Chart: prevent unexpected page scrolling on zoom (T1314606)

[anna-shakhova]

No description provided.

[Copilot]

Pull request overview

This PR fixes an issue (T1314606) where unexpected page scrolling occurs when performing zoom operations on a chart using the mouse wheel. The fix introduces a timeout-based mechanism to prevent default scroll behavior for a brief window after zoom interactions, even when the zoom limit has been reached.

Key Changes:

• Introduced a 500ms prevention window that continues to block page scrolling after zoom operations
• Modified the event handling logic to track and extend the prevention window on subsequent wheel events
• Added comprehensive test coverage for the timeout-based scroll prevention behavior

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
packages/devextreme/js/__internal/viz/chart_components/zoom_and_pan.ts	Implements timer-based scroll prevention logic with new lastWheelTimer variable, setLastWheelTimer() function, and modified preventDefaults() signature; exports SCROLL_PREVENTION_TIMEOUT constant
packages/devextreme/testing/tests/DevExpress.viz.charts/zoomAndPan.tests.js	Adds test case verifying that scroll prevention continues for 500ms after zoom limit is reached, testing timer reset on subsequent wheel events within the window

Comments suppressed due to low confidence (1)

packages/devextreme/js/__internal/viz/chart_components/zoom_and_pan.ts:573

• The lastWheelTimer should be cleared in the cleanup() function to prevent potential memory leaks when the chart is disposed. Add clearTimeout(lastWheelTimer); at the beginning of the cleanup() function.

      cleanup() {
        renderer.root.off(EVENTS_NS);
        // @ts-expect-error
        zoomAndPan.actionData?.rect?.dispose();
        // @ts-expect-error
        zoomAndPan.actionData = null;
        renderer.root.css({ 'touch-action': '' });
      },

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

Comments suppressed due to low confidence (1)

packages/devextreme/js/__internal/viz/chart_components/zoom_and_pan.ts:573

• The lastWheelTimer should be cleared in the cleanup() function to prevent potential memory leaks. When the zoom and pan functionality is disposed or reconfigured, the timer may still be active. Add clearTimeout(lastWheelTimer); at the beginning of the cleanup function, similar to how other timers are handled in the codebase (e.g., tracker.ts).

      cleanup() {
        renderer.root.off(EVENTS_NS);
        // @ts-expect-error
        zoomAndPan.actionData?.rect?.dispose();
        // @ts-expect-error
        zoomAndPan.actionData = null;
        renderer.root.css({ 'touch-action': '' });
      },

[EugeniyKiyashko]

[minor]

Suggested change

	let lastWheelTimer: number | undefined;
	let lastWheelTimer?: ReturnType<typeof setTimeout>;