How to fix zooming position?

[UmerTaptap]

Currently, what is happening in the graph when I try to zoom from a specific area on the screen, I mean I want to zoom in particular node to see the picture, but it is zooming entire view that specific node zoomed in but move down somewhere, please see example video, I want to zoom in "Spider man XII" node but it is moving out of position where i start zooming...

[CorvusYe]

Regarding the scaling issue, I mainly use this mouse with a central point on the PC. For mobile devices, using two fingers may be more suitable. See if you can fork it and modify it based on this segment.

https://github.com/graph-cn/flutter_graph_view/blob/main/lib/widgets/graph_component.dart#L180-L214

[CorvusYe]

The video looks more centered around the touch point in the upper left corner.

[UmerTaptap]

i started zooming from center node dark green one, but when I try to zoom in it, it go away :(

[CorvusYe]

You may need to pay attention to whether the component disappears from the world or from the viewport.

[UmerTaptap]

From viewport, but i want to keep it at the same point/position from where I start zooming..

[CorvusYe]

It is still a problem of scaling the center point.
The graph_component code snippet mentioned earlier needs to be modified.

[UmerTaptap]

Any way to set the zooming range? I mean i want to stop zooming out at a certain point..

[CorvusYe]

At present, there is no selection that can directly control scaling. However, it can be found that the height and width control nodes are fixed and do not change with the viewport.

[UmerTaptap]

Distance between the vertices changes on zoom in and out, how can I stop it? distance should not change

[CorvusYe]

Distance between the vertices changes on zoom in and out, how can I stop it? distance should not change

You can define a GraphAlgorithm implementation as a decorator. Inside it, get the viewport's scaling ratio, and then recalculate the position. When zooming in or out, the node's position remains unchanged, and the change in distance is due to the change in the viewport's scale.