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package java.awt.font;


The LineMetrics class allows access to the metrics needed to layout characters along a line and to layout of a set of lines. A LineMetrics object encapsulates the measurement information associated with a run of text. 
 Fonts can have different metrics for different ranges of characters. The getLineMetrics methods of Font take some text as an argument and return a LineMetrics object describing the metrics of the initial number of characters in that text, as returned by getNumChars. 
/**
* The {@code LineMetrics} class allows access to the
* metrics needed to layout characters along a line
* and to layout of a set of lines.  A {@code LineMetrics}
* object encapsulates the measurement information associated
* with a run of text.
* <p>
* Fonts can have different metrics for different ranges of
* characters.  The {@code getLineMetrics} methods of
* {@link java.awt.Font Font} take some text as an argument
* and return a {@code LineMetrics} object describing the
* metrics of the initial number of characters in that text, as
* returned by {@link #getNumChars}.
*/


public abstract class LineMetrics {

    
Constructor for subclasses to call.

/**
     * Constructor for subclasses to call.
     */
    protected LineMetrics() {}

    
Returns the number of characters (char values) in the text whose metrics are encapsulated by this LineMetrics object. 
Returns:the number of characters (char values) in the text with which this LineMetrics was created.
/**
     * Returns the number of characters ({@code char} values) in the text whose
     * metrics are encapsulated by this {@code LineMetrics}
     * object.
     * @return the number of characters ({@code char} values) in the text with which
     *         this {@code LineMetrics} was created.
     */
    public abstract int getNumChars();

    
Returns the ascent of the text.  The ascent
is the distance from the baseline
to the ascender line.  The ascent usually represents the
the height of the capital letters of the text.  Some characters
can extend above the ascender line.

Returns:the ascent of the text.
/**
     * Returns the ascent of the text.  The ascent
     * is the distance from the baseline
     * to the ascender line.  The ascent usually represents the
     * the height of the capital letters of the text.  Some characters
     * can extend above the ascender line.
     * @return the ascent of the text.
     */
    public abstract float getAscent();

    
Returns the descent of the text.  The descent
is the distance from the baseline
to the descender line.  The descent usually represents
the distance to the bottom of lower case letters like
'p'.  Some characters can extend below the descender
line.

Returns:the descent of the text.
/**
     * Returns the descent of the text.  The descent
     * is the distance from the baseline
     * to the descender line.  The descent usually represents
     * the distance to the bottom of lower case letters like
     * 'p'.  Some characters can extend below the descender
     * line.
     * @return the descent of the text.
     */
    public abstract float getDescent();

    
Returns the leading of the text. The
leading is the recommended
distance from the bottom of the descender line to the
top of the next line.

Returns:the leading of the text.
/**
     * Returns the leading of the text. The
     * leading is the recommended
     * distance from the bottom of the descender line to the
     * top of the next line.
     * @return the leading of the text.
     */
    public abstract float getLeading();

    
Returns the height of the text.  The
height is equal to the sum of the ascent, the
descent and the leading.

Returns:the height of the text.
/**
     * Returns the height of the text.  The
     * height is equal to the sum of the ascent, the
     * descent and the leading.
     * @return the height of the text.
     */
    public abstract float getHeight();

    
Returns the baseline index of the text. The index is one of ROMAN_BASELINE, CENTER_BASELINE, HANGING_BASELINE. 
Returns:the baseline of the text.
/**
     * Returns the baseline index of the text.
     * The index is one of
     * {@link java.awt.Font#ROMAN_BASELINE ROMAN_BASELINE},
     * {@link java.awt.Font#CENTER_BASELINE CENTER_BASELINE},
     * {@link java.awt.Font#HANGING_BASELINE HANGING_BASELINE}.
     * @return the baseline of the text.
     */
    public abstract int getBaselineIndex();

    
Returns the baseline offsets of the text, relative to the baseline of the text. The offsets are indexed by baseline index. For example, if the baseline index is CENTER_BASELINE then offsets[HANGING_BASELINE] is usually negative, offsets[CENTER_BASELINE] is zero, and offsets[ROMAN_BASELINE] is usually positive. 
Returns:the baseline offsets of the text.
/**
     * Returns the baseline offsets of the text,
     * relative to the baseline of the text.  The
     * offsets are indexed by baseline index.  For
     * example, if the baseline index is
     * {@code CENTER_BASELINE} then
     * {@code offsets[HANGING_BASELINE]} is usually
     * negative, {@code offsets[CENTER_BASELINE]}
     * is zero, and {@code offsets[ROMAN_BASELINE]}
     * is usually positive.
     * @return the baseline offsets of the text.
     */
    public abstract float[] getBaselineOffsets();

    
Returns the position of the strike-through line
relative to the baseline.

Returns:the position of the strike-through line.
/**
     * Returns the position of the strike-through line
     * relative to the baseline.
     * @return the position of the strike-through line.
     */
    public abstract float getStrikethroughOffset();

    
Returns the thickness of the strike-through line.

Returns:the thickness of the strike-through line.
/**
     * Returns the thickness of the strike-through line.
     * @return the thickness of the strike-through line.
     */
    public abstract float getStrikethroughThickness();

    
Returns the position of the underline relative to
the baseline.

Returns:the position of the underline.
/**
     * Returns the position of the underline relative to
     * the baseline.
     * @return the position of the underline.
     */
    public abstract float getUnderlineOffset();

    
Returns the thickness of the underline.

Returns:the thickness of the underline.
/**
     * Returns the thickness of the underline.
     * @return the thickness of the underline.
     */
    public abstract float getUnderlineThickness();
}