Handle real modifier events in `ChartView`

Ignore modifier-only key events before action dispatch so Qt's real
Ctrl-G sequence reaches the chart-local gap-overlay binding.

Drive a shown and focused widget through `QtBot.keyPress()` to cover
the production event relay without synthetic event dispatch.

(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))

piker/ui/_interaction.py

@@ -226,6 +226,16 @@ async def handle_viewmode_kb_inputs(
             if mods == Qt.KeyboardModifier.ControlModifier:
                 ctrl = True
 
+            # Real key chords deliver modifier-only events before the
+            # bound key. Nothing below handles those as actions.
+            if key in {
+                Qt.Key.Key_Alt,
+                Qt.Key.Key_Control,
+                Qt.Key.Key_Meta,
+                Qt.Key.Key_Shift,
+            }:
+                continue
+
             # UI REPL-shell, with ctrl-p (for "pause")
             if (
                 ctrl

tests/test_gap_overlays.py

@@ -10,7 +10,6 @@ from types import SimpleNamespace
 
 import msgspec
 import numpy as np
-from PyQt6.QtGui import QKeyEvent
 from PyQt6.QtWidgets import QGraphicsScene
 import pyqtgraph as pg
 import pytest
@@ -36,7 +35,6 @@ from piker.ui._interaction import (
 )
 from piker.ui.qt import (
     QApplication,
-    QEvent,
     QPointF,
     QRectF,
     Qt,
@@ -630,14 +628,16 @@ def test_ctrl_g_event_renders_real_history_overlay(
 
 ) -> None:
     '''
-    Route a real Qt Ctrl-G event into a rendered history gap layer.
+    Route real QtBot Ctrl-G input into a rendered history gap layer.
 
     Calling the toggle helper directly does not prove that Qt event
     filtering, `KeyboardMsg` conversion or the asynchronous view-mode
     handler recognizes the configured binding. Install the production
-    `EventRelay` on a real widget, send one offscreen `QKeyEvent`,
+    `EventRelay` on a shown and focused widget, press Ctrl-G through
+    `QtBot.keyPress()` so Qt emits its modifier-only event before G,
     and wait until the handler blocks again. The resulting manager
-    and scene state prove the complete local keyboard path ran.
+    and scene state prove the complete local keyboard path ran
+    without crashing or directly dispatching a synthetic event.
 
     '''
     ds: SimpleNamespace
@@ -670,6 +670,13 @@ def test_ctrl_g_event_renders_real_history_overlay(
         cursor=SimpleNamespace(in_query_mode=False),
     )
     source.setMouseMode = lambda mode: None
+    source.setFocusPolicy(Qt.FocusPolicy.StrongFocus)
+    with qtbot.waitExposed(source):
+        source.show()
+    source.raise_()
+    source.activateWindow()
+    source.setFocus()
+    qtbot.waitUntil(lambda: source.hasFocus())
 
     async def drive_key_event() -> None:
         '''
@@ -680,13 +687,13 @@ def test_ctrl_g_event_renders_real_history_overlay(
             source,
             dss={FQME: ds},
         ):
-            key_event: QKeyEvent = QKeyEvent(
-                QEvent.Type.KeyPress,
+            qtbot.keyPress(
+                source,
                 Qt.Key.Key_G,
-                Qt.KeyboardModifier.ControlModifier,
-                'g',
+                modifier=(
+                    Qt.KeyboardModifier.ControlModifier
+                ),
             )
-            assert QApplication.sendEvent(source, key_event)
             await wait_all_tasks_blocked()
 
     try: