bumbu/svg-pan-zoom

minZoom and maxZoom not updated when updateBBox( ) is called

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#267 opened on Oct 26, 2017

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 (1 comment) (0 reactions) (0 assignees)JavaScript (1,585 stars) (383 forks)batch import
bughelp wanted

Description

Expected behaviour

When adding new elements to the SVG that fall outside the current BBox, and calling updateBBox(), i should be able to zoom out to see those elements

Actual behaviour

The amount that I can zoom out is still based on the original BBox, meaning that i may not be able to zoom out to see all elements, even if minZoom is <1

Steps to reproduce the behaviour

  1. activate the lib on an SVG with minZoom: 1
  2. add elements outside the SVG's outer edge
  3. call updateBBox()
  4. try to zoom out to see the new elements

Note: Although it feels a bit weird to have them diverge, I'm not sure that the maximum zoom level should be affected by removing elements in the same way -- it would feel kinda strange to not be able to zoom into existing elements just because new ones have been added

Contributor guide

Tech stack
javascript
Domain
frontend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaScriptsvg pan zoom APISVG coordinate system
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
Examine the 'updateBBox' function in the library source code to understand how it handles viewport bounds. Current behavior suggests that minZoom and maxZoom are set only during initialization and not recalculated when the bounding box changes. The fix should ensure that after updateBBox, the zoom limits are recalculated based on the new bbox, allowing minZoom to be adjusted below 1 if needed. Check relevant comments in the issue #267 for additional context.