Java tutorial
/* * This file is part of LanternServer, licensed under the MIT License (MIT). * * Copyright (c) LanternPowered <https://www.lanternpowered.org> * Copyright (c) SpongePowered <https://www.spongepowered.org> * Copyright (c) contributors * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the Software), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package org.lanternpowered.server.service.pagination; import static com.google.common.base.Preconditions.checkNotNull; import static org.spongepowered.api.command.CommandMessageFormatting.error; import com.google.common.collect.ImmutableList; import com.google.common.collect.Maps; import org.spongepowered.api.command.CommandException; import org.spongepowered.api.command.source.ProxySource; import org.spongepowered.api.service.pagination.PaginationList; import org.spongepowered.api.text.Text; import org.spongepowered.api.text.channel.MessageReceiver; import java.util.List; import java.util.Map; import java.util.Optional; import java.util.stream.Collectors; import java.util.stream.StreamSupport; public class LanternPaginationList implements PaginationList { private final LanternPaginationService service; private Iterable<Text> contents; private Optional<Text> title; private Optional<Text> header; private Optional<Text> footer; private Text paginationSpacer; private int linesPerPage; public LanternPaginationList(LanternPaginationService service, Iterable<Text> contents, Text title, Text header, Text footer, Text paginationSpacer, int linesPerPage) { this.service = service; this.contents = contents; this.title = Optional.ofNullable(title); this.header = Optional.ofNullable(header); this.footer = Optional.ofNullable(footer); this.paginationSpacer = paginationSpacer; this.linesPerPage = linesPerPage; } @Override public Iterable<Text> getContents() { return this.contents; } @Override public Optional<Text> getTitle() { return this.title; } @Override public Optional<Text> getHeader() { return this.header; } @Override public Optional<Text> getFooter() { return this.footer; } @Override public Text getPadding() { return this.paginationSpacer; } @Override public int getLinesPerPage() { return this.linesPerPage; } @SuppressWarnings("rawtypes") @Override public void sendTo(final MessageReceiver receiver) { checkNotNull(this.contents, "contents"); checkNotNull(receiver, "source"); this.service.registerCommandOnce(); MessageReceiver realSource = receiver; while (realSource instanceof ProxySource) { realSource = ((ProxySource) realSource).getOriginalSource(); } @SuppressWarnings("unchecked") PaginationCalculator calculator = new PaginationCalculator(this.linesPerPage); Iterable<Map.Entry<Text, Integer>> counts = StreamSupport.stream(this.contents.spliterator(), false) .map(input -> { int lines = calculator.getLines(receiver, input); return Maps.immutableEntry(input, lines); }).collect(Collectors.toList()); Text title = this.title.orElse(null); if (title != null) { title = calculator.center(receiver, title, this.paginationSpacer); } ActivePagination pagination; if (this.contents instanceof List) { // If it started out as a list, it's probably reasonable to copy it to another list pagination = new ListPagination(receiver, calculator, ImmutableList.copyOf(counts), title, this.header.orElse(null), this.footer.orElse(null), this.paginationSpacer); } else { pagination = new IterablePagination(receiver, calculator, counts, title, this.header.orElse(null), this.footer.orElse(null), this.paginationSpacer); } this.service.getPaginationState(receiver, true).put(pagination); try { pagination.nextPage(); } catch (CommandException e) { receiver.sendMessage(error(e.getText())); } } }