java.awt

Class FontMetrics

  • java.lang.Object
    • java.awt.FontMetrics
  • All Implemented Interfaces:
    java.io.Serializable
    public abstract class FontMetrics extends java.lang.Object implements java.io.Serializable
    The FontMetrics class defines a font metrics object, which encapsulates information about the rendering of a particular font on a particular screen.

    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 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):

    The letter 'p' showing its 'reference point' Note that the implementations of these methods are inefficient, so they are usually overridden with more efficient toolkit-specific implementations.

    When an application asks to place a character at the position (xy), the character is placed so that its reference point (shown as the dot in the accompanying image) is put at that position. The reference point specifies a horizontal line called the baseline of the character. In normal printing, the baselines of characters should align.

    In addition, every character in a font has an ascent, a descent, and an advance width. The ascent is the amount by which the character ascends above the baseline. The descent is the amount by which the character descends below the baseline. The advance width indicates the position at which AWT should place the next character.

    An array of characters or a string can also have an ascent, a descent, and an advance width. The ascent of the array is the maximum ascent of any character in the array. The descent is the maximum descent of any character in the array. The advance width is the sum of the advance widths of each of the characters in the character array. The advance of a String is the distance along the baseline of the String. This distance is the width that should be used for centering or right-aligning the String.

    Note that the advance of a String is not necessarily the sum of the advances of its characters measured in isolation because the width of a character can vary depending on its context. For example, in Arabic text, the shape of a character can change in order to connect to other characters. Also, in some scripts, certain character sequences can be represented by a single shape, called a ligature. Measuring characters individually does not account for these transformations.

    Font metrics are baseline-relative, meaning that they are generally independent of the rotation applied to the font (modulo possible grid hinting effects). See Font.

    Since:
    JDK1.0
    See Also:
    Font, Serialized Form
    • Methods 
      Modifier and Type Method and Description
      Ordinary member indicator bytesWidth Reveal DetailHide Detail
      Returns the total advance width for showing the specified array of bytes in this Font.
      Ordinary member indicator charsWidth Reveal DetailHide Detail
      Returns the total advance width for showing the specified array of characters in this Font.
      Ordinary member indicator charWidth Reveal DetailHide Detail
      Returns the advance width of the specified character in this Font.
      Ordinary member indicator charWidth Reveal DetailHide Detail
      Returns the advance width of the specified character in this Font.
      Ordinary member indicator getAscent Reveal DetailHide Detail
      Determines the font ascent of the Font described by this FontMetrics object.
      Ordinary member indicator getDescent Reveal DetailHide Detail
      Determines the font descent of the Font described by this FontMetrics object.
      Ordinary member indicator getFont Reveal DetailHide Detail
      Gets the Font described by this FontMetrics object.
      Ordinary member indicator getFontRenderContext Reveal DetailHide Detail
      Gets the FontRenderContext used by this FontMetrics object to measure text.
      Ordinary member indicator getHeight Reveal DetailHide Detail
      Gets the standard height of a line of text in this font.
      Ordinary member indicator getLeading Reveal DetailHide Detail
      Determines the standard leading of the Font described by this FontMetrics object.
      Ordinary member indicator getLineMetrics Reveal DetailHide Detail
      Returns the LineMetrics object for the specified character array in the specified Graphics context.
      Ordinary member indicator getLineMetrics Reveal DetailHide Detail
      Returns the LineMetrics object for the specified CharacterIterator in the specified Graphics context.
      Ordinary member indicator getLineMetrics Reveal DetailHide Detail
      Returns the LineMetrics object for the specified String in the specified Graphics context.
      Ordinary member indicator getLineMetrics Reveal DetailHide Detail
      Returns the LineMetrics object for the specified String in the specified Graphics context.
      Ordinary member indicator getMaxAdvance Reveal DetailHide Detail
      Gets the maximum advance width of any character in this Font.
      Ordinary member indicator getMaxAscent Reveal DetailHide Detail
      Determines the maximum ascent of the Font described by this FontMetrics object.
      Ordinary member indicator getMaxCharBounds Reveal DetailHide Detail
      Returns the bounds for the character with the maximum bounds in the specified Graphics context.
      Ordinary member indicator getMaxDecent Reveal DetailHide Detail
      Deprecated. As of JDK version 1.1.1, replaced by getMaxDescent().
      Ordinary member indicator getMaxDescent Reveal DetailHide Detail
      Determines the maximum descent of the Font described by this FontMetrics object.
      Ordinary member indicator getStringBounds Reveal DetailHide Detail
      Returns the bounds of the specified array of characters in the specified Graphics context.
      Ordinary member indicator getStringBounds Reveal DetailHide Detail
      Returns the bounds of the characters indexed in the specified CharacterIterator in the specified Graphics context.
      Ordinary member indicator getStringBounds Reveal DetailHide Detail
      Returns the bounds of the specified String in the specified Graphics context.
      Ordinary member indicator getStringBounds Reveal DetailHide Detail
      Returns the bounds of the specified String in the specified Graphics context.
      Ordinary member indicator getWidths Reveal DetailHide Detail
      Gets the advance widths of the first 256 characters in the Font.
      Ordinary member indicator hasUniformLineMetrics Reveal DetailHide Detail
      Checks to see if the Font has uniform line metrics.
      Ordinary member indicator stringWidth Reveal DetailHide Detail
      Returns the total advance width for showing the specified String in this Font.
      Overridden member indicator toString Reveal DetailHide Detail
      Returns a representation of this FontMetrics object's values as a String.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
This document was created by Dulcet from the OpenJDK sources. Copyright © 1993, 2012 Oracle and/or its affiliates. All rights reserved.

SourceForge