src/java.desktop/share/classes/sun/font/FontManager.java

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 * accompanied this code).
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package sun.font;

import java.awt.Font;
import java.awt.FontFormatException;
import java.io.File;

/**
 * Interface between Java Fonts (java.awt.Font) and the underlying
 * font files/native font resources and the Java and native font scalers.
 */
public interface FontManager {

    // These constants are used in findFont().
    public static final int NO_FALLBACK = 0;
    public static final int PHYSICAL_FALLBACK = 1;
    public static final int LOGICAL_FALLBACK = 2;

    /**
     * Register a new font. Please, note that {@code null} is not a valid
     * argument, and it's caller's responsibility to ensure that, but to keep
     * compatibility, if {@code null} is passed as an argument, {@code false}
     * is returned, and no {@link NullPointerException}
     * is thrown.
     *
     * As additional note, an implementation should ensure that this font
     * cannot override existing installed fonts.
     *
     * @param font
     * @return {@code true} is the font is successfully registered,
     * {@code false} otherwise.
     */
    public boolean registerFont(Font font);

    public void deRegisterBadFont(Font2D font2D);

    /**
     * The client supplies a name and a style.
     * The name could be a family name, or a full name.
     * A font may exist with the specified style, or it may
     * exist only in some other style. For non-native fonts the scaler
     * may be able to emulate the required style.
     */
    public Font2D findFont2D(String name, int style, int fallback);

    /**
     * Creates a Font2D for the specified font file, that is expected
     * to be in the specified font format (according to the constants
     * in java.awt.Font). The parameter {@code isCopy} is set to true
     * when the specified font file is actually a copy of the font data
     * and needs to be deleted afterwards. This method is called
     * for the Font.createFont() methods.
     *
     * @param fontFile the file holding the font data
     * @param fontFormat the expected font format
     * @param all whether to retrieve all fonts in the resource or
     *        just the first one.
     * @param isCopy {@code true} if the file is a copy and needs to be
     *        deleted, {@code false} otherwise
     *
     * @return the created Font2D instance
     */
    public Font2D[] createFont2D(File fontFile, int fontFormat, boolean all,
                                 boolean isCopy)
        throws FontFormatException;

    /**
     * Creates a derived composite font from the specified font (handle).
     *
     * @param family the font family of the derived font
     * @param style the font style of the derived font
     * @param handle the original font (handle)
     *
     * @return the handle for the derived font
     */
    public Font2DHandle getNewComposite(String family, int style,
                                        Font2DHandle handle);

    /**
     * Indicates a preference for locale-specific fonts in the mapping of
     * logical fonts to physical fonts. Calling this method indicates that font
     * rendering should primarily use fonts specific to the primary writing
     * system (the one indicated by the default encoding and the initial
     * default locale). For example, if the primary writing system is
     * Japanese, then characters should be rendered using a Japanese font
     * if possible, and other fonts should only be used for characters for
     * which the Japanese font doesn't have glyphs.
     * <p>
     * The actual change in font rendering behavior resulting from a call
     * to this method is implementation dependent; it may have no effect at
     * all, or the requested behavior may already match the default behavior.
     * The behavior may differ between font rendering in lightweight
     * and peered components.  Since calling this method requests a
     * different font, clients should expect different metrics, and may need
     * to recalculate window sizes and layout. Therefore this method should
     * be called before user interface initialisation.
     *
     * @see #preferProportionalFonts()
     * @since 1.5
     */
    public void preferLocaleFonts();

    /**
     * preferLocaleFonts() and preferProportionalFonts() are called to inform
     * that the application could be using an alternate set of composite
     * fonts, and so the implementation should try to create a CompositeFonts
     * with this directive in mind.
     *
     * @see #preferLocaleFonts()
     */
    public void preferProportionalFonts();

}