Path Control


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Path Control

The Path control is a windowless Microsoft® DirectAnimation™ control that animates the position of other controls along a defined vector or spline shape-based path.
To use the Path control, you must first instantiate it on the HTML page, as shown in the following syntax:
Syntax
<OBJECT ID=object
CLASSID="CLSID:D7A7D7C3-D47F-11d0-89D3-00A0C90833E6">
[<PARAM NAME="property" VALUE="setting">]
</OBJECT>
Parameters

object String identifying the object.
property One of the properties in the following table.
setting Value for the property.

Path Control Properties

Property Description
AutoStart Determines whether the Path control starts playback upon loading.
Bounce Sets the path behavior to either reverse direction and return to the beginning, or stop at the end of its playback.
Direction Sets the direction of the path playback.
Duration Sets the duration of the path playback.
Library Retrieves the DirectAnimation library reference.
PlayState Retrieves the path's current playback state.
Relative Determines whether the Path control starts playing from its current position or from the absolute position in the target object's coordinate space.
Repeat Sets the number of times the path loops during playback.
Target Sets the object that will follow the path.
Time Retrieves the elapsed playback time from the start of the path.
TimerInterval Sets or retrieves the length of time, in seconds.milliseconds, between path updates.

Path Control Methods

Method Description
AddTimeMarker Sets a marker to fire an event when playback reaches the marker position.
Oval Specifies an oval structured graphics primitive to be used as the path, with starting point at top center (12 o'clock)
KeyFrame Specifies points along the path, in x, y coordinates, and a designated time to reach each point.
Pause Stops playback and maintains current elapsed time.
Play Begins playback from the current elapsed time.
Polygon Specifies a closed series of line segments to use as the path.
PolyLine Specifies an open set of line segments to use as the path.
Rect Specifies a rectangular structured graphics primitive to use as the path, with starting point at top left.
Seek Resets the current playback position to a new, specified position.
Spline Specifies a spline to be used as the path.
Stop Stops playback at current elapsed time and returns path to the beginning.

Path Control Events

Event Description
onmarker Occurs when the path playback reaches a marker at the specified playback position, either when the Path control is playing or when it is stopped (and reaches the marker through a Seek call, for example).
onpause Occurs when path playback pauses.
onplay Occurs when the Path control plays back.
onplaymarker Occurs when path playback reaches a marker at the specified playback position.
onseek Occurs when the Path control completes a Seek call.
onstop Occurs when path playback stops.

AutoStart Property
Path Control
Determines whether the path starts playback immediately after loading. Read/write at run time; write access is available at run time only when the path is stopped.
PARAM Tag Syntax

<PARAM NAME="AutoStart" VALUE=0 | -1>

Script Syntax

object.AutoStart=[fStart]
Parameters

object
String identifying the Path object.
fStart
Starts playback as soon as the path is loaded if True (–1 or nonzero) or, if False (0), simply loads and does not play until explicitly started with the Play method. The default value is False.

Bounce Property
Path Control
Sets the path to either stop at the end of the path or reverse direction and continue playback. Read/write at run time; write access is available at run time only when the path is stopped.
PARAM Tag Syntax

<PARAM NAME="Bounce" VALUE=0 | -1>

Script Syntax

object.Bounce=[fBounce]
Parameters

object
String identifying the Path object.
fBounce
Stops playback at the end of the path if False (0), or reverses direction and continues playback if True (–1 or nonzero). The default value is False.

Direction Property
Path Control
Sets the direction of the path playback, either forward or reverse. Read/write at run time; write access is available at run time only when the path is stopped.
PARAM Tag Syntax

<PARAM NAME="Direction" VALUE=0 | 1>

Script Syntax

object.Direction=fDirection
Parameters

object
String identifying the Path object.
fDirection
Forward (0) or reverse (1). Default setting is 0.

Duration Property
Path Control
Sets the duration of the path playback. Read/write at run time; write access is available at run time only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME=" Duration" VALUE=" time ">

Script Syntax

object.Duration=[ time ]
Parameters

object
String identifying the Path object.
time
Double value, format 0.000 (seconds.milliseconds), that sets the length of time for the object to move from start to end of the path.

Remarks

The Duration property does not take Bounce behavior into account. If the path is set to bounce, the Duration property sets the time between the start and the end of its playback, and does not include the time when the path behavior reverses direction and returns to the start of the path.
Library Property
Path Control
Retrieves the reference to the DirectAnimation library functions.

Script Syntax

IDALibrary=object.Library
Parameters

IDALibrary
DirectAnimation library pointer.
object
String identifying the Path object.

Playstate Property
Path Control
Retrieves the path's playback state: stopped, playing, or paused. Read-only at run time.

Script Syntax

state=object.Playstate
Parameters

state
Playback state of the Path object; 0 if stopped, 1 if playing, 2 if paused.
object
String identifying the Path object.

Relative Property
Path Control
Determines whether the Path control starts playing from its current position or from the absolute position in the target object's coordinate space. Read/write at run time; write access is available at run time only when the path is stopped.
PARAM Tag Syntax

<PARAM NAME=Relative VALUE=0 | -1>

Script Syntax

object.Relative=fPos
Parameters

object
Path object.
fpos
True (–1 or nonzero) or False (0). If True, then the path playback starts from the target's current position. If False, then the path playback starts from the absolute position in the target's coordinate space. (For example, if you are using a Rect path, the absolute position starting point is the top left.) The default value is False.

Remarks

The Relative property means relative to the target object's position. The target object's position is set to relative or absolute with the STYLE="POSITION: ABSOLUTE | RELATIVE" attribute.
Relative Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

Repeat Property
Path Control
Sets the number of times the path loops playback. Read/write at run time; write access is available at run time only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME=" Repeat " VALUE=nRepeat >

Script Syntax

object.Repeat=[ nRepeat ]
Parameters

object
String identifying the Path object.
nRepeat
Integer expression setting the number of times the path repeats playback. Default value is 1. Set to –1 to cause the path to repeat infinitely; other negative values are treated as unsigned. Set to 0 to disable the Repeat property.

Target Property
Path Control
Sets the object to follow the path. Read/write at run time; write access is available at run time only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME=" Target" VALUE=" objTarget ">

Script Syntax

object.Target=[ objTarget ]
Parameters

object
String identifying the Path object.
objTarget
String identifying the path's target object.

Remarks

The target object must have an initial position. This can be set with the target object's STYLE attribute, as shown in the following examples:
<IMG SRC="target1.gif" ID="target1" STYLE="position:relative">
— or —
<IMG SRC="target1.gif" ID="target1" STYLE="position:absolute; left=100; top=100">
Target Property example
Right-click inside the frame and select View Source to see the HTML code for this example.

Time Property
Path Control
Retrieves the elapsed playback time (in milliseconds) from the start of the path playback. Repetitions set with Repeat are included in returned time calculations. Read-only at run time.

Script Syntax

time=object.Time
Parameters

object
String identifying the Path object.
time
Number of milliseconds into path playback. Default value is zero.

TimerInterval Property
Path Control
The default length of time, in seconds.milliseconds, between the path update. Read/write at run time; write access is available at run time only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME="TimerInterval" VALUE="nInterval">

Script Syntax

object.TimerInterval=nInterval
Parameters

nInterval
Integer expression giving the minimum number of seconds.milliseconds between path updates. The default interval is 0.100.

AddTimeMarker Method
Path Control
Adds marker at specified playback position, enabling author to generate an event when that playback position is reached. This method can be used or modified only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME=" AddTimeMarkerX" VALUE=" time,
  markername ,
  [ 0 | -1 ]">

Script Syntax

object.AddTimeMarker (
  time,
  "markername",
  [fAbsolute] )
Parameters

object
String identifying the Path object.
X
A sequential integer identifying the time marker, starting at 1 (PARAM tag syntax only). If you are adding more than one time marker through PARAM tag syntax, you must make each AddTimeMarker method call distinct by adding an sequential integer at the end of the AddTimeMarker PARAM name.
time
Time at which the onmarker or onplaymarker event fires.
markername
Name of the marker.
fAbsolute
An optional flag that specifies event firing. Default is True. If True (absolute) the event fires at the specified time once and ignores looping. If False (relative) the event fires everytime, including in loops. For PARAM tag syntax, use 0 for False and use –1 or nonzero for True. For script, use the predefined constants True and False.

Remarks

The onmarker event occurs whenever the path is at the specified marker, whether or not the path is playing. The onplaymarker event occurs only when the path is playing.
This example sets three time markers named MyMark, FrameFour, and FrameZero at 0.0, 4.7, and 8.0 respectively. MyMark and FrameZero are set to occur every time the path reaches that time marker, and FrameFour is set to occur only the first time the path reaches that time marker during uninterrupted playback.
<PARAM name="AddTimeMarker1" value="0.0, MyMark, 0">
<PARAM name="AddTimeMarker2" value="4.7, FrameFour, -1">
<PARAM name="AddTimeMarker3" value="8.0, FrameZero, 0">
AddFrameMarker Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

KeyFrame Method
Path Control
Specifies x and y coordinates along the path, and a time to reach each point. The first point defines the path's starting point. This method can be used or modified only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME=" KeyFrame" VALUE=" npoints,
  [ x1,
  y1 ,
  ...,
  xN,
  yN ],
  [ time2,
  ...,
  timeN ]">

Script Syntax

KeyFrameArray=Array(
  x1,
  y,
  ...,
  xN,
  yN )
TimeFrameArray=Array(
  time2 ,
  ...,
  timeN )
object.KeyFrame(
  npoints,
  KeyFrameArray ,
  TimeFrameArray )
Parameters

object
String identifying the Path object.
npoints
Number of points to be used to define the polyline.
x1, y1,...,xN, yN
Set of x and y coordinates that identify the keyframe points.
time2,..., timeN
Respective times that the path takes to reach each of the respective points from the previous point.
KeyFrameArray
Array that contains the x and y point definitions (script only).
TimeFrameArray
Array that contains the time values between the points that define the path, starting at the x1 and y1 point through xN and yN points (the last set of points in the path). The path begins at point x1 and y1 with a time value of 0. Script only.

Remarks

The Duration property is ignored when this method is invoked.
KeyFrame Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

Oval Method
Path Control
Specifies an oval path, with its starting point at the top center point of the oval (12 o'clock position). This method can be used or modified only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME="Shape" VALUE=" Oval(
  xpos,
  ypos,
  width,
  height
  ) ">

Script Syntax

object.Oval(
  xpos ,
  ypos ,
  width ,
  height )
Parameters

object
String identifying the Path object.
xpos
The x position defining the topmost point of the oval.
ypos
The y position defining the leftmost point of the oval.
width
Width of the oval.
height
Height of the oval.

Oval Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

Pause Method
Path Control
Pauses Path playback at current elapsed time and maintains current playback position.

VBscript Syntax

object.Pause

JScript Syntax

object.Pause( )
Parameters

object
String identifying the Path object.

Play Method
Path Control
Begins Path playback at current elapsed time.

VBscript Syntax

object.Play

JScript Syntax

object.Play( )
Parameters

object
String identifying the Path object.

Remarks

Calls to the Play method while a path is playing are ignored.
Polygon Method
Path Control
Specifies a set of closed line segments to use as a path. The first point defines the path's starting point. This method can be used or modified only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME="Shape" VALUE=" Polygon(
  npoints,
  [ x1,
  y1,
  ...,
  xN,
  yN ]
  ) ">

Script Syntax

PolygonArray=Array(
  x1,
  y1,
  ...,
  xN,
  yN )
object.Polygon(
  npoints,
  PolygonArray )
Parameters

object
String identifying the Path object.
n_Points
Number of points in the polygon.
x1, y1,..., xN, yN
Set of x and y coordinates that identify the polygon points.
PolygonArray
Array that contains the x and y point definitions (script only).

Remarks

The array of x, y coordinates can be specified either as an array, or as a comma-delimited string of numbers that will be passed into the coordinates.
Polygon Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

PolyLine Method
Path Control
Specifies a set of line segments to use as a path. The first point defines the path's starting point. This method can be used or modified only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME="Shape" VALUE=" PolyLine (
  npoints,
  [ x1,
  y1,
  ...,
  xN,
  yN ]
  ) ">

Script Syntax

PolyLineArray=Array(
  x1,
  y1,
  ...,
  xN,
  yN )
object.PolyLine (
  npoints,
  PolyLineArray
  )
Parameters

object
String identifying the Path object.
npoints
Number of points to be used to define the PolyLine.
x1, y1,..., xN, yN
Set of x and y coordinates that identify the polygon points.
PolyLineArray
Array that contains the x and y point definitions (script only).

Polyline Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

Rect Method
Path Control
Specifies a rectangular path, with its starting point at the top left point of the rectangle. This method can be used or modified only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME="Shape" VALUE="Rect(
  xpos,
  ypos,
  width,
  height ) ">

Script Syntax

object.Rect (
  xpos ,
  ypos ,
  width ,
  height )
Parameters

object
String identifying the Path object.
xpos
The x position for the starting point of the rectangle.
ypos
The y position for the starting point of the rectangle.
width
Width of the rectangle.
height
Height of the rectangle.

Rect Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

Seek Method
Path Control
Seeks to another position in the Path playback.

Script Syntax

object.Seek (
  time )
Parameters

object
String identifying the Path object.
time
Double value, format seconds.milliseconds (s.mss) that represents a different path playback elapsed time.

Spline Method
Path Control
Specifies a vector spline to be used as a path. The first point defines the path's starting point. This method can be used or modified only when the path is stopped.

PARAM Tag Syntax

<PARAM NAME="Shape" VALUE=" Spline(
  npoints,
  [ x1,
  y1,
  x2,
  y2... ]
  ) ">

Script Syntax

object.Spline (
  npoints,
  [ x1,
  y1,
  x2,
  y2... ] )
Parameters

object
String identifying the Path object.
npoints
Number of points to be used to define the Spline.
x1
First x point for the spline.
y1
First y point for the spline.
x2
Second x point for the spline.
y2
Second y point for the spline.

Remarks

You need to specify four points for each curve in the spline. You can specify the array of x, y coordinates either as an array or as a comma-delimited string of numbers that will be passed as the coordinate set. The number of points in the spline and their spacing can have an effect on the path's speed. Having too many points too close together along the path can cause the path to seem as if it is slowing down when it traverses those points.
Spline Method example
Right-click inside the frame and select View Source to see the HTML code for this example.

Stop Method
Path Control
Stops playback of the path at the current position and rewinds the path to its beginning.

VBscript Syntax

object.Stop

JScript Syntax

object.Stop( )
onmarker Event
Path Control
Occurs when the path playback reaches a marker at the specified playback position.

VBScript Syntax

Sub object _ onmarker (
  markername )
script
End Sub

JScript Syntax

<SCRIPT LANGUAGE="JavaScript" FOR=object EVENT=onmarker (
  markername ) >
script
<SCRIPT>
Parameters

object
String identifying the Path object.
markername
String containing the marker name established in the AddTimeMarker method.
script
Script to be executed.

Remarks

This event occurs whenever playback reaches the marker point, either when the path is playing or stopped. For example, if you seek to the marker position while the path is paused or stopped, the onmarker event will occur.
onpause Event
Path Control
Occurs when path playback is paused.

VBScript Syntax

Sub object _ onpause ( )
script
End Sub

JScript Syntax

<SCRIPT LANGUAGE="JavaScript" FOR=object EVENT=onpause >
script
<SCRIPT>
Parameters

object
String identifying the Path object.
script
Script to be executed.

onplay Event
Path Control
Occurs when path playback starts.

VBScript Syntax

Sub object _ onplay ( )
script
End Sub

JScript Syntax

<SCRIPT LANGUAGE="JavaScript" FOR=object EVENT=onplay >
script
<SCRIPT>
Parameters

object
String identifying the Path object.
script
Script to be executed.

onplaymarker Event
Path Control
Occurs when a marker is reached during path playback.

VBScript Syntax

Sub object _ onplaymarker (
  markername )
script
End Sub

JScript Syntax

<SCRIPT LANGUAGE="JavaScript" FOR=object EVENT=onplaymarker (
  markername ) >
script
<SCRIPT>
Parameters

object
String identifying the Path object.
markername
String containing the marker name established in the AddTimeMarker method.
script
Script to be executed.

onseek Event
Path Control
Occurs after a Seek call has been completed.

VBScript Syntax

Sub object _ onseek (
  newtime )
script
End Sub

JScript Syntax

<SCRIPT LANGUAGE="JavaScript" FOR=object EVENT=onseek (
  newtime ) >
script
<SCRIPT>
Parameters

object
String identifying the Path object.
newtime
Double value, format seconds.milliseconds (s.mss), that represents the new different path playback elapsed time.
script
Script to be executed.

onstop Event
Path Control
Occurs when the path stops playing.

VBScript Syntax

Sub object _ onstop ( )
script
End Sub

JScript Syntax

<SCRIPT LANGUAGE="JavaScript" FOR=object EVENT=onstop >
script
<SCRIPT>
Parameters

object
String identifying the Path object.

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object	String identifying the object.
property	One of the properties in the following table.
setting	Value for the property.

Property	Description
AutoStart	Determines whether the Path control starts playback upon loading.
Bounce	Sets the path behavior to either reverse direction and return to the beginning, or stop at the end of its playback.
Direction	Sets the direction of the path playback.
Duration	Sets the duration of the path playback.
Library	Retrieves the DirectAnimation library reference.
PlayState	Retrieves the path's current playback state.
Relative	Determines whether the Path control starts playing from its current position or from the absolute position in the target object's coordinate space.
Repeat	Sets the number of times the path loops during playback.
Target	Sets the object that will follow the path.
Time	Retrieves the elapsed playback time from the start of the path.
TimerInterval	Sets or retrieves the length of time, in seconds.milliseconds, between path updates.

Method	Description
AddTimeMarker	Sets a marker to fire an event when playback reaches the marker position.
Oval	Specifies an oval structured graphics primitive to be used as the path, with starting point at top center (12 o'clock)
KeyFrame	Specifies points along the path, in x, y coordinates, and a designated time to reach each point.
Pause	Stops playback and maintains current elapsed time.
Play	Begins playback from the current elapsed time.
Polygon	Specifies a closed series of line segments to use as the path.
PolyLine	Specifies an open set of line segments to use as the path.
Rect	Specifies a rectangular structured graphics primitive to use as the path, with starting point at top left.
Seek	Resets the current playback position to a new, specified position.
Spline	Specifies a spline to be used as the path.
Stop	Stops playback at current elapsed time and returns path to the beginning.

Event	Description
onmarker	Occurs when the path playback reaches a marker at the specified playback position, either when the Path control is playing or when it is stopped (and reaches the marker through a Seek call, for example).
onpause	Occurs when path playback pauses.
onplay	Occurs when the Path control plays back.
onplaymarker	Occurs when path playback reaches a marker at the specified playback position.
onseek	Occurs when the Path control completes a Seek call.
onstop	Occurs when path playback stops.