Class Spot

A Spot represents a relative point from (0,0) to (1,1) within the bounds of a rectangular area plus an absolute offset.

Use the static functions Spot.parse and Spot.stringify to convert to and from a standard string representation that is independent of the current locale.

When an instance of this class is the value of a property of a GraphObject class or Diagram or CommandHandler or a Tool class, you should treat the object as if it were frozen or read-only -- you cannot modify its properties. This allows the property to return a value without allocating a new instance. If you need to do your own calculations with the value, call copy to make a new instance with the same values that you can modify.

Many methods modify the object's properties and then return a reference to "this" object. The only instance method to allocate a new object is the copy method. The static Spot.parse method also allocates a new object.

The "Debug" implementation of this class is significantly slower than the "Release" implementation, mostly due to additional error checking.

You cannot inherit from this class.

Constructor Summary Details

Name Description
Spot(x, y, offx, offy)

The default constructor produces the Spot(0, 0, 0, 0), at the top-left corner.More...

Parameters:
{number=} x
The x value of the Spot. Default is zero.
{number=} y
The y value of the Spot. Default is zero.
{number=} offx
(Optional) The absolute x offset. Default is zero.
{number=} offy
(Optional) The absolute y offset. Default is zero.

Properties Summary Details

Name, Value Type Description
offsetX
{number}

Gets or sets the offsetX value of the Spot.More... The value may be negative. If this represents a side value instead of a specific spot, this value is meaningless.

A Spot(0,0,5,5) of a large rectangle is near the top-left corner, inside the rectangle. A Spot(1,1,5,5) would be near the bottom-right corner, outside the rectangle. A Spot(1,1,-5,-5) would also be near the bottom-right corner, but inside the rectangle.

offsetY
{number}

Gets or sets the offsetY value of the Spot.More... The value may be negative. If this represents a side value instead of a specific spot, this value is meaningless.

A Spot(0,0,5,5) of a large rectangle is near the top-left corner, inside the rectangle. A Spot(1,1,5,5) would be near the bottom-right corner, outside the rectangle. A Spot(1,1,-5,-5) would also be near the bottom-right corner, but inside the rectangle.

x
{number}

Gets or sets the x value of the Spot, a fractional value between zero and one.More...

The Spot(0,0) of a rectangle is at the top-left corner. This value is commonly available as Spot.TopLeft. The Spot(0.5,1) would be at the middle of the bottom side. That value is commonly available as Spot.MiddleBottom.

y
{number}

Gets or sets the y value of the Spot, a fractional value between zero and one.More...

The Spot(0,1) of a rectangle is at the bottom-left corner. This value is commonly available as Spot.BottomLeft. The Spot(1,0.5) would be at the middle of the right side. That value is commonly available as Spot.MiddleRight.

Method Summary Details

Name, Return Type Description
copy()
{Spot}

Create a copy of this Spot, with the same values.

Returns:
{Spot}
equals(spot)
{boolean}

Two spots are equal if all four property values are the same.More...

Parameters:
{Spot} spot
The Spot to compare to the current Spot.
Returns:
{boolean} True if the two spots are equal, false otherwise.
includesSide(side)
{boolean}

This predicate is true if this Spot is a side that includes the side(s) given by the argument Spot.More...

Parameters:
{Spot} side
Returns:
{boolean} false if either this Spot or the argument Spot is not a "Side"; true if the side(s) that this Spot represents are a superset or the same set of sides represented by the argument Spot.
isDefault()
{boolean}

True if this is a special spot referring to the default spot.

Returns:
{boolean}
isNoSpot()
{boolean}

True if this is an unspecific special spot, such as Spot.None or one of the sides.

Returns:
{boolean}
isSide()
{boolean}

True if this is a special spot referring to one (or more) of the sides.More... This is false if the spot is Spot.None.

Returns:
{boolean}
isSpot()
{boolean}

True if this is a specific spot, not a side nor Spot.None.

Returns:
{boolean}
opposite()
{Spot}

Return a new spot that is opposite this spot.More... The X and Y values will be an equal distance away from the center on the other side of the center. The OffsetX and OffsetY values are also negated.

The result is meaningless if isNoSpot is true.

Returns:
{Spot}
<static>
Spot.parse(str)
{Spot}

This static function can be used to read in a Spot from a string that was produced by Spot.stringify.More...

go.Spot.parse("0 1 2 3") produces the Spot new go.Spot(0, 1, 2, 3).

Parameters:
{string} str
Returns:
{Spot}
set(s)
{Spot}

Modify this Spot so that its X, Y, OffsetX, and OffsetY values are the same as the given Spot.More...

Parameters:
{Spot} s
the given Spot.
Returns:
{Spot} this.
setTo(x, y, offx, offy)
{Spot}

Modify this Spot with new X, Y, OffsetX, and OffsetY values.More...

Parameters:
{number} x
{number} y
{number} offx
{number} offy
Returns:
{Spot} this.
<static>
Spot.stringify(val)
{string}

This static function can be used to write out a Spot as a string that can be read by Spot.parse.More...

go.Spot.stringify(new go.Spot(0, 1, 2, 3)) produces the string "0 1 2 3".

Parameters:
{Spot} val
Returns:
{string}

Constants Summary Details

Name Description
AllSides {Spot}

The set of points on all sides of the bounding rectangle.

Bottom {Spot}

A synonym for Spot.BottomCenter.

BottomCenter {Spot}

The specific point at the middle of the bottom side of bounding rectangle.

BottomLeft {Spot}

The specific point at the bottom-left corner of the bounding rectangle.

BottomLeftSides {Spot}

The set of points at the left or bottom sides of the bounding rectangle.

BottomRight {Spot}

The specific point at the bottom-right corner of the bounding rectangle.

BottomRightSides {Spot}

The set of points at the right or bottom sides of the bounding rectangle.

BottomSide {Spot}

The set of points at the bottom side of the bounding rectangle.

Center {Spot}

The specific point at the very center of the bounding rectangle.

Default {Spot}

Use this value to indicate that the real spot value is inherited from elsewhere.

Left {Spot}

A synonym for Spot.LeftCenter.

LeftCenter {Spot}

The specific point at the middle of the left side of bounding rectangle.

LeftRightSides {Spot}

The set of points at the left or right sides of the bounding rectangle.

LeftSide {Spot}

The set of points at the left side of the bounding rectangle.

MiddleBottom {Spot}

A synonym for Spot.BottomCenter.

MiddleLeft {Spot}

A synonym for Spot.LeftCenter.

MiddleRight {Spot}

A synonym for Spot.RightCenter.

MiddleTop {Spot}

A synonym for Spot.TopCenter.

None {Spot}

Use this Spot value to indicate no particular spot -- code looking for a particular point on an element will need to do their own calculations to determine the desired point depending on the circumstances.

NotBottomSide {Spot}

The set of points on all sides of bounding rectangle except bottom side.

NotLeftSide {Spot}

The set of points on all sides of the bounding rectangle except left side.

NotRightSide {Spot}

The set of points on all sides of the bounding rectangle except right side.

NotTopSide {Spot}

The set of points on all sides of the bounding rectangle except top side.

RightCenter {Spot}

The specific point at the middle of the right side of bounding rectangle.

RightSide {Spot}

The set of points at the right side of the bounding rectangle.

Top {Spot}

A synonym for Spot.TopCenter.

TopBottomSides {Spot}

The set of points at the top or bottom sides of the bounding rectangle.

TopCenter {Spot}

The specific point at the center of the top side of the bounding rectangle.

TopLeft {Spot}

The specific point at the top-left corner of the bounding rectangle.

TopLeftSides {Spot}

The set of points at the top or left sides of the bounding rectangle.

TopRight {Spot}

The specific point at the top-right corner of the bounding rectangle.

TopRightSides {Spot}

The set of points at the top or right sides of the bounding rectangle.

TopSide {Spot}

The set of points at the top side of the bounding rectangle.