Truss.java

/*
 * Copyright 2014 Jake Wharton. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.ticketmaster.servos.util;

import android.text.SpannableStringBuilder;
import java.util.ArrayDeque;
import java.util.Deque;

import static android.text.Spanned.SPAN_INCLUSIVE_EXCLUSIVE;

/**
 * A {@link SpannableStringBuilder} wrapper whose API doesn't make me want to stab my eyes out.
 *
 * Extremely simple wrapper around SpannableStringBuilder to make the API more logical and less awful. Apache 2 licensed.
 *
 * https://gist.github.com/JakeWharton/11274467
 *
 * @author Jake Wharton
 */
public class Truss {
    private final SpannableStringBuilder builder;
    private final Deque<Span> stack;

    public Truss() {
        builder = new SpannableStringBuilder();
        stack = new ArrayDeque<Span>();
    }

    public Truss append(String string) {
        builder.append(string);
        return this;
    }

    public Truss append(CharSequence charSequence) {
        builder.append(charSequence);
        return this;
    }

    public Truss append(char c) {
        builder.append(c);
        return this;
    }

    public Truss append(int number) {
        builder.append(String.valueOf(number));
        return this;
    }

    /** Starts {@code span} at the current position in the builder. */
    public Truss pushSpan(Object span) {
        stack.addLast(new Span(builder.length(), span));
        return this;
    }

    /** End the most recently pushed span at the current position in the builder. */
    public Truss popSpan() {
        Span span = stack.removeLast();
        builder.setSpan(span.span, span.start, builder.length(), SPAN_INCLUSIVE_EXCLUSIVE);
        return this;
    }

    /** Create the final {@link CharSequence}, popping any remaining spans. */
    public CharSequence build() {
        while (!stack.isEmpty()) {
            popSpan();
        }
        return builder;
    }

    private static final class Span {
        final int start;
        final Object span;

        public Span(int start, Object span) {
            this.start = start;
            this.span = span;
        }
    }
}