The GeneralPath class represents a geometric path constructed from straight lines, and quadratic and cubic (Bézier) curves. It can contain multiple subpaths.

The winding rule specifies how the interior of a path is determined. There are two types of winding rules: EVEN_ODD and NON_ZERO.

An EVEN_ODD winding rule means that enclosed regions of the path alternate between interior and exterior areas as traversed from the outside of the path towards a point inside the region.

A NON_ZERO winding rule means that if a ray is drawn in any direction from a given point to infinity and the places where the path intersects the ray are examined, the point is inside of the path if and only if the number of times that the path crosses the ray from left to right does not equal the number of times that the path crosses the ray from right to left.

@version
1.59, 12/19/03
@author
Jim Graham
Constructs a new GeneralPath object. If an operation performed on this path requires the interior of the path to be defined then the default NON_ZERO winding rule is used.
Constructs a new GeneralPath object with the specified winding rule to control operations that require the interior of the path to be defined.
Parameters
rulethe winding rule
Constructs a new GeneralPath object with the specified winding rule and the specified initial capacity to store path coordinates. This number is an initial guess as to how many path segments are in the path, but the storage is expanded as needed to store whatever path segments are added to this path.
Parameters
rulethe winding rule
initialCapacitythe estimate for the number of path segments in the path
Constructs a new GeneralPath object from an arbitrary Shape object. All of the initial geometry and the winding rule for this path are taken from the specified Shape object.
Parameters
sthe specified Shape object
An even-odd winding rule for determining the interior of a path.
A non-zero winding rule for determining the interior of a path.
Appends the geometry of the specified PathIterator object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect parameter is true and the path is not empty then any initial moveTo in the geometry of the appended Shape is turned into a lineTo segment. If the destination coordinates of such a connecting lineTo segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape is ignored and the appended geometry is governed by the winding rule specified for this path.
Parameters
pithe PathIterator whose geometry is appended to this path
connecta boolean to control whether or not to turn an initial moveTo segment into a lineTo segment to connect the new geometry to the existing path
Appends the geometry of the specified Shape object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect parameter is true and the path is not empty then any initial moveTo in the geometry of the appended Shape is turned into a lineTo segment. If the destination coordinates of such a connecting lineTo segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape is ignored and the appended geometry is governed by the winding rule specified for this path.
Parameters
sthe Shape whose geometry is appended to this path
connecta boolean to control whether or not to turn an initial moveTo segment into a lineTo segment to connect the new geometry to the existing path
Creates a new object of the same class as this object.
Return
a clone of this instance.
Throws
OutOfMemoryErrorif there is not enough memory.
@since
1.2
Closes the current subpath by drawing a straight line back to the coordinates of the last moveTo. If the path is already closed then this method has no effect.
Tests if the specified coordinates are inside the boundary of the Shape.
Parameters
xthe specified x coordinate
ythe specified y coordinate
Return
true if the specified coordinates are inside the Shape boundary; false otherwise.
Tests if the interior of the Shape entirely contains the specified rectangular area. All coordinates that lie inside the rectangular area must lie within the Shape for the entire rectanglar area to be considered contained within the Shape.

This method might conservatively return false when:

  • the intersect method returns true and
  • the calculations to determine whether or not the Shape entirely contains the rectangular area are prohibitively expensive.
This means that this method might return false even though the Shape contains the rectangular area. The Area class can be used to perform more accurate computations of geometric intersection for any Shape object if a more precise answer is required.
Parameters
xthe x coordinate of the specified rectangular area
ythe y coordinate of the specified rectangular area
wthe width of the specified rectangular area
hthe height of the specified rectangular area
Return
true if the interior of the Shape entirely contains the specified rectangular area; false otherwise or, if the Shape contains the rectangular area and the intersects method returns true and the containment calculations would be too expensive to perform.
Tests if a specified Point2D is inside the boundary of the Shape.
Parameters
pa specified Point2D
Return
true if the specified Point2D is inside the boundary of the Shape; false otherwise.
Tests if the interior of the Shape entirely contains the specified Rectangle2D. This method might conservatively return false when:
  • the intersect method returns true and
  • the calculations to determine whether or not the Shape entirely contains the Rectangle2D are prohibitively expensive.
This means that this method might return false even though the Shape contains the Rectangle2D. The Area class can be used to perform more accurate computations of geometric intersection for any Shape object if a more precise answer is required.
Parameters
rThe specified Rectangle2D
Return
true if the interior of the Shape entirely contains the Rectangle2D; false otherwise or, if the Shape contains the Rectangle2D and the intersects method returns true and the containment calculations would be too expensive to perform.
Returns a new transformed Shape.
Parameters
atthe AffineTransform used to transform a new Shape.
Return
a new Shape, transformed with the specified AffineTransform.
Adds a curved segment, defined by three new points, to the path by drawing a Bézier curve that intersects both the current coordinates and the coordinates (x3, y3), using the specified points (x1, y1) and (x2, y2) as Bézier control points.
Parameters
x1, y1the coordinates of the first Béezier control point
x2, y2the coordinates of the second Bézier control point
x3, y3the coordinates of the final endpoint
Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

  • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
  • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
  • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
  • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
  • For any non-null reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

Parameters
objthe reference object with which to compare.
Return
true if this object is the same as the obj argument; false otherwise.
Returns an integer Rectangle that completely encloses the Shape. Note that there is no guarantee that the returned Rectangle is the smallest bounding box that encloses the Shape, only that the Shape lies entirely within the indicated Rectangle. The returned Rectangle might also fail to completely enclose the Shape if the Shape overflows the limited range of the integer data type. The getBounds2D method generally returns a tighter bounding box due to its greater flexibility in representation.
Return
an integer Rectangle that completely encloses the Shape.
See Also
Returns a high precision and more accurate bounding box of the Shape than the getBounds method. Note that there is no guarantee that the returned Rectangle2D is the smallest bounding box that encloses the Shape, only that the Shape lies entirely within the indicated Rectangle2D. The bounding box returned by this method is usually tighter than that returned by the getBounds method and never fails due to overflow problems since the return value can be an instance of the Rectangle2D that uses double precision values to store the dimensions.
Return
an instance of Rectangle2D that is a high-precision bounding box of the Shape.
See Also
Returns the runtime class of an object. That Class object is the object that is locked by static synchronized methods of the represented class.
Return
The java.lang.Class object that represents the runtime class of the object. The result is of type {@code Class} where X is the erasure of the static type of the expression on which getClass is called.
Returns the coordinates most recently added to the end of the path as a Point2D object.
Return
a Point2D object containing the ending coordinates of the path or null if there are no points in the path.
Returns an iterator object that iterates along the Shape boundary and provides access to the geometry of the Shape outline. If an optional AffineTransform is specified, the coordinates returned in the iteration are transformed accordingly.

Each call to this method returns a fresh PathIterator object that traverses the geometry of the Shape object independently from any other PathIterator objects in use at the same time.

It is recommended, but not guaranteed, that objects implementing the Shape interface isolate iterations that are in process from any changes that might occur to the original object's geometry during such iterations.

Before using a particular implementation of the Shape interface in more than one thread simultaneously, refer to its documentation to verify that it guarantees that iterations are isolated from modifications.

Parameters
atan optional AffineTransform to be applied to the coordinates as they are returned in the iteration, or null if untransformed coordinates are desired
Return
a new PathIterator object, which independently traverses the geometry of the Shape.
Returns an iterator object that iterates along the Shape boundary and provides access to a flattened view of the Shape outline geometry.

Only SEG_MOVETO, SEG_LINETO, and SEG_CLOSE point types are returned by the iterator.

If an optional AffineTransform is specified, the coordinates returned in the iteration are transformed accordingly.

The amount of subdivision of the curved segments is controlled by the flatness parameter, which specifies the maximum distance that any point on the unflattened transformed curve can deviate from the returned flattened path segments. Note that a limit on the accuracy of the flattened path might be silently imposed, causing very small flattening parameters to be treated as larger values. This limit, if there is one, is defined by the particular implementation that is used.

Each call to this method returns a fresh PathIterator object that traverses the Shape object geometry independently from any other PathIterator objects in use at the same time.

It is recommended, but not guaranteed, that objects implementing the Shape interface isolate iterations that are in process from any changes that might occur to the original object's geometry during such iterations.

Before using a particular implementation of this interface in more than one thread simultaneously, refer to its documentation to verify that it guarantees that iterations are isolated from modifications.

Parameters
atan optional AffineTransform to be applied to the coordinates as they are returned in the iteration, or null if untransformed coordinates are desired
flatnessthe maximum distance that the line segments used to approximate the curved segments are allowed to deviate from any point on the original curve
Return
a new PathIterator that independently traverses the Shape geometry.
Returns the fill style winding rule.
Return
an integer representing the current winding rule.
Returns a hash code value for the object. This method is supported for the benefit of hashtables such as those provided by java.util.Hashtable.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hashtables.

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)

Return
a hash code value for this object.
Tests if the interior of the Shape intersects the interior of a specified rectangular area. The rectangular area is considered to intersect the Shape if any point is contained in both the interior of the Shape and the specified rectangular area.

This method might conservatively return true when:

  • there is a high probability that the rectangular area and the Shape intersect, but
  • the calculations to accurately determine this intersection are prohibitively expensive.
This means that this method might return true even though the rectangular area does not intersect the Shape. The Area class can be used to perform more accurate computations of geometric intersection for any Shape object if a more precise answer is required.
Parameters
xthe x coordinate of the specified rectangular area
ythe y coordinate of the specified rectangular area
wthe width of the specified rectangular area
hthe height of the specified rectangular area
Return
true if the interior of the Shape and the interior of the rectangular area intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; false otherwise.
Tests if the interior of the Shape intersects the interior of a specified Rectangle2D. This method might conservatively return true when:
  • there is a high probability that the Rectangle2D and the Shape intersect, but
  • the calculations to accurately determine this intersection are prohibitively expensive.
This means that this method might return true even though the Rectangle2D does not intersect the Shape.
Parameters
rthe specified Rectangle2D
Return
true if the interior of the Shape and the interior of the specified Rectangle2D intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; false otherwise.
Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates.
Parameters
x, ythe specified coordinates
Adds a point to the path by moving to the specified coordinates.
Parameters
x, ythe specified coordinates
Wakes up a single thread that is waiting on this object's monitor. If any threads are waiting on this object, one of them is chosen to be awakened. The choice is arbitrary and occurs at the discretion of the implementation. A thread waits on an object's monitor by calling one of the wait methods.

The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:

  • By executing a synchronized instance method of that object.
  • By executing the body of a synchronized statement that synchronizes on the object.
  • For objects of type Class, by executing a synchronized static method of that class.

Only one thread at a time can own an object's monitor.

Throws
IllegalMonitorStateExceptionif the current thread is not the owner of this object's monitor.
Wakes up all threads that are waiting on this object's monitor. A thread waits on an object's monitor by calling one of the wait methods.

The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.

Throws
IllegalMonitorStateExceptionif the current thread is not the owner of this object's monitor.
Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the coordinates (x2, y2), using the specified point (x1, y1) as a quadratic parametric control point.
Parameters
x1, y1the coordinates of the first quadratic control point
x2, y2the coordinates of the final endpoint
Resets the path to empty. The append position is set back to the beginning of the path and all coordinates and point types are forgotten.
Sets the winding rule for this path to the specified value.
Parameters
rulean integer representing the specified winding rule
Throws
IllegalArgumentExceptionif rule is not either WIND_EVEN_ODD or WIND_NON_ZERO
Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())
 
Return
a string representation of the object.
Transforms the geometry of this path using the specified AffineTransform . The geometry is transformed in place, which permanently changes the boundary defined by this object.
Parameters
atthe AffineTransform used to transform the area
Causes current thread to wait until another thread invokes the method or the method for this object. In other words, this method behaves exactly as if it simply performs the call wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until another thread notifies threads waiting on this object's monitor to wake up either through a call to the notify method or the notifyAll method. The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait();
         ... // Perform action appropriate to condition
     }
 
This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.
Throws
IllegalMonitorStateExceptionif the current thread is not the owner of the object's monitor.
InterruptedExceptionif another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.
Causes current thread to wait until either another thread invokes the method or the method for this object, or a specified amount of time has elapsed.

The current thread must own this object's monitor.

This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:

  • Some other thread invokes the notify method for this object and thread T happens to be arbitrarily chosen as the thread to be awakened.
  • Some other thread invokes the notifyAll method for this object.
  • Some other thread interrupts thread T.
  • The specified amount of real time has elapsed, more or less. If timeout is zero, however, then real time is not taken into consideration and the thread simply waits until notified.
The thread T is then removed from the wait set for this object and re-enabled for thread scheduling. It then competes in the usual manner with other threads for the right to synchronize on the object; once it has gained control of the object, all its synchronization claims on the object are restored to the status quo ante - that is, to the situation as of the time that the wait method was invoked. Thread T then returns from the invocation of the wait method. Thus, on return from the wait method, the synchronization state of the object and of thread T is exactly as it was when the wait method was invoked.

A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait(timeout);
         ... // Perform action appropriate to condition
     }
 
(For more information on this topic, see Section 3.2.3 in Doug Lea's "Concurrent Programming in Java (Second Edition)" (Addison-Wesley, 2000), or Item 50 in Joshua Bloch's "Effective Java Programming Language Guide" (Addison-Wesley, 2001).

If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.

Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.

This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.

Parameters
timeoutthe maximum time to wait in milliseconds.
Throws
IllegalArgumentExceptionif the value of timeout is negative.
IllegalMonitorStateExceptionif the current thread is not the owner of the object's monitor.
InterruptedExceptionif another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.
Causes current thread to wait until another thread invokes the method or the method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.

This method is similar to the wait method of one argument, but it allows finer control over the amount of time to wait for a notification before giving up. The amount of real time, measured in nanoseconds, is given by:

 1000000*timeout+nanos

In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:

  • Another thread notifies threads waiting on this object's monitor to wake up either through a call to the notify method or the notifyAll method.
  • The timeout period, specified by timeout milliseconds plus nanos nanoseconds arguments, has elapsed.

The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

     synchronized (obj) {
         while (<condition does not hold>)
             obj.wait(timeout, nanos);
         ... // Perform action appropriate to condition
     }
 
This method should only be called by a thread that is the owner of this object's monitor. See the notify method for a description of the ways in which a thread can become the owner of a monitor.
Parameters
timeoutthe maximum time to wait in milliseconds.
nanosadditional time, in nanoseconds range 0-999999.
Throws
IllegalArgumentExceptionif the value of timeout is negative or the value of nanos is not in the range 0-999999.
IllegalMonitorStateExceptionif the current thread is not the owner of this object's monitor.
InterruptedExceptionif another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.