Package org.gnome.gsk

Class Path

java.lang.Object

org.javagi.base.ProxyInstance

org.gnome.gsk.Path

All Implemented Interfaces:

Proxy

@Generated("io.github.jwharm.JavaGI")
public class Path
extends ProxyInstance

Describes lines and curves that are more complex than simple rectangles.

Paths can used for rendering (filling or stroking) and for animations (e.g. as trajectories).

GskPath is an immutable, opaque, reference-counted struct. After creation, you cannot change the types it represents. Instead, new GskPath objects have to be created. The Gsk.PathBuilder structure is meant to help in this endeavor.

Conceptually, a path consists of zero or more contours (continuous, connected curves), each of which may or may not be closed. Contours are typically constructed from Bézier segments.

Since:

4.14

Constructor Summary

Constructors

Constructor	Description
Path(MemorySegment address)	Create a Path proxy instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
boolean	foreach(Set<PathForeachFlags> flags, @Nullable PathForeachFunc func)	Calls func for every operation of the path.
boolean	foreach(PathForeachFlags flags, @Nullable PathForeachFunc func)	Calls func for every operation of the path.
boolean	foreachIntersection(@Nullable Path path2, @Nullable PathIntersectionFunc func)	Finds intersections between two paths.
boolean	getBounds(Rect bounds)	Computes the bounds of the given path.
boolean	getClosestPoint(Point point, float threshold, PathPoint result, @Nullable Out<Float> distance)	Computes the closest point on the path to the given point.
boolean	getEndPoint(PathPoint result)	Gets the end point of the path.
boolean	getStartPoint(PathPoint result)	Gets the start point of the path.
boolean	getStrokeBounds(Stroke stroke, Rect bounds)	Computes the bounds for stroking the given path with the given parameters.
static @Nullable Type	getType()	Get the GType of the Path class
boolean	inFill(Point point, FillRule fillRule)	Returns whether a point is inside the fill area of a path.
boolean	isClosed()	Returns if the path represents a single closed contour.
boolean	isEmpty()	Checks if the path is empty, i.e.
static @Nullable Path	parse(String string)	Constructs a path from a serialized form.
void	print(String string)	Converts the path into a human-readable representation.
Path	ref()	Increases the reference count of a path by one.
void	toCairo(org.freedesktop.cairo.Context cr)	Appends the path to a cairo context for drawing with Cairo.
String	toString()	Converts the path into a human-readable string.
void	unref()	Decreases the reference count of a path by one.

Methods inherited from class org.javagi.base.ProxyInstance

equals, handle, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

Path

public Path(MemorySegment address)

Create a Path proxy instance for the provided memory address.

Parameters:

address - the memory address of the native object

Method Details

getType

public static @Nullable Type getType()

Get the GType of the Path class

Returns:

the GType

parse

public static @Nullable Path parse(String string)

Constructs a path from a serialized form.

The string is expected to be in (a superset of) SVG path syntax, as e.g. produced by toString().

A high-level summary of the syntax:

• M x y Move to (x, y)
• L x y Add a line from the current point to (x, y)
• Q x1 y1 x2 y2 Add a quadratic Bézier from the current point to (x2, y2), with control point (x1, y1)
• C x1 y1 x2 y2 x3 y3 Add a cubic Bézier from the current point to (x3, y3), with control points (x1, y1) and (x2, y2)
• Z Close the contour by drawing a line back to the start point
• H x Add a horizontal line from the current point to the given x value
• V y Add a vertical line from the current point to the given y value
• T x2 y2 Add a quadratic Bézier, using the reflection of the previous segments' control point as control point
• S x2 y2 x3 y3 Add a cubic Bézier, using the reflection of the previous segments' second control point as first control point
• A rx ry r l s x y Add an elliptical arc from the current point to (x, y) with radii rx and ry. See the SVG documentation for how the other parameters influence the arc.
• O x1 y1 x2 y2 w Add a rational quadratic Bézier from the current point to (x2, y2) with control point (x1, y1) and weight w.

All the commands have lowercase variants that interpret coordinates relative to the current point.

The O command is an extension that is not supported in SVG.

Parameters:

string - a string

Returns:

a new GskPath, or NULL if string could not be parsed

Since:

4.14

foreach

public boolean foreach(Set<PathForeachFlags> flags,
 @Nullable PathForeachFunc func)

Calls func for every operation of the path.

Note that this may only approximate self, because paths can contain optimizations for various specialized contours, and depending on the flags, the path may be decomposed into simpler curves than the ones that it contained originally.

This function serves two purposes:

• When the flags allow everything, it provides access to the raw, unmodified data of the path.
• When the flags disallow certain operations, it provides an approximation of the path using just the allowed operations.

Parameters:

flags - flags to pass to the foreach function

func - the function to call for operations

Returns:

false if func returned false, true otherwise.

Since:

4.14

foreach

public boolean foreach(PathForeachFlags flags,
 @Nullable PathForeachFunc func)

Calls func for every operation of the path.

Note that this may only approximate self, because paths can contain optimizations for various specialized contours, and depending on the flags, the path may be decomposed into simpler curves than the ones that it contained originally.

This function serves two purposes:

• When the flags allow everything, it provides access to the raw, unmodified data of the path.
• When the flags disallow certain operations, it provides an approximation of the path using just the allowed operations.

Parameters:

flags - flags to pass to the foreach function

func - the function to call for operations

Returns:

false if func returned false, true otherwise.

Since:

4.14

foreachIntersection

public boolean foreachIntersection(@Nullable Path path2,
 @Nullable PathIntersectionFunc func)

Finds intersections between two paths.

This function finds intersections between this Path and path2, and calls func for each of them, in increasing order for path1.

If path2 is not provided or equal to path1, the function finds non-trivial self-intersections of path1.

When segments of the paths coincide, the callback is called once for the start of the segment, with GSKPATHINTERSECTIONSTART, and once for the end of the segment, with GSKPATHINTERSECTIONEND. Note that other intersections may occur between the start and end of such a segment.

If func returns FALSE, the iteration is stopped.

Parameters:

path2 - the second path

func - the function to call for intersections

Returns:

FALSE if func returned FALSE, TRUE` otherwise.

Since:

4.20

getBounds

public boolean getBounds(Rect bounds)

Computes the bounds of the given path.

The returned bounds may be larger than necessary, because this function aims to be fast, not accurate. The bounds are guaranteed to contain the path.

It is possible that the returned rectangle has 0 width and/or height. This can happen when the path only describes a point or an axis-aligned line.

If the path is empty, false is returned and bounds are set to graphene_rect_zero(). This is different from the case where the path is a single point at the origin, where the bounds will also be set to the zero rectangle but true will be returned.

Parameters:

bounds - return location for the bounds

Returns:

true if the path has bounds, false if the path is known to be empty and have no bounds

Since:

4.14

getClosestPoint

public boolean getClosestPoint(Point point,
 float threshold,
 PathPoint result,
 @Nullable Out<Float> distance)

Computes the closest point on the path to the given point.

If there is no point closer than the given threshold, false is returned.

Parameters:

point - the point

threshold - maximum allowed distance

result - return location for the closest point

distance - return location for the distance

Returns:

true if point was set to the closest point on self, false if no point is closer than threshold

Since:

4.14

getEndPoint

public boolean getEndPoint(PathPoint result)

Gets the end point of the path.

An empty path has no points, so false is returned in this case.

Parameters:

result - return location for point

Returns:

true if result was filled

Since:

4.14

getStartPoint

public boolean getStartPoint(PathPoint result)

Gets the start point of the path.

An empty path has no points, so false is returned in this case.

Parameters:

result - return location for point

Returns:

true if result was filled

Since:

4.14

getStrokeBounds

public boolean getStrokeBounds(Stroke stroke,
 Rect bounds)

Computes the bounds for stroking the given path with the given parameters.

The returned bounds may be larger than necessary, because this function aims to be fast, not accurate. The bounds are guaranteed to contain the area affected by the stroke, including protrusions like miters.

Parameters:

stroke - stroke parameters

bounds - the bounds to fill in

Returns:

true if the path has bounds, false if the path is known to be empty and have no bounds.

Since:

4.14

inFill

public boolean inFill(Point point,
 FillRule fillRule)

Returns whether a point is inside the fill area of a path.

Note that this function assumes that filling a contour implicitly closes it.

Parameters:

point - the point to test

fillRule - the fill rule to follow

Returns:

true if point is inside

Since:

4.14

isClosed

public boolean isClosed()

Returns if the path represents a single closed contour.

Returns:

true if the path is closed

Since:

4.14

isEmpty

public boolean isEmpty()

Checks if the path is empty, i.e. contains no lines or curves.

Returns:

true if the path is empty

Since:

4.14

print

public void print(String string)

Converts the path into a human-readable representation.

The string is compatible with (a superset of) SVG path syntax, see parse(java.lang.String) for a summary of the syntax.

Parameters:

string - the string to print into

Since:

4.14

ref

public Path ref()

Increases the reference count of a path by one.

Returns:

the passed in GskPath

Since:

4.14

toCairo

public void toCairo(org.freedesktop.cairo.Context cr)

Appends the path to a cairo context for drawing with Cairo.

This may cause some suboptimal conversions to be performed as Cairo does not support all features of GskPath.

This function does not clear the existing Cairo path. Call cairo_new_path() if you want this.

Parameters:

cr - a cairo context

Since:

4.14

toString

public String toString()

Converts the path into a human-readable string.

You can use this function in a debugger to get a quick overview of the path.

This is a wrapper around print(java.lang.String), see that function for details.

Overrides:

toString in class Object

Returns:

a new string for this Path

Since:

4.14

unref

public void unref()

Decreases the reference count of a path by one.

If the resulting reference count is zero, frees the path.

Since:

4.14