Support min and max keyboard pauses

Some providers do well with a "longer" debounce period (like ib) since
searching them too frequently causes latency and stalls.  By supporting
both a min and max debounce period on keyboard input we can only send
patterns to the slower engines when that period is triggered via
`trio.move_on_after()` and continue to relay to faster engines when the
measured period permits. Allow search routines to register their "min
period" such that they can choose to ignore patterns that arrive before
their heuristically known ideal wait.

piker/ui/_search.py

@@ -38,6 +38,7 @@ from typing import (
     Awaitable, Sequence, Dict,
     Any, AsyncIterator, Tuple,
 )
+import time
 # from pprint import pformat
 
 from fuzzywuzzy import process as fuzzy
@@ -207,7 +208,6 @@ class CompleterView(QTreeView):
             # values just needs to be sequence-like
             for i, s in enumerate(values):
 
-                # blank = QStandardItem('')
                 ix = QStandardItem(str(i))
                 item = QStandardItem(s)
                 # item.setCheckable(False)
@@ -220,16 +220,20 @@ class CompleterView(QTreeView):
         # XXX: these 2 lines MUST be in sequence in order
         # to get the view to show right after typing input.
         sel = self.selectionModel()
+
+        # select row without selecting.. :eye_rollzz:
+        # https://doc.qt.io/qt-5/qabstractitemview.html#setCurrentIndex
         sel.setCurrentIndex(
             model.index(0, 0, QModelIndex()),
             QItemSelectionModel.ClearAndSelect |
             QItemSelectionModel.Rows
         )
+
+        # ensure we're **not** selecting the first level parent node and
+        # instead its child.
         self.select_from_idx(model.index(0, 0, QModelIndex()))
 
-
     def show_matches(self) -> None:
-        # print(f"SHOWING {self}")
         self.show()
         self.resize()
 
@@ -242,7 +246,6 @@ class CompleterView(QTreeView):
 
         # inclusive of search bar and header "rows" in pixel terms
         rows = 100
-        # print(f'row count: {rows}')
         # max_rows = 8  # 6 + search and headers
         row_px = self.rowHeight(self.currentIndex())
         # print(f'font_h: {font_h}\n px_height: {px_height}')
@@ -374,7 +377,11 @@ async def fill_results(
     symsearch: Callable[..., Awaitable],
     recv_chan: trio.abc.ReceiveChannel,
     # cached_symbols: Dict[str,
-    pause_time: float = 0.0616,
+
+    # kb debouncing pauses
+    min_pause_time: float = 0.0616,
+    # long_pause_time: float = 0.4,
+    max_pause_time: float = 6/16,
 
 ) -> None:
     """Task to search through providers and fill in possible
@@ -385,26 +392,28 @@ async def fill_results(
 
     bar = search.bar
     view = bar.view
-    sel = bar.view.selectionModel()
-    model = bar.view.model()
 
-    last_search_text = ''
     last_text = bar.text()
     repeats = 0
 
+    while True:
+        await _search_active.wait()
+        period = None
+
         while True:
 
             last_text = bar.text()
-        await _search_active.wait()
+            wait_start = time.time()
 
-        with trio.move_on_after(pause_time) as cs:
+            with trio.move_on_after(max_pause_time):
-            # cs.shield = True
                 pattern = await recv_chan.receive()
-            print(pattern)
+
+            period = time.time() - wait_start
+            print(f'{pattern} after {period}')
 
             # during fast multiple key inputs, wait until a pause
             # (in typing) to initiate search
-        if not cs.cancelled_caught:
+            if period < min_pause_time:
                 log.debug(f'Ignoring fast input for {pattern}')
                 continue
 
@@ -414,49 +423,32 @@ async def fill_results(
             if not text:
                 print('idling')
                 _search_active = trio.Event()
-            continue
+                break
+
+            if repeats > 2 and period >= max_pause_time:
+                _search_active = trio.Event()
+                repeats = 0
+                break
 
             if text == last_text:
                 repeats += 1
 
-        if repeats > 1:
-            _search_active = trio.Event()
-            repeats = 0
-
             if not _search_enabled:
-            print('search not ENABLED?')
+                print('search currently disabled')
-            continue
+                break
-
-        if last_search_text and last_search_text == text:
-            continue
 
             log.debug(f'Search req for {text}')
 
-        last_search_text = text
+            results = await symsearch(text, period=period)
-        results = await symsearch(text)
+
             log.debug(f'Received search result {results}')
 
             if results and _search_enabled:
 
-            # TODO: indented branch results for each provider
+                # show the results in the completer view
                 view.set_results(results)
-
-            # XXX: these 2 lines MUST be in sequence in order
-            # to get the view to show right after typing input.
-            # ensure we select first indented entry
-            # view.select_from_idx(model.index(0, 0, QModelIndex()))
-
-            # sel.setCurrentIndex(
-            #     model.index(0, 0, QModelIndex()),
-            #     QItemSelectionModel.ClearAndSelect |
-            #     QItemSelectionModel.Rows
-            # )
-
                 bar.show()
 
-            # # ensure we select first indented entry
-            # view.select_from_idx(sel.currentIndex())
-
 
 class SearchWidget(QtGui.QWidget):
     def __init__(
@@ -491,21 +483,18 @@ class SearchWidget(QtGui.QWidget):
             view=self.view,
         )
         self.vbox.addWidget(self.bar)
-        self.vbox.setAlignment(self.bar, Qt.AlignTop | Qt.AlignLeft)
+        self.vbox.setAlignment(self.bar, Qt.AlignTop | Qt.AlignRight)
         self.vbox.addWidget(self.bar.view)
         self.vbox.setAlignment(self.view, Qt.AlignTop | Qt.AlignLeft)
 
-
     def focus(self) -> None:
         # fill cache list
         self.view.set_results({'cache': list(self.chart_app._chart_cache)})
         self.bar.focus()
 
 
-
 async def handle_keyboard_input(
 
-    # chart: 'ChartSpace',  # type: igore # noqa
     search: SearchWidget,
     recv_chan: trio.abc.ReceiveChannel,
     keyboard_pause_period: float = 0.0616,
@@ -533,7 +522,6 @@ async def handle_keyboard_input(
                 search,
                 symsearch,
                 recv,
-                pause_time=keyboard_pause_period,
             )
         )
 
@@ -601,21 +589,24 @@ async def handle_keyboard_input(
                     elif key == Qt.Key_J:
                         nidx = view.select_next()
 
-                    # select row without selecting.. :eye_rollzz:
-                    # https://doc.qt.io/qt-5/qabstractitemview.html#setCurrentIndex
                     if nidx.isValid():
                         i, item = view.select_from_idx(nidx)
 
                         if item:
                             parent_item = item.parent()
                             if parent_item and parent_item.text() == 'cache':
-                                node = model.itemFromIndex(i.siblingAtColumn(1))
+                                node = model.itemFromIndex(
+                                    i.siblingAtColumn(1)
+                                )
                                 if node:
+
+                                    # TODO: parse out provider from
+                                    # cached value.
                                     value = node.text()
-                                    print(f'cache selection')
+
                                     search.chart_app.load_symbol(
                                         app.linkedcharts.symbol.brokers[0],
-                                        value,
+                                        node.text(),
                                         'info',
                                     )
 
@@ -631,10 +622,6 @@ async def search_simple_dict(
     source: dict,
 ) -> Dict[str, Any]:
 
-    # matches_per_src = {}
-
-    # for source, data in source.items():
-
     # search routine can be specified as a function such
     # as in the case of the current app's local symbol cache
     matches = fuzzy.extractBests(
@@ -656,6 +643,8 @@ def get_multi_search() -> Callable[..., Awaitable]:
 
     async def multisearcher(
         pattern: str,
+        period: str,
+
     ) -> dict:
 
         matches = {}
@@ -664,7 +653,9 @@ def get_multi_search() -> Callable[..., Awaitable]:
             provider: str,
             pattern: str,
             search: Callable[..., Awaitable[dict]],
+
         ) -> None:
+
             log.debug(f'Searching {provider} for "{pattern}"')
             results = await search(pattern)
             if results:
@@ -673,8 +664,14 @@ def get_multi_search() -> Callable[..., Awaitable]:
         # TODO: make this an async stream?
         async with trio.open_nursery() as n:
 
-            for brokername, search in _searcher_cache.items():
+            for provider, (search, min_pause) in _searcher_cache.items():
-                n.start_soon(pack_matches, brokername, pattern, search)
+
+                # only conduct search on this backend if it's registered
+                # for the corresponding pause period.
+                if period >= min_pause:
+                    # print(
+                    #   f'searching {provider} after {period} > {min_pause}')
+                    n.start_soon(pack_matches, provider, pattern, search)
 
         return matches
 
@@ -686,15 +683,19 @@ async def register_symbol_search(
 
     provider_name: str,
     search_routine: Callable,
+    pause_period: Optional[float] = None,
 
 ) -> AsyncIterator[dict]:
 
     global _searcher_cache
 
+    pause_period = pause_period or 0.061
+
     # deliver search func to consumer
     try:
-        _searcher_cache[provider_name] = search_routine
+        _searcher_cache[provider_name] = (search_routine, pause_period)
         yield search_routine
+
     finally:
         _searcher_cache.pop(provider_name)