Summary

Provide API to access Unicode Emoji properties for each character.

Problem

Emoji has become an integral part of text processing. The Unicode Consortium releases Unicode Emoji Technical Standard (UTS #51), but there is no way to retrieve those Emoji related information with the JDK libraries. It would be desirable to provide API to access those Emoji properties.

Solution

UTS #51 defines 6 Emoji related properties as follows:

• Emoji
• Emoji Presentation
• Emoji Modifier
• Emoji Modifier Base
• Emoji Component
• Extended Pictograph

Providing public methods in java.lang.Character class would allow applications to programmatically access those properties.

Specification

Provide the following 6 new methods in java.lang.Character class:

/**
 * Determines if the specified character (Unicode code point) is an Emoji.
 * <p>
 * A character is considered to be an Emoji if and only if it has the {@code Emoji}
 * property, defined in
 * <a href="https://unicode.org/reports/tr51/#Emoji_Properties_and_Data_Files">
 * Unicode Emoji (Technical Standard #51)</a>.
 *
 * @param   codePoint the character (Unicode code point) to be tested.
 * @return  {@code true} if the character is an Emoji;
 *          {@code false} otherwise.
 * @since   21
 */
public static boolean isEmoji(int codePoint);

/**
 * Determines if the specified character (Unicode code point) has the
 * Emoji Presentation property by default.
 * <p>
 * A character is considered to have the Emoji Presentation property if and
 * only if it has the {@code Emoji_Presentation} property, defined in
 * <a href="https://unicode.org/reports/tr51/#Emoji_Properties_and_Data_Files">
 * Unicode Emoji (Technical Standard #51)</a>.
 *
 * @param   codePoint the character (Unicode code point) to be tested.
 * @return  {@code true} if the character has the Emoji Presentation
 *.               property; {@code false} otherwise.
 * @since   21
 */
public static boolean isEmojiPresentation(int codePoint);

/**
 * Determines if the specified character (Unicode code point) is an
 * Emoji Modifier.
 * <p>
 * A character is considered to be an Emoji Modifier if and only if it has
 * the {@code Emoji_Modifier} property, defined in
 * <a href="https://unicode.org/reports/tr51/#Emoji_Properties_and_Data_Files">
 * Unicode Emoji (Technical Standard #51)</a>.
 *
 * @param   codePoint the character (Unicode code point) to be tested.
 * @return  {@code true} if the character is an Emoji Modifier;
 *          {@code false} otherwise.
 * @since   21
 */
public static boolean isEmojiModifier(int codePoint);

/**
 * Determines if the specified character (Unicode code point) is an
 * Emoji Modifier Base.
 * <p>
 * A character is considered to be an Emoji Modifier Base if and only if it has
 * the {@code Emoji_Modifier_Base} property, defined in
 * <a href="https://unicode.org/reports/tr51/#Emoji_Properties_and_Data_Files">
 * Unicode Emoji (Technical Standard #51)</a>.
 *
 * @param   codePoint the character (Unicode code point) to be tested.
 * @return  {@code true} if the character is an Emoji Modifier Base;
 *          {@code false} otherwise.
 * @since   21
 */
public static boolean isEmojiModifierBase(int codePoint);

/**
 * Determines if the specified character (Unicode code point) is an
 * Emoji Component.
 * <p>
 * A character is considered to be an Emoji Component if and only if it has
 * the {@code Emoji_Component} property, defined in
 * <a href="https://unicode.org/reports/tr51/#Emoji_Properties_and_Data_Files">
 * Unicode Emoji (Technical Standard #51)</a>.
 *
 * @param   codePoint the character (Unicode code point) to be tested.
 * @return  {@code true} if the character is an Emoji Component;
 *          {@code false} otherwise.
 * @since   21
 */
public static boolean isEmojiComponent(int codePoint);

/**
 * Determines if the specified character (Unicode code point) is
 * an Extended Pictographic.
 * <p>
 * A character is considered to be an Extended Pictographic if and only if it has
 * the {@code Extended_Pictographic} property, defined in
 * <a href="https://unicode.org/reports/tr51/#Emoji_Properties_and_Data_Files">
 * Unicode Emoji (Technical Standard #51)</a>.
 *
 * @param   codePoint the character (Unicode code point) to be tested.
 * @return  {@code true} if the character is an Extended Pictographic;
 *          {@code false} otherwise.
 * @since   21
 */
public static boolean isExtendedPictographic(int codePoint);