(#1704) Implement a Multiline Text

src/main/java/org/cactoos/text/Multiline.java

@@ -0,0 +1,139 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2022 Yegor Bugayenko
+ *
+ * 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 NON-INFRINGEMENT. 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.cactoos.text;
+
+import org.cactoos.Text;
+import org.cactoos.iterable.IterableEnvelope;
+import org.cactoos.iterable.IterableOf;
+import org.cactoos.iterable.Mapped;
+import org.cactoos.iterator.IteratorOf;
+
+/**
+ * Break a Text according a limit.
+ *
+ * <p>There is no thread-safety guarantee.
+ *
+ * @since 0.56.0
+ */
+public final class Multiline extends IterableEnvelope<Text> {
+    /**
+     * New line character.
+     */
+    private static final String NEW_LINE = "\n";
+
+    /**
+     * Word separator.
+     */
+    private static final String SPACE = " ";
+
+    /**
+     * Split regular expression.
+     */
+    private static final String SPLIT_REGEX = "\\s+";
+
+    /**
+     * Default max limit.
+     */
+    private static final int MAX_LIMIT = 80;
+
+    /**
+     * Ctor.
+     *
+     * <p> By default, the limit is 80 characters.
+     *
+     * @param text A CharSequence
+     */
+    public Multiline(final CharSequence text) {
+        this(new TextOf(text));
+    }
+
+    /**
+     * Ctor.
+     *
+     * <p> By default, the limit is 80 characters.
+     *
+     * @param text The Text
+     */
+    public Multiline(final Text text) {
+        this(text, Multiline.MAX_LIMIT);
+    }
+
+    /**
+     * Ctor.
+     *
+     * @param text A CharSequence
+     * @param limit Limit of the result string
+     */
+    public Multiline(final CharSequence text, final int limit) {
+        this(new TextOf(text), limit);
+    }
+
+    /**
+     * Ctor.
+     *
+     * @param text The Text
+     * @param limit Limit of the result string
+     */
+    public Multiline(final Text text, final int limit) {
+        super(
+            new Mapped<>(
+                TextOf::new,
+                new IterableOf<>(
+                    () -> {
+                        final String[] words = text.asString().split(
+                            Multiline.SPLIT_REGEX
+                        );
+                        final StringBuilder lines = new StringBuilder();
+                        final StringBuilder word = new StringBuilder(0);
+                        int length = 0;
+                        for (int idx = 0; idx < words.length; ++idx) {
+                            word.setLength(0);
+                            word.append(words[idx]);
+                            final int size = Multiline.SPACE.length()
+                                + word.length();
+                            if (length + size > limit) {
+                                if (idx > 0) {
+                                    lines.append(Multiline.NEW_LINE);
+                                }
+                                length = 0;
+                            }
+                            if (
+                                idx < words.length - 1
+                                    && length + size + words[idx + 1].length()
+                                        <= limit
+                            ) {
+                                word.append(Multiline.SPACE);
+                            }
+                            lines.append(word);
+                            length = length + word.length();
+                        }
+                        return new IteratorOf<>(
+                            lines.toString().split(Multiline.NEW_LINE)
+                        );
+                    }
+                )
+            )
+        );
+    }
+}

src/test/java/org/cactoos/text/MultilineTest.java

@@ -0,0 +1,113 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017-2022 Yegor Bugayenko
+ *
+ * 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 NON-INFRINGEMENT. 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.cactoos.text;
+
+import org.cactoos.Text;
+import org.cactoos.iterable.IterableOf;
+import org.hamcrest.core.IsEqual;
+import org.junit.jupiter.api.Test;
+import org.llorllale.cactoos.matchers.Assertion;
+
+/**
+ * Test case for {@link Multiline}.
+ * @since 0.56.0
+ * @checkstyle JavadocMethodCheck (500 lines)
+ */
+final class MultilineTest {
+    @Test
+    void multilineAnEmptyText() {
+        final String content = "";
+        new Assertion<>(
+            "Must multiline an empty text",
+            new Multiline(content, 8),
+            new IsEqual<>(new IterableOf<>(new TextOf(content)))
+        ).affirm();
+    }
+
+    @Test
+    void multilineText() {
+        final Text content = new Joined(
+            " ",
+            "Lorem ea et aliquip culpa aute amet elit nostrud culpa veniam",
+            "dolore eu irure incididunt. Velit officia occaecat est",
+            "adipisicing mollit veniam. Minim sunt est culpa labore."
+        );
+        new Assertion<>(
+            "Must multiline a text at limit 50 characters",
+            new Multiline(content, 50),
+            new IsEqual<>(
+                new IterableOf<>(
+                    new TextOf("Lorem ea et aliquip culpa aute amet elit nostrud"),
+                    new TextOf("culpa veniam dolore eu irure incididunt. Velit"),
+                    new TextOf("officia occaecat est adipisicing mollit veniam."),
+                    new TextOf("Minim sunt est culpa labore.")
+                )
+            )
+        ).affirm();
+    }
+
+    @Test
+    void multilineTextOneCharSmaller() {
+        final String msg = "Hello World!";
+        new Assertion<>(
+            "Must multiline a text with same length",
+            new Multiline(msg, 5),
+            new IsEqual<>(new IterableOf<>(new TextOf("Hello"), new TextOf("World!")))
+        ).affirm();
+    }
+
+    @Test
+    void multilineTextWithLimitBiggerThanLength() {
+        final String msg = "cactoos framework";
+        new Assertion<>(
+            "Must multiline a text with limit bigger than length",
+            new Multiline(msg, 50),
+            new IsEqual<>(new IterableOf<>(new TextOf("cactoos framework")))
+        ).affirm();
+    }
+
+    @Test
+    void multilineTextBiggerThanDefaultLimit() {
+        new Assertion<>(
+            "Must abbreviate a text bigger than default max width",
+            new Multiline(
+                new Joined(
+                    " ",
+                    "The quick brown fox jumps over the lazy black dog",
+                    "and after that returned to the cave"
+                )
+            ),
+            new IsEqual<>(
+                new IterableOf<>(
+                    new Joined(
+                        " ",
+                        "The quick brown fox jumps over the lazy",
+                        "black dog and after that returned to "
+                    ),
+                    new TextOf("the cave")
+                )
+            )
+        ).affirm();
+    }
+}