The BasicStroke class defines a basic set of rendering attributes for the outlines of graphics primitives, which are rendered with a Graphics2D object that has its Stroke attribute set to this BasicStroke. The rendering attributes defined by BasicStroke describe the shape of the mark made by a pen drawn along the outline of a Shape and the decorations applied at the ends and joins of path segments of the Shape. These rendering attributes include:
width
The pen width, measured perpendicularly to the pen trajectory.
end caps
The decoration applied to the ends of unclosed subpaths and dash segments. Subpaths that start and end on the same point are still considered unclosed if they do not have a CLOSE segment. See SEG_CLOSE for more information on the CLOSE segment. The three different decorations are: #CAP_BUTT , #CAP_ROUND , and #CAP_SQUARE .
line joins
The decoration applied at the intersection of two path segments and at the intersection of the endpoints of a subpath that is closed using SEG_CLOSE . The three different decorations are: #JOIN_BEVEL , #JOIN_MITER , and #JOIN_ROUND .
miter limit
The limit to trim a line join that has a JOIN_MITER decoration. A line join is trimmed when the ratio of miter length to stroke width is greater than the miterlimit value. The miter length is the diagonal length of the miter, which is the distance between the inside corner and the outside corner of the intersection. The smaller the angle formed by two line segments, the longer the miter length and the sharper the angle of intersection. The default miterlimit value of 10.0f causes all angles less than 11 degrees to be trimmed. Trimming miters converts the decoration of the line join to bevel.
dash attributes
The definition of how to make a dash pattern by alternating between opaque and transparent sections.
All attributes that specify measurements and distances controlling the shape of the returned outline are measured in the same coordinate system as the original unstroked Shape argument. When a Graphics2D object uses a Stroke object to redefine a path during the execution of one of its draw methods, the geometry is supplied in its original form before the Graphics2D transform attribute is applied. Therefore, attributes such as the pen width are interpreted in the user space coordinate system of the Graphics2D object and are subject to the scaling and shearing effects of the user-space-to-device-space transform in that particular Graphics2D. For example, the width of a rendered shape's outline is determined not only by the width attribute of this BasicStroke, but also by the transform attribute of the Graphics2D object. Consider this code:
// sets the Graphics2D object's Tranform attribute g2d.scale(10, 10); // sets the Graphics2D object's Stroke attribute g2d.setStroke(new BasicStroke(1.5f));
Assuming there are no other scaling transforms added to the Graphics2D object, the resulting line will be approximately 15 pixels wide. As the example code demonstrates, a floating-point line offers better precision, especially when large transforms are used with a Graphics2D object. When a line is diagonal, the exact width depends on how the rendering pipeline chooses which pixels to fill as it traces the theoretical widened outline. The choice of which pixels to turn on is affected by the antialiasing attribute because the antialiasing rendering pipeline can choose to color partially-covered pixels.

For more information on the user space coordinate system and the rendering process, see the Graphics2D class comments.

@version
1.42, 01/04/05
@author
Jim Graham
See Also
Constructs a new BasicStroke with the specified attributes.
Parameters
widththe width of this BasicStroke. The width must be greater than or equal to 0.0f. If width is set to 0.0f, the stroke is rendered as the thinnest possible line for the target device and the antialias hint setting.
capthe decoration of the ends of a BasicStroke
jointhe decoration applied where path segments meet
miterlimitthe limit to trim the miter join. The miterlimit must be greater than or equal to 1.0f.
dashthe array representing the dashing pattern
dash_phasethe offset to start the dashing pattern
Throws
IllegalArgumentExceptionif width is negative
IllegalArgumentExceptionif cap is not either CAP_BUTT, CAP_ROUND or CAP_SQUARE
IllegalArgumentExceptionif miterlimit is less than 1 and join is JOIN_MITER
IllegalArgumentExceptionif join is not either JOIN_ROUND, JOIN_BEVEL, or JOIN_MITER
IllegalArgumentExceptionif dash_phase is negative and dash is not null
IllegalArgumentExceptionif the length of dash is zero
IllegalArgumentExceptionif dash lengths are all zero.
Constructs a solid BasicStroke with the specified attributes.
Parameters
widththe width of the BasicStroke
capthe decoration of the ends of a BasicStroke
jointhe decoration applied where path segments meet
miterlimitthe limit to trim the miter join
Throws
IllegalArgumentExceptionif width is negative
IllegalArgumentExceptionif cap is not either CAP_BUTT, CAP_ROUND or CAP_SQUARE
IllegalArgumentExceptionif miterlimit is less than 1 and join is JOIN_MITER
IllegalArgumentExceptionif join is not either JOIN_ROUND, JOIN_BEVEL, or JOIN_MITER
Constructs a solid BasicStroke with the specified attributes. The miterlimit parameter is unnecessary in cases where the default is allowable or the line joins are not specified as JOIN_MITER.
Parameters
widththe width of the BasicStroke
capthe decoration of the ends of a BasicStroke
jointhe decoration applied where path segments meet
Throws
IllegalArgumentExceptionif width is negative
IllegalArgumentExceptionif cap is not either CAP_BUTT, CAP_ROUND or CAP_SQUARE
IllegalArgumentExceptionif join is not either JOIN_ROUND, JOIN_BEVEL, or JOIN_MITER
Constructs a solid BasicStroke with the specified line width and with default values for the cap and join styles.
Parameters
widththe width of the BasicStroke
Throws
IllegalArgumentExceptionif width is negative
Constructs a new BasicStroke with defaults for all attributes. The default attributes are a solid line of width 1.0, CAP_SQUARE, JOIN_MITER, a miter limit of 10.0.
Ends unclosed subpaths and dash segments with no added decoration.
Ends unclosed subpaths and dash segments with a round decoration that has a radius equal to half of the width of the pen.
Ends unclosed subpaths and dash segments with a square projection that extends beyond the end of the segment to a distance equal to half of the line width.
Joins path segments by connecting the outer corners of their wide outlines with a straight segment.
Joins path segments by extending their outside edges until they meet.
Joins path segments by rounding off the corner at a radius of half the line width.
Returns an outline Shape which encloses the area that should be painted when the Shape is stroked according to the rules defined by the object implementing the Stroke interface.
Parameters
pa Shape to be stroked
Return
the stroked outline Shape.
Tests if a specified object is equal to this BasicStroke by first testing if it is a BasicStroke and then comparing its width, join, cap, miter limit, dash, and dash phase attributes with those of this BasicStroke.
Parameters
objthe specified object to compare to this BasicStroke
Return
true if the width, join, cap, miter limit, dash, and dash phase are the same for both objects; false otherwise.
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 array representing the lengths of the dash segments. Alternate entries in the array represent the user space lengths of the opaque and transparent segments of the dashes. As the pen moves along the outline of the Shape to be stroked, the user space distance that the pen travels is accumulated. The distance value is used to index into the dash array. The pen is opaque when its current cumulative distance maps to an even element of the dash array and transparent otherwise.
Return
the dash array.
Returns the current dash phase. The dash phase is a distance specified in user coordinates that represents an offset into the dashing pattern. In other words, the dash phase defines the point in the dashing pattern that will correspond to the beginning of the stroke.
Return
the dash phase as a float value.
Returns the end cap style.
Return
the end cap style of this BasicStroke as one of the static int values that define possible end cap styles.
Returns the line join style.
Return
the line join style of the BasicStroke as one of the static int values that define possible line join styles.
Returns the line width. Line width is represented in user space, which is the default-coordinate space used by Java 2D. See the Graphics2D class comments for more information on the user space coordinate system.
Return
the line width of this BasicStroke.
See Also
Returns the limit of miter joins.
Return
the limit of miter joins of the BasicStroke.
Returns the hashcode for this stroke.
Return
a hash code for this stroke.
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.
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.
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.