1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.imaging.palette; 18 19 import org.apache.commons.imaging.ImageWriteException; 20 21 /** 22 * Color palette. 23 */ 24 public interface Palette { 25 26 // TODO: shouldn't it be an ImageReadException for getPaletteIndex? 27 /** 28 * Looks up the palette index for a given color. 29 * @param rgb the color to look up 30 * @return the palette index 31 * @throws ImageWriteException if it fails to read the palette index 32 */ 33 int getPaletteIndex(int rgb) throws ImageWriteException; 34 35 /** 36 * Looks up the color for a given palette index. 37 * @param index the palette index to look up 38 * @return the color in ARGB format 39 */ 40 int getEntry(int index); 41 42 /** 43 * The number of entries in the palette. 44 * @return the number of palette entries 45 */ 46 int length(); 47 48 }