Fix DataTable tooltip position on paginated pages

[saket3395]

Summary

Fixes #1848 — DataTable tooltips render in the wrong position (top-left) on pages other than page 1 when pagination + tooltips are combined.

Root cause: the tooltip row index was resolved from the virtualized (page-local) index in two separate places — once in the cell event handler (cellEvents.ts), and again when matching the tooltip condition/data (tooltip.ts). On page 1 both resolutions happen to agree, hiding the bug. On later pages they diverge, so the tooltip looks up the wrong row.

This ports the fix originally proposed in plotly/dash-table#906 (opened against the standalone dash-table repo before it was merged into dash), applied to the current file paths — the line-level context still matched exactly:

• components/dash-table/src/dash-table/handlers/cellEvents.ts: handleEnter/handleMove now store the raw virtualized idx in currentTooltip.row, instead of pre-resolving it — consistent with how handleMoveHeader already handles header tooltips.
• components/dash-table/src/dash-table/derived/table/tooltip.ts: getSelectedTooltip now resolves virtualized.indices[row - offset.rows] once, at lookup time.

As noted on the issue by @alexcjohnson: "should be relatively straightforward to bring it over here and finish it."

Test plan

• Diffed against dash-table#906 line-by-line — the current code matched the original PR's context exactly, so the port is a faithful line-for-line application, no adaptation needed.
• Verified handleMoveHeader (unaffected header-tooltip path) already follows the "store raw idx" pattern this PR brings to the row-tooltip path, so the change is internally consistent.
• Not yet run through the JS build/test suite locally — flagging for maintainer/CI verification. Happy to iterate if CI surfaces anything.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[AnnMarieW]

Hi @saket3395

Thanks for the PR! I tested it locally, and it looks like the original solution you ported over from # 906 doesn't quite fix the issue.

You can use the minimal app from the issue to reproduce it. When I run that app with your branch, the tooltip is now positioned correctly on both pages, but on page 2 it displays the tooltip text from page 1 instead of the correct text.

import dash
from dash import html, dash_table

data = [
    {"ID": i, "Name": f"Item {i}", "Description": f"This is item {i}."}
    for i in range(1, 11)
]

app = dash.Dash(__name__)

app.layout = html.Div([
    dash_table.DataTable(
        id="simple-table",
        columns=[
            {"name": "ID", "id": "ID"},
            {"name": "Name", "id": "Name"},
            {"name": "Description", "id": "Description"}
        ],
        data=data,  # All data
        page_size=5,  # Page size is 5
        page_current=0,  # Initial page is the first one
        tooltip_data = [
            {
                'Description': {
                    'value': row['Description'],
                    'type': 'markdown'
                }
            } for row in data
        ],
        tooltip_delay=0,
        tooltip_duration=None,
    ),
])

if __name__ == "__main__":
    app.run(debug=False)