StylingHelper.java

  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.graphics.Color;
 33import android.graphics.Typeface;
 34import android.support.annotation.ColorInt;
 35import android.text.Editable;
 36import android.text.ParcelableSpan;
 37import android.text.Spanned;
 38import android.text.TextWatcher;
 39import android.text.style.ForegroundColorSpan;
 40import android.text.style.StrikethroughSpan;
 41import android.text.style.StyleSpan;
 42import android.text.style.TypefaceSpan;
 43import android.widget.EditText;
 44
 45import java.util.Arrays;
 46import java.util.List;
 47
 48public class StylingHelper {
 49
 50	private static List<? extends Class<? extends ParcelableSpan>> SPAN_CLASSES = Arrays.asList(
 51			StyleSpan.class,
 52			StrikethroughSpan.class,
 53			TypefaceSpan.class,
 54			ForegroundColorSpan.class
 55	);
 56
 57	public static void clear(final Editable editable) {
 58		final int end = editable.length() - 1;
 59		for(Class<?extends ParcelableSpan> clazz : SPAN_CLASSES) {
 60			for (ParcelableSpan span : editable.getSpans(0, end, clazz)) {
 61				editable.removeSpan(span);
 62			}
 63		}
 64	}
 65
 66	public static void format(final Editable editable, @ColorInt int color) {
 67		final int syntaxColor = Color.argb(
 68				Math.round(Color.alpha(color) * 0.6f),
 69				Color.red(color),
 70				Color.green(color),
 71				Color.blue(color)
 72		);
 73		for(ImStyleParser.Style style : ImStyleParser.parse(editable)) {
 74			editable.setSpan(createSpanForStyle(style), style.getStart() + 1, style.getEnd(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
 75			editable.setSpan(new ForegroundColorSpan(syntaxColor),style.getStart(),style.getStart()+1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
 76			editable.setSpan(new ForegroundColorSpan(syntaxColor),style.getEnd(),style.getEnd()+1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
 77		}
 78	}
 79
 80	private static ParcelableSpan createSpanForStyle(ImStyleParser.Style style) {
 81		switch (style.getCharacter()) {
 82			case '*':
 83				return new StyleSpan(Typeface.BOLD);
 84			case '_':
 85				return new StyleSpan(Typeface.ITALIC);
 86			case '~':
 87				return new StrikethroughSpan();
 88			case '`':
 89				return new TypefaceSpan("monospace");
 90			default:
 91				throw new AssertionError("Unknown Style");
 92		}
 93	}
 94
 95	public static class MessageEditorStyler implements TextWatcher {
 96
 97		private final EditText mEditText;
 98
 99		public MessageEditorStyler(EditText editText) {
100			this.mEditText = editText;
101		}
102
103		@Override
104		public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
105
106		}
107
108		@Override
109		public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
110
111		}
112
113		@Override
114		public void afterTextChanged(Editable editable) {
115			clear(editable);
116			format(editable,mEditText.getCurrentTextColor());
117		}
118	}
119}