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| java.lang.Object
 java.awt.font.TextMeasurer
| TextMeasurer | | final public class TextMeasurer implements Cloneable(Code) | | The TextMeasurer class provides the primitive operations
needed for line break: measuring up to a given advance, determining the
advance of a range of characters, and generating a
TextLayout for a range of characters. It also provides
methods for incremental editing of paragraphs.
A TextMeasurer object is constructed with an
java.text.AttributedCharacterIterator AttributedCharacterIterator
representing a single paragraph of text. The value returned by the
AttributedCharacterIterator.getBeginIndex getBeginIndex
method of AttributedCharacterIterator
defines the absolute index of the first character. The value
returned by the
AttributedCharacterIterator.getEndIndex getEndIndex method of AttributedCharacterIterator defines the index
past the last character. These values define the range of indexes to
use in calls to the TextMeasurer. For example, calls to
get the advance of a range of text or the line break of a range of text
must use indexes between the beginning and end index values. Calls to
TextMeasurer.insertChar(java.text.AttributedCharacterIterator,int) insertChar
and
TextMeasurer.deleteChar(java.text.AttributedCharacterIterator,int) deleteChar
reset the TextMeasurer to use the beginning index and end
index of the AttributedCharacterIterator passed in those calls.
Most clients will use the more convenient LineBreakMeasurer,
which implements the standard line break policy (placing as many words
as will fit on each line).
author:
John Raley
version:
1.31, 04/20/01
See Also: LineBreakMeasurer
since:
1.3 |
| Method Summary | |
| protected Object | clone()
| | public void | deleteChar(AttributedCharacterIterator newParagraph, int deletePos)
Updates the TextMeasurer after a single character has
been deleted
from the paragraph currently represented by this
TextMeasurer. | | public float | getAdvanceBetween(int start, int limit)
Returns the graphical width of a line beginning at start
and including characters up to limit.
start and limit are absolute indices,
not relative to the start of the paragraph.
Parameters:
start - the character index at which to start measuring
Parameters:
limit - the character index at which to stop measuring the graphical width of a line beginning at startand including characters up to limit
throws:
IndexOutOfBoundsException - if limit is lessthan start
throws:
IllegalArgumentException - if start or limit is not between the beginning ofthe paragraph and the end of the paragraph. | | char[] | getChars()
NOTE: This method is only for LineBreakMeasurer's use. | | public TextLayout | getLayout(int start, int limit)
Returns a TextLayout on the given character range.
Parameters:
start - the index of the first character
Parameters:
limit - the index after the last character. | | public int | getLineBreakIndex(int start, float maxAdvance)
Returns the index of the first character which will not fit on
on a line beginning at start and possible
measuring up to maxAdvance in graphical width. | | public void | insertChar(AttributedCharacterIterator newParagraph, int insertPos)
Updates the TextMeasurer after a single character has
been inserted
into the paragraph currently represented by this
TextMeasurer. |
| layoutCharCount | | int layoutCharCount(Code) | | |
| layoutCount | | int layoutCount(Code) | | |
| TextMeasurer | | public TextMeasurer(AttributedCharacterIterator text, FontRenderContext frc)(Code) | | Constructs a TextMeasurer from the source text.
The source text should be a single entire paragraph.
Parameters:
text - the source paragraph. Cannot be null.
Parameters:
frc - the information about a graphics device which is needed to measure the text correctly. Cannot be null. |
| deleteChar | | public void deleteChar(AttributedCharacterIterator newParagraph, int deletePos)(Code) | | Updates the TextMeasurer after a single character has
been deleted
from the paragraph currently represented by this
TextMeasurer. After this call, this
TextMeasurer is equivalent to a new TextMeasurer
created from the text; however, it will usually be more efficient
to update an existing TextMeasurer than to create a new one
from scratch.
Parameters:
newParagraph - the text of the paragraph after performingthe deletion. Cannot be null.
Parameters:
deletePos - the position in the text where the character was removed. Must not be less thanthe start of newParagraph, and must not be greater than theend of newParagraph.
throws:
IndexOutOfBoundsException - if deletePos isless than the start of newParagraph or greaterthan the end of newParagraph
throws:
NullPointerException - if newParagraph isnull |
| getAdvanceBetween | | public float getAdvanceBetween(int start, int limit)(Code) | | Returns the graphical width of a line beginning at start
and including characters up to limit.
start and limit are absolute indices,
not relative to the start of the paragraph.
Parameters:
start - the character index at which to start measuring
Parameters:
limit - the character index at which to stop measuring the graphical width of a line beginning at startand including characters up to limit
throws:
IndexOutOfBoundsException - if limit is lessthan start
throws:
IllegalArgumentException - if start or limit is not between the beginning ofthe paragraph and the end of the paragraph. |
| getChars | | char[] getChars()(Code) | | NOTE: This method is only for LineBreakMeasurer's use. It is package-
private because it returns internal data.
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| getLayout | | public TextLayout getLayout(int start, int limit)(Code) | | Returns a TextLayout on the given character range.
Parameters:
start - the index of the first character
Parameters:
limit - the index after the last character. Must be greaterthan start a TextLayout for the characters beginning atstart up to (but not including) limit
throws:
IndexOutOfBoundsException - if limit is lessthan start
throws:
IllegalArgumentException - if start or limit is not between the beginning ofthe paragraph and the end of the paragraph. |
| getLineBreakIndex | | public int getLineBreakIndex(int start, float maxAdvance)(Code) | | Returns the index of the first character which will not fit on
on a line beginning at start and possible
measuring up to maxAdvance in graphical width.
Parameters:
start - the character index at which to start measuring.start is an absolute index, not relative to thestart of the paragraph
Parameters:
maxAdvance - the graphical width in which the line must fit the index after the last character that will fiton a line beginning at start, which is not longerthan maxAdvance in graphical width
throws:
IllegalArgumentException - if start isless than the beginning of the paragraph. |
| insertChar | | public void insertChar(AttributedCharacterIterator newParagraph, int insertPos)(Code) | | Updates the TextMeasurer after a single character has
been inserted
into the paragraph currently represented by this
TextMeasurer. After this call, this
TextMeasurer is equivalent to a new
TextMeasurer created from the text; however, it will
usually be more efficient to update an existing
TextMeasurer than to create a new one from scratch.
Parameters:
newParagraph - the text of the paragraph after performingthe insertion. Cannot be null.
Parameters:
insertPos - the position in the text where the character was inserted. Must not be less than the start of newParagraph, and must be less than the end ofnewParagraph.
throws:
IndexOutOfBoundsException - if insertPos is lessthan the start of newParagraph or greater thanor equal to the end of newParagraph
throws:
NullPointerException - if newParagraph is null |
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