Add contentX/contentY to ZoomableViewEvent by elliottkember · Pull Request #181 · openspacelabs/react-native-zoomable-view

elliottkember · 2026-05-18T23:45:33Z

Summary

Add optional contentX / contentY to ZoomableViewEvent carrying the gesture's first touch in content (bitmap) coordinates — so consumers can tell where the user tapped on the contents.
Populated when the callback has an associated GestureTouchEvent AND both contentWidth and contentHeight props are set. Computed via the existing viewportPositionToImagePosition helper (same contain resize-mode assumption).
Undefined for non-gesture call sites (onTransformWorklet, onZoomEnd after a programmatic zoomTo() completes naturally) and when content dimensions aren't configured.
SPECS.md updated to reflect the new event shape and document when the fields are populated.

Test plan

Verify a single tap fires onSingleTap with contentX/contentY set when contentWidth/contentHeight are configured.
Verify contentX/contentY are undefined when contentWidth/contentHeight are not set.
Verify contentX/contentY are undefined on onZoomEnd fired from programmatic zoomTo() completion (no gesture event).
Verify values are reasonable across zoom levels (taps near edges and after pan/zoom).

🤖 Generated with Claude Code

Expose the gesture's first touch in content (bitmap) coordinates on ZoomableViewEvent so consumers can tell where the user tapped on the contents. Populated when the callback has an associated gesture event and both contentWidth/contentHeight props are set; undefined otherwise. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

cursor · 2026-05-18T23:45:39Z

PR Summary

Low Risk
Low risk additive change: event payloads gain optional contentX/contentY computed only when a gesture event and contentWidth/contentHeight are available, with guards to avoid emitting invalid values.

Overview
Adds optional content-space touch coordinates to callback event payloads by extending ZoomableViewEvent with contentX/contentY.

Updates ReactNativeZoomableView to compute these fields from the first touch via viewportPositionToImagePosition and to pass the gesture event into _getZoomableViewEventObject for gesture-driven callbacks, while leaving the fields undefined for non-gesture call sites and when content dimensions are unknown. Documentation in SPECS.md is updated to describe the new fields and when they are populated.

^{Reviewed by Cursor Bugbot for commit 2903b19. Configure here.}

cursor

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 2903b19. Configure here.}

`{}` placeholders showed up at almost every call site after adding the gesture-event parameter — a signal the override slot was carrying its weight for exactly one caller (`onDoubleTapAfter`, which substitutes the target `zoomLevel`). Let that one caller spread the override externally and simplify the helper to just `(gestureEvent?)`. Also drops the redundant override in `_staticPinPosition` that re-passed the same SharedValues the function already reads. Side effect: at `onDoubleTapAfter`, `contentX`/`contentY` are now computed using the current zoom level rather than the target, which matches the touch's actual content-space position (the touch occurred before the zoom animation started). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

thomasttvo · 2026-05-19T00:31:24Z

+    // size, so it returns null pre-measurement or with no content size set —
+    // leave `contentX`/`contentY` undefined in that case rather than emit
+    // NaN/Infinity to consumers.
+    const touch = gestureEvent?.allTouches[0];


🟡 we only need x and y from the touch here. Passing the whole event could lead to misinterpretation of the event when the first touch is not intended to be the source for the x and y.

What do you mean by passing the whole event? We're only passing this touch to viewportPositionToImagePosition to calculate the content position?

Sorry I meant passing the whole event into the getZoomableViewObject function

thomasttvo · 2026-05-19T00:33:31Z

-        offsetY: offsetY.value,
-        zoomLevel: zoom.value,
-      }),
+      zoomableEvent: _getZoomableViewEventObject(),


🟣 _staticPinPosition can probably be replaced by _getZoomableViewEventObject(staticPinPosition.value) making the interface for static pin more standardized

Not without changing the _getZoomableViewEventObject because it needs a GestureTouchEvent we don't have?

thomasttvo · 2026-05-19T00:36:33Z

+   * programmatic `zoomTo()`) and when content dimensions are unknown.
+   */
+  contentX?: number;
+  contentY?: number;


🟣 this might create confusion from the client in the form of: "is there a time where we have contentX but not contentY?" it's probably best to use TS to make them either both undefined or exists, or even better, group them in a property

Maybe all this complexity is an indicator that ZoomableViewEvent is doing too much. Thinking about it - why would onSingleTap need to return originalHeight and originalWidth. This is probably a flawed legacy design we need to move away in v3.

I don't know, but I imagine it's so that the consumer can have all the info it needs packed into the event. Which I think is fairly reasonable if you already have an event object. It could definitely be better arranged, that's for sure. I don't really know why most of these attributes are exposed to the client

Separate optional values is okay here, it's consistent with contentWidth? / contentHeight? which are both optional. They're all flat in this interface:

initialOffsetX?: number; initialOffsetY?: number; contentWidth?: number; contentHeight?: number;

elliottkember · 2026-05-19T01:45:20Z

@thomasttvo ~~After trying to integrate this, I think these attributes probably should live on the TouchData event instead~~

Scratch that — the touchData is part of react-native-gesture-handler

cursor Bot reviewed May 18, 2026

View reviewed changes

Comment thread src/ReactNativeZoomableView.tsx Outdated

thomasttvo reviewed May 19, 2026

View reviewed changes

Comment thread src/ReactNativeZoomableView.tsx Outdated

thomasttvo reviewed May 19, 2026

View reviewed changes

thomasttvo approved these changes May 19, 2026

View reviewed changes

thomasttvo reviewed May 19, 2026

View reviewed changes

elliottkember merged commit d549867 into master May 19, 2026
1 check passed

elliottkember deleted the add-content-coordinates-to-zoomable-view-event branch May 19, 2026 01:05

Conversation

elliottkember commented May 18, 2026

Summary

Test plan

Uh oh!

cursor Bot commented May 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

PR Summary

Uh oh!

cursor Bot left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

thomasttvo May 19, 2026

Choose a reason for hiding this comment

Uh oh!

elliottkember May 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

thomasttvo May 19, 2026

Choose a reason for hiding this comment

Uh oh!

thomasttvo May 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

elliottkember May 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

thomasttvo May 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

thomasttvo May 19, 2026

Choose a reason for hiding this comment

Uh oh!

elliottkember May 19, 2026

Choose a reason for hiding this comment

Uh oh!

elliottkember May 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

elliottkember commented May 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

cursor Bot commented May 18, 2026 •

edited

Loading

elliottkember May 19, 2026 •

edited

Loading

thomasttvo May 19, 2026 •

edited

Loading

elliottkember May 19, 2026 •

edited

Loading

thomasttvo May 19, 2026 •

edited

Loading

elliottkember May 19, 2026 •

edited

Loading

elliottkember commented May 19, 2026 •

edited

Loading