Summary

Provide a public API that will inform the caller if some text represented by an array of type char will require complex script text rendering.

Problem

sun.font.FontUtilities.isComplexCharCode is internal API - now encapsulated by jigsaw and developers would like a standard public equivalent

Solution

Add a new method that performs the same function

Specification

   /**
     * Return true if any part of the specified text is from a
     * complex script for which the implementation will need to invoke
     * layout processing in order to render correctly when using
     * {@link Graphics#drawString(String,int,int) drawString(String,int,int)}
     * and other text rendering methods. Measurement of the text
     * may similarly need the same extra processing.
     * The {@code start} and {@code end} indices are provided so that
     * the application can request only a subset of the text be considered.
     * The last char index examined is at {@code "end-1"},
     * i.e a request to examine the entire array would be
     * <pre>
     * {@code Font.textRequiresLayout(chars, 0, chars.length);}
     * </pre>
     * An application may find this information helpful in
     * performance sensitive code.
     * <p>
     * Note that even if this method returns {@code false}, layout processing
     * may still be invoked when used with any {@code Font}
     * for which {@link #hasLayoutAttributes()} returns {@code true},
     * so that method will need to be consulted for the specific font,
     * in order to obtain an answer which accounts for such font attributes.
     *
     * @param chars the text.
     * @param start the index of the first char to examine.
     * @param end the ending index, exclusive.
     * @return {@code true} if the specified text will need special layout.
     * @throws NullPointerException if {@code chars} is null.
     * @throws ArrayIndexOutOfBoundsException if {@code start} is negative or
     * {@code end} is greater than the length of the {@code chars} array.
     * @since 9
     */
    public static boolean textRequiresLayout(char[] chars,
                                             int start, int end);