dashboard: Add "Quick Open" dialog for experiments on global shortcut

This is similar to functionality in Sublime Text, VS Code, etc.

RELEASE_NOTES.rst

@@ -15,7 +15,11 @@ Highlights:
 * Zotino now exposes `voltage_to_mu()`
 * `ad9910`: The maximum amplitude scale factor is now `0x3fff` (was `0x3ffe`
   before).
-* Applets now restart if they are running and a ccb call changes their spec
+* Dashboard:
+   - Applets now restart if they are running and a ccb call changes their spec
+   - A "Quick Open" dialog to open experiments by typing part of their name can
+     be brought up Ctrl-P (Ctrl+Return to immediately submit the selected entry
+     with the default arguments).
 * Experiment results are now always saved to HDF5, even if run() fails.
 
 Breaking changes:

artiq/dashboard/experiments.py

@@ -9,8 +9,9 @@ import h5py
 
 from sipyco import pyon
 
-from artiq.gui.tools import LayoutWidget, log_level_to_name, get_open_file_name
 from artiq.gui.entries import procdesc_to_entry, ScanEntry
+from artiq.gui.fuzzy_select import FuzzySelectWidget
+from artiq.gui.tools import LayoutWidget, log_level_to_name, get_open_file_name
 
 
 logger = logging.getLogger(__name__)
@@ -488,6 +489,60 @@ class _ExperimentDock(QtWidgets.QMdiSubWindow):
         self.hdf5_load_directory = state["hdf5_load_directory"]
 
 
+class _QuickOpenDialog(QtWidgets.QDialog):
+    """Modal dialog for opening/submitting experiments from a
+    FuzzySelectWidget."""
+    closed = QtCore.pyqtSignal()
+
+    def __init__(self, manager):
+        super().__init__(manager.main_window)
+        self.setModal(True)
+
+        self.manager = manager
+
+        self.setWindowTitle("Quick open…")
+
+        layout = QtWidgets.QGridLayout(self)
+        layout.setSpacing(0)
+        layout.setContentsMargins(0, 0, 0, 0)
+        self.setLayout(layout)
+
+        # Find matching experiment names. Open experiments are preferred to
+        # matches from the repository to ease quick window switching.
+        open_exps = list(self.manager.open_experiments.keys())
+        repo_exps = set("repo:" + k
+                        for k in self.manager.explist.keys()) - set(open_exps)
+        choices = [(o, 100) for o in open_exps] + [(r, 0) for r in repo_exps]
+
+        self.select_widget = FuzzySelectWidget(choices)
+        layout.addWidget(self.select_widget)
+        self.select_widget.aborted.connect(self.close)
+        self.select_widget.finished.connect(self._open_experiment)
+
+        font_metrics = QtGui.QFontMetrics(self.select_widget.line_edit.font())
+        self.select_widget.setMinimumWidth(font_metrics.averageCharWidth() * 70)
+
+    def done(self, r):
+        if self.select_widget:
+            self.select_widget.abort()
+        self.closed.emit()
+        QtWidgets.QDialog.done(self, r)
+
+    def _open_experiment(self, exp_name, modifiers):
+        if modifiers & QtCore.Qt.ControlModifier:
+            try:
+                self.manager.submit(exp_name)
+            except:
+                # Not all open_experiments necessarily still exist in the explist
+                # (e.g. if the repository has been re-scanned since).
+                logger.warning("failed to submit experiment '%s'",
+                               exp_name,
+                               exc_info=True)
+        else:
+            self.manager.open_experiment(exp_name)
+        self.close()
+
+
 class ExperimentManager:
     def __init__(self, main_window,
                  explist_sub, schedule_sub,
@@ -508,6 +563,13 @@ class ExperimentManager:
 
         self.open_experiments = dict()
 
+        self.is_quick_open_shown = False
+        quick_open_shortcut = QtWidgets.QShortcut(
+            QtCore.Qt.CTRL + QtCore.Qt.Key_P,
+            main_window)
+        quick_open_shortcut.setContext(QtCore.Qt.ApplicationShortcut)
+        quick_open_shortcut.activated.connect(self.show_quick_open)
+
     def set_explist_model(self, model):
         self.explist = model.backing_store
 
@@ -708,3 +770,14 @@ class ExperimentManager:
         self.submission_arguments = state["arguments"]
         for expurl in state["open_docks"]:
             self.open_experiment(expurl)
+
+    def show_quick_open(self):
+        if self.is_quick_open_shown:
+            return
+
+        self.is_quick_open_shown = True
+        dialog = _QuickOpenDialog(self)
+        def closed():
+            self.is_quick_open_shown = False
+        dialog.closed.connect(closed)
+        dialog.show()

artiq/gui/fuzzy_select.py

@@ -0,0 +1,272 @@
+import re
+
+from functools import partial
+from typing import List, Tuple
+from PyQt5 import QtCore, QtWidgets
+
+from artiq.gui.tools import LayoutWidget
+
+
+class FuzzySelectWidget(LayoutWidget):
+    """Widget to select from a list of pre-defined choices by typing in a
+    substring match (cf. Ctrl+P "Quick Open"/"Goto anything" functions in
+    editors/IDEs).
+    """
+
+    #: Raised when the selection process is aborted by the user (Esc, loss of
+    #: focus, etc.).
+    aborted = QtCore.pyqtSignal()
+
+    #: Raised when an entry has been selected, giving the label of the user
+    #: choice and any additional QEvent.modifiers() (e.g. Ctrl key pressed).
+    finished = QtCore.pyqtSignal(str, int)
+
+    def __init__(self,
+                 choices: List[Tuple[str, int]] = [],
+                 entry_count_limit: int = 10,
+                 *args):
+        """
+        :param choices: The choices the user can select from, given as tuples
+            of labels to display and an additional weight added to the
+            fuzzy-matching score.
+        :param entry_count_limit: Maximum number of entries to show.
+        """
+        super().__init__(*args)
+        self.choices = choices
+        self.entry_count_limit = entry_count_limit
+        assert entry_count_limit >= 2, ("Need to allow at least two entries " +
+                                        "to show the '<n> not shown' hint")
+
+        self.line_edit = QtWidgets.QLineEdit(self)
+        self.layout.addWidget(self.line_edit)
+
+        line_edit_focus_filter = _FocusEventFilter(self.line_edit)
+        line_edit_focus_filter.focus_gained.connect(self._activate)
+        line_edit_focus_filter.focus_lost.connect(self._line_edit_focus_lost)
+        self.line_edit.installEventFilter(line_edit_focus_filter)
+        self.line_edit.textChanged.connect(self._update_menu)
+
+        escape_filter = _EscapeKeyFilter(self)
+        escape_filter.escape_pressed.connect(self.abort)
+        self.line_edit.installEventFilter(escape_filter)
+
+        self.menu = None
+
+        self.update_when_text_changed = True
+        self.menu_typing_filter = None
+        self.line_edit_up_down_filter = None
+        self.abort_when_menu_hidden = False
+        self.abort_when_line_edit_unfocussed = True
+
+    def set_choices(self, choices: List[Tuple[str, int]]) -> None:
+        """Update the list of choices available to the user."""
+        self.choices = choices
+        if self.menu:
+            self._update_menu()
+
+    def _activate(self):
+        self.update_when_text_changed = True
+        if not self.menu:
+            # Show menu after initial layout is complete.
+            QtCore.QTimer.singleShot(0, self._update_menu)
+
+    def _ensure_menu(self):
+        if self.menu:
+            return
+
+        self.menu = QtWidgets.QMenu(self)
+
+        # Display menu with search results beneath line edit.
+        menu_pos = self.line_edit.mapToGlobal(self.line_edit.pos())
+        menu_pos.setY(menu_pos.y() + self.line_edit.height())
+
+        self.menu.popup(menu_pos)
+        self.menu.aboutToHide.connect(self._menu_hidden)
+
+    def _menu_hidden(self):
+        if self.abort_when_menu_hidden:
+            self.abort_when_menu_hidden = False
+            self.abort()
+
+    def _line_edit_focus_lost(self):
+        if self.abort_when_line_edit_unfocussed:
+            self.abort()
+
+    def _update_menu(self):
+        if not self.update_when_text_changed:
+            return
+
+        filtered_choices = self._filter_choices()
+
+        if not filtered_choices:
+            # No matches, don't display menu at all.
+            if self.menu:
+                self.abort_when_menu_hidden = False
+                self.menu.close()
+            self.menu = None
+            self.abort_when_line_edit_unfocussed = True
+            self.line_edit.setFocus()
+            return
+
+        # Truncate the list, leaving room for the "<n> not shown" entry.
+        num_omitted = 0
+        if len(filtered_choices) > self.entry_count_limit:
+            num_omitted = len(filtered_choices) - (self.entry_count_limit - 1)
+            filtered_choices = filtered_choices[:self.entry_count_limit - 1]
+
+        # We are going to end up with a menu shown and the line edit losing
+        # focus.
+        self.abort_when_line_edit_unfocussed = False
+
+        if self.menu:
+            # Hide menu temporarily to avoid re-layouting on every added item.
+            self.abort_when_menu_hidden = False
+            self.menu.hide()
+            self.menu.clear()
+
+        self._ensure_menu()
+
+        first_action = None
+        last_action = None
+        for choice in filtered_choices:
+            action = QtWidgets.QAction(choice, self.menu)
+            action.triggered.connect(partial(self._finish, action, choice))
+            action.modifiers = 0
+            self.menu.addAction(action)
+            if not first_action:
+                first_action = action
+            last_action = action
+
+        if num_omitted > 0:
+            action = QtWidgets.QAction("<{} not shown>".format(num_omitted),
+                                       self.menu)
+            action.setEnabled(False)
+            self.menu.addAction(action)
+
+        if self.menu_typing_filter:
+            self.menu.removeEventFilter(self.menu_typing_filter)
+        self.menu_typing_filter = _NonUpDownKeyFilter(self.menu,
+                                                      self.line_edit)
+        self.menu.installEventFilter(self.menu_typing_filter)
+
+        if self.line_edit_up_down_filter:
+            self.line_edit.removeEventFilter(self.line_edit_up_down_filter)
+        self.line_edit_up_down_filter = _UpDownKeyFilter(
+            self.line_edit, self.menu, first_action, last_action)
+        self.line_edit.installEventFilter(self.line_edit_up_down_filter)
+
+        self.abort_when_menu_hidden = True
+        self.menu.show()
+        if first_action:
+            self.menu.setActiveAction(first_action)
+            self.menu.setFocus()
+        else:
+            self.line_edit.setFocus()
+
+    def _filter_choices(self):
+        """Return a filtered and ranked list of choices based on the current
+        user input.
+        
+        For a choice not to be filtered out, it needs to contain the entered
+        characters in order. Entries are further sorted by the length of the
+        match (i.e. preferring matches where the entered string occurrs
+        without interruptions), then the position of the match, and finally
+        lexicographically.
+        """
+        # TODO: More SublimeText-like heuristics taking capital letters and
+        # punctuation into account. Also, requiring the matches to be in order
+        # seems to be a bit annoying in practice.
+        text = self.line_edit.text()
+        suggestions = []
+        # `re` seems to be the fastest way of matching this in CPython, even
+        # with all the wildcards.
+        pat = '.*?'.join(map(re.escape, text.lower()))
+        regex = re.compile(pat)
+        for label, weight in self.choices:
+            r = regex.search(label.lower())
+            if r:
+                suggestions.append((len(r.group()) - weight, r.start(), label))
+        return [x for _, _, x in sorted(suggestions)]
+
+    def _close(self):
+        if self.menu:
+            self.menu.close()
+            self.menu = None
+        self.update_when_text_changed = False
+        self.line_edit.clear()
+
+    def abort(self):
+        self._close()
+        self.aborted.emit()
+
+    def _finish(self, action, name):
+        self._close()
+        self.finished.emit(name, action.modifiers)
+
+
+class _FocusEventFilter(QtCore.QObject):
+    """Emits signals when focus is gained/lost."""
+    focus_gained = QtCore.pyqtSignal()
+    focus_lost = QtCore.pyqtSignal()
+
+    def eventFilter(self, obj, event):
+        if event.type() == QtCore.QEvent.FocusIn:
+            self.focus_gained.emit()
+        elif event.type() == QtCore.QEvent.FocusOut:
+            self.focus_lost.emit()
+        return False
+
+
+class _EscapeKeyFilter(QtCore.QObject):
+    """Emits a signal if the Escape key is pressed."""
+    escape_pressed = QtCore.pyqtSignal()
+
+    def eventFilter(self, obj, event):
+        if event.type() == QtCore.QEvent.KeyPress:
+            if event.key() == QtCore.Qt.Key_Escape:
+                self.escape_pressed.emit()
+        return False
+
+
+class _UpDownKeyFilter(QtCore.QObject):
+    """Handles focussing the menu when pressing up/down in the line edit."""
+    def __init__(self, parent, menu, first_item, last_item):
+        super().__init__(parent)
+        self.menu = menu
+        self.first_item = first_item
+        self.last_item = last_item
+
+    def eventFilter(self, obj, event):
+        if event.type() == QtCore.QEvent.KeyPress:
+            if event.key() == QtCore.Qt.Key_Down:
+                self.menu.setActiveAction(self.first_item)
+                self.menu.setFocus()
+                return True
+
+            if event.key() == QtCore.Qt.Key_Up:
+                self.menu.setActiveAction(self.last_item)
+                self.menu.setFocus()
+                return True
+        return False
+
+
+class _NonUpDownKeyFilter(QtCore.QObject):
+    """Forwards input while the menu is focussed to the line edit."""
+    def __init__(self, parent, target):
+        super().__init__(parent)
+        self.target = target
+
+    def eventFilter(self, obj, event):
+        if event.type() == QtCore.QEvent.KeyPress:
+            k = event.key()
+            if k in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
+                action = obj.activeAction()
+                if action is not None:
+                    action.modifiers = event.modifiers()
+                    return False
+            if (k != QtCore.Qt.Key_Down and k != QtCore.Qt.Key_Up
+                    and k != QtCore.Qt.Key_Enter
+                    and k != QtCore.Qt.Key_Return):
+                QtWidgets.QApplication.sendEvent(self.target, event)
+                return True
+        return False