1/*
2 * Copyright (c) 2017, Daniel Gultsch All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without modification,
5 * are permitted provided that the following conditions are met:
6 *
7 * 1. Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation and/or
12 * other materials provided with the distribution.
13 *
14 * 3. Neither the name of the copyright holder nor the names of its contributors
15 * may be used to endorse or promote products derived from this software without
16 * specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
25 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30package eu.siacs.conversations.utils;
31
32import android.content.Context;
33import android.graphics.Color;
34import android.graphics.Typeface;
35import android.support.annotation.ColorInt;
36import android.support.v4.content.ContextCompat;
37import android.text.Editable;
38import android.text.ParcelableSpan;
39import android.text.SpannableString;
40import android.text.Spanned;
41import android.text.TextWatcher;
42import android.text.style.BackgroundColorSpan;
43import android.text.style.ForegroundColorSpan;
44import android.text.style.StrikethroughSpan;
45import android.text.style.StyleSpan;
46import android.text.style.TypefaceSpan;
47import android.widget.EditText;
48import android.widget.TextView;
49
50import java.util.Arrays;
51import java.util.List;
52
53import eu.siacs.conversations.R;
54import eu.siacs.conversations.entities.Message;
55import eu.siacs.conversations.ui.text.QuoteSpan;
56
57public class StylingHelper {
58
59 private static List<? extends Class<? extends ParcelableSpan>> SPAN_CLASSES = Arrays.asList(
60 StyleSpan.class,
61 StrikethroughSpan.class,
62 TypefaceSpan.class,
63 ForegroundColorSpan.class
64 );
65
66 public static void clear(final Editable editable) {
67 final int end = editable.length() - 1;
68 for (Class<? extends ParcelableSpan> clazz : SPAN_CLASSES) {
69 for (ParcelableSpan span : editable.getSpans(0, end, clazz)) {
70 editable.removeSpan(span);
71 }
72 }
73 }
74
75 public static void format(final Editable editable, int start, int end, @ColorInt int textColor) {
76 for (ImStyleParser.Style style : ImStyleParser.parse(editable, start, end)) {
77 final int keywordLength = style.getKeyword().length();
78 editable.setSpan(createSpanForStyle(style), style.getStart() + keywordLength, style.getEnd() - keywordLength + 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
79 makeKeywordOpaque(editable, style.getStart(), style.getStart() + keywordLength, textColor);
80 makeKeywordOpaque(editable, style.getEnd() - keywordLength + 1, style.getEnd() + 1, textColor);
81 }
82 }
83
84 public static void format(final Editable editable, @ColorInt int textColor) {
85 int end = 0;
86 Message.MergeSeparator[] spans = editable.getSpans(0, editable.length() - 1, Message.MergeSeparator.class);
87 for (Message.MergeSeparator span : spans) {
88 format(editable, end, editable.getSpanStart(span), textColor);
89 end = editable.getSpanEnd(span);
90 }
91 format(editable, end, editable.length() - 1, textColor);
92 }
93
94 public static void highlight(final Context context, final Editable editable, String needle, boolean dark) {
95 final int length = needle.length();
96 String string = editable.toString();
97 int start = indexOfIgnoreCase(string, needle, 0);
98 while (start != -1) {
99 int end = start + length;
100 editable.setSpan(new BackgroundColorSpan(ContextCompat.getColor(context, dark ? R.color.deep_purple_a100 : R.color.deep_purple_a200)), start, end, SpannableString.SPAN_EXCLUSIVE_EXCLUSIVE);
101 editable.setSpan(new ForegroundColorSpan(ContextCompat.getColor(context, dark ? R.color.black87 : R.color.white)), start, end, SpannableString.SPAN_EXCLUSIVE_EXCLUSIVE);
102 start = indexOfIgnoreCase(string, needle, start + length);
103 }
104
105 }
106
107 public static boolean isDarkText(TextView textView) {
108 int argb = textView.getCurrentTextColor();
109 return Color.red(argb) + Color.green(argb) + Color.blue(argb) == 0;
110 }
111
112 private static ParcelableSpan createSpanForStyle(ImStyleParser.Style style) {
113 switch (style.getKeyword()) {
114 case "*":
115 return new StyleSpan(Typeface.BOLD);
116 case "_":
117 return new StyleSpan(Typeface.ITALIC);
118 case "~":
119 return new StrikethroughSpan();
120 case "`":
121 case "```":
122 return new TypefaceSpan("monospace");
123 default:
124 throw new AssertionError("Unknown Style");
125 }
126 }
127
128 private static void makeKeywordOpaque(final Editable editable, int start, int end, @ColorInt int fallbackTextColor) {
129 QuoteSpan[] quoteSpans = editable.getSpans(start, end, QuoteSpan.class);
130 @ColorInt int textColor = quoteSpans.length > 0 ? quoteSpans[0].getColor() : fallbackTextColor;
131 @ColorInt int keywordColor = transformColor(textColor);
132 editable.setSpan(new ForegroundColorSpan(keywordColor), start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
133 }
134
135 private static
136 @ColorInt
137 int transformColor(@ColorInt int c) {
138 return Color.argb(Math.round(Color.alpha(c) * 0.6f), Color.red(c), Color.green(c), Color.blue(c));
139 }
140
141 private static int indexOfIgnoreCase(final String haystack, final String needle, final int start) {
142 if (haystack == null || needle == null) {
143 return -1;
144 }
145 final int endLimit = haystack.length() - needle.length() + 1;
146 if (start > endLimit) {
147 return -1;
148 }
149 if (needle.length() == 0) {
150 return start;
151 }
152 for (int i = start; i < endLimit; i++) {
153 if (haystack.regionMatches(true, i, needle, 0, needle.length())) {
154 return i;
155 }
156 }
157 return -1;
158 }
159
160 public static class MessageEditorStyler implements TextWatcher {
161
162 private final EditText mEditText;
163
164 public MessageEditorStyler(EditText editText) {
165 this.mEditText = editText;
166 }
167
168 @Override
169 public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
170
171 }
172
173 @Override
174 public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
175
176 }
177
178 @Override
179 public void afterTextChanged(Editable editable) {
180 clear(editable);
181 format(editable, mEditText.getCurrentTextColor());
182 }
183 }
184}