java.lang.Object | |
↳ | android.graphics.PathMeasure |
Constants | |||||||||||
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int | POSITION_MATRIX_FLAG | ||||||||||
int | TANGENT_MATRIX_FLAG |
Public Constructors | |||||||||||
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Create an empty PathMeasure object.
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Create a PathMeasure object associated with the specified path object
(already created and specified).
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Public Methods | |||||||||||
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Return the total length of the current contour, or 0 if no path is
associated with this measure object.
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Pins distance to 0 <= distance <= getLength(), and then computes the
corresponding matrix.
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Pins distance to 0 <= distance <= getLength(), and then computes the
corresponding position and tangent.
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Given a start and stop distance, return in dst the intervening
segment(s).
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Return true if the current contour is closed()
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Move to the next contour in the path.
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Assign a new path, or null to have none.
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Protected Methods | |||||||||||
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Invoked when the garbage collector has detected that this instance is no longer reachable.
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[Expand]
Inherited Methods | |||||||||||
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From class
java.lang.Object
|
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 the measure object is used. If the path is modified, you must call setPath with the path.
Create a PathMeasure object associated with the specified path object (already created and specified). The meansure 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 the measure object is used. If the path is modified, you must call setPath with the path.
path | The path that will be measured by this object |
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forceClosed | If true, then the path will be considered as "closed" even if its contour was not explicitly closed. |
Return the total length of the current contour, or 0 if no path is associated with this measure object.
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.
distance | The distance along the associated path |
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matrix | Allocated by the caller, this is set to the transformation associated with the position and tangent at the specified distance |
flags | Specified what aspects should be returned in the matrix. |
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.
distance | The distance along the current contour to sample |
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pos | If not null, eturns the sampled position (x==[0], y==[1]) |
tan | If not null, returns the sampled tangent (x==[0], y==[1]) |
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 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)
.
Move to the next contour in the path. Return true if one exists, or false if we're done with the path.
Assign a new path, or null to have none.
Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.
Note that objects that override finalize
are significantly more expensive than
objects that don't. Finalizers may be run a long time after the object is no longer
reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup.
Note also that finalizers are run on a single VM-wide finalizer thread,
so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary
for a class that has a native peer and needs to call a native method to destroy that peer.
Even then, it's better to provide an explicit close
method (and implement
Closeable
), and insist that callers manually dispose of instances. This
works well for something like files, but less well for something like a BigInteger
where typical calling code would have to deal with lots of temporaries. Unfortunately,
code that creates lots of temporaries is the worst kind of code from the point of view of
the single finalizer thread.
If you must use finalizers, consider at least providing your own
ReferenceQueue
and having your own thread process that queue.
Unlike constructors, finalizers are not automatically chained. You are responsible for
calling super.finalize()
yourself.
Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.
Throwable |
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