A Raster defines values for pixels occupying a particular rectangular area of the plane, not necessarily including (0, 0). The rectangle, known as the Raster's bounding rectangle and available by means of the getBounds method, is defined by minX, minY, width, and height values. The minX and minY values define the coordinate of the upper left corner of the Raster. References to pixels outside of the bounding rectangle may result in an exception being thrown, or may result in references to unintended elements of the Raster's associated DataBuffer. It is the user's responsibility to avoid accessing such pixels.
A SampleModel describes how samples of a Raster are stored in the primitive array elements of a DataBuffer. Samples may be stored one per data element, as in a PixelInterleavedSampleModel or BandedSampleModel, or packed several to an element, as in a SinglePixelPackedSampleModel or MultiPixelPackedSampleModel. The SampleModel is also controls whether samples are sign extended, allowing unsigned data to be stored in signed Java data types such as byte, short, and int.
Although a Raster may live anywhere in the plane, a SampleModel makes use of a simple coordinate system that starts at (0, 0). A Raster therefore contains a translation factor that allows pixel locations to be mapped between the Raster's coordinate system and that of the SampleModel. The translation from the SampleModel coordinate system to that of the Raster may be obtained by the getSampleModelTranslateX and getSampleModelTranslateY methods.
A Raster may share a DataBuffer with another Raster either by explicit construction or by the use of the createChild and createTranslatedChild methods. Rasters created by these methods can return a reference to the Raster they were created from by means of the getParent method. For a Raster that was not constructed by means of a call to createTranslatedChild or createChild, getParent will return null.
The createTranslatedChild method returns a new Raster that shares all of the data of the current Raster, but occupies a bounding rectangle of the same width and height but with a different starting point. For example, if the parent Raster occupied the region (10, 10) to (100, 100), and the translated Raster was defined to start at (50, 50), then pixel (20, 20) of the parent and pixel (60, 60) of the child occupy the same location in the DataBuffer shared by the two Rasters. In the first case, (-10, -10) should be added to a pixel coordinate to obtain the corresponding SampleModel coordinate, and in the second case (-50, -50) should be added.
The translation between a parent and child Raster may be determined by subtracting the child's sampleModelTranslateX and sampleModelTranslateY values from those of the parent.
The createChild method may be used to create a new Raster occupying only a subset of its parent's bounding rectangle (with the same or a translated coordinate system) or with a subset of the bands of its parent.
All constructors are protected. The correct way to create a Raster is to use one of the static create methods defined in this class. These methods create instances of Raster that use the standard Interleaved, Banded, and Packed SampleModels and that may be processed more efficiently than a Raster created by combining an externally generated SampleModel and DataBuffer.
The upper left corner of the Raster is given by the location argument. The dataType parameter should be one of the enumerated values defined in the DataBuffer class.
The only dataTypes supported currently are TYPE_BYTE, TYPE_USHORT, and TYPE_INT.
The upper left corner of the Raster is given by the location argument. If location is null, (0, 0) will be used. The dataType parameter should be one of the enumerated values defined in the DataBuffer class.
The only dataTypes supported currently are TYPE_BYTE, TYPE_USHORT, and TYPE_INT.
The parentX, parentY, width and height parameters form a Rectangle in this Raster's coordinate space, indicating the area of pixels to be shared. An error will be thrown if this Rectangle is not contained with the bounds of the current Raster.
The new Raster may additionally be translated to a different coordinate system for the plane than that used by the current Raster. The childMinX and childMinY parameters give the new (x, y) coordinate of the upper-left pixel of the returned Raster; the coordinate (childMinX, childMinY) in the new Raster will map to the same pixel as the coordinate (parentX, parentY) in the current Raster.
The new Raster may be defined to contain only a subset of the bands of the current Raster, possibly reordered, by means of the bandList parameter. If bandList is null, it is taken to include all of the bands of the current Raster in their current order.
To create a new Raster that contains a subregion of the current Raster, but shares its coordinate system and bands, this method should be called with childMinX equal to parentX, childMinY equal to parentY, and bandList equal to null.
Note that interleaved DataBuffer.TYPE_INT
Rasters are not supported. To create a 1-band Raster of type
DataBuffer.TYPE_INT, use
Raster.createPackedRaster().
The upper left corner of the Raster is given by the location argument. If location is null, (0, 0) will be used. The dataType parameter should be one of the enumerated values defined in the DataBuffer class.
Note that interleaved DataBuffer.TYPE_INT
Rasters are not supported. To create a 1-band Raster of type
DataBuffer.TYPE_INT, use
Raster.createPackedRaster().
The only dataTypes supported currently are TYPE_BYTE and TYPE_USHORT.
The upper left corner of the Raster is given by the location argument. If location is null, (0, 0) will be used. The dataType parameter should be one of the enumerated values defined in the DataBuffer class.
Note that interleaved DataBuffer.TYPE_INT
Rasters are not supported. To create a 1-band Raster of type
DataBuffer.TYPE_INT, use
Raster.createPackedRaster().
The only dataTypes supported currently are TYPE_BYTE and TYPE_USHORT.
The upper left corner of the Raster is given by the location argument. If location is null, (0, 0) will be used. The dataType parameter should be one of the enumerated values defined in the DataBuffer class.
The only dataTypes supported currently are TYPE_BYTE, TYPE_USHORT, and TYPE_INT.
If the number of bands is more than one, the SampleModel will be a SinglePixelPackedSampleModel, with each band having bitsPerBand bits. In either case, the requirements on dataType and bitsPerBand imposed by the corresponding SampleModel must be met.
The upper left corner of the Raster is given by the location argument. If location is null, (0, 0) will be used. The dataType parameter should be one of the enumerated values defined in the DataBuffer class.
The only dataTypes supported currently are TYPE_BYTE, TYPE_USHORT, and TYPE_INT.
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
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.
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.
java.util.Hashtable.
The general contract of hashCode is:
hashCode method on each of
the two objects must produce the same integer result.
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.)
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:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
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.
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())
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.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:
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.
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:
notify method
or the notifyAll method.
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.