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Class java.awt.FontMetrics

java.lang.Object
   |
   +----java.awt.FontMetrics

public abstract class FontMetrics
extends Object
implements Serializable
A font metrics object. Note that the implementations of these methods are inefficient, they are usually overridden with more efficient toolkit specific implementations.

Note to subclassers: Since many of these methods form closed mutually recursive loops, you must take care that you implement at least one of the methods in each such loop in order to prevent infinite recursion when your subclass is used. In particular, the following is the minimal suggested set of methods to override in order to ensure correctness and prevent infinite recursion (though other subsets are equally feasible):


Variable Index

 o font
The actual font.

Constructor Index

 o FontMetrics(Font)
Creates a new FontMetrics object with the specified font.

Method Index

 o bytesWidth(byte[], int, int)
Returns the total advance width for showing the specified array of bytes in this Font.
 o charsWidth(char[], int, int)
Returns the total advance width for showing the specified array of characters in this Font.
 o charWidth(char)
Returns the advance width of the specified character in this Font.
 o charWidth(int)
Returns the advance width of the specified character in this Font.
 o getAscent()
Gets the font ascent.
 o getDescent()
Gets the font descent.
 o getFont()
Gets the font.
 o getHeight()
Gets the standard height of a line of text in this font.
 o getLeading()
Gets the standard leading, or line spacing, for the font.
 o getMaxAdvance()
Gets the maximum advance width of any character in this Font.
 o getMaxAscent()
Gets the maximum ascent of all characters in this Font.
 o getMaxDecent()
For backward compatibility only. Deprecated.
 o getMaxDescent()
Gets the maximum descent of all characters in this Font.
 o getWidths()
Gets the advance widths of the first 256 characters in the Font.
 o stringWidth(String)
Returns the total advance width for showing the specified String in this Font.
 o toString()
Returns the String representation of this FontMetric's values.

Variables

 o font
 protected Font font
The actual font.

See Also:
getFont

Constructors

 o FontMetrics
 protected FontMetrics(Font font)
Creates a new FontMetrics object with the specified font.

Parameters:
font - the font
See Also:
Font

Methods

 o getFont
 public Font getFont()
Gets the font.

 o getLeading
 public int getLeading()
Gets the standard leading, or line spacing, for the font. This 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.

 o getAscent
 public int getAscent()
Gets the font ascent. The font ascent is the distance from the base line to the top of most Alphanumeric characters. Note, however, that some characters in the font may extend above this height.

See Also:
getMaxAscent
 o getDescent
 public int getDescent()
Gets the font descent. The font descent is the distance from the base line to the bottom of most Alphanumeric characters. Note, however, that some characters in the font may extend below this height.

See Also:
getMaxDescent
 o getHeight
 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. There is no guarantee that lines of text spaced at this distance will be disjoint; such lines may overlap if some characters overshoot either the standard ascent or the standard descent metric.

 o getMaxAscent
 public int getMaxAscent()
Gets the maximum ascent of all characters in this Font. No character will extend further above the baseline than this distance.

See Also:
getAscent
 o getMaxDescent
 public int getMaxDescent()
Gets the maximum descent of all characters in this Font. No character will descend futher below the baseline than this distance.

See Also:
getDescent
 o getMaxDecent
 public int getMaxDecent()
Note: getMaxDecent() is deprecated. As of JDK version 1.1.1, replaced by getMaxDescent().

For backward compatibility only.

See Also:
getMaxDescent
 o getMaxAdvance
 public int getMaxAdvance()
Gets the maximum advance width of any character in this Font. The advance width is the amount by which the current point is moved from one character to the next in a line of text.

Returns:
-1 if the max advance is not known.
 o charWidth
 public int charWidth(int ch)
Returns the advance width of the specified character in this Font. The advance width is the amount by which the current point is moved from one character to the next in a line of text.

Parameters:
ch - the character to be measured
See Also:
stringWidth
 o charWidth
 public int charWidth(char ch)
Returns the advance width of the specified character in this Font. The advance width is the amount by which the current point is moved from one character to the next in a line of text.

Parameters:
ch - the character to be measured
See Also:
stringWidth
 o stringWidth
 public int stringWidth(String str)
Returns the total advance width for showing the specified String in this Font. The advance width is the amount by which the current point is moved from one character to the next in a line of text.

Parameters:
str - the String to be measured
See Also:
charsWidth, bytesWidth
 o charsWidth
 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 width is the amount by which the current point is moved from one character to the next in a line of text.

Parameters:
data - the array of characters to be measured
off - the start offset of the characters in the array
len - the number of characters to be measured from the array
See Also:
stringWidth, bytesWidth
 o bytesWidth
 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 width is the amount by which the current point is moved from one character to the next in a line of text.

Parameters:
data - the array of bytes to be measured
off - the start offset of the bytes in the array
len - the number of bytes to be measured from the array
See Also:
stringWidth, charsWidth
 o getWidths
 public int[] getWidths()
Gets the advance widths of the first 256 characters in the Font. The advance width is the amount by which the current point is moved from one character to the next in a line of text.

 o toString
 public String toString()
Returns the String representation of this FontMetric's values.

Overrides:
toString in class Object

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