How to trigger center action by passing position/coordinates as parameter

[sathya-1994]

I am using vscode version of GLSP,

Currently we can use org.eclipse.glsp.server.actions.CenterAction to bring any element to center of the viewport by passing ID as parameter.

But I want pass extra parameter along with ID so that particular region/part of element will be shown at the center of viewport.

example :

1. coordinate (10,10) which will bring relative position of node to center of the viewport
2. Top Left Corner : Top left corner of node will be placed at the center of viewport

Is any way we can implement this requirement in GLSP?

[planger]

Yes, you can create an own action that extends CenterAction and register a custom command for your new action that takes a relative offset into account. So best look at the implementation of the CenterAction and adjust to your needs:

• Center Action
• Registration of the existing center command

So you would create a new subclass of CenterAction and a subclass of CenterCommand (or BoundsAwareViewportCommand), register the command as linked above in your di.config.ts and adjust the implementation of your CenterCommand, e.g. as follows (see this.action.yourRelativeOffsetX and Y):

    getNewViewport(bounds: Bounds, model: SModelRoot): Viewport | undefined {
        if (!Dimension.isValid(model.canvasBounds)) {
            return undefined;
        }
        const zoom = (this.action.retainZoom && isViewport(model)) ? model.zoom : 1;
        const c = Bounds.center(bounds);
        return {
            scroll: {
                x: c.x + this.action.yourRelativeOffsetX - 0.5 * model.canvasBounds.width / zoom,
                y: c.y + this.action.yourRelativeOffsetY - 0.5 * model.canvasBounds.height / zoom
            },
            zoom: zoom
        };
    }

Alternatively, you can add a child node to your node and place it somehwere within its parent node and then center child node instead of the parent node. This may even be the better solution, depending on the structure of your GModel.