java.awt.font
Class FontRenderContext

java.lang.Object
  |
  +--java.awt.font.FontRenderContext

public class FontRenderContext

extends Object

The FontRenderContext class is a container for the information needed to correctly measure text. The measurement of text can vary because of rules that map outlines to pixels, and rendering hints provided by an application.

One such piece of information is a transform that scales typographical points to pixels. (A point is defined to be exactly 1/72 of an inch, which is slightly different than the traditional mechanical measurement of a point.) A character that is rendered at 12pt on a 600dpi device might have a different size than the same character rendered at 12pt on a 72dpi device because of such factors as rounding to pixel boundaries and hints that the font designer may have specified.

Anti-aliasing and Fractional-metrics specified by an application can also affect the size of a character because of rounding to pixel boundaries.

Typically, instances of FontRenderContext are obtained from a Graphics2D object. A FontRenderContext which is directly constructed will most likely not represent any actual graphics device, and may lead to unexpected or incorrect results.

See Also:

RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.KEY_FRACTIONALMETRICS, Graphics2D.getFontRenderContext(), LineMetrics

Constructor Summary

protected	FontRenderContext() Constructs a new FontRenderContext object.
	FontRenderContext(AffineTransform tx, boolean isAntiAliased, boolean usesFractionalMetrics) Constructs a FontRenderContext object from an optional AffineTransform and two boolean values that determine if the newly constructed object has anti-aliasing or fractional metrics.

Method Summary

AffineTransform	getTransform() Gets the transform that is used to scale typographical points to pixels in this FontRenderContext.
boolean	isAntiAliased() Gets the text anti-aliasing mode used in this FontRenderContext.
boolean	usesFractionalMetrics() Gets the text fractional metrics mode requested by the application for use in this FontRenderContext.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FontRenderContext

protected FontRenderContext()

Constructs a new FontRenderContext object.

FontRenderContext

public FontRenderContext(AffineTransform tx,
                         boolean isAntiAliased,
                         boolean usesFractionalMetrics)

Constructs a FontRenderContext object from an optional AffineTransform and two boolean values that determine if the newly constructed object has anti-aliasing or fractional metrics.

Parameters:

tx - the transform which is used to scale typographical points to pixels in this FontRenderContext. If null, an identity tranform is used.

isAntiAliased - determines if the newly contructed object has anti-aliasing

usesFractionalMetrics - determines if the newly constructed object uses fractional metrics

Method Detail

getTransform

public AffineTransform getTransform()

Gets the transform that is used to scale typographical points to pixels in this FontRenderContext.

See Also:

AffineTransform

isAntiAliased

public boolean isAntiAliased()

Gets the text anti-aliasing mode used in this FontRenderContext.

See Also:

RenderingHints.KEY_TEXT_ANTIALIASING

usesFractionalMetrics

public boolean usesFractionalMetrics()

Gets the text fractional metrics mode requested by the application for use in this FontRenderContext.

See Also:

RenderingHints.KEY_FRACTIONALMETRICS