Class FontMetrics

protected Font font

The actual Font from which the font metrics are created. This cannot be null.

protected FontMetrics(Font font)

Creates a new FontMetrics object for finding out height and width information about the specified Font and specific character glyphs in that Font.

public Font getFont()

Gets the Font described by this FontMetrics object.

public FontRenderContext getFontRenderContext()

Gets the FontRenderContext used by this FontMetrics object to measure text.

Note that methods in this class which take a Graphics parameter measure text using the FontRenderContext of that Graphics object, and not this FontRenderContext

public int getLeading()

Determines the standard leading of the Font described by this FontMetrics object. The standard leading, or interline spacing, is the logical amount of space to be reserved between the descent of one line of text and the ascent of the next line. The height metric is calculated to include this extra space.

public int getAscent()

Determines the font ascent of the Font described by this FontMetrics object. The font ascent is the distance from the font's baseline to the top of most alphanumeric characters. Some characters in the Font might extend above the font ascent line.

public int getDescent()

Determines the font descent of the Font described by this FontMetrics object. The font descent is the distance from the font's baseline to the bottom of most alphanumeric characters with descenders. Some characters in the Font might extend below the font descent line.

public int getHeight()

Gets the standard height of a line of text in this font. This is the distance between the baseline of adjacent lines of text. It is the sum of the leading + ascent + descent. Due to rounding this may not be the same as getAscent() + getDescent() + getLeading(). There is no guarantee that lines of text spaced at this distance are disjoint; such lines may overlap if some characters overshoot either the standard ascent or the standard descent metric.

public int getMaxAscent()

Determines the maximum ascent of the Font described by this FontMetrics object. No character extends further above the font's baseline than this height.

public int getMaxDescent()

Determines the maximum descent of the Font described by this FontMetrics object. No character extends further below the font's baseline than this height.

@Deprecated public int getMaxDecent()

For backward compatibility only.

public int getMaxAdvance()

Returns an estimate of the maximum advance width of any character in the Font described by this FontMetrics object, with important caveats, enumerated below.

The advance is the distance from the leftmost point used to position the character to the rightmost point along the baseline. This is not the same thing as the visible width of the glyph image representing the character.

The advance of a String is not necessarily the sum of the advances of its characters. It may differ substantially if complex text layout is required for proper rendering.

Some of the caveats of the reported value include

• The returned value is relying upon information from some underlying system font, and the correctness of that information is outside of AWT's control.
• When specific characters are mapped into glyphs in some rendering context, instructions in the font itself together with the rasterization process may cause some glyph to have a wider advance than reported.
• When a font is requested in some style, eg Font.BOLD, for which no exact match is available, then techniques to satisfy the requested rendering may similarly result in glyphs that are wider than the reported maximum.
• Depending on the implementation, an AWT logical font or physical font may need to locate some characters from one or more "fall back" fonts, when the primary underlying physical font does not support the character. These fonts may not all be known or considered in the calculation of the reported maximum advance. It is common for the design center of such fall back fonts to be for a different script than the design center of the primary font, so their advances can be quite different. This can also lead to the unexpected result that a font such as Font.MONOSPACED can render glyphs that are not all the same width.

None of these caveats are exposed as they are all implementation details, and there is no practical way to determine when these are in effect. An application which needs a better estimate of the maximum advance, and knows the subset of characters it expects to display can query the advance of each such character to find the widest, however, as discussed above, since the displayed width of a String is not necessarily the sum of the advances the value still needs to be used with caution.

In summary, this method makes no absolute guarantee, nor can it even make a guarantee to be correct within some margin of error. So it should be used at most only for estimating the total space sufficient to display some number of as yet unknown characters from the font. And that might be either an overestimate, or an underestimate depending on the specific text and rendering conext.

public int charWidth(int codePoint)

Returns the advance width of the specified character in this Font. The advance is the distance from the leftmost point to the rightmost point on the character's baseline. Note that the advance of a String is not necessarily the sum of the advances of its characters.

This method doesn't validate the specified character to be a valid Unicode code point. The caller must validate the character value using Character.isValidCodePoint if necessary.

public int charWidth(char ch)

Returns the advance width of the specified character in this Font. The advance is the distance from the leftmost point to the rightmost point on the character's baseline. Note that the advance of a String is not necessarily the sum of the advances of its characters.

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the charWidth(int) method.

public int stringWidth(String str)

Returns the total advance width for showing the specified String in this Font. The advance is the distance from the leftmost point to the rightmost point on the string's baseline.

Note that the advance of a String is not necessarily the sum of the advances of its characters.

public int charsWidth(char[] data, int off, int len)

Returns the total advance width for showing the specified array of characters in this Font. The advance is the distance from the leftmost point to the rightmost point on the string's baseline. The advance of a String is not necessarily the sum of the advances of its characters. This is equivalent to measuring a String of the characters in the specified range.

public int bytesWidth(byte[] data, int off, int len)

Returns the total advance width for showing the specified array of bytes in this Font. The advance is the distance from the leftmost point to the rightmost point on the string's baseline. The advance of a String is not necessarily the sum of the advances of its characters. This is equivalent to measuring a String of the characters in the specified range.

public int[] getWidths()

Gets the advance widths of the first 256 characters in the Font. The advance is the distance from the leftmost point to the rightmost point on the character's baseline. Note that the advance of a String is not necessarily the sum of the advances of its characters.

public boolean hasUniformLineMetrics()

Checks to see if the Font has uniform line metrics. A composite font may consist of several different fonts to cover various character sets. In such cases, the FontLineMetrics objects are not uniform. Different fonts may have a different ascent, descent, metrics and so on. This information is sometimes necessary for line measuring and line breaking.

public LineMetrics getLineMetrics(String str, Graphics context)

Returns the LineMetrics object for the specified String in the specified Graphics context.

public LineMetrics getLineMetrics(String str, int beginIndex, int limit, Graphics context)

Returns the LineMetrics object for the specified String in the specified Graphics context.

public LineMetrics getLineMetrics(char[] chars, int beginIndex, int limit, Graphics context)

Returns the LineMetrics object for the specified character array in the specified Graphics context.

public LineMetrics getLineMetrics(CharacterIterator ci, int beginIndex, int limit, Graphics context)

Returns the LineMetrics object for the specified CharacterIterator in the specified Graphics context.

public Rectangle2D getStringBounds(String str, Graphics context)

Returns the bounds of the specified String in the specified Graphics context. The bounds is used to layout the String.

Note: The returned bounds is in baseline-relative coordinates (see class notes).

public Rectangle2D getStringBounds(String str, int beginIndex, int limit, Graphics context)

Returns the bounds of the specified String in the specified Graphics context. The bounds is used to layout the String.

Note: The returned bounds is in baseline-relative coordinates (see class notes).

public Rectangle2D getStringBounds(char[] chars, int beginIndex, int limit, Graphics context)

Returns the bounds of the specified array of characters in the specified Graphics context. The bounds is used to layout the String created with the specified array of characters, beginIndex and limit.

Note: The returned bounds is in baseline-relative coordinates (see class notes).

public Rectangle2D getStringBounds(CharacterIterator ci, int beginIndex, int limit, Graphics context)

Returns the bounds of the characters indexed in the specified CharacterIterator in the specified Graphics context.

Note: The returned bounds is in baseline-relative coordinates (see class notes).

public Rectangle2D getMaxCharBounds(Graphics context)

Returns the bounds for the character with the maximum bounds in the specified Graphics context.

public String toString()

Returns a representation of this FontMetrics object's values as a String.