org.eclipse.swt.graphics

Class Font

java.lang.Object

org.eclipse.swt.graphics.Resource

org.eclipse.swt.graphics.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

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
int	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.

Fields inherited from class org.eclipse.swt.graphics.Resource

device

Constructor Summary

Constructors

Constructor and Description
Font(Device device) Prevents uninitialized instances from being created outside the package.
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.
Font(Device device, java.lang.String name, float height, int style)
Font(Device device, java.lang.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.

Method Summary

Methods

Modifier and Type	Method and Description
(package private) void	destroy()
boolean	equals(java.lang.Object object) Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
FontData[]	getFontData() Returns an array of FontDatas representing the receiver.
int	hashCode() Returns an integer hash code for the receiver.
(package private) void	init(FontData fd)
boolean	isDisposed() Returns true if the font has been disposed, and false otherwise.
java.lang.String	toString() Returns a string containing a concise, human-readable description of the receiver.
static Font	win32_new(Device device, int handle) Invokes platform specific functionality to allocate a new font.

Methods inherited from class org.eclipse.swt.graphics.Resource

dispose, getDevice, init

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

handle

public int 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.

Constructor Detail

Font

Font(Device device)

Prevents uninitialized instances from being created outside the package.

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:

java.lang.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

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:

java.lang.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

Font

public Font(Device device,
    java.lang.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:

java.lang.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

Font

Font(Device device,
    java.lang.String name,
    float height,
    int style)

Method Detail

destroy

void destroy()

Overrides:

destroy in class Resource

equals

public boolean equals(java.lang.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 java.lang.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 java.lang.Object

Returns:

the receiver's hash

See Also:

equals(java.lang.Object)

init

void init(FontData fd)

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 java.lang.String toString()

Returns a string containing a concise, human-readable description of the receiver.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the receiver

win32_new

public static Font win32_new(Device device,
             int 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