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) {
alert(bounds);
}
});
map.addControl(control);
Summary
| Controls affect the display or behavior of the map. |
| |
| Create an OpenLayers Control. |