PathMeasure
public
class
PathMeasure
extends Object
java.lang.Object | |
↳ | android.graphics.PathMeasure |
Summary
Constants | |
---|---|
int |
POSITION_MATRIX_FLAG
|
int |
TANGENT_MATRIX_FLAG
|
Public constructors | |
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PathMeasure()
Create an empty PathMeasure object. |
|
PathMeasure(Path path, boolean forceClosed)
Create a PathMeasure object associated with the specified path object (already created and specified). |
Public methods | |
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float
|
getLength()
Return the total length of the current contour, or 0 if no path is associated with this measure object. |
boolean
|
getMatrix(float distance, Matrix matrix, int flags)
Pins distance to 0 <= distance <= getLength(), and then computes the corresponding matrix. |
boolean
|
getPosTan(float distance, float[] pos, float[] tan)
Pins distance to 0 <= distance <= getLength(), and then computes the corresponding position and tangent. |
boolean
|
getSegment(float startD, float stopD, Path dst, boolean startWithMoveTo)
Given a start and stop distance, return in dst the intervening segment(s). |
boolean
|
isClosed()
Return true if the current contour is closed() |
boolean
|
nextContour()
Move to the next contour in the path. |
void
|
setPath(Path path, boolean forceClosed)
Assign a new path, or null to have none. |
Protected methods | |
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void
|
finalize()
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
Inherited methods | |
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Constants
POSITION_MATRIX_FLAG
public static final int POSITION_MATRIX_FLAG
Constant Value: 1 (0x00000001)
TANGENT_MATRIX_FLAG
public static final int TANGENT_MATRIX_FLAG
Constant Value: 2 (0x00000002)
Public constructors
PathMeasure
public PathMeasure ()
Create an empty PathMeasure object. To uses this to measure the length of a path, and/or to find the position and tangent along it, call setPath. Note that once a path is associated with the measure object, it is undefined if the path is subsequently modified and the measure object is used. If the path is modified, you must call setPath with the path.
PathMeasure
public PathMeasure (Path path, boolean forceClosed)
Create a PathMeasure object associated with the specified path object (already created and specified). The measure object can now return the path's length, and the position and tangent of any position along the path. Note that once a path is associated with the measure object, it is undefined if the path is subsequently modified and the measure object is used. If the path is modified, you must call setPath with the path.
Parameters | |
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path |
Path : The path that will be measured by this object |
forceClosed |
boolean : If true, then the path will be considered as "closed"
even if its contour was not explicitly closed. |
Public methods
getLength
public float getLength ()
Return the total length of the current contour, or 0 if no path is associated with this measure object.
Returns | |
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float |
getMatrix
public boolean getMatrix (float distance, Matrix matrix, int flags)
Pins distance to 0 <= distance <= getLength(), and then computes the corresponding matrix. Returns false if there is no path, or a zero-length path was specified, in which case matrix is unchanged.
Parameters | |
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distance |
float : The distance along the associated path |
matrix |
Matrix : Allocated by the caller, this is set to the transformation
associated with the position and tangent at the specified distance |
flags |
int : Specified what aspects should be returned in the matrix. |
Returns | |
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boolean |
getPosTan
public boolean getPosTan (float distance, float[] pos, float[] tan)
Pins distance to 0 <= distance <= getLength(), and then computes the corresponding position and tangent. Returns false if there is no path, or a zero-length path was specified, in which case position and tangent are unchanged.
Parameters | |
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distance |
float : The distance along the current contour to sample |
pos |
float : If not null, returns the sampled position (x==[0], y==[1]) |
tan |
float : If not null, returns the sampled tangent (x==[0], y==[1]) |
Returns | |
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boolean |
false if there was no path associated with this measure object |
getSegment
public boolean getSegment (float startD, float stopD, Path dst, boolean startWithMoveTo)
Given a start and stop distance, return in dst the intervening segment(s). If the segment is zero-length, return false, else return true. startD and stopD are pinned to legal values (0..getLength()). If startD >= stopD then return false (and leave dst untouched). Begin the segment with a moveTo if startWithMoveTo is true.
On Build.VERSION_CODES.KITKAT
and earlier
releases, the resulting path may not display on a hardware-accelerated
Canvas. A simple workaround is to add a single operation to this path,
such as dst.rLineTo(0, 0)
.
Parameters | |
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startD |
float |
stopD |
float |
dst |
Path |
startWithMoveTo |
boolean |
Returns | |
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boolean |
isClosed
public boolean isClosed ()
Return true if the current contour is closed()
Returns | |
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boolean |
nextContour
public boolean nextContour ()
Move to the next contour in the path. Return true if one exists, or false if we're done with the path.
Returns | |
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boolean |
setPath
public void setPath (Path path, boolean forceClosed)
Assign a new path, or null to have none.
Parameters | |
---|---|
path |
Path |
forceClosed |
boolean |
Protected methods
finalize
protected void finalize ()
Called by the garbage collector on an object when garbage collection
determines that there are no more references to the object.
A subclass overrides the finalize
method to dispose of
system resources or to perform other cleanup.
The general contract of finalize
is that it is invoked
if and when the Java virtual
machine has determined that there is no longer any
means by which this object can be accessed by any thread that has
not yet died, except as a result of an action taken by the
finalization of some other object or class which is ready to be
finalized. The finalize
method may take any action, including
making this object available again to other threads; the usual purpose
of finalize
, however, is to perform cleanup actions before
the object is irrevocably discarded. For example, the finalize method
for an object that represents an input/output connection might perform
explicit I/O transactions to break the connection before the object is
permanently discarded.
The finalize
method of class Object
performs no
special action; it simply returns normally. Subclasses of
Object
may override this definition.
The Java programming language does not guarantee which thread will
invoke the finalize
method for any given object. It is
guaranteed, however, that the thread that invokes finalize will not
be holding any user-visible synchronization locks when finalize is
invoked. If an uncaught exception is thrown by the finalize method,
the exception is ignored and finalization of that object terminates.
After the finalize
method has been invoked for an object, no
further action is taken until the Java virtual machine has again
determined that there is no longer any means by which this object can
be accessed by any thread that has not yet died, including possible
actions by other objects or classes which are ready to be finalized,
at which point the object may be discarded.
The finalize
method is never invoked more than once by a Java
virtual machine for any given object.
Any exception thrown by the finalize
method causes
the finalization of this object to be halted, but is otherwise
ignored.
Throws | |
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Throwable |