Scale view to measured results row count

In other words instead of some static view size previously determined by
the accompanying (slow) chart's height, (recursively) calculate the
number of displayed rows and compute the minimal height needed. This
still caps the view at the height of the chart such that the view will
switch to scroll bar mode when too many results are shown and can't all
be fit in the vertical space.

Deats:
- add a ``CompleterView.iter_df_rows()`` which recursively iterates all
  rows in depth-first order making it simple to compute the absolute
  number of result rows in view and thus the minimal number of pixels to
  show all results.
- always pass the height in the `.on_resize()` handler to ensure
  triggering the height logic when new results are generated in the
  search loop.

piker/ui/_search.py

@@ -35,9 +35,13 @@ from collections import defaultdict
 from contextlib import asynccontextmanager
 from functools import partial
 from typing import (
-    Optional, Callable,
-    Awaitable, Sequence,
-    Any, AsyncIterator
+    Optional,
+    Callable,
+    Awaitable,
+    Sequence,
+    Any,
+    AsyncIterator,
+    Iterator,
 )
 import time
 # from pprint import pformat
@@ -119,7 +123,7 @@ class CompleterView(QTreeView):
         # TODO: size this based on DPI font
         self.setIndentation(_font.px_size)
 
-        # self.setUniformRowHeights(True)
+        self.setUniformRowHeights(True)
         # self.setColumnWidth(0, 3)
         # self.setVerticalBarPolicy(Qt.ScrollBarAlwaysOff)
         # self.setSizeAdjustPolicy(QAbstractScrollArea.AdjustIgnored)
@@ -166,11 +170,15 @@ class CompleterView(QTreeView):
     ) -> None:
         model = self.model()
         cols = model.columnCount()
-
-        # rows = model.rowCount()
         cidx = self.selectionModel().currentIndex()
-        row_h = self.rowHeight(cidx)
-        # print(f'row_h: {row_h}')
+        rows = model.rowCount()
+        self.expandAll()
+
+        row_h = rows_h = self.rowHeight(cidx) * rows
+        for idx, item in self.iter_df_rows():
+            row_h = self.rowHeight(idx)
+            rows_h += row_h
+            # print(f'row_h: {row_h}\nrows_h: {rows_h}')
 
         col_w_tot = 0
         for i in range(cols):
@@ -195,16 +203,16 @@ class CompleterView(QTreeView):
 
         if h:
             h: int = round(h)
-            # mn = row_h * 2
-            # self.setMinimumHeight(mn)
-            # abs_mx = h - row_h
-            # print(f'set min {abs_mx}')
-            # self.setFixedHeight(round(0.9 * h))
-            self.setMinimumHeight(round(0.91 * h))
+            abs_mx = round(0.91 * h)
+            self.setMaximumHeight(abs_mx)
 
-            # self.setMaximumHeight(0.9 * abs_mx)
-            # 6 result row slots and 3 rows for sections and headers
-            # mn = (6 + 3) * row_h
+            if rows_h <= abs_mx:
+                # self.setMinimumHeight(rows_h)
+                self.setMinimumHeight(rows_h)
+                # self.setFixedHeight(rows_h)
+
+            else:
+                self.setMinimumHeight(abs_mx)
 
         # dyncamically size to width of longest result seen
         curr_w = self.width()
@@ -335,6 +343,23 @@ class CompleterView(QTreeView):
             item = model.itemFromIndex(idx)
             yield idx, item
 
+    def iter_df_rows(
+        self,
+        iparent: QModelIndex = QModelIndex(),
+
+    ) -> Iterator[tuple[QModelIndex, QStandardItem]]:
+
+        model = self.model()
+        isections = model.rowCount(iparent)
+        for i in range(isections):
+            idx = model.index(i, 0, iparent)
+            item = model.itemFromIndex(idx)
+            yield idx, item
+
+            if model.hasChildren(idx):
+                # recursively yield child items depth-first
+                yield from self.iter_df_rows(idx)
+
     def find_section(
         self,
         section: str,
@@ -358,7 +383,8 @@ class CompleterView(QTreeView):
         status_field: str = None,
 
     ) -> None:
-        '''Clear all result-rows from under the depth = 1 section.
+        '''
+        Clear all result-rows from under the depth = 1 section.
 
         '''
         idx = self.find_section(section)
@@ -459,7 +485,7 @@ class CompleterView(QTreeView):
             # a resize of some higher level parent-container widget.
             search = self.parent()
             w, h = search.space_dims()
-            self.resize_to_results(w=w)
+            self.resize_to_results(w=w, h=h)
 
         self.show()
 
@@ -942,8 +968,8 @@ async def handle_keyboard_input(
             if key in (Qt.Key_Enter, Qt.Key_Return):
                 _search_enabled = False
                 await search.chart_current_item(clear_to_cache=True)
-                view.show_matches()
                 search.show_only_cache_entries()
+                view.show_matches()
                 search.focus()
 
             elif not ctl and not bar.text():