Property: feature {<OpenLayers.Feature.Vector>} The current editable feature.
Property: map {<OpenLayers.Map>} this gets set in the addControl() function in OpenLayers.Map
Property: precedence {Array} List representing precedence of different snapping types. Default is "node", "vertex", "edge".
Static
TYPE_Constant: OpenLayers.Control.TYPE_BUTTON
Static
TYPE_Constant: OpenLayers.Control.TYPE_TOGGLE
Static
TYPE_Constant: OpenLayers.Control.TYPE_TOOL
APIMethod: activate Explicitly activates a control and it's associated handler if one has been set. Controls can be deactivated by calling the deactivate() method.
Returns: {Boolean} True if the control was successfully activated or false if the control was already active.
APIMethod: deactivate Deactivates a control and it's associated handler if any. The exact effect of this depends on the control itself.
Returns: {Boolean} True if the control was effectively deactivated or false if the control was already inactive.
Method: destroy The destroy method is used to perform any clean up before the control is dereferenced. Typically this is where event listeners are removed to prevent memory leaks.
Method: draw The draw method is called when the control is ready to be displayed on the page. If a div has not been created one is created. Controls with a visual component will almost always want to override this method to customize the look of control.
Parameters: px - {<OpenLayers.Pixel>} The top-left pixel position of the control or null.
Returns: {DOMElement} A reference to the DIV DOMElement containing the control
Optional
px: null | PixelMethod: setMap Set the map property for the control. This is done through an accessor so that subclasses can override this and take special action once they have their map variable set.
Parameters: map - {<OpenLayers.Map>}
Constructor: OpenLayers.Control.Snapping Creates a new snapping control. A control is constructed with an editable layer and a set of configuration objects for target layers. While the control is active, dragging vertices while drawing new features or modifying existing features on the editable layer will engage snapping to features on the target layers. Whether a vertex snaps to a feature on a target layer depends on the target layer configuration.
Parameters: options - {Object} An object containing all configuration properties for the control.
Valid options: layer - {<OpenLayers.Layer.Vector>} The editable layer. Features from this layer that are digitized or modified may have vertices snapped to features from any of the target layers. targets - {Array(Object | OpenLayers.Layer.Vector)} A list of objects for configuring target layers. See valid properties of the target objects below. If the items in the targets list are vector layers (instead of configuration objects), the defaults from the
property will apply. The editable layer itself may be a target
layer, allowing newly created or edited features to be snapped to
existing features from the same layer. If no targets are provided
the layer given in the constructor (as ) will become the
initial target.
defaults - {Object} An object with default properties to be applied
to all target objects.
greedy - {Boolean} Snap to closest feature in first target layer that
applies. Default is true. If false, all features in all target
layers will be checked and the closest feature in all target layers
will be chosen. The greedy property determines if the order of the
target layers is significant. By default, the order of the target
layers is significant where layers earlier in the target layer list
have precedence over layers later in the list. Within a single
layer, the closest feature is always chosen for snapping. This
property only determines whether the search for a closer feature
continues after an eligible feature is found in a target layer.
Valid target properties: layer - {<OpenLayers.Layer.Vector>} A target layer. Features from this layer will be eligible to act as snapping target for the editable layer. tolerance - {Float} The distance (in pixels) at which snapping may occur. Default is 10. node - {Boolean} Snap to nodes (first or last point in a geometry) in target layer. Default is true. nodeTolerance - {Float} Optional distance at which snapping may occur for nodes specifically. If none is provided, will be
used.
vertex - {Boolean} Snap to vertices in target layer. Default is true.
vertexTolerance - {Float} Optional distance at which snapping may occur
for vertices specifically. If none is provided, will be
used.
edge - {Boolean} Snap to edges in target layer. Default is true.
edgeTolerance - {Float} Optional distance at which snapping may occur
for edges specifically. If none is provided, will be
used.
filter - {<OpenLayers.Filter>} Optional filter to evaluate to determine if
feature is eligible for snapping. If filter evaluates to true for a
target feature a vertex may be snapped to the feature.
minResolution - {Number} If a minResolution is provided, snapping to this
target will only be considered if the map resolution is greater than
or equal to this value (the minResolution is inclusive). Default is
no minimum resolution limit.
maxResolution - {Number} If a maxResolution is provided, snapping to this
target will only be considered if the map resolution is strictly
less than this value (the maxResolution is exclusive). Default is
no maximum resolution limit.