Manually set zoom/position of viewport?

[bgribble]

In my application, I have custom keyboard and pointer bindings for many navigation operations. I would like to bind the + and - keys to incrementally zoom in and out the node editor, for example, and bind shift-mouse1-motion to drag the viewport. I would like to be able to set the viewport origin and zoom under control of my code rather than exclusively by pointy-clicky interaction with the node editor.

Zoom

I am aware of he GetCurrentZoom() function to read the zoom, but I can't find a corresponding SetCurrentZoom(zoom_val) or other way to change the zoom.

The implementation of GetCurrentZoom implies that I might be able to just change GetView().InvScale:

float ax::NodeEditor::GetCurrentZoom()
{
    return s_Editor->GetView().InvScale;
}

but I am using a Python binding of imgui-node-editor so I can't try that out. Is there an official API somewhere that I am missing?

Viewport position

I see the NavigateToContent() and NavigateToSelection() helpers, which look to move the viewport in specific ways, but I don't see any API to just say "place the viewport at upper_left, lower_right" or even to get the (upper_left, lower_right) of the current viewport. Internally, there's the NavigateTo action, but again I am working with a Python binding so I'm restricted to the public API.

[bgribble]

Bumping this with a pseudo-workaround.

• Clear the selection with ClearSelection
• Create an invisible (empty, no padding or border) node in at the upper-left of where you want the viewport to be
• Create another invisible node at the lower-right
• Select them with SelectNode
• NavigateToSelection()

I am still working on restoring the original selection after this navigation, but the basic concept works for adjusting the viewport position and zoom from code.

[skaman]

I added in my fork two methods GetViewRect and NavigateToBounds that let met get the current state and restore it.

skaman/zgui@1fbfa47#diff-3c1e967b01be7798d4fc37c6a4e69695f25e0fd4abe50ebc2b59d74a6ce8ccab

I think it should be refactored because now it use ImRect in the public API but it's an internal API, but with this change you should be able to get and restore your canvas state.