oscar.Control.PreviousView

@requires OpenLayers.Control.Button Inherits from: - <OpenLayers.Control.Button

Descriptiont: Keeps track of map movements to allow the user to go back to a previous view.

Properties

type {String} Note that this control is not

intended to be added directly to a control panel.  Instead, add the sub-controls previous and next.  These sub-controls are button type controls that activate and deactivate themselves.  If this parent control is added to a panel, it will act as a toggle.

activateOnDraw {Boolean} Activate the control

when it is first added to the map.  Default is true.

registry {Object} An object with keys

corresponding to event types.  Values are functions that return an object representing the current state.

nextStack {Array} Array of items in the

history.

previousStack {Array} List of items in the

history.  First item represents the current state.

listeners {Object} An object containing

properties corresponding to event types.  This object is used to configure the control and is modified on construction.

restoring {Boolean} Currently restoring a

history state.  This is set to true before calling restore and set to false after restore returns.

Functions

OpenLayers.Control.NavigationHistory

Parameters: options{Object} An optional object whose properties will be used to extend the control.

trigger Restore the previous state.  If no items

are in the previous history stack, this has no effect.

Returns: {Object} Item representing state that was restored.  Undefined if no items are in the previous history stack.

onPreviousChange Called when the previous history

stack changes.

Parameters: state{Object} An object representing the state to be restored if previous is triggered again or
null if no previous states remain. length{Integer} The number of remaining previous states that can be restored.

setMap Set the map property for the control and

<previous> and &lt;next&gt; child controls.

Parameters

map{&lt;OpenLayers.Map&gt;}

draw Called when the control is added to the map.

restore Update the state with the given object.

Parameters: state{Object} An object representing the state to restore.

initStack Called after the control is activated

if the previous history stack is empty.