[OpenLayers-Dev] A generic button class:

[Paul Spencer]

Hi Jeff,

nice little control!  A couple of (very picky) comments if you are  
advocating including this in OL, please don't take these the wrong  
way :)

* the class should be declared as OpenLayers.Control.GenericButton

* CLASS_NAME should be OpenLayers.Control.GenericButton

* OL is using a different style of documentation now

Cheers

Paul

On 27-Jul-07, at 5:49 PM, Jeff Dege wrote:

> The OpenLayers source is collecting a useful bunch of controls, but  
> most
> of them are designed to do something specific.
>
> What I've found is a need for generic buttons - click on them, and  
> they
> do something.  But what they do is different, and specific to the
> particular application.  I've been adding them to a Panel control,
> alongside Navigation, Zoombox, etc.  But building a distinct class
> seemed like overkill, and taking advantage of Javascripts ability to
> extend an object at runtime struck me as a nightmare for future
> maintainers.
>
> So I built a very simple little control:
>
> /**
>  * @class
>  *
>  */
> GenericButton = OpenLayers.Class.create();
> GenericButton.prototype =
>   OpenLayers.Class.inherit( OpenLayers.Control, {
>     onClick: null,
>     type: OpenLayers.Control.TYPE_BUTTON,
> 	
>     trigger: function() {
>       if (this.onClick)
>         this.onClick();
>     },
>     /**
>     * @param {Event} evt
>     */
>     /** @final @type String */
>     CLASS_NAME: "OpenLayers.Class.GenericButton"
> });
>
>
> Usage is simple:
>
>   var nav = new OpenLayers.Control.Navigation();
>   var panel = new OpenLayers.Control.Panel({defaultControl: nav});
>   panel.addControls([nav,
>     new OpenLayers.Class.GenericButton(
>       {'displayClass': 'MyGenericButton', 'onClick': myFunction});
>   ]);
>
>   openLayersMap.addControl(panel);
>
> The 'displayClass' option is what is used in building the className,
> which you'd used in the css to set the background image, etc.  In this
> case, it'd be .MyGenericButtonItemInactive.  (These buttons never  
> become
> active, so there's no need for .MyGenericButtonItemActive.  The
> 'onClick' function is a javascript function that's called when the
> button is clicked.
>
> It's pretty simple stuff, and I'm sure everyone has their own ways of
> handling this problem.  But I thought I'd throw out mine.
>
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|Paul Spencer                          pspencer at dmsolutions.ca    |
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|Chief Technology Officer                                         |
|DM Solutions Group Inc                http://www.dmsolutions.ca/ |
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