Class Font


  • public final class Font
    extends Resource
    Instances of this class manage operating system resources that define how text looks when it is displayed. Fonts may be constructed by providing a device and either name, size and style information or a FontData object which encapsulates this data.

    Application code must explicitly invoke the Font.dispose() method to release the operating system resources managed by each instance when those instances are no longer required.

    See Also:
    FontData, Font snippets, SWT Examples: GraphicsExample, PaintExample, Sample code and further information
    • Field Summary

      Fields 
      Modifier and Type Field Description
      long handle
      the handle to the OS font resource (Warning: This field is platform dependent)
    • Constructor Summary

      Constructors 
      Constructor Description
      Font​(Device device, String name, int height, int style)
      Constructs a new font given a device, a font name, the height of the desired font in points, and a font style.
      Font​(Device device, FontData fd)
      Constructs a new font given a device and font data which describes the desired font's appearance.
      Font​(Device device, FontData[] fds)
      Constructs a new font given a device and an array of font data which describes the desired font's appearance.
    • Field Detail

      • handle

        public long handle
        the handle to the OS font resource (Warning: This field is platform dependent)

        IMPORTANT: This field is not part of the SWT public API. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms and should never be accessed from application code.

        Restriction:
        This field is not intended to be referenced by clients.
    • Constructor Detail

      • Font

        public Font​(Device device,
                    FontData fd)
        Constructs a new font given a device and font data which describes the desired font's appearance.

        You must dispose the font when it is no longer required.

        Parameters:
        device - the device to create the font on
        fd - the FontData that describes the desired font (must not be null)
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if device is null and there is no current device
        • ERROR_NULL_ARGUMENT - if the fd argument is null
        SWTError -
        • ERROR_NO_HANDLES - if a font could not be created from the given font data
        See Also:
        Resource.dispose()
      • Font

        public Font​(Device device,
                    FontData[] fds)
        Constructs a new font given a device and an array of font data which describes the desired font's appearance.

        You must dispose the font when it is no longer required.

        Parameters:
        device - the device to create the font on
        fds - the array of FontData that describes the desired font (must not be null)
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if device is null and there is no current device
        • ERROR_NULL_ARGUMENT - if the fds argument is null
        • ERROR_INVALID_ARGUMENT - if the length of fds is zero
        • ERROR_NULL_ARGUMENT - if any fd in the array is null
        SWTError -
        • ERROR_NO_HANDLES - if a font could not be created from the given font data
        Since:
        2.1
        See Also:
        Resource.dispose()
      • Font

        public Font​(Device device,
                    String name,
                    int height,
                    int style)
        Constructs a new font given a device, a font name, the height of the desired font in points, and a font style.

        You must dispose the font when it is no longer required.

        Parameters:
        device - the device to create the font on
        name - the name of the font (must not be null)
        height - the font height in points
        style - a bit or combination of NORMAL, BOLD, ITALIC
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if device is null and there is no current device
        • ERROR_NULL_ARGUMENT - if the name argument is null
        • ERROR_INVALID_ARGUMENT - if the height is negative
        SWTError -
        • ERROR_NO_HANDLES - if a font could not be created from the given arguments
        See Also:
        Resource.dispose()
    • Method Detail

      • equals

        public boolean equals​(Object object)
        Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
        Overrides:
        equals in class Object
        Parameters:
        object - the object to compare with this object
        Returns:
        true if the object is the same as this object and false otherwise
        See Also:
        hashCode()
      • getFontData

        public FontData[] getFontData()
        Returns an array of FontDatas representing the receiver. On Windows, only one FontData will be returned per font. On X however, a Font object may be composed of multiple X fonts. To support this case, we return an array of font data objects.
        Returns:
        an array of font data objects describing the receiver
        Throws:
        SWTException -
        • ERROR_GRAPHIC_DISPOSED - if the receiver has been disposed
      • hashCode

        public int hashCode()
        Returns an integer hash code for the receiver. Any two objects that return true when passed to equals must return the same value for this method.
        Overrides:
        hashCode in class Object
        Returns:
        the receiver's hash
        See Also:
        equals(java.lang.Object)
      • isDisposed

        public boolean isDisposed()
        Returns true if the font has been disposed, and false otherwise.

        This method gets the dispose state for the font. When a font has been disposed, it is an error to invoke any other method (except Resource.dispose()) using the font.

        Specified by:
        isDisposed in class Resource
        Returns:
        true when the font is disposed and false otherwise
      • toString

        public String toString()
        Returns a string containing a concise, human-readable description of the receiver.
        Overrides:
        toString in class Object
        Returns:
        a string representation of the receiver
      • win32_new

        public static Font win32_new​(Device device,
                                     long handle)
        Invokes platform specific functionality to allocate a new font.

        IMPORTANT: This method is not part of the public API for Font. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

        Parameters:
        device - the device on which to allocate the color
        handle - the handle for the font
        Returns:
        a new font object containing the specified device and handle
        Restriction:
        This method is not intended to be referenced by clients.