com.alee.utils

Class FontUtils

java.lang.Object

com.alee.utils.FontUtils

public final class FontUtils
extends java.lang.Object

This class provides a set of utilities to work with fonts.

Field Summary

Fields

Modifier and Type	Field and Description
static int	HI_SURROGATE_START Temporary constants moved from CharToGlyphMapper.
static int	LO_SURROGATE_END
static int	MAX_LAYOUT_CHARCODE Referenced by code in the JDK which wants to test for the maximum char code for which layout may be required.
static int	MIN_LAYOUT_CHARCODE Referenced by code in the JDK which wants to test for the minimum char code for which layout may be required.

Constructor Summary

Constructors

Constructor and Description
FontUtils()

Method Summary

Modifier and Type	Method and Description
static void	clearDerivedFontsCache() Clears derived fonts cache.
static java.awt.Font	getCachedDerivedFont(java.awt.Font font, int style, int size) Get derived font by font, style and size.
protected static DerivedFontAttributes	getFontAttribute(java.awt.Font font, int style, int size) Returns derived font attributes object.
static boolean	isComplexLayout(char[] text, int start, int limit) checks whether TextLayout is required to handle characters.
static boolean	isComplexText(char[] chs, int start, int limit) If there is anything in the text which triggers a case where char->glyph does not map 1:1 in straightforward left->right ordering, then this method returns true.

Methods inherited from class java.lang.Object

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

Field Detail

MIN_LAYOUT_CHARCODE

public static final int MIN_LAYOUT_CHARCODE

Referenced by code in the JDK which wants to test for the minimum char code for which layout may be required. Note that even basic latin text can benefit from ligatures, eg "ffi" but we presently apply those only if explicitly requested with TextAttribute.LIGATURES_ON. The value here indicates the lowest char code for which failing to invoke layout would prevent acceptable rendering.

See Also:

Constant Field Values

MAX_LAYOUT_CHARCODE

public static final int MAX_LAYOUT_CHARCODE

Referenced by code in the JDK which wants to test for the maximum char code for which layout may be required. Note this does not account for supplementary characters where the caller interprets 'layout' to mean any case where one 'char' (ie the java type char) does not map to one glyph

See Also:

Constant Field Values

HI_SURROGATE_START

public static final int HI_SURROGATE_START

Temporary constants moved from CharToGlyphMapper.

See Also:

Constant Field Values

LO_SURROGATE_END

public static final int LO_SURROGATE_END

See Also:

Constant Field Values

Constructor Detail

FontUtils

public FontUtils()

Method Detail

clearDerivedFontsCache

public static void clearDerivedFontsCache()

Clears derived fonts cache.

getCachedDerivedFont

public static java.awt.Font getCachedDerivedFont(java.awt.Font font,
                                                 int style,
                                                 int size)

Get derived font by font, style and size. At first it will get the derived font from cache. If it cannot hit the derived font, it will invoke font.deriveFont to derive a font.

Parameters:

font - original font

style - new font style

size - new font size

Returns:

the derived font.

getFontAttribute

protected static DerivedFontAttributes getFontAttribute(java.awt.Font font,
                                                        int style,
                                                        int size)

Returns derived font attributes object.

Parameters:

font - original font

style - new font style

size - new font size

Returns:

font attributes object

isComplexLayout

public static boolean isComplexLayout(char[] text,
                                      int start,
                                      int limit)

checks whether TextLayout is required to handle characters.

Parameters:

text - characters to be tested

start - start

limit - limit

Returns:

true if TextLayout is required false if TextLayout is not required

isComplexText

public static boolean isComplexText(char[] chs,
                                    int start,
                                    int limit)

If there is anything in the text which triggers a case where char->glyph does not map 1:1 in straightforward left->right ordering, then this method returns true. Scripts which might require it but are not treated as such due to JDK implementations will not return true. ie a 'true' return is an indication of the treatment by the implementation. Whether supplementary characters should be considered is dependent on the needs of the caller. Since this method accepts the 'char' type then such chars are always represented by a pair. From a rendering perspective these will all (in the cases I know of) still be one unicode character -> one glyph. But if a caller is using this to discover any case where it cannot make naive assumptions about the number of chars, and how to index through them, then it may need the option to have a 'true' return in such a case.