Opera Presto offers partial support for the CSS3 2D Transforms Module. As stated by the W3C, the CSS visual formatting model describes a coordinate system within which each element is positioned. Positions and sizes in this coordinate space can be thought of as being expressed in pixels, starting in the upper left corner of the parent with positive values proceeding to the right and down.
This coordinate space can be modified with the "transform" property. Using transform, elements can be translated, rotated and scaled in two dimensional space. The coordinate space behaves as described in the coordinate system transformations section of the SVG 1.1 specification. This is a coordinate system with two axes: the X axis increases horizontally to the right; the Y axis increases vertically downwards.
For further information, please see the W3C CSS3 2D Transforms Module.
Opera Presto supports the following CSS3 2D Transform properties. Note that since this CSS3 module is still experimental,
-o- is prefixed to each of the properties, enabling the Opera Presto 2.6 rendering engine to identify and use
them.
-o-transform property
A two-dimensional transformation is applied to an element through the -o-transform property. This property
contains a list of transform functions. The final transformation value for an element is obtained by performing a matrix
concatenation of each entry in the list. The set of transform functions is similar to those allowed by SVG.
| Property name |
-o-transform
|
|---|---|
| Value(s) |
none | <transform-function> [ <transform-function> ]*
|
| Initial |
none
|
| Applies to | Block-level and inline-level elements |
| Inherited | No |
| Percentages | Refer to the size of the element's box |
| Media | Visual |
| Computed value | Same as specified value |
| Support | Yes |
-o-transform-origin property
The -o-transform-origin property establishes the origin of transformation for an element. This property is
applied by first translating the element by the negated value of the property, then applying the element's transform, then
translating by the property value. This effectively moves the desired transformation origin of the element to (0,0) in the
local coordinate system, then applies the element's transform, then moves the element back to its original position.
| Property name |
-o-transform-origin
|
|---|---|
| Value(s) |
[ [ <percentage> | <length> | left | center | right ] [ <percentage> | <length> | top | center
| bottom ]? ] | [ [ left | center | right ] || [ top | center | bottom ] ]
|
| Initial |
50% 50%
|
| Applies to | Block-level and inline-level elements |
| Inherited | No |
| Percentages | Refer to the size of the element's box |
| Media | Visual |
| Computed value | For <length> the absolute value, otherwise a percentage |
| Support | Yes |
Opera supports the following CSS3 2D Transform functions. Note that the Opera -o- prefix is not needed with
these functions.
The value of the transform property is a list of <transform-functions> applied in the order provided.
The individual transform functions are separated by whitespace. The set of allowed transform functions is given below. In
this list the type <translation-value> is defined as a <length> or <percentage>
value, and the <angle> type is defined by CSS Values and Units.
matrix(<number>, <number>, <number>, <number>, <number>, <number>)matrix(a,b,c,d,e,f) is equivalent to applying the transformation matrix
[a b c d e f].translate(<translation-value>[, <translation-value>])[tx,
ty], where tx is the first translation-value parameter and ty is the optional second
translation-value parameter. If <ty> is not provided, ty has zero as a value.translateX(<translation-value>)X direction.translateY(<translation-value>)Y direction.scale(<number>[, <number>])[sx,sy]
scaling vector described by the 2 parameters. If the second parameter is not provided, it is takes a value equal to the
first.scaleX(<number>)[sx,1] scaling vector, where sx is given as the parameter.scaleY(<number>)[1,sy] scaling vector, where sy is given as the parameter.rotate(<angle>)-o-transform-origin property.skewX(<angle>)skewY(<angle>)skew(<angle> [, <angle>])| Attribute names |
a-f of type float
|
|---|---|
| Description | Each of these attributes represents one of the values in the 3x2 matrix. |
| Support | Yes |
| Method |
setMatrixValue
|
|---|---|
| Description | This method replaces the existing matrix with one computed from parsing the passed string as though it had been assigned to the transform property in a CSS style rule. |
| Parameters |
string of type DOMString- The string to parse. |
| Return value | None |
| Exceptions |
DOMException SYNTAX_ERR- Thrown when the provided string can not be parsed into a CSSMatrix. |
| Support | Yes |
| Method |
multiply
|
|---|---|
| Description | The multiply method returns a new CSSMatrix which is the result of this matrix multiplied by the passed matrix, with the passed matrix to the right. This matrix is not modified. |
| Parameters |
secondMatrix of type CSSMatrix- The matrix to multiply. |
| Return value |
CSSMatrix- The result matrix. |
| Exceptions | None |
| Support | Yes |
| Method |
inverse
|
|---|---|
| Description | The inverse method returns a new matrix which is the inverse of this matrix. This matrix is not modified. |
| Parameters | None |
| Return value |
CSSMatrix- The inverted matrix. |
| Exceptions |
DOMException NOT_SUPPORTED_ERR- Thrown when the CSSMatrix can not be inverted. |
| Support | Yes |
| Method |
translate
|
|---|---|
| Description | This method returns a new matrix which is this matrix post multiplied by a translation matrix containing the passed values. This matrix is not modified. |
| Parameters |
x of type float- The X component of the translation value. y of type float- The Y component of the translation value. |
| Return value |
CSSMatrix- The result matrix. |
| Exceptions | None |
| Support | Yes |
| Method |
scale
|
|---|---|
| Description | The scale method returns a new matrix which is this matrix post multiplied by a scale matrix containing the passed values. If the y component is undefined, the x component value is used in its place. This matrix is not modified. |
| Parameters |
scaleX of type float- The X component of the scale value. scaleY of type float- The (optional) Y component of the scale value. |
| Return value |
CSSMatrix- The result matrix. |
| Exceptions | None |
| Support | Yes |
| Method |
rotate
|
|---|---|
| Description | This method returns a new matrix which is this matrix post multiplied by a rotation matrix. The rotation value is in degrees. This matrix is not modified. |
| Parameters |
angle of type - The angle of rotation. |
| Return value |
CSSMatrix- The result matrix. |
| Exceptions | None |
| Support | Yes |
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