public class FontRenderContext extends Object
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.
| Modifier | Constructor and Description |
|---|---|
protected |
FontRenderContext()
Constructs a new
FontRenderContext object.
|
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FontRenderContext(AffineTransform
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.
|
|
FontRenderContext(AffineTransform
Constructs a
FontRenderContext object from an optional
AffineTransform and two
Object values that determine if the newly constructed object has anti-aliasing or fractional metrics.
|
| Modifier and Type | Method and Description |
|---|---|
boolean |
equals(FontRenderContext
Return true if rhs has the same transform, antialiasing, and fractional metrics values as this.
|
boolean |
equals(Object
Return true if obj is an instance of FontRenderContext and has the same transform, antialiasing, and fractional metrics values as this.
|
Object |
getAntiAliasingHint()
Return the text anti-aliasing rendering mode hint used in this
FontRenderContext.
|
Object |
getFractionalMetricsHint()
Return the text fractional metrics rendering mode hint used in this
FontRenderContext.
|
AffineTransform |
getTransform()
Gets the transform that is used to scale typographical points to pixels in this
FontRenderContext.
|
int |
getTransformType()
Returns the integer type of the affine transform for this
FontRenderContext as specified by
AffineTransform
|
int |
hashCode()
Return a hashcode for this FontRenderContext.
|
boolean |
isAntiAliased()
Returns a boolean which indicates whether or not some form of antialiasing is specified by this
FontRenderContext.
|
boolean |
isTransformed()
Indicates whether or not this
FontRenderContext object measures text in a transformed render context.
|
boolean |
usesFractionalMetrics()
Returns a boolean which whether text fractional metrics mode is used in this
FontRenderContext.
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protected FontRenderContext()
FontRenderContext object.
public FontRenderContext(AffineTransformtx, boolean isAntiAliased, boolean usesFractionalMetrics)
FontRenderContext object from an optional
AffineTransform and two
boolean values that determine if the newly constructed object has anti-aliasing or fractional metrics. In each case the boolean values
true and
false correspond to the rendering hint values
ON and
OFF respectively.
To specify other hint values, use the constructor which specifies the rendering hint values as parameters : FontRenderContext(AffineTransform, Object, Object).
tx - the transform which is used to scale typographical points to pixels in this
FontRenderContext. If null, an identity transform is used.
isAntiAliased - determines if the newly constructed object has anti-aliasing.
usesFractionalMetrics - determines if the newly constructed object has fractional metrics.
public FontRenderContext(AffineTransformtx, Object aaHint, Object fmHint)
FontRenderContext object from an optional
AffineTransform and two
Object values that determine if the newly constructed object has anti-aliasing or fractional metrics.
tx - the transform which is used to scale typographical points to pixels in this
FontRenderContext. If null, an identity transform is used.
aaHint - - one of the text antialiasing rendering hint values defined in
java.awt.RenderingHints. Any other value will throw
IllegalArgumentException.
VALUE_TEXT_ANTIALIAS_DEFAULT may be specified, in which case the mode used is implementation dependent.
fmHint - - one of the text fractional rendering hint values defined in
java.awt.RenderingHints.
VALUE_FRACTIONALMETRICS_DEFAULT may be specified, in which case the mode used is implementation dependent. Any other value will throw
IllegalArgumentException
IllegalArgumentException - if the hints are not one of the legal values.
public boolean isTransformed()
FontRenderContext object measures text in a transformed render context.
true if this
FontRenderContext object has a non-identity AffineTransform attribute.
false otherwise.
getTransform()
public int getTransformType()
FontRenderContext as specified by
AffineTransform.getType()
AffineTransform
public AffineTransformgetTransform()
FontRenderContext.
AffineTransform of this
FontRenderContext.
AffineTransform
public boolean isAntiAliased()
FontRenderContext. Call
getAntiAliasingHint() for the specific rendering hint value.
true, if text is anti-aliased in this
FontRenderContext;
false otherwise.
RenderingHints.KEY_TEXT_ANTIALIASING ,
FontRenderContext(AffineTransform,boolean,boolean),
FontRenderContext(AffineTransform,Object,Object)
public boolean usesFractionalMetrics()
FontRenderContext. Call
getFractionalMetricsHint() to obtain the corresponding rendering hint value.
true, if layout should be performed with fractional metrics;
false otherwise. in this
FontRenderContext.
RenderingHints.KEY_FRACTIONALMETRICS ,
FontRenderContext(AffineTransform,boolean,boolean),
FontRenderContext(AffineTransform,Object,Object)
public ObjectgetAntiAliasingHint()
FontRenderContext. This will be one of the text antialiasing rendering hint values defined in
java.awt.RenderingHints.
FontRenderContext.
public ObjectgetFractionalMetricsHint()
FontRenderContext. This will be one of the text fractional metrics rendering hint values defined in
java.awt.RenderingHints.
FontRenderContext.
public boolean equals(Objectobj)
equals in class
Object
obj - the object to test for equality
true if the specified object is equal to this
FontRenderContext;
false otherwise.
Object.hashCode() ,
HashMap
public boolean equals(FontRenderContextrhs)
rhs - the
FontRenderContext to test for equality
true if
rhs is equal to this
FontRenderContext;
false otherwise.
public int hashCode()
hashCode in class
Object
Object.equals(java.lang.Object) ,
System.identityHashCode(java.lang.Object)