 float b = minColour.getBlue()
163 + prop * (maxColour.getBlue() - minColour.getBlue());
164 return new Color(r / 255, g / 255, b / 255);
168 * 'Fades' the given colour towards white by the specified proportion. A
169 * factor of 1 or more results in White, a factor of 0 leaves the colour
170 * unchanged, and a factor between 0 and 1 results in a proportionate change
171 * of RGB values towards (255, 255, 255).
173 * A negative bleachFactor can be specified to darken the colour towards Black
177 * @param bleachFactor
180 public static Color bleachColour(Color colour, float bleachFactor)
182 if (bleachFactor >= 1f)
186 if (bleachFactor <= -1f)
190 if (bleachFactor == 0f)
195 int red = colour.getRed();
196 int green = colour.getGreen();
197 int blue = colour.getBlue();
199 if (bleachFactor > 0)
201 red += (255 - red) * bleachFactor;
202 green += (255 - green) * bleachFactor;
203 blue += (255 - blue) * bleachFactor;
204 return new Color(red, green, blue);
208 float factor = 1 + bleachFactor;
212 return new Color(red, green, blue);
217 * Parses a string into a Color, where the accepted formats are
219 * <li>an AWT colour name e.g. white</li>
220 * <li>a hex colour value (without prefix) e.g. ff0000</li>
221 * <li>an rgb triple e.g. 100,50,150</li>
225 * @return the parsed colour, or null if parsing fails
227 public static Color parseColourString(String colour)
233 colour = colour.trim();
238 int value = Integer.parseInt(colour, 16);
239 col = new Color(value);
240 } catch (NumberFormatException ex)
246 col = ColorUtils.getAWTColorFromName(colour);
253 String[] tokens = colour.split(",");
254 if (tokens.length == 3)
256 int r = Integer.parseInt(tokens[0].trim());
257 int g = Integer.parseInt(tokens[1].trim());
258 int b = Integer.parseInt(tokens[2].trim());
259 col = new Color(r, g, b);
261 } catch (Exception ex)
263 // non-numeric token or out of 0-255 range
271 * Constructs a colour from a text string. The hashcode of the whole string is
272 * scaled to the range 0-135. This is added to RGB values made from the
273 * hashcode of each third of the string, and scaled to the range 20-229.
278 public static Color createColourFromName(String name)
284 if (myColours.containsKey(name))
286 return myColours.get(name);
288 int lsize = name.length();
292 int rgbOffset = Math.abs(name.hashCode() % 10) * 15; // 0-135
297 int r = Math.abs(name.substring(start, end).hashCode() + rgbOffset)
307 * green: second third
309 int g = Math.abs(name.substring(start, end).hashCode() + rgbOffset)
315 int b = Math.abs(name.substring(end).hashCode() + rgbOffset) % 210 + 20;
317 Color color = new Color(r, g, b);
319 if (myColours.size() < MAX_CACHE_SIZE)
321 myColours.put(name, color);
328 * Returns the Color constant for a given colour name e.g. "pink", or null if
329 * the name is not recognised
334 public static Color getAWTColorFromName(String name)
341 name = name.toLowerCase(Locale.ROOT);
343 // or make a static map; or use reflection on the field name
356 col = Color.darkGray;
365 col = Color.lightGray;