src/otko/views/canvas_plotly/html.py

@@ -77,36 +77,16 @@ _PAGE = """<!DOCTYPE html>
       var meta = gd.data[i] && gd.data[i].meta;
       if (meta && meta.kind === 'hover') { hoverIndex = i; break; }
     }
-    // A freshly pushed figure has an empty hover marker again.
-    hoverShown = false;
-    hoverPoint = null;
   }
 
-  // --- snap-target marker ------------------------------------------------
+  function setHover(x, y, z) {
-  // Updated synchronously but only when the visual state actually changes.
-  // Restyling on every hover/unhover made the plot redraw per mouse move,
-  // which re-fired hover and ended in a runaway redraw loop (RangeError:
-  // Maximum call stack size exceeded, frozen canvas). Timers were avoided
-  // deliberately: WebEngine throttles them to ~1 s when the page is not
-  // compositing, which made the preview lag.
-  var hoverShown = false;
-  var hoverPoint = null;
-
-  function samePoint(a, b) {
-    return !!a && !!b && a[0] === b[0] && a[1] === b[1] && a[2] === b[2];
-  }
-
-  function setHoverMarker(point) {
-    var want = snapEnabled ? point : null;
-    if (samePoint(want, hoverPoint) && !!want === hoverShown) return;
-    if (!want && !hoverShown) { hoverPoint = null; return; }
-    hoverPoint = want;
-    hoverShown = !!want;
     if (hoverIndex < 0) return;
-    var x = want ? [want[0]] : [];
+    Plotly.restyle('plot', { x: [[x]], y: [[y]], z: [[z]] }, [hoverIndex]);
-    var y = want ? [want[1]] : [];
+  }
-    var z = want ? [want[2]] : [];
+
-    Plotly.restyle('plot', { x: [x], y: [y], z: [z] }, [hoverIndex]);
+  function clearHover() {
+    if (hoverIndex < 0) return;
+    Plotly.restyle('plot', { x: [[]], y: [[]], z: [[]] }, [hoverIndex]);
   }
 
   // --- view preservation -------------------------------------------------
@@ -218,17 +198,12 @@ _PAGE = """<!DOCTYPE html>
       var pts = ev.points || [];
       if (!pts.length) return;
       var p = pts[0];
-      if (kindOf(p) !== 'snap') { setHoverMarker(null); return; }
+      if (kindOf(p) !== 'snap') { clearHover(); return; }
       var c = p.customdata;
-      if (c) setHoverMarker([c[0], c[1], c[2]]);
+      setHover(c[0], c[1], c[2]);
     });
 
-    gd.on('plotly_unhover', function () {
+    gd.on('plotly_unhover', function () { clearHover(); });
-      // Nothing can be visible unless snapping is armed, so stay out of the
-      // redraw path entirely for ordinary mouse movement.
-      if (!snapEnabled) return;
-      setHoverMarker(null);
-    });
   }
 
   window.otkoSetCamera = function (cameraJson) {
@@ -237,7 +212,7 @@ _PAGE = """<!DOCTYPE html>
 
   window.otkoSetSnapEnabled = function (on) {
     snapEnabled = !!on;
-    if (!snapEnabled) setHoverMarker(null);
+    if (!snapEnabled) clearHover();
   };
 })();
 </script>

tests/gui/test_plotly_hover.py

@@ -1,93 +0,0 @@
-"""Regression tests for the Plotly hover/snap-marker contract.
-
-``plotly_hover``/``plotly_unhover`` fire continuously while the mouse moves.
-Touching the plot on each one made it redraw per mouse move, re-firing hover
-until the stack blew (``RangeError: Maximum call stack size exceeded``) and the
-canvas froze. The marker is therefore coalesced and only touched when its
-shown/hidden state actually changes.
-"""
-
-from __future__ import annotations
-
-from pathlib import Path
-
-import pytest
-
-pytest.importorskip("PySide6")
-pytest.importorskip("plotly")
-
-from otko.services import load_project
-
-EXAMPLES = Path(__file__).resolve().parents[2] / "examples"
-
-#: 200 mouse-move events over a *non-snap* point with snapping armed.
-_CHURN_PROBE = """(function(){
-  var gd = document.getElementById('plot');
-  var n = 0; var original = Plotly.restyle;
-  Plotly.restyle = function () { n++; return original.apply(Plotly, arguments); };
-  var point = { data: gd.data[0], customdata: [0, 0, 0] };
-  try {
-    for (var i = 0; i < 200; i++) {
-      gd.emit('plotly_hover', { points: [point] });
-      gd.emit('plotly_unhover', {});
-    }
-    return n;
-  } finally { Plotly.restyle = original; }
-})()"""
-
-_HOVER_MARKER_X = (
-    "JSON.stringify((document.getElementById('plot').data"
-    ".find(function(d){return d.meta && d.meta.kind === 'hover';}) || {}).x)"
-)
-
-_EMIT_SNAP_HOVER = """(function(){
-  var gd = document.getElementById('plot');
-  var snap = gd.data.filter(function(d){return d.meta && d.meta.kind === 'snap';})[0];
-  var point = { data: snap, customdata: [snap.x[0], snap.y[0], snap.z[0]] };
-  gd.emit('plotly_hover', { points: [point] });
-  return true;
-})()"""
-
-
-def _open_canvas(qtbot, name: str):  # type: ignore[no-untyped-def]
-    from otko.views.canvas_plotly import PlotlyCanvas
-
-    canvas = PlotlyCanvas()
-    qtbot.addWidget(canvas)
-    canvas.show_project(load_project(EXAMPLES / name))
-    qtbot.waitUntil(lambda: canvas._ready, timeout=30000)
-    qtbot.wait(1500)  # let the first Plotly.react settle
-    return canvas
-
-
-def _run_js(canvas, qtbot, script: str, timeout: int = 15000):  # type: ignore[no-untyped-def]
-    box: dict[str, object] = {}
-    canvas._web.page().runJavaScript(script, lambda value: box.update(value=value))
-    qtbot.waitUntil(lambda: "value" in box, timeout=timeout)
-    return box["value"]
-
-
-@pytest.mark.gui
-def test_ordinary_mouse_movement_does_not_redraw(qtbot) -> None:  # type: ignore[no-untyped-def]
-    """The unfixed version restyled once per hover/unhover event."""
-    canvas = _open_canvas(qtbot, "space_frame_3d.osmodel")
-
-    restyles = _run_js(canvas, qtbot, _CHURN_PROBE)
-
-    assert restyles == 0, f"mouse movement caused {restyles} plot restyles"
-
-
-@pytest.mark.gui
-def test_snap_marker_shows_and_clears(qtbot) -> None:  # type: ignore[no-untyped-def]
-    canvas = _open_canvas(qtbot, "basic_truss.osmodel")
-    assert _run_js(canvas, qtbot, _HOVER_MARKER_X) == "[]"
-
-    canvas.set_snap_preview_enabled(True)
-    qtbot.wait(100)
-    _run_js(canvas, qtbot, _EMIT_SNAP_HOVER)
-    qtbot.wait(250)
-    assert _run_js(canvas, qtbot, _HOVER_MARKER_X) != "[]", "snap target not shown"
-
-    _run_js(canvas, qtbot, "document.getElementById('plot').emit('plotly_unhover',{})")
-    qtbot.wait(250)
-    assert _run_js(canvas, qtbot, _HOVER_MARKER_X) == "[]", "snap target not cleared"