OpenLayers. Control

Controls affect the display or behavior of the map.  They allow everything from panning and zooming to displaying a scale indicator.  Controls by default are added to the map they are contained within however it is possible to add a control to an external div by passing the div in the options parameter.

Example

The following example shows how to add many of the common controls to a map.

var map = new OpenLayers.Map('map', { controls: [] });

map.addControl(new OpenLayers.Control.PanZoomBar());
map.addControl(new OpenLayers.Control.MouseToolbar());
map.addControl(new OpenLayers.Control.LayerSwitcher({'ascending':false}));
map.addControl(new OpenLayers.Control.Permalink());
map.addControl(new OpenLayers.Control.Permalink('permalink'));
map.addControl(new OpenLayers.Control.MousePosition());
map.addControl(new OpenLayers.Control.OverviewMap());
map.addControl(new OpenLayers.Control.KeyboardDefaults());

The next code fragment is a quick example of how to intercept shift-mouse click to display the extent of the bounding box dragged out by the user.  Usually controls are not created in exactly this manner.  See the source for a more complete example:

var control = new OpenLayers.Control();
OpenLayers.Util.extend(control, {
    draw: function () {
        // this Handler.Box will intercept the shift-mousedown
        // before Control.MouseDefault gets to see it
        this.box = new OpenLayers.Handler.Box( control,
            {"done": this.notice},
            {keyMask: OpenLayers.Handler.MOD_SHIFT});
        this.box.activate();
    },

    notice: function (bounds) {
        OpenLayers.Console.userError(bounds);
    }
});
map.addControl(control);
Summary
OpenLayers. ControlControls affect the display or behavior of the map.
Properties
autoActivate{Boolean} Activate the control when it is added to a map.
eventListeners{Object} If set as an option at construction, the eventListeners object will be registered with <OpenLayers.Events.on>.
Constants
EVENT_TYPES{Array(String)} Supported application event types.
Constructor
OpenLayers. ControlCreate an OpenLayers Control.

Properties

autoActivate

{Boolean} Activate the control when it is added to a map.  Default is false.

eventListeners

{Object} If set as an option at construction, the eventListeners object will be registered with <OpenLayers.Events.on>.  Object structure must be a listeners object as shown in the example for the events.on method.

Constants

EVENT_TYPES

{Array(String)} Supported application event types.  Register a listener for a particular event with the following syntax:

control.events.register(type, obj, listener);

Listeners will be called with a reference to an event object.  The properties of this event depends on exactly what happened.

All event objects have at least the following properties

object{Object} A reference to control.events.object (a reference to the control).
element{DOMElement} A reference to control.events.element (which will be null unless documented otherwise).

Supported map event types

activateTriggered when activated.
deactivateTriggered when deactivated.

Constructor

OpenLayers. Control

Create an OpenLayers Control.  The options passed as a parameter directly extend the control.  For example passing the following:

var control = new OpenLayers.Control({div: myDiv});

Overrides the default div attribute value of null.

Parameters

options{Object}
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