Package ej.microui.display

Class Font

  • public abstract class Font
extends Object
    A Font defines how characters are drawn on a GraphicsContext.

    A font has a set of identifiers. An identifier is an integer which specifies whether the font is able to render specific languages and alphabets. A value has been assigned to the built-in identifiers: see FontIdentifiers. Custom identifiers may be defined in order to identify or find a specific font. For example, a font which contains some special characters like arrows or emojis can be tagged by the font creator with a specific identifier.

    A font has a style, which is a combination of the following style constants: STYLE_PLAIN, STYLE_BOLD and SYTLE_ITALIC.

    A font has a descriptor, which is a string describing the font.

    Fonts can not be created by applications and are rather retrieved from the implementation environment. An application can get the list of all the fonts, the default font or a font with a specific path.

    • Constructor Detail

      • Font

        protected Font​(Format format,
               byte[] fontData)
        Creates a font.

        The format must be a custom font format, a value between Format.CUSTOM_0 and Format.CUSTOM_7.

        The given byte array is used to identify and to use a font in the native world.

        Parameters:
        format - the custom font format
        fontData - the data of this font
        Throws:
        IllegalArgumentException - if the format is not a custom format.

    • Method Detail

      • getAllFonts

        public static Font[] getAllFonts()
        Returns an array containing all the fonts of the system.
        Returns:
        an array containing all the fonts.
        Throws:
        MicroUIException - if MicroUI is not started.

      • getDefaultFont

        public static Font getDefaultFont()
        Returns the default font of the system.
        Returns:
        the default font.
        Throws:
        MicroUIException - if no font is declared in the system.
        MicroUIException - if MicroUI is not started.

      • getFont

        public static Font getFont​(String path)
        Returns the font matching a given path.
        Parameters:
        path - the path of the desired font.
        Returns:
        the font matching the given path.
        Throws:
        MicroUIException - if the resource path does not start with "/".
        MicroUIException - if no font matches the given path.
        MicroUIException - if MicroUI is not started.

      • charWidth

        public int charWidth​(char character)
        Returns the width of a character when it is drawn using this font.

        The width is the horizontal space that would be occupied if the given character were drawn using this font. It also includes the horizontal space that would be added after the character to separate it appropriately from the following characters.

        This method only supports characters in the range U+0000 to U+FFFF. It does not handle characters with code points greater than U+FFFF, which are represented as a pair of char values (referred to as "surrogate pair").

        Parameters:
        character - the character to measure.
        Returns:
        the width of the given character.

      • stringWidth

        public int stringWidth​(String string)
        Returns the width of a string when it is drawn using this font.

        The width is the horizontal space that would be occupied if the given string were drawn using this font. It also includes the horizontal space between the characters of the string to separate them appropriately.

        Parameters:
        string - the string to measure.
        Returns:
        the width of the given string.

      • substringWidth

        public int substringWidth​(String string,
                          int offset,
                          int length)
        Returns the width of a part of a string when it is drawn using this font.

        The width is the horizontal space that would be occupied if the given substring were drawn using this font. It also includes the horizontal space between the characters of the substring to separate them appropriately.

        Parameters:
        string - the string containing the substring to measure.
        offset - the index of the first character in the substring to measure.
        length - the number of characters to measure.
        Returns:
        the width of the given substring.
        Throws:
        StringIndexOutOfBoundsException - if the given offset and length are out of the string bounds.

      • getHeight

        public abstract int getHeight()
        Returns the height of a line of text when it is drawn using this font.

        The height includes the size of the font as well as sufficient spacing below the line of text to separate it appropriately from the following lines.

        Returns:
        height of a line of text with this font.

      • getBaselinePosition

        public abstract int getBaselinePosition()
        Returns the vertical distance in pixels between the top of this font and its baseline.
        Returns:
        the baseline of this font.

      • charsWidth

        protected int charsWidth​(char[] chars,
                         int offset,
                         int length)
        Computes the width of the given char array.
        Parameters:
        chars - the char array
        offset - the starting offset
        length - the length
        Returns:
        the width of the given char array
        See Also:
        charWidth(char), stringWidth(String), substringWidth(String, int, int)

      • getIdentifiers

        @Deprecated
public int[] getIdentifiers()
        Deprecated.
        only available in for fonts retrieved with getDefaultFont(), getFont(String) or getAllFonts().
        Returns an array containing all the identifiers supported by this font.

        An identifier can be either one of the identifier constants specified in this class or an specific identifier value defined by the MicroUI implementation.

        Returns:
        an array containing all the identifier supported by this font.

      • isIdentifierSupported

        @Deprecated
public boolean isIdentifierSupported​(int identifier)
        Deprecated.
        only available in for fonts retrieved with getDefaultFont(), getFont(String) or getAllFonts().
        Returns whether this font supports the given identifier.
        Parameters:
        identifier - the identifier to check.
        Returns:
        true if this font supports the given identifier, false otherwise.

      • getStyle

        @Deprecated
public int getStyle()
        Deprecated.
        only available in for fonts retrieved with getDefaultFont(), getFont(String) or getAllFonts().
        Returns the style of this font.

        The returned value is a combination of the following style constants: STYLE_PLAIN, STYLE_BOLD and SYTLE_ITALIC.

        Returns:
        the style of this font.

      • getDescriptor

        @Deprecated
public String getDescriptor()
        Deprecated.
        only available in for fonts retrieved with getDefaultFont(), getFont(String) or getAllFonts().
        Returns the descriptor of this font.

        This method returns an empty string if this font does not have a descriptor.

        Returns:
        the descriptor of this font.

      • isMonospaced

        @Deprecated
public boolean isMonospaced()
        Deprecated.
        only available in for fonts retrieved with getDefaultFont(), getFont(String) or getAllFonts().
        Returns whether this font is monospaced.

        A monospaced font is a font in which every character has the same width.

        Returns:
        true if this font is monospaced, false otherwise.