Paths represent the outline of a shape which can be filled, stroked, used as a clipping path, or any combination of the three. (See Filling, Stroking and Paint Servers and Clipping, Masking and Compositing.)
A path is described using the concept of a current point. In an analogy with drawing on paper, the current point can be thought of as the location of the pen. The position of the pen can be changed, and the outline of a shape (open or closed) can be traced by dragging the pen in either straight lines or curves.
Paths represent the geometry of the outline of an object, defined in terms of moveto (set a new current point), lineto (draw a straight line), curveto (draw a curve using a cubic Bézier), arc (elliptical or circular arc) and closepath (close the current shape by drawing a line to the last moveto) elements. Compound paths (i.e., a path with multiple subpaths) are possible to allow effects such as "donut holes" in objects.
This chapter describes the syntax, behavior and DOM interfaces for SVG paths. Various implementation notes for SVG paths can be found in ‘path’ element implementation notes and Elliptical arc implementation notes.
A path is defined in SVG using the ‘path’ element.
8.2 The ‘path’ element
‘path’
Categories:
Graphics element, shape element
Content model:
Any number of the following elements, in any order:
animation elements
descriptive elements
Attributes:
conditional processing attributes
core attributes
graphical event attributes
presentation attributes
‘class’
‘style’
‘externalResourcesRequired’
‘transform’
‘d’
‘pathLength’
DOM Interfaces:
SVGPathElement
Attribute definitions:
d = "
path data"
The definition of the outline of a shape. See Path data.
Animatable: yes. Path data animation is only possible when each path data specification within an animation specification has exactly the same list of path data commands as the
‘d’ attribute. If an animation is specified and the list of path data commands is not the same, then the animation specification is in error (see Error Processing). The animation engine interpolates each parameter to each path data command separately based on the attributes to the given animation element. Flags and booleans are interpolated as fractions between zero and one, with any non-zero value considered to be a value of one/true.
pathLength = " "
The author's computation of the total length of the path, in user units. This value is used to calibrate the user agent's own distance-along-a-path calculations with that of the author. The user agent will scale all distance-along-a-path computations by the ratio of
‘pathLength’ to the user agent's own computed value for total path length.
‘pathLength’ potentially affects calculations for text on a path, motion animation and various stroke operations.
A negative value is an error (see Error processing).
Animatable: yes.
8.3 Path data
8.3.1 General information about path data
A path is defined by including a ‘path’ element which contains a d="(path data)" attribute, where the ‘d’ attribute contains the moveto, line, curve (both cubic and quadratic Béziers), arc and closepath instructions.
Example triangle01 specifies a path in the shape of a triangle. (The M indicates a moveto, the Ls indicate linetos, and the z indicates a closepath).
Example triangle01
View this example as SVG (SVG-enabled browsers only)
Path data can contain newline characters and thus can be broken up into multiple lines to improve readability. Because of line length limitations with certain related tools, it is recommended that SVG generators split long path data strings across multiple lines, with each line not exceeding 255 characters. Also note that newline characters are only allowed at certain places within path data.
The syntax of path data is concise in order to allow for minimal file size and efficient downloads, since many SVG files will be dominated by their path data. Some of the ways that SVG attempts to minimize the size of path data are as follows:
All instructions are expressed as one character (e.g., a moveto is expressed as an M).
Superfluous white space and separators such as commas can be eliminated (e.g., "M 100 100 L 200 200" contains unnecessary spaces and could be expressed more compactly as "M100 100L200 200").
The command letter can be eliminated on subsequent commands if the same command is used multiple times in a row (e.g., you can drop the second "L" in "M 100 200 L 200 100 L -100 -200" and use "M 100 200 L 200 100 -100 -200" instead).
Relative versions of all commands are available (uppercase means absolute coordinates, lowercase means relative coordinates).
Alternate forms of lineto are available to optimize the special cases of horizontal and vertical lines (absolute and relative).
Alternate forms of curve are available to optimize the special cases where some of the control points on the current segment can be determined automatically from the control points on the previous segment.
The path data syntax is a prefix notation (i.e., commands followed by parameters). The only allowable decimal point is a Unicode U+0046 FULL STOP (".") character (also referred to in Unicode as PERIOD, dot and decimal point) and no other delimiter characters are allowed [UNICODE]. (For example, the following is an invalid numeric value in a path data stream: "13,000.56". Instead, say: "13000.56".)
For the relative versions of the commands, all coordinate values are relative to the current point at the start of the command.
In the tables below, the following notation is used:
(): grouping of parameters
+: 1 or more of the given parameter(s) is required
The following sections list the commands.
8.3.2 The "moveto" commands
The "moveto" commands (M or m) establish a new current point. The effect is as if the "pen" were lifted and moved to a new location. A path data segment (if there is one) must begin with a "moveto" command. Subsequent "moveto" commands (i.e., when the "moveto" is not the first command) represent the start of a new subpath:
Command
Name
Parameters
Description
M(absolute) m(relative)
moveto
(x y)+
Start a new sub-path at the given (x,y) coordinate. M (uppercase) indicates that absolute coordinates will follow; m (lowercase) indicates that relative coordinates will follow. If a moveto is followed by multiple pairs of coordinates, the subsequent pairs are treated as implicit lineto commands. Hence, implicit lineto commands will be relative if the moveto is relative, and absolute if the moveto is absolute. If a relative moveto (m) appears as the first element of the path, then it is treated as a pair of absolute coordinates. In this case, subsequent pairs of coordinates are treated as relative even though the initial moveto is interpreted as an absolute moveto.
8.3.3 The "closepath" command
The "closepath" (Z or z) ends the current subpath and causes an automatic straight line to be drawn from the current point to the initial point of the current subpath. If a "closepath" is followed immediately by a "moveto", then the "moveto" identifies the start point of the next subpath. If a "closepath" is followed immediately by any other command, then the next subpath starts at the same initial point as the current subpath.
When a subpath ends in a "closepath," it differs in behavior from what happens when "manually" closing a subpath via a "lineto" command in how ‘stroke-linejoin’ and ‘stroke-linecap’ are implemented. With "closepath", the end of the final segment of the subpath is "joined" with the start of the initial segment of the subpath using the current value of ‘stroke-linejoin’. If you instead "manually" close the subpath via a "lineto" command, the start of the first segment and the end of the last segment are not joined but instead are each capped using the current value of ‘stroke-linecap’. At the end of the command, the new current point is set to the initial point of the current subpath.
Command
Name
Parameters
Description
Z or z
closepath
(none)
Close the current subpath by drawing a straight line from the current point to current subpath's initial point. Since the Z and z commands take no parameters, they have an identical effect.
8.3.4 The "lineto" commands
The various "lineto" commands draw straight lines from the current point to a new point:
Command
Name
Parameters
Description
L(absolute) l(relative)
lineto
(x y)+
Draw a line from the current point to the given (x,y) coordinate which becomes the new current point. L (uppercase) indicates that absolute coordinates will follow; l (lowercase) indicates that relative coordinates will follow. A number of coordinates pairs may be specified to draw a polyline. At the end of the command, the new current point is set to the final set of coordinates provided.
H(absolute) h(relative)
horizontal lineto
x+
Draws a horizontal line from the current point (cpx, cpy) to (x, cpy). H (uppercase) indicates that absolute coordinates will follow; h (lowercase) indicates that relative coordinates will follow. Multiple x values can be provided (although usually this doesn't make sense). At the end of the command, the new current point becomes (x, cpy) for the final value of x.
V(absolute) v(relative)
vertical lineto
y+
Draws a vertical line from the current point (cpx, cpy) to (cpx, y). V (uppercase) indicates that absolute coordinates will follow; v (lowercase) indicates that relative coordinates will follow. Multiple y values can be provided (although usually this doesn't make sense). At the end of the command, the new current point becomes (cpx, y) for the final value of y.
8.3.5 The curve commands
These three groups of commands draw curves:
Cubic Bézier commands (C, c, S and s). A cubic Bézier segment is defined by a start point, an end point, and two control points.
Quadratic Bézier commands (Q, q, T and t). A quadratic Bézier segment is defined by a start point, an end point, and one control point.
Elliptical arc commands (A and a). An elliptical arc segment draws a segment of an ellipse.
8.3.6 The cubic Bézier curve commands
The cubic Bézier commands are as follows:
Command
Name
Parameters
Description
C(absolute) c(relative)
curveto
(x1 y1 x2 y2 x y)+
Draws a cubic Bézier curve from the current point to (x,y) using (x1,y1) as the control point at the beginning of the curve and (x2,y2) as the control point at the end of the curve. C (uppercase) indicates that absolute coordinates will follow; c (lowercase) indicates that relative coordinates will follow. Multiple sets of coordinates may be specified to draw a polybézier. At the end of the command, the new current point becomes the final (x,y) coordinate pair used in the polybézier.
S(absolute) s(relative)
shorthand/smooth curveto
(x2 y2 x y)+
Draws a cubic Bézier curve from the current point to (x,y). The first control point is assumed to be the reflection of the second control point on the previous command relative to the current point. (If there is no previous command or if the previous command was not an C, c, S or s, assume the first control point is coincident with the current point.) (x2,y2) is the second control point (i.e., the control point at the end of the curve). S (uppercase) indicates that absolute coordinates will follow; s (lowercase) indicates that relative coordinates will follow. Multiple sets of coordinates may be specified to draw a polybézier. At the end of the command, the new current point becomes the final (x,y) coordinate pair used in the polybézier.
Example cubic01 shows some simple uses of cubic Bézier commands within a path. The example uses an internal CSS style sheet to assign styling properties. Note that the control point for the "S" command is computed automatically as the reflection of the control point for the previous "C" command relative to the start point of the "S" command.
Example cubic01
View this example as SVG (SVG-enabled browsers only)
The following picture shows some how cubic Bézier curves change their shape depending on the position of the control points. The first five examples illustrate a single cubic Bézier path segment. The example at the lower right shows a "C" command followed by an "S" command.
View this example as SVG (SVG-enabled browsers only)
8.3.7 The quadratic Bézier curve commands
The quadratic Bézier commands are as follows:
Command
Name
Parameters
Description
Q(absolute) q(relative)
quadratic Bézier curveto
(x1 y1 x y)+
Draws a quadratic Bézier curve from the current point to (x,y) using (x1,y1) as the control point. Q (uppercase) indicates that absolute coordinates will follow; q (lowercase) indicates that relative coordinates will follow. Multiple sets of coordinates may be specified to draw a polybézier. At the end of the command, the new current point becomes the final (x,y) coordinate pair used in the polybézier.
T(absolute) t(relative)
Shorthand/smooth quadratic Bézier curveto
(x y)+
Draws a quadratic Bézier curve from the current point to (x,y). The control point is assumed to be the reflection of the control point on the previous command relative to the current point. (If there is no previous command or if the previous command was not a Q, q, T or t, assume the control point is coincident with the current point.) T (uppercase) indicates that absolute coordinates will follow; t (lowercase) indicates that relative coordinates will follow. At the end of the command, the new current point becomes the final (x,y) coordinate pair used in the polybézier.
Example quad01 shows some simple uses of quadratic Bézier commands within a path. Note that the control point for the "T" command is computed automatically as the reflection of the control point for the previous "Q" command relative to the start point of the "T" command.
Example quad01
View this example as SVG (SVG-enabled browsers only)
8.3.8 The elliptical arc curve commands
The elliptical arc commands are as follows:
Command
Name
Parameters
Description
A(absolute) a(relative)
elliptical arc
(rx ry x-axis-rotation large-arc-flag sweep-flag x y)+
Draws an elliptical arc from the current point to (x, y). The size and orientation of the ellipse are defined by two radii (rx, ry) and an x-axis-rotation, which indicates how the ellipse as a whole is rotated relative to the current coordinate system. The center (cx, cy) of the ellipse is calculated automatically to satisfy the constraints imposed by the other parameters. large-arc-flag and sweep-flag contribute to the automatic calculations and help determine how the arc is drawn.
Example arcs01 shows some simple uses of arc commands within a path.
Example arcs01
View this example as SVG (SVG-enabled browsers only)
The elliptical arc command draws a section of an ellipse which meets the following constraints:
the arc starts at the current point
the arc ends at point (x, y)
the ellipse has the two radii (rx, ry)
the x-axis of the ellipse is rotated by x-axis-rotation relative to the x-axis of the current coordinate system.
For most situations, there are actually four different arcs (two different ellipses, each with two different arc sweeps) that satisfy these constraints. large-arc-flag and sweep-flag indicate which one of the four arcs are drawn, as follows:
Of the four candidate arc sweeps, two will represent an arc sweep of greater than or equal to 180 degrees (the "large-arc"), and two will represent an arc sweep of less than or equal to 180 degrees (the "small-arc"). If large-arc-flag is '1', then one of the two larger arc sweeps will be chosen; otherwise, if large-arc-flag is '0', one of the smaller arc sweeps will be chosen,
If sweep-flag is '1', then the arc will be drawn in a "positive-angle" direction (i.e., the ellipse formula x=cx+rx*cos(theta) and y=cy+ry*sin(theta) is evaluated such that theta starts at an angle corresponding to the current point and increases positively until the arc reaches (x,y)). A value of 0 causes the arc to be drawn in a "negative-angle" direction (i.e., theta starts at an angle value corresponding to the current point and decreases until the arc reaches (x,y)).
The following illustrates the four combinations of large-arc-flag and sweep-flag and the four different arcs that will be drawn based on the values of these flags. For each case, the following path data command was used:
where "?,?" is replaced by "0,0" "0,1" "1,0" and "1,1" to generate the four possible cases.
View this example as SVG (SVG-enabled browsers only)
Refer to Elliptical arc implementation notes for detailed implementation notes for the path data elliptical arc commands.
8.3.9 The grammar for path data
The following notation is used in the Backus-Naur Form (BNF) description of the grammar for path data:
The processing of the BNF must consume as much of a given BNF production as possible, stopping at the point when a character is encountered which no longer satisfies the production. Thus, in the string "M 100-200", the first coordinate for the "moveto" consumes the characters "100" and stops upon encountering the minus sign because the minus sign cannot follow a digit in the production of a "coordinate". The result is that the first coordinate will be "100" and the second coordinate will be "-200".
Similarly, for the string "M 0.6.5", the first coordinate of the "moveto" consumes the characters "0.6" and stops upon encountering the second decimal point because the production of a "coordinate" only allows one decimal point. The result is that the first coordinate will be "0.6" and the second coordinate will be ".5".
Note that the BNF allows the path ‘d’ attribute to be empty. This is not an error, instead it disables rendering of the path.
8.4 Distance along a path
Various operations, including text on a path and motion animation and various stroke operations, require that the user agent compute the distance along the geometry of a graphics element, such as a ‘path’.
Exact mathematics exist for computing distance along a path, but the formulas are highly complex and require substantial computation. It is recommended that authoring products and user agents employ algorithms that produce as precise results as possible; however, to accommodate implementation differences and to help distance calculations produce results that approximate author intent, the ‘pathLength’ attribute can be used to provide the author's computation of the total length of the path so that the user agent can scale distance-along-a-path computations by the ratio of ‘pathLength’ to the user agent's own computed value for total path length.
A "moveto" operation within a ‘path’ element is defined to have zero length. Only the various "lineto", "curveto" and "arcto" commands contribute to path length calculations.
8.5 DOM interfaces
8.5.1 Interface SVGPathSeg
The SVGPathSeg
interface is a base interface that corresponds to a single command within a path data specification.
interface SVGPathSeg {
// Path Segment Types
const unsigned short PATHSEG_UNKNOWN = 0;
const unsigned short PATHSEG_CLOSEPATH = 1;
const unsigned short PATHSEG_MOVETO_ABS = 2;
const unsigned short PATHSEG_MOVETO_REL = 3;
const unsigned short PATHSEG_LINETO_ABS = 4;
const unsigned short PATHSEG_LINETO_REL = 5;
const unsigned short PATHSEG_CURVETO_CUBIC_ABS = 6;
const unsigned short PATHSEG_CURVETO_CUBIC_REL = 7;
const unsigned short PATHSEG_CURVETO_QUADRATIC_ABS = 8;
const unsigned short PATHSEG_CURVETO_QUADRATIC_REL = 9;
const unsigned short PATHSEG_ARC_ABS = 10;
const unsigned short PATHSEG_ARC_REL = 11;
const unsigned short PATHSEG_LINETO_HORIZONTAL_ABS = 12;
const unsigned short PATHSEG_LINETO_HORIZONTAL_REL = 13;
const unsigned short PATHSEG_LINETO_VERTICAL_ABS = 14;
const unsigned short PATHSEG_LINETO_VERTICAL_REL = 15;
const unsigned short PATHSEG_CURVETO_CUBIC_SMOOTH_ABS = 16;
const unsigned short PATHSEG_CURVETO_CUBIC_SMOOTH_REL = 17;
const unsigned short PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS = 18;
const unsigned short PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL = 19;
readonly attribute unsigned short pathSegType;
readonly attribute DOMString pathSegTypeAsLetter;
};
Constants in group “Path Segment Types”:
PATHSEG_UNKNOWN (unsigned short)
The unit type is not one of predefined types. It is invalid to attempt to define a new value of this type or to attempt to switch an existing value to this type.
PATHSEG_CLOSEPATH (unsigned short)
Corresponds to a "closepath" (z) path data command.
PATHSEG_MOVETO_ABS (unsigned short)
Corresponds to a "absolute moveto" (M) path data command.
PATHSEG_MOVETO_REL (unsigned short)
Corresponds to a "relative moveto" (m) path data command.
PATHSEG_LINETO_ABS (unsigned short)
Corresponds to a "absolute lineto" (L) path data command.
PATHSEG_LINETO_REL (unsigned short)
Corresponds to a "relative lineto" (l) path data command.
PATHSEG_CURVETO_CUBIC_ABS (unsigned short)
Corresponds to a "absolute cubic Bézier curveto" (C) path data command.
PATHSEG_CURVETO_CUBIC_REL (unsigned short)
Corresponds to a "relative cubic Bézier curveto" (c) path data command.
PATHSEG_CURVETO_QUADRATIC_ABS (unsigned short)
Corresponds to a "absolute quadratic Bézier curveto" (Q) path data command.
PATHSEG_CURVETO_QUADRATIC_REL (unsigned short)
Corresponds to a "relative quadratic Bézier curveto" (q) path data command.
PATHSEG_ARC_ABS (unsigned short)
Corresponds to a "absolute arcto" (A) path data command.
PATHSEG_ARC_REL (unsigned short)
Corresponds to a "relative arcto" (a) path data command.
PATHSEG_LINETO_HORIZONTAL_ABS (unsigned short)
Corresponds to a "absolute horizontal lineto" (H) path data command.
PATHSEG_LINETO_HORIZONTAL_REL (unsigned short)
Corresponds to a "relative horizontal lineto" (h) path data command.
PATHSEG_LINETO_VERTICAL_ABS (unsigned short)
Corresponds to a "absolute vertical lineto" (V) path data command.
PATHSEG_LINETO_VERTICAL_REL (unsigned short)
Corresponds to a "relative vertical lineto" (v) path data command.
PATHSEG_CURVETO_CUBIC_SMOOTH_ABS (unsigned short)
Corresponds to a "absolute smooth cubic curveto" (S) path data command.
PATHSEG_CURVETO_CUBIC_SMOOTH_REL (unsigned short)
Corresponds to a "relative smooth cubic curveto" (s) path data command.
The SVGPathSegCurvetoQuadraticSmoothRel
interface corresponds to a "relative smooth cubic curveto" (t) path data command.
interface SVGPathSegCurvetoQuadraticSmoothRel : SVGPathSeg {
attribute float x setraises(DOMException);
attribute float y setraises(DOMException);
};
Attributes:
x (float)
The relative X coordinate for the end point of this path segment.
Exceptions on setting
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised on an attempt to change the value of a read only attribute.
y (float)
The relative Y coordinate for the end point of this path segment.
Exceptions on setting
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised on an attempt to change the value of a read only attribute.
8.5.21 Interface SVGPathSegList
This interface defines a list of SVGPathSeg objects.
SVGPathSegList has the same attributes and methods as other SVGxxxList interfaces. Implementers may consider using a single base class to implement the various SVGxxxList interfaces.
interface SVGPathSegList {
readonly attribute unsigned long numberOfItems;
void clear() raises(DOMException);
SVGPathSeg initialize(in SVGPathSeg newItem) raises(DOMException);
SVGPathSeg getItem(in unsigned long index) raises(DOMException);
SVGPathSeg insertItemBefore(in SVGPathSeg newItem, in unsigned long index) raises(DOMException);
SVGPathSeg replaceItem(in SVGPathSeg newItem, in unsigned long index) raises(DOMException);
SVGPathSeg removeItem(in unsigned long index) raises(DOMException);
SVGPathSeg appendItem(in SVGPathSeg newItem) raises(DOMException);
};
Attributes:
numberOfItems (readonly unsigned long)
The number of items in the list.
Operations:
void
clear()
Clears all existing current items from the list, with the result being an empty list.
Exceptions
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised when the list cannot be modified.
SVGPathSeg
initialize(in SVGPathSeg newItem)
Clears all existing current items from the list and re-initializes the list to hold the single item specified by the parameter. If the inserted item is already in a list, it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy.
Parameters
SVGPathSeg newItem
The item which should become the only member of the list.
Returns
The item being inserted into the list.
Exceptions
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised when the list cannot be modified.
SVGPathSeg
getItem(in unsigned long index)
Returns the specified item from the list. The returned item is the item itself and not a copy. Any changes made to the item are immediately reflected in the list.
Parameters
unsigned long index
The index of the item from the list which is to be returned. The first item is number 0.
Returns
The selected item.
Exceptions
DOMException, code INDEX_SIZE_ERR
Raised if the index number is greater than or equal to numberOfItems.
SVGPathSeg
insertItemBefore(in SVGPathSeg newItem, in unsigned long index)
Inserts a new item into the list at the specified position. The first item is number 0. If newItem is already in a list, it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy. If the item is already in this list, note that the index of the item to insert before is
before the removal of the item.
Parameters
SVGPathSeg newItem
The item which is to be inserted into the list.
unsigned long index
The index of the item before which the new item is to be inserted. The first item is number 0. If the index is equal to 0, then the new item is inserted at the front of the list. If the index is greater than or equal to numberOfItems, then the new item is appended to the end of the list.
Returns
The inserted item.
Exceptions
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised when the list cannot be modified.
SVGPathSeg
replaceItem(in SVGPathSeg newItem, in unsigned long index)
Replaces an existing item in the list with a new item. If newItem is already in a list, it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy. If the item is already in this list, note that the index of the item to replace is
before the removal of the item.
Parameters
SVGPathSeg newItem
The item which is to be inserted into the list.
unsigned long index
The index of the item which is to be replaced. The first item is number 0.
Returns
The inserted item.
Exceptions
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised when the list cannot be modified.
DOMException, code INDEX_SIZE_ERR
Raised if the index number is greater than or equal to numberOfItems.
SVGPathSeg
removeItem(in unsigned long index)
Removes an existing item from the list.
Parameters
unsigned long index
The index of the item which is to be removed. The first item is number 0.
Returns
The removed item.
Exceptions
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised when the list cannot be modified.
DOMException, code INDEX_SIZE_ERR
Raised if the index number is greater than or equal to numberOfItems.
SVGPathSeg
appendItem(in SVGPathSeg newItem)
Inserts a new item at the end of the list. If newItem is already in a list, it is removed from its previous list before it is inserted into this list. The inserted item is the item itself and not a copy.
Parameters
SVGPathSeg newItem
The item which is to be inserted. The first item is number 0.
Returns
The inserted item.
Exceptions
DOMException, code NO_MODIFICATION_ALLOWED_ERR
Raised when the list cannot be modified.
8.5.22 Interface SVGAnimatedPathData
The SVGAnimatedPathData interface supports elements which have a ‘d’ attribute which holds SVG path data, and supports the ability to animate that attribute.
The SVGAnimatedPathData interface provides two lists to access and modify the base (i.e., static) contents of the ‘d’ attribute:
DOM attribute pathSegList provides access to the static/base contents of the ‘d’ attribute in a form which matches one-for-one with SVG's syntax.
DOM attribute normalizedPathSegList provides normalized access to the static/base contents of the ‘d’ attribute where all path data commands are expressed in terms of the following subset of SVGPathSeg types: SVG_PATHSEG_MOVETO_ABS (M), SVG_PATHSEG_LINETO_ABS (L), SVG_PATHSEG_CURVETO_CUBIC_ABS (C) and SVG_PATHSEG_CLOSEPATH (z).
and two lists to access the current animated values of the ‘d’ attribute:
DOM attribute animatedPathSegList provides access to the current animated contents of the ‘d’ attribute in a form which matches one-for-one with SVG's syntax.
DOM attribute animatedNormalizedPathSegList provides normalized access to the current animated contents of the ‘d’ attribute where all path data commands are expressed in terms of the following subset of SVGPathSegtypes: SVG_PATHSEG_MOVETO_ABS (M), SVG_PATHSEG_LINETO_ABS (L), SVG_PATHSEG_CURVETO_CUBIC_ABS (C) and SVG_PATHSEG_CLOSEPATH (z).
Each of the two lists are always kept synchronized. Modifications to one list will immediately cause the corresponding list to be modified. Modifications to normalizedPathSegList might cause entries in pathSegList to be broken into a set of normalized path segments.
Additionally, the ‘d’ attribute on the ‘path’ element accessed via the XML DOM (e.g., using the getAttribute() method call) will reflect any changes made to pathSegList or normalizedPathSegList.
Provides access to the base (i.e., static) contents of the
‘d’ attribute in a form which matches one-for-one with SVG's syntax. Thus, if the
‘d’ attribute has an "absolute moveto (M)" and an "absolute arcto (A)" command, then pathSegList will have two entries: a SVG_PATHSEG_MOVETO_ABS and a SVG_PATHSEG_ARC_ABS.
normalizedPathSegList (readonly SVGPathSegList)
Provides access to the base (i.e., static) contents of the ‘d’ attribute in a form where all path data commands are expressed in terms of the following subset of SVGPathSeg types: SVG_PATHSEG_MOVETO_ABS (M), SVG_PATHSEG_LINETO_ABS (L), SVG_PATHSEG_CURVETO_CUBIC_ABS (C) and SVG_PATHSEG_CLOSEPATH (z). Thus, if the ‘d’ attribute has an "absolute moveto (M)" and an "absolute arcto (A)" command, then pathSegList will have one SVG_PATHSEG_MOVETO_ABS entry followed by a series of SVG_PATHSEG_LINETO_ABS entries which approximate the arc. This alternate representation is available to provide a simpler interface to developers who would benefit from a more limited set of commands.
The only valid SVGPathSeg types are SVG_PATHSEG_MOVETO_ABS (M), SVG_PATHSEG_LINETO_ABS (L), SVG_PATHSEG_CURVETO_CUBIC_ABS (C) and SVG_PATHSEG_CLOSEPATH (z).
animatedPathSegList (readonly SVGPathSegList)
Provides access to the current animated contents of the
‘d’ attribute in a form which matches one-for-one with SVG's syntax. If the given attribute or property is being animated, contains the current animated value of the attribute or property, and both the object itself and its contents are read only. If the given attribute or property is not currently being animated, contains the same value as pathSegList.
Provides access to the current animated contents of the
‘d’ attribute in a form where all path data commands are expressed in terms of the following subset of SVGPathSeg types: SVG_PATHSEG_MOVETO_ABS (M), SVG_PATHSEG_LINETO_ABS (L), SVG_PATHSEG_CURVETO_CUBIC_ABS (C) and SVG_PATHSEG_CLOSEPATH (z). If the given attribute or property is being animated, contains the current animated value of the attribute or property, and both the object itself and its contents are read only. If the given attribute or property is not currently being animated, contains the same value as normalizedPathSegList.
8.5.23 Interface SVGPathElement
The SVGPathElement
interface corresponds to the ‘path’ element.
interface SVGPathElement : SVGElement,
SVGTests,
SVGLangSpace,
SVGExternalResourcesRequired,
SVGStylable,
SVGTransformable,
SVGAnimatedPathData {
readonly attribute SVGAnimatedNumber pathLength;
float getTotalLength();
SVGPoint getPointAtLength(in float distance);
unsigned long getPathSegAtLength(in float distance);
SVGPathSegClosePath createSVGPathSegClosePath();
SVGPathSegMovetoAbs createSVGPathSegMovetoAbs(in float x, in float y);
SVGPathSegMovetoRel createSVGPathSegMovetoRel(in float x, in float y);
SVGPathSegLinetoAbs createSVGPathSegLinetoAbs(in float x, in float y);
SVGPathSegLinetoRel createSVGPathSegLinetoRel(in float x, in float y);
SVGPathSegCurvetoCubicAbs createSVGPathSegCurvetoCubicAbs(in float x, in float y, in float x1, in float y1, in float x2, in float y2);
SVGPathSegCurvetoCubicRel createSVGPathSegCurvetoCubicRel(in float x, in float y, in float x1, in float y1, in float x2, in float y2);
SVGPathSegCurvetoQuadraticAbs createSVGPathSegCurvetoQuadraticAbs(in float x, in float y, in float x1, in float y1);
SVGPathSegCurvetoQuadraticRel createSVGPathSegCurvetoQuadraticRel(in float x, in float y, in float x1, in float y1);
SVGPathSegArcAbs createSVGPathSegArcAbs(in float x, in float y, in float r1, in float r2, in float angle, in boolean largeArcFlag, in boolean sweepFlag);
SVGPathSegArcRel createSVGPathSegArcRel(in float x, in float y, in float r1, in float r2, in float angle, in boolean largeArcFlag, in boolean sweepFlag);
SVGPathSegLinetoHorizontalAbs createSVGPathSegLinetoHorizontalAbs(in float x);
SVGPathSegLinetoHorizontalRel createSVGPathSegLinetoHorizontalRel(in float x);
SVGPathSegLinetoVerticalAbs createSVGPathSegLinetoVerticalAbs(in float y);
SVGPathSegLinetoVerticalRel createSVGPathSegLinetoVerticalRel(in float y);
SVGPathSegCurvetoCubicSmoothAbs createSVGPathSegCurvetoCubicSmoothAbs(in float x, in float y, in float x2, in float y2);
SVGPathSegCurvetoCubicSmoothRel createSVGPathSegCurvetoCubicSmoothRel(in float x, in float y, in float x2, in float y2);
SVGPathSegCurvetoQuadraticSmoothAbs createSVGPathSegCurvetoQuadraticSmoothAbs(in float x, in float y);
SVGPathSegCurvetoQuadraticSmoothRel createSVGPathSegCurvetoQuadraticSmoothRel(in float x, in float y);
};
Attributes:
pathLength (readonly SVGAnimatedNumber)
Corresponds to attribute pathLength on the given
‘path’ element.
Operations:
float
getTotalLength()
Returns the user agent's computed value for the total length of the path using the user agent's distance-along-a-path algorithm, as a distance in the current user coordinate system.
Returns
The total length of the path.
SVGPoint
getPointAtLength(in float distance)
Returns the (x,y) coordinate in user space which is distance units along the path, utilizing the user agent's distance-along-a-path algorithm.
Parameters
float distance
The distance along the path, relative to the start of the path, as a distance in the current user coordinate system.
Returns
The returned point in user space.
unsigned long
getPathSegAtLength(in float distance)
Returns the index into pathSegList which is distance units along the path, utilizing the user agent's distance-along-a-path algorithm.
Parameters
float distance
The distance along the path, relative to the start of the path, as a distance in the current user coordinate system.
Returns
The index of the path segment, where the first path segment is number 0.
SVGPathSegClosePath
createSVGPathSegClosePath()
Returns a stand-alone, parentless SVGPathSegClosePath object.
Returns
A stand-alone, parentless SVGPathSegClosePath object.
SVGPathSegMovetoAbs
createSVGPathSegMovetoAbs(in float x, in float y)
Returns a stand-alone, parentless SVGPathSegMovetoAbs object.
Parameters
float x
The absolute X coordinate for the end point of this path segment.
float y
The absolute Y coordinate for the end point of this path segment.
Returns
A stand-alone, parentless SVGPathSegMovetoAbs object.
SVGPathSegMovetoRel
createSVGPathSegMovetoRel(in float x, in float y)
Returns a stand-alone, parentless SVGPathSegMovetoRel object.
Parameters
float x
The relative X coordinate for the end point of this path segment.
float y
The relative Y coordinate for the end point of this path segment.
Returns
A stand-alone, parentless SVGPathSegMovetoRel object.
SVGPathSegLinetoAbs
createSVGPathSegLinetoAbs(in float x, in float y)
Returns a stand-alone, parentless SVGPathSegLinetoAbs object.
Parameters
float x
The absolute X coordinate for the end point of this path segment.
float y
The absolute Y coordinate for the end point of this path segment.
Returns
A stand-alone, parentless SVGPathSegLinetoAbs object.
SVGPathSegLinetoRel
createSVGPathSegLinetoRel(in float x, in float y)
Returns a stand-alone, parentless SVGPathSegLinetoRel object.
Parameters
float x
The relative X coordinate for the end point of this path segment.
float y
The relative Y coordinate for the end point of this path segment.
Returns
A stand-alone, parentless SVGPathSegLinetoRel object.
SVGPathSegCurvetoCubicAbs
createSVGPathSegCurvetoCubicAbs(in float x, in float y, in float x1, in float y1, in float x2, in float y2)
Returns a stand-alone, parentless SVGPathSegCurvetoCubicAbs object.
Parameters
float x
The absolute X coordinate for the end point of this path segment.
float y
The absolute Y coordinate for the end point of this path segment.
float x1
The absolute X coordinate for the first control point.
float y1
The absolute Y coordinate for the first control point.
float x2
The absolute X coordinate for the second control point.
float y2
The absolute Y coordinate for the second control point.
Returns
A stand-alone, parentless SVGPathSegCurvetoCubicAbs object.
SVGPathSegCurvetoCubicRel
createSVGPathSegCurvetoCubicRel(in float x, in float y, in float x1, in float y1, in float x2, in float y2)
Returns a stand-alone, parentless SVGPathSegCurvetoCubicRel object.
Parameters
float x
The relative X coordinate for the end point of this path segment.
float y
The relative Y coordinate for the end point of this path segment.
float x1
The relative X coordinate for the first control point.
float y1
The relative Y coordinate for the first control point.
float x2
The relative X coordinate for the second control point.
float y2
The relative Y coordinate for the second control point.
Returns
A stand-alone, parentless SVGPathSegCurvetoCubicRel object.
SVGPathSegCurvetoQuadraticAbs
createSVGPathSegCurvetoQuadraticAbs(in float x, in float y, in float x1, in float y1)
Returns a stand-alone, parentless SVGPathSegCurvetoQuadraticAbs object.
Parameters
float x
The absolute X coordinate for the end point of this path segment.
float y
The absolute Y coordinate for the end point of this path segment.
float x1
The absolute X coordinate for the first control point.
float y1
The absolute Y coordinate for the first control point.
Returns
A stand-alone, parentless SVGPathSegCurvetoQuadraticAbs object.
SVGPathSegCurvetoQuadraticRel
createSVGPathSegCurvetoQuadraticRel(in float x, in float y, in float x1, in float y1)
Returns a stand-alone, parentless SVGPathSegCurvetoQuadraticRel object.
Parameters
float x
The relative X coordinate for the end point of this path segment.
float y
The relative Y coordinate for the end point of this path segment.
float x1
The relative X coordinate for the first control point.
float y1
The relative Y coordinate for the first control point.
Returns
A stand-alone, parentless SVGPathSegCurvetoQuadraticRel object.
SVGPathSegArcAbs
createSVGPathSegArcAbs(in float x, in float y, in float r1, in float r2, in float angle, in boolean largeArcFlag, in boolean sweepFlag)
Returns a stand-alone, parentless SVGPathSegArcAbs object.
Parameters
float x
The absolute X coordinate for the end point of this path segment.
float y
The absolute Y coordinate for the end point of this path segment.
float r1
The x-axis radius for the ellipse (i.e., r1).
float r2
The y-axis radius for the ellipse (i.e., r2).
float angle
The rotation angle in degrees for the ellipse's x-axis relative to the x-axis of the user coordinate system.
boolean largeArcFlag
The value of the large-arc-flag parameter.
boolean sweepFlag
The value of the large-arc-flag parameter.
Returns
A stand-alone, parentless SVGPathSegArcAbs object.
SVGPathSegArcRel
createSVGPathSegArcRel(in float x, in float y, in float r1, in float r2, in float angle, in boolean largeArcFlag, in boolean sweepFlag)
Returns a stand-alone, parentless SVGPathSegArcRel object.
Parameters
float x
The relative X coordinate for the end point of this path segment.
float y
The relative Y coordinate for the end point of this path segment.
float r1
The x-axis radius for the ellipse (i.e., r1).
float r2
The y-axis radius for the ellipse (i.e., r2).
float angle
The rotation angle in degrees for the ellipse's x-axis relative to the x-axis of the user coordinate system.
boolean largeArcFlag
The value of the large-arc-flag parameter.
boolean sweepFlag
The value of the large-arc-flag parameter.
Returns
A stand-alone, parentless SVGPathSegArcRel object.
终端仿真器是一款用其它显示架构重现可视终端的计算机程序。换句话说就是终端仿真器能使哑终端看似像一台连接上了服务器的客户机。终端仿真器允许最终用户用文本用户界面和命令行来访问控制台和应用程序。(LCTT 译注:终端仿真器原意指对大型机-哑终端方式的模拟,不过在当今的 Linux 环境中,常指通过远程或本地方式连接的伪终端,俗称“终端”。)
你能从开源世界中找到大量的终端仿真器,它们
功能:在控制台每秒输出一次
代码:
package Main;
import javax.swing.Timer;
import java.awt.event.*;
public class T {
private static int count = 0;
public static void main(String[] args){
1,获取样式属性值
top 与顶部的距离
left 与左边的距离
right 与右边的距离
bottom 与下边的距离
zIndex 层叠层次
例子:获取左边的宽度,当css写在body标签中时
<div id="adver" style="position:absolute;top:50px;left:1000p
spring data jpa 支持以方法名进行查询/删除/统计。
查询的关键字为find
删除的关键字为delete/remove (>=1.7.x)
统计的关键字为count (>=1.7.x)
修改需要使用@Modifying注解
@Modifying
@Query("update User u set u.firstna
项目中controller的方法跳转的到ModelAndView类,一直很好奇spring怎么实现的?
/*
* Copyright 2002-2010 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* yo
(1)npm是什么
npm is the package manager for node
官方网站:https://www.npmjs.com/
npm上有很多优秀的nodejs包,来解决常见的一些问题,比如用node-mysql,就可以方便通过nodejs链接到mysql,进行数据库的操作
在开发过程往往会需要用到其他的包,使用npm就可以下载这些包来供程序调用
&nb
Controller层的拦截器继承于HandlerInterceptorAdapter
HandlerInterceptorAdapter.java 1 public abstract class HandlerInterceptorAdapter implements HandlerIntercep