[FEATURE]:Enable external render functions for treeview

[mlankamp]

In the TreeViewPlugin move the functions:

• _createNodeElement
• _expandSwitchElement
• _collapseNode
• _collapseSwitchElement

to the constructor and allow these functions to be overwritten via the constructor configuration.

This allows users to create their own styling.

Alternative solution: Create a render service, which can be passed via the constructor (same as the localeService).

[mlankamp]

I created a PR to support this scenario #1329

[xeolabs]

Looks good, thanks @mlankamp. Could we please also get an HTML example page to demo it? Maybe just base it off this one: https://github.com/xeokit/xeokit-sdk/blob/master/examples/navigation/TreeViewPlugin_Containment.html

[mlankamp]

Yes, I will create an example! Will include the x-rayed style as well.

[mlankamp]

Done, see PR #1331

[mlankamp]

@xeolabs is it possible to create a new beta? Will upgrade my typescript based solution and can check if the typings are ok

[xeolabs]

@mlankamp yip, done - 2.5.2-beta-5

[mlankamp]

Nice, with the latest merge the example works: https://xeokit.github.io/xeokit-sdk/examples/navigation/#TreeViewPlugin_options_renderService

[xeolabs]

Could it be extended to create IFC element icons on the tree nodes, do you think? Maybe extend the callback to take a MetaObject, then add class names to node elements to style them with the corresponding icon?

[mlankamp]

That should be possible, will try tomorrow

[mlankamp]

The MetaObject contains the type, which I can use to render an icon in the treeview. I came up with this example:

We could a helper class, which maps a ifc type to a specific icon (font-awesome and material design icons). Or even better, is there a defined icon set?

[mlankamp]

Found this: https://aecgeeks.github.io/ifc-icons/ (source: https://github.com/AECgeeks/ifc-icons)

[xeolabs]

Found this: https://aecgeeks.github.io/ifc-icons/ (source: https://github.com/AECgeeks/ifc-icons)

Yip that's the one I had in mind!

[mlankamp]

This uses the google Material Icons, I've created my example based on the material design icons library.