Prev Class | Next Class | Frames | No Frames |

Summary: Nested | Field | Method | Constr | Detail: Nested | Field | Method | Constr |

**Known Implementing Classes:**- FlatteningPathIterator

`public interface `**PathIterator**

This interface provides a directed path over the boundary of a shape. The
path can contain 1st through 3rd order Bezier curves (lines, and quadratic
and cubic splines). A shape can have multiple disjoint paths via the
MOVETO directive, and can close a circular path back to the previos
MOVETO via the CLOSE directive.

**Since:**- 1.2

**See Also:**`Shape`

,`Stroke`

,`FlatteningPathIterator`

## Field Summary

`static int`

`SEG_CLOSE`

- The current segment closes a loop by an implicit line to the previous SEG_MOVETO coordinate.

`static int`

`SEG_CUBICTO`

- The current segment is a cubic parametric curve (more commonly known as a Bezier curve).

`static int`

`SEG_LINETO`

- The current segment is a line.

`static int`

`SEG_MOVETO`

- Starts a new subpath.

`static int`

`SEG_QUADTO`

- The current segment is a quadratic parametric curve.

`static int`

`WIND_EVEN_ODD`

- The even-odd winding mode: a point is internal to the shape if a ray from the point to infinity (in any direction) crosses an odd number of segments.

`static int`

`WIND_NON_ZERO`

- The non-zero winding mode: a point is internal to the shape if a ray from the point to infinity (in any direction) crosses a different number of segments headed clockwise than those headed counterclockwise.

## Method Summary

`int`

`currentSegment(double[] coords)`

- Returns the coordinates of the next point(s), as well as the type of line segment.

`int`

`currentSegment(float[] coords)`

- Returns the coordinates of the next point(s), as well as the type of line segment.

`int`

`getWindingRule()`

- Returns the winding rule to determine which points are inside this path.

`boolean`

`isDone()`

- Tests if the iterator is exhausted.

`void`

`next()`

- Advance to the next segment in the iteration.

public static final int SEG_CLOSE

The current segment closes a loop by an implicit line to the previous SEG_MOVETO coordinate.

Field Value:- 4

public static final int SEG_CUBICTO

The current segment is a cubic parametric curve (more commonly known as a Bezier curve). It is interpolated as t varies from 0 to 1 over the current point (CP), first control point (P1), the second control point (P2), and final interpolated control point (P3):P(t) = B(3,0)*CP + B(3,1)*P1 + B(3,2)*P2 + B(3,3)*P3 0 <= t <= 1 B(n,m) = mth coefficient of nth degree Bernstein polynomial = C(n,m) * t^(m) * (1 - t)^(n-m) C(n,m) = Combinations of n things, taken m at a time = n! / (m! * (n-m)!)

Field Value:- 3

public static final int SEG_MOVETO

Starts a new subpath. There is no segment from the previous vertex.

Field Value:- 0

public static final int SEG_QUADTO

The current segment is a quadratic parametric curve. It is interpolated as t varies from 0 to 1 over the current point (CP), first control point (P1), and final interpolated control point (P2):P(t) = B(2,0)*CP + B(2,1)*P1 + B(2,2)*P2 0 <= t <= 1 B(n,m) = mth coefficient of nth degree Bernstein polynomial = C(n,m) * t^(m) * (1 - t)^(n-m) C(n,m) = Combinations of n things, taken m at a time = n! / (m! * (n-m)!)

Field Value:- 2

public static final int WIND_EVEN_ODD

The even-odd winding mode: a point is internal to the shape if a ray from the point to infinity (in any direction) crosses an odd number of segments.

Field Value:- 0

public static final int WIND_NON_ZERO

The non-zero winding mode: a point is internal to the shape if a ray from the point to infinity (in any direction) crosses a different number of segments headed clockwise than those headed counterclockwise.

Field Value:- 1

public int currentSegment(double[] coords)

Returns the coordinates of the next point(s), as well as the type of line segment. The input array must be at least a double[6], to accomodate up to three (x,y) point pairs (although if you know the iterator is flat, you can probably get by with a double[2]). If the returned type is SEG_MOVETO or SEG_LINETO, the first point in the array is modified; if the returned type is SEG_QUADTO, the first two points are modified; if the returned type is SEG_CUBICTO, all three points are modified; and if the returned type is SEG_CLOSE, the array is untouched.

Parameters:`coords`

- the array to place the point coordinates in

Returns:- the segment type

Throws:`NullPointerException`

- if coords is null`ArrayIndexOutOfBoundsException`

- if coords is too small`NoSuchElementException`

- optional when isDone() is true

See Also:`SEG_MOVETO`

,`SEG_LINETO`

,`SEG_QUADTO`

,`SEG_CUBICTO`

,`SEG_CLOSE`

public int currentSegment(float[] coords)

Returns the coordinates of the next point(s), as well as the type of line segment. The input array must be at least a float[6], to accomodate up to three (x,y) point pairs (although if you know the iterator is flat, you can probably get by with a float[2]). If the returned type is SEG_MOVETO or SEG_LINETO, the first point in the array is modified; if the returned type is SEG_QUADTO, the first two points are modified; if the returned type is SEG_CUBICTO, all three points are modified; and if the returned type is SEG_CLOSE, the array is untouched.

Parameters:`coords`

- the array to place the point coordinates in

Returns:- the segment type

Throws:`NullPointerException`

- if coords is null`ArrayIndexOutOfBoundsException`

- if coords is too small`NoSuchElementException`

- optional when isDone() is true

See Also:`SEG_MOVETO`

,`SEG_LINETO`

,`SEG_QUADTO`

,`SEG_CUBICTO`

,`SEG_CLOSE`

public int getWindingRule()

Returns the winding rule to determine which points are inside this path.

Returns:- the winding rule

See Also:`WIND_EVEN_ODD`

,`WIND_NON_ZERO`

public boolean isDone()

Tests if the iterator is exhausted. If this returns true, currentSegment and next may throw a NoSuchElementException (although this is not required).

Returns:- true if the iteration is complete

public void next()

Advance to the next segment in the iteration. It is not specified what this does if called when isDone() returns true.

Throws:`NoSuchElementException`

- optional when isDone() is true

PathIterator.java -- describes a shape by iterating over its vertices
Copyright (C) 2000, 2002, 2003 Free Software Foundation
This file is part of GNU Classpath.
GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.
As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module. An independent module is a module which is not derived from
or based on this library. If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so. If you do not wish to do so, delete this
exception statement from your version.