The main SvgCanvas class that manages all SVG-related functions
container | The container HTML element that should hold the SVG root element |
config | An object that contains configuration data |
SvgCanvas | The main SvgCanvas class that manages all SVG-related functions |
toXml | Converts characters in a string to XML-friendly entities. |
fromXml | Converts XML entities in a string to single characters. |
Unit conversion functions | |
convertToNum | Converts given values to numbers. |
setUnitAttr | Sets an element’s attribute based on the unit in its current value. |
isValidUnit | Check if an attribute’s value is in a valid format |
Undo/ | |
ChangeElementCommand | History command to make a change to an element. |
ChangeElementCommand. | Performs the stored change action |
ChangeElementCommand. | Reverses the stored change action |
ChangeElementCommand. | Returns array with element associated with this command |
InsertElementCommand | History command for an element that was added to the DOM |
InsertElementCommand. | Re-Inserts the new element |
InsertElementCommand. | Removes the element |
InsertElementCommand. | Returns array with element associated with this command |
RemoveElementCommand | History command for an element removed from the DOM |
RemoveElementCommand. | Re-removes the new element |
RemoveElementCommand. | Re-adds the new element |
RemoveElementCommand. | Returns array with element associated with this command |
MoveElementCommand | History command for an element that had its DOM position changed |
MoveElementCommand. | Re-positions the element |
MoveElementCommand. | Positions the element back to its original location |
MoveElementCommand. | Returns array with element associated with this command |
BatchCommand | History command that can contain/execute multiple other commands |
BatchCommand. | Runs “apply” on all subcommands |
BatchCommand. | Runs “unapply” on all subcommands |
BatchCommand. | Iterate through all our subcommands and returns all the elements we are changing |
BatchCommand. | Adds a given command to the history stack |
BatchCommand. | Returns a boolean indicating whether or not the batch command is empty |
resetUndoStack | Resets the undo stack, effectively clearing the undo/redo history |
undoMgr. | Integer with the current size of the undo history stack |
undoMgr. | Integer with the current size of the redo history stack |
undoMgr. | String associated with the next undo command |
undoMgr. | String associated with the next redo command |
undoMgr.undo | Performs an undo step |
undoMgr.redo | Performs a redo step |
addCommandToHistory | Adds a command object to the undo history stack |
beginUndoableChange | This function tells the canvas to remember the old values of the attrName attribute for each element sent in. |
finishUndoableChange | This function returns a BatchCommand object which summarizes the change since beginUndoableChange was called. |
Selector | Private class for DOM element selection boxes |
Functions | |
Selector. | Used to reset the id and element that the selector is attached to |
Selector. | Show the resize grips of this selector |
Selector. | Updates cursors for corner grips on rotation so arrows point the right way |
Selector. | Updates the selector to match the element’s size |
SelectorManager | Public class to manage all selector objects (selection boxes) |
SelectorManager. | Resets the parent selector group element |
SelectorManager. | Returns the selector based on the given element |
SelectorManager. | Removes the selector of the given element (hides selection box) |
SelectorManager. | Returns the rubberBandBox DOM element. |
Helper functions | |
walkTree | Walks the tree and executes the callback on each element in a top-down fashion |
walkTreePost | Walks the tree and executes the callback on each element in a depth-first fashion |
assignAttributes | Assigns multiple attributes to an element. |
cleanupElement | Remove unneeded (default) attributes, makes resulting SVG smaller |
addSvgElementFromJson | Create a new SVG element based on the given object keys/values and add it to the current layer The element will be ran through cleanupElement before being returned |
shortFloat | Rounds a given value to a float with number of digits defined in save_options |
getId | Returns the last created DOM element ID string |
getNextId | Creates and returns a unique ID string for a DOM element |
bind | Attaches a callback function to an event |
setIdPrefix | Changes the ID prefix to the given value |
sanitizeSvg | Sanitizes the input node and its children It only keeps what is allowed from our whitelist defined above |
getUrlFromAttr | Extracts the URL from the url(...) |
Element Transforms | |
recalculateAllSelectedDimensions | Runs recalculateDimensions on the selected elements, adding the changes to a single batch command |
remapElement | Applies coordinate changes to an element based on the given matrix |
recalculateDimensions | Decides the course of action based on the element’s transform list |
transformPoint | A (hopefully) quicker function to transform a point by a matrix (this function avoids any DOM calls and just does the math) |
isIdentity | Helper function to check if the matrix performs no actual transform (i.e. |
matrixMultiply | This function tries to return a SVGMatrix that is the multiplication m1*m2. |
transformListToTransform | This returns a single matrix Transform for a given Transform List (this is the equivalent of SVGTransformList.consolidate() but unlike that method, this one does not modify the actual SVGTransformList) This function is very liberal with its min,max arguments |
hasMatrixTransform | See if the given transformlist includes a non-indentity matrix transform |
getMatrix | Get the matrix object for a given element |
transformBox | Transforms a rectangle based on the given matrix |
Selection | |
clearSelection | Clears the selection. |
addToSelection | Adds a list of elements to the selection. |
removeFromSelection | Removes elements from the selection. |
smoothControlPoints | Takes three points and creates a smoother line based on them |
getMouseTarget | Gets the desired element from a mouse event |
textActions | Functions relating to editing text elements |
pathActions | Functions relating to editing path elements |
Serialization | |
removeUnusedDefElems | Looks at DOM elements inside the <defs> to see if they are referred to, removes them from the DOM if they are not. |
svgCanvasToString | Main function to set up the SVG content for output |
svgToString | Sub function ran on each SVG element to convert it to a string as desired |
embedImage | Converts a given image file to a data URL when possible, then runs a given callback |
save | Serializes the current drawing into SVG XML text and returns it to the ‘saved’ handler. |
rasterExport | Generates a PNG Data URL based on the current image, then calls “exported” with an object including the string and any issues found |
getSvgString | Returns the current drawing as raw SVG XML text. |
setSvgString | This function sets the current drawing as the input SVG XML. |
importSvgString | This function imports the input SVG XML into the current layer in the drawing |
Layers | |
createLayer | Creates a new top-level layer in the drawing with the given name, sets the current layer to it, and then clears the selection This function then calls the ‘changed’ handler. |
deleteCurrentLayer | Deletes the current layer from the drawing and then clears the selection. |
getNumLayers | Returns the number of layers in the current drawing. |
getLayer | Returns the name of the ith layer. |
getCurrentLayer | Returns the name of the currently selected layer. |
setCurrentLayer | Sets the current layer. |
renameCurrentLayer | Renames the current layer. |
setCurrentLayerPosition | Changes the position of the current layer to the new value. |
getLayerVisibility | Returns whether the layer is visible. |
setLayerVisibility | Sets the visibility of the layer. |
moveSelectedToLayer | Moves the selected elements to layername. |
getLayerOpacity | Returns the opacity of the given layer. |
setLayerOpacity | Sets the opacity of the given layer. |
selectAllInCurrentLayer | Clears the selection, then adds all elements in the current layer to the selection. |
clear | Clears the current document. |
Fill and Stroke | |
convertToPath | Convert selected element to a path, or get the BBox of an element-as-path |
getVersion | Returns a string which describes the revision number of SvgCanvas. |
var ChangeElementCommand = this.undoCmd.changeElement = function( elem, attrs, text )
History command to make a change to an element. Usually an attribute change, but can also be textcontent.
elem | The DOM element that was changed |
attrs | An object with the attributes to be changed and the values they had before the change |
text | An optional string visible to user related to this change |
var MoveElementCommand = this.undoCmd.moveElement = function( elem, oldNextSibling, oldParent, text )
History command for an element that had its DOM position changed
elem | The DOM element that was moved |
oldNextSibling | The element’s next sibling before it was moved |
oldParent | The element’s parent before it was moved |
text | An optional string visible to user related to this change |
c.beginUndoableChange = function( attrName, elems )
This function tells the canvas to remember the old values of the attrName attribute for each element sent in. The elements and values are stored on a stack, so the next call to finishUndoableChange() will pop the elements and old values off the stack, gets the current values from the DOM and uses all of these to construct the undo-able command.
attrName | The name of the attribute being changed |
elems | Array of DOM elements being changed |
Private class for DOM element selection boxes
id | integer to internally indentify the selector |
elem | DOM element associated with this selector |
Functions | |
Selector. | Used to reset the id and element that the selector is attached to |
Selector. | Show the resize grips of this selector |
Selector. | Updates cursors for corner grips on rotation so arrows point the right way |
Selector. | Updates the selector to match the element’s size |
Public class to manage all selector objects (selection boxes)
SelectorManager. | Resets the parent selector group element |
SelectorManager. | Returns the selector based on the given element |
SelectorManager. | Removes the selector of the given element (hides selection box) |
SelectorManager. | Returns the rubberBandBox DOM element. |
Helper functions | |
walkTree | Walks the tree and executes the callback on each element in a top-down fashion |
walkTreePost | Walks the tree and executes the callback on each element in a depth-first fashion |
assignAttributes | Assigns multiple attributes to an element. |
cleanupElement | Remove unneeded (default) attributes, makes resulting SVG smaller |
addSvgElementFromJson | Create a new SVG element based on the given object keys/values and add it to the current layer The element will be ran through cleanupElement before being returned |
shortFloat | Rounds a given value to a float with number of digits defined in save_options |
getId | Returns the last created DOM element ID string |
getNextId | Creates and returns a unique ID string for a DOM element |
bind | Attaches a callback function to an event |
setIdPrefix | Changes the ID prefix to the given value |
sanitizeSvg | Sanitizes the input node and its children It only keeps what is allowed from our whitelist defined above |
getUrlFromAttr | Extracts the URL from the url(...) |
Element Transforms | |
recalculateAllSelectedDimensions | Runs recalculateDimensions on the selected elements, adding the changes to a single batch command |
remapElement | Applies coordinate changes to an element based on the given matrix |
recalculateDimensions | Decides the course of action based on the element’s transform list |
transformPoint | A (hopefully) quicker function to transform a point by a matrix (this function avoids any DOM calls and just does the math) |
isIdentity | Helper function to check if the matrix performs no actual transform (i.e. |
matrixMultiply | This function tries to return a SVGMatrix that is the multiplication m1*m2. |
transformListToTransform | This returns a single matrix Transform for a given Transform List (this is the equivalent of SVGTransformList.consolidate() but unlike that method, this one does not modify the actual SVGTransformList) This function is very liberal with its min,max arguments |
hasMatrixTransform | See if the given transformlist includes a non-indentity matrix transform |
getMatrix | Get the matrix object for a given element |
transformBox | Transforms a rectangle based on the given matrix |
Selection | |
clearSelection | Clears the selection. |
addToSelection | Adds a list of elements to the selection. |
removeFromSelection | Removes elements from the selection. |
smoothControlPoints | Takes three points and creates a smoother line based on them |
getMouseTarget | Gets the desired element from a mouse event |
var assignAttributes = this.assignAttributes = function( node, attrs, suspendLength, unitCheck )
Assigns multiple attributes to an element.
node | DOM element to apply new attribute values to |
attrs | Object with attribute keys/values |
suspendLength | Optional integer of milliseconds to suspend redraw |
unitCheck | Boolean to indicate the need to use setUnitAttr |
var addSvgElementFromJson = this.addSvgElementFromJson = function( data )
Create a new SVG element based on the given object keys/values and add it to the current layer The element will be ran through cleanupElement before being returned
data | Object with the following keys/values: |
Returns: The new element
var shortFloat = function( val )
Rounds a given value to a float with number of digits defined in save_options
val | The value as a String, Number or Array of two numbers to be rounded |
If a string/number was given, returns a Float. If an array, return a string with comma-seperated floats
var getUrlFromAttr = this.getUrlFromAttr = function( attrVal )
Extracts the URL from the url(...) syntax of some attributes. Three variants:
attrVal | The attribute value as a string |
String with just the URL, like someFile.svg#foo
var transformPoint = function( x, y, m )
A (hopefully) quicker function to transform a point by a matrix (this function avoids any DOM calls and just does the math)
x | Float representing the x coordinate |
y | Float representing the y coordinate |
m | Matrix object to transform the point with Returns a x,y object representing the transformed point |
var transformListToTransform = this.transformListToTransform = function( tlist, min, max )
This returns a single matrix Transform for a given Transform List (this is the equivalent of SVGTransformList.consolidate() but unlike that method, this one does not modify the actual SVGTransformList) This function is very liberal with its min,max arguments
tlist | The transformlist object |
min | Optional integer indicating start transform position |
max | Optional integer indicating end transform position |
A single matrix transform object
var transformBox = this.transformBox = function( l, t, w, h, m )
Transforms a rectangle based on the given matrix
l | Float with the box’s left coordinate |
t | Float with the box’s top coordinate |
w | Float with the box width |
h | Float with the box height |
m | Matrix object to transform the box by |
An object with the following values:
var smoothControlPoints = this.smoothControlPoints = function( ct1, ct2, pt )
Takes three points and creates a smoother line based on them
ct1 | Object with x and y values (first control point) |
ct2 | Object with x and y values (second control point) |
pt | Object with x and y values (third point) |
Array of two “smoothed” point objects
Functions relating to editing path elements
Serialization | |
removeUnusedDefElems | Looks at DOM elements inside the <defs> to see if they are referred to, removes them from the DOM if they are not. |
svgCanvasToString | Main function to set up the SVG content for output |
svgToString | Sub function ran on each SVG element to convert it to a string as desired |
embedImage | Converts a given image file to a data URL when possible, then runs a given callback |
save | Serializes the current drawing into SVG XML text and returns it to the ‘saved’ handler. |
rasterExport | Generates a PNG Data URL based on the current image, then calls “exported” with an object including the string and any issues found |
getSvgString | Returns the current drawing as raw SVG XML text. |
setSvgString | This function sets the current drawing as the input SVG XML. |
importSvgString | This function imports the input SVG XML into the current layer in the drawing |
Layers | |
createLayer | Creates a new top-level layer in the drawing with the given name, sets the current layer to it, and then clears the selection This function then calls the ‘changed’ handler. |
deleteCurrentLayer | Deletes the current layer from the drawing and then clears the selection. |
getNumLayers | Returns the number of layers in the current drawing. |
getLayer | Returns the name of the ith layer. |
getCurrentLayer | Returns the name of the currently selected layer. |
setCurrentLayer | Sets the current layer. |
renameCurrentLayer | Renames the current layer. |
setCurrentLayerPosition | Changes the position of the current layer to the new value. |
getLayerVisibility | Returns whether the layer is visible. |
setLayerVisibility | Sets the visibility of the layer. |
moveSelectedToLayer | Moves the selected elements to layername. |
getLayerOpacity | Returns the opacity of the given layer. |
setLayerOpacity | Sets the opacity of the given layer. |
selectAllInCurrentLayer | Clears the selection, then adds all elements in the current layer to the selection. |
clear | Clears the current document. |
Fill and Stroke | |
convertToPath | Convert selected element to a path, or get the BBox of an element-as-path |
getVersion | Returns a string which describes the revision number of SvgCanvas. |
this.embedImage = function( val, callback )
Converts a given image file to a data URL when possible, then runs a given callback
val | String with the path/URL of the image |
callback | Optional function to run when image data is found, supplies the result (data URL or false) as first parameter. |
this.importSvgString = function( xmlString )
This function imports the input SVG XML into the current layer in the drawing
xmlString | The SVG as XML text. |
This function returns false if the import was unsuccessful, true otherwise. TODO: properly handle if namespace is introduced by imported content (must add to svgcontent and update all prefixes in the imported node) TODO: properly handle recalculating dimensions, recalculateDimensions() doesn’t handle arbitrary transform lists, but makes some assumptions about how the transform list was obtained TODO: import should happen in top-left of current zoomed viewport TODO: create a new layer for the imported SVG
this.setCurrentLayer = function( name )
Sets the current layer. If the name is not a valid layer name, then this function returns false. Otherwise it returns true. This is not an undo-able action.
name | the name of the layer you want to switch to. |
true if the current layer was switched, otherwise false
this.renameCurrentLayer = function( newname )
Renames the current layer. If the layer name is not valid (i.e. unique), then this function does nothing and returns false, otherwise it returns true. This is an undo-able action.
newname | the new name you want to give the current layer. This name must be unique among all layer names. |
true if the rename succeeded, false otherwise.
this.setCurrentLayerPosition = function( newpos )
Changes the position of the current layer to the new value. If the new index is not valid, this function does nothing and returns false, otherwise it returns true. This is an undo-able action.
newpos | The zero-based index of the new position of the layer. This should be between |
0 and (number of layers | 1) |
true if the current layer position was changed, false otherwise.
this.getLayerVisibility = function( layername )
Returns whether the layer is visible. If the layer name is not valid, then this function returns false.
layername | the name of the layer which you want to query. |
The visibility state of the layer, or false if the layer name was invalid.
this.setLayerVisibility = function( layername, bVisible )
Sets the visibility of the layer. If the layer name is not valid, this function return false, otherwise it returns true. This is an undo-able action.
layername | the name of the layer to change the visibility |
bVisible | true/false, whether the layer should be visible |
true if the layer’s visibility was set, false otherwise
this.moveSelectedToLayer = function( layername )
Moves the selected elements to layername. If the name is not a valid layer name, then false is returned. Otherwise it returns true. This is an undo-able action.
layername | the name of the layer you want to which you want to move the selected elements |
true if the selected elements were moved to the layer, false otherwise.
this.getLayerOpacity = function( layername )
Returns the opacity of the given layer. If the input name is not a layer, null is returned.
layername | name of the layer on which to get the opacity |
The opacity value of the given layer. This will be a value between 0.0 and 1.0, or null if layername is not a valid layer
this.setLayerOpacity = function( layername, opacity )
Sets the opacity of the given layer. If the input name is not a layer, nothing happens. This is not an undo-able action. NOTE: this function exists solely to apply a highlighting/de-emphasis effect to a layer, when it is possible for a user to affect the opacity of a layer, we will need to allow this function to produce an undo-able action. If opacity is not a value between 0.0 and 1.0, then nothing happens.
layername | name of the layer on which to set the opacity |
opacity | a float value in the range 0.0-1.0 |
this.convertToPath = function( elem, getBBox )
Convert selected element to a path, or get the BBox of an element-as-path
elem | The DOM element to be converted |
getBBox | Boolean on whether or not to only return the path’s BBox |
If the getBBox flag is true, the resulting path’s bounding box object. Otherwise the resulting path element is returned.
Converts characters in a string to XML-friendly entities.
toXml = function( str )
Converts XML entities in a string to single characters.
fromXml = function( str )
Converts given values to numbers.
convertToNum = function( attr, val )
Sets an element’s attribute based on the unit in its current value.
setUnitAttr = function( elem, attr, val )
Check if an attribute’s value is in a valid format
canvas.isValidUnit = function( attr, val )
History command to make a change to an element.
var ChangeElementCommand = this.undoCmd.changeElement = function( elem, attrs, text )
History command for an element that was added to the DOM
var InsertElementCommand = this.undoCmd.insertElement = function( elem, text )
History command for an element removed from the DOM
var RemoveElementCommand = this.undoCmd.removeElement = function( elem, parent, text )
History command for an element that had its DOM position changed
var MoveElementCommand = this.undoCmd.moveElement = function( elem, oldNextSibling, oldParent, text )
History command that can contain/execute multiple other commands
var BatchCommand = this.undoCmd.batch = function( text )
Resets the undo stack, effectively clearing the undo/redo history
resetUndoStack = function()
Adds a command object to the undo history stack
addCommandToHistory = c.undoCmd.add = function( cmd )
This function tells the canvas to remember the old values of the attrName attribute for each element sent in.
c.beginUndoableChange = function( attrName, elems )
This function returns a BatchCommand object which summarizes the change since beginUndoableChange was called.
c.finishUndoableChange = function()
Walks the tree and executes the callback on each element in a top-down fashion
function walkTree( elem, cbFn )
Walks the tree and executes the callback on each element in a depth-first fashion
function walkTreePost( elem, cbFn )
Assigns multiple attributes to an element.
var assignAttributes = this.assignAttributes = function( node, attrs, suspendLength, unitCheck )
Remove unneeded (default) attributes, makes resulting SVG smaller
var cleanupElement = this.cleanupElement = function( element )
Create a new SVG element based on the given object keys/values and add it to the current layer The element will be ran through cleanupElement before being returned
var addSvgElementFromJson = this.addSvgElementFromJson = function( data )
Rounds a given value to a float with number of digits defined in save_options
var shortFloat = function( val )
Returns the last created DOM element ID string
getId = c.getId = function()
Creates and returns a unique ID string for a DOM element
getNextId = c.getNextId = function()
Attaches a callback function to an event
c.bind = function( event, f )
Changes the ID prefix to the given value
c.setIdPrefix = function( p )
Sanitizes the input node and its children It only keeps what is allowed from our whitelist defined above
var sanitizeSvg = this.sanitizeSvg = function( node )
Extracts the URL from the url(...)
var getUrlFromAttr = this.getUrlFromAttr = function( attrVal )
Runs recalculateDimensions on the selected elements, adding the changes to a single batch command
var recalculateAllSelectedDimensions = this.recalculateAllSelectedDimensions = function()
Applies coordinate changes to an element based on the given matrix
var remapElement = this.remapElement = function( selected, changes, m )
Decides the course of action based on the element’s transform list
var recalculateDimensions = this.recalculateDimensions = function( selected )
A (hopefully) quicker function to transform a point by a matrix (this function avoids any DOM calls and just does the math)
var transformPoint = function( x, y, m )
Helper function to check if the matrix performs no actual transform (i.e.
var isIdentity = function( m )
This function tries to return a SVGMatrix that is the multiplication m1*m2.
var matrixMultiply = this.matrixMultiply = function()
This returns a single matrix Transform for a given Transform List (this is the equivalent of SVGTransformList.consolidate() but unlike that method, this one does not modify the actual SVGTransformList) This function is very liberal with its min,max arguments
var transformListToTransform = this.transformListToTransform = function( tlist, min, max )
See if the given transformlist includes a non-indentity matrix transform
var hasMatrixTransform = this.hasMatrixTransform = function( tlist )
Get the matrix object for a given element
var getMatrix = function( elem )
Transforms a rectangle based on the given matrix
var transformBox = this.transformBox = function( l, t, w, h, m )
Clears the selection.
this.clearSelection = function( noCall )
Adds a list of elements to the selection.
this.addToSelection = function( elemsToAdd, showGrips )
Removes elements from the selection.
this.removeFromSelection = function( elemsToRemove )
Takes three points and creates a smoother line based on them
var smoothControlPoints = this.smoothControlPoints = function( ct1, ct2, pt )
Gets the desired element from a mouse event
var getMouseTarget = this.getMouseTarget = function( evt )
Looks at DOM elements inside the defs to see if they are referred to, removes them from the DOM if they are not.
var removeUnusedDefElems = this.removeUnusedDefElems = function()
Main function to set up the SVG content for output
var svgCanvasToString = this.svgCanvasToString = function()
Sub function ran on each SVG element to convert it to a string as desired
var svgToString = this.svgToString = function( elem, indent )
Converts a given image file to a data URL when possible, then runs a given callback
this.embedImage = function( val, callback )
Serializes the current drawing into SVG XML text and returns it to the ‘saved’ handler.
this.save = function( opts )
Generates a PNG Data URL based on the current image, then calls “exported” with an object including the string and any issues found
this.rasterExport = function()
Returns the current drawing as raw SVG XML text.
this.getSvgString = function()
This function sets the current drawing as the input SVG XML.
this.setSvgString = function( xmlString )
This function imports the input SVG XML into the current layer in the drawing
this.importSvgString = function( xmlString )
Creates a new top-level layer in the drawing with the given name, sets the current layer to it, and then clears the selection This function then calls the ‘changed’ handler.
this.createLayer = function( name )
Deletes the current layer from the drawing and then clears the selection.
this.deleteCurrentLayer = function()
Returns the number of layers in the current drawing.
this.getNumLayers = function()
Returns the name of the ith layer.
this.getLayer = function( i )
Returns the name of the currently selected layer.
this.getCurrentLayer = function()
Sets the current layer.
this.setCurrentLayer = function( name )
Renames the current layer.
this.renameCurrentLayer = function( newname )
Changes the position of the current layer to the new value.
this.setCurrentLayerPosition = function( newpos )
Returns whether the layer is visible.
this.getLayerVisibility = function( layername )
Sets the visibility of the layer.
this.setLayerVisibility = function( layername, bVisible )
Moves the selected elements to layername.
this.moveSelectedToLayer = function( layername )
Returns the opacity of the given layer.
this.getLayerOpacity = function( layername )
Sets the opacity of the given layer.
this.setLayerOpacity = function( layername, opacity )
Clears the selection, then adds all elements in the current layer to the selection.
this.selectAllInCurrentLayer = function()
Clears the current document.
this.clear = function()
Convert selected element to a path, or get the BBox of an element-as-path
this.convertToPath = function( elem, getBBox )
Returns a string which describes the revision number of SvgCanvas.
this.getVersion = function()