Add find bar for searching for text in the editor

tests/test_find_bar.py

@@ -0,0 +1,100 @@
+from PySide6.QtCore import Qt
+from PySide6.QtGui import QKeySequence, QTextCursor
+from PySide6.QtTest import QTest
+
+from tests.qt_helpers import trigger_menu_action
+
+
+def _cursor_info(editor):
+    """Return (start, end, selectedText) for the current selection."""
+    tc: QTextCursor = editor.textCursor()
+    start = min(tc.anchor(), tc.position())
+    end = max(tc.anchor(), tc.position())
+    return start, end, tc.selectedText()
+
+
+def test_find_actions_and_shortcuts(open_window, qtbot):
+    win = open_window
+
+    # Actions should be present under Navigate and advertise canonical shortcuts
+    act_find = trigger_menu_action(win, "Find on page")
+    assert act_find.shortcut().matches(QKeySequence.Find) == QKeySequence.ExactMatch
+
+    act_next = trigger_menu_action(win, "Find Next")
+    assert act_next.shortcut().matches(QKeySequence.FindNext) == QKeySequence.ExactMatch
+
+    act_prev = trigger_menu_action(win, "Find Previous")
+    assert (
+        act_prev.shortcut().matches(QKeySequence.FindPrevious)
+        == QKeySequence.ExactMatch
+    )
+
+    # "Find on page" should open the bar and focus the input
+    act_find.trigger()
+    qtbot.waitUntil(lambda: win.findBar.isVisible())
+    qtbot.waitUntil(lambda: win.findBar.edit.hasFocus())
+
+
+def test_find_navigate_case_sensitive_and_close_focus(open_window, qtbot):
+    win = open_window
+
+    # Mixed-case content with three matches
+    text = "alpha … ALPHA … alpha"
+    win.editor.setPlainText(text)
+    qtbot.waitUntil(lambda: win.editor.toPlainText() == text)
+
+    # Open the find bar from the menu
+    trigger_menu_action(win, "Find on page").trigger()
+    qtbot.waitUntil(lambda: win.findBar.isVisible())
+    win.findBar.edit.clear()
+    QTest.keyClicks(win.findBar.edit, "alpha")
+
+    # 1) First hit (case-insensitive default)
+    QTest.keyClick(win.findBar.edit, Qt.Key_Return)
+    qtbot.waitUntil(lambda: win.editor.textCursor().hasSelection())
+    s0, e0, sel0 = _cursor_info(win.editor)
+    assert sel0.lower() == "alpha"
+
+    # 2) Next → uppercase ALPHA (case-insensitive)
+    trigger_menu_action(win, "Find Next").trigger()
+    qtbot.waitUntil(lambda: win.editor.textCursor().hasSelection())
+    s1, e1, sel1 = _cursor_info(win.editor)
+    assert sel1.upper() == "ALPHA"
+
+    # 3) Next → the *other* lowercase "alpha"
+    trigger_menu_action(win, "Find Next").trigger()
+    qtbot.waitUntil(lambda: win.editor.textCursor().hasSelection())
+    s2, e2, sel2 = _cursor_info(win.editor)
+    assert sel2.lower() == "alpha"
+    # Ensure we didn't wrap back to the very first "alpha"
+    assert s2 != s0
+
+    # 4) Case-sensitive: skip ALPHA and only hit lowercase
+    win.findBar.case.setChecked(True)
+    # Put the caret at start to make the next search deterministic
+    tc = win.editor.textCursor()
+    tc.setPosition(0)
+    win.editor.setTextCursor(tc)
+
+    win.findBar.find_next()
+    qtbot.waitUntil(lambda: win.editor.textCursor().hasSelection())
+    s_cs1, e_cs1, sel_cs1 = _cursor_info(win.editor)
+    assert sel_cs1 == "alpha"
+
+    win.findBar.find_next()
+    qtbot.waitUntil(lambda: win.editor.textCursor().hasSelection())
+    s_cs2, e_cs2, sel_cs2 = _cursor_info(win.editor)
+    assert sel_cs2 == "alpha"
+    assert s_cs2 != s_cs1  # it's the other lowercase match
+
+    # 5) Previous goes back to the earlier lowercase match
+    win.findBar.find_prev()
+    qtbot.waitUntil(lambda: win.editor.textCursor().hasSelection())
+    s_prev, e_prev, sel_prev = _cursor_info(win.editor)
+    assert sel_prev == "alpha"
+    assert s_prev == s_cs1
+
+    # 6) Close returns focus to editor
+    win.findBar.closeBtn.click()
+    qtbot.waitUntil(lambda: not win.findBar.isVisible())
+    qtbot.waitUntil(lambda: win.editor.hasFocus())