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Diffstat (limited to 'src/main/java/de/pixart/messenger/utils/ImStyleParser.java')
| -rw-r--r-- | src/main/java/de/pixart/messenger/utils/ImStyleParser.java | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/main/java/de/pixart/messenger/utils/ImStyleParser.java b/src/main/java/de/pixart/messenger/utils/ImStyleParser.java new file mode 100644 index 000000000..0046ba464 --- /dev/null +++ b/src/main/java/de/pixart/messenger/utils/ImStyleParser.java @@ -0,0 +1,107 @@ +/* + * Copyright (c) 2017, Daniel Gultsch All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation and/or + * other materials provided with the distribution. + * + * 3. Neither the name of the copyright holder nor the names of its contributors + * may be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +package de.pixart.messenger.utils; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; + +public class ImStyleParser { + final static List<Character> KEYWORDS = Arrays.asList('*', '_', '~', '`'); + final static List<Character> NO_SUB_PARSING_KEYWORDS = Arrays.asList('`'); + final static boolean ALLOW_EMPTY = false; + + public static List<Style> parse(CharSequence text) { + return parse(text, 0, text.length() - 1); + } + + public static List<Style> parse(CharSequence text, int start, int end) { + List<Style> styles = new ArrayList<>(); + for (int i = start; i <= end; ++i) { + char c = text.charAt(i); + if (KEYWORDS.contains(c) && precededByWhiteSpace(text, i, start) && !followedByWhitespace(text, i, end)) { + int to = seekEnd(text, c, i + 1, end); + if (to != -1 && (to != i + 1 || ALLOW_EMPTY)) { + styles.add(new Style(c, i, to)); + if (!NO_SUB_PARSING_KEYWORDS.contains(c)) { + styles.addAll(parse(text, i + 1, to - 1)); + } + i = to; + } + } + } + return styles; + } + + private static boolean precededByWhiteSpace(CharSequence text, int index, int start) { + return index == start || Character.isWhitespace(text.charAt(index - 1)); + } + + private static boolean followedByWhitespace(CharSequence text, int index, int end) { + return index >= end || Character.isWhitespace(text.charAt(index + 1)); + } + + private static int seekEnd(CharSequence text, char needle, int start, int end) { + for (int i = start; i <= end; ++i) { + char c = text.charAt(i); + if (c == needle) { + return i; + } else if (c == '\n') { + return -1; + } + } + return -1; + } + + public static class Style { + + private final char c; + private final int start; + private final int end; + + public Style(char c, int start, int end) { + this.c = c; + this.start = start; + this.end = end; + } + + public char getCharacter() { + return c; + } + + public int getStart() { + return start; + } + + public int getEnd() { + return end; + } + } +}
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