nix: make Qt6 work on wayland

Taking many tips from our `default.nix` (thanks @nt!) this seems to be
the minimal overlay required for a flake to get up and running with
`piker chart` B)

Notes,
- for now, we're pinning to a major `cpython` version (3.13)
- ensure we (can) build with `nixpkgs.qt6.qtwayland`
- add the minimal Qt ld-lib-path linkings including those for plugin
  use (required for wayland mode).
- for now, hardcode "wayland" platform-mode and the linux standard
  "xdg-shell" integration.
- leave some TODOs to better parameterize around py versions.

default.nix

@@ -11,12 +11,11 @@ let
   libxkbcommonStorePath = lib.getLib libxkbcommon;
   xcbutilcursorStorePath = lib.getLib xcb-util-cursor;
 
-  pypkgs = python313Packages;
+  qtpyStorePath = lib.getLib python312Packages.qtpy;
-  qtpyStorePath = lib.getLib pypkgs.qtpy;
+  pyqt6StorePath = lib.getLib python312Packages.pyqt6;
-  pyqt6StorePath = lib.getLib pypkgs.pyqt6;
+  pyqt6SipStorePath = lib.getLib python312Packages.pyqt6-sip;
-  pyqt6SipStorePath = lib.getLib pypkgs.pyqt6-sip;
+  rapidfuzzStorePath = lib.getLib python312Packages.rapidfuzz;
-  rapidfuzzStorePath = lib.getLib pypkgs.rapidfuzz;
+  qdarkstyleStorePath = lib.getLib python312Packages.qdarkstyle;
-  qdarkstyleStorePath = lib.getLib pypkgs.qdarkstyle;
 
   xorgLibX11StorePath = lib.getLib xorg.libX11;
   xorgLibxcbStorePath = lib.getLib xorg.libxcb;
@@ -52,12 +51,12 @@ stdenv.mkDerivation {
     xorg.xcbutilrenderutil
 
     # Python requirements.
-    python313
+    python312Full
-    uv
+    python312Packages.uv
-    pypkgs.qdarkstyle
+    python312Packages.qdarkstyle
-    pypkgs.rapidfuzz
+    python312Packages.rapidfuzz
-    pypkgs.pyqt6
+    python312Packages.pyqt6
-    pypkgs.qtpy
+    python312Packages.qtpy
   ];
   src = null;
   shellHook = ''
@@ -114,11 +113,11 @@ stdenv.mkDerivation {
 
     export LD_LIBRARY_PATH
 
-    RPDFUZZ_PATH="${rapidfuzzStorePath}/lib/python3.13/site-packages"
+    RPDFUZZ_PATH="${rapidfuzzStorePath}/lib/python3.12/site-packages"
-    QDRKSTYLE_PATH="${qdarkstyleStorePath}/lib/python3.13/site-packages"
+    QDRKSTYLE_PATH="${qdarkstyleStorePath}/lib/python3.12/site-packages"
-    QTPY_PATH="${qtpyStorePath}/lib/python3.13/site-packages"
+    QTPY_PATH="${qtpyStorePath}/lib/python3.12/site-packages"
-    PYQT6_PATH="${pyqt6StorePath}/lib/python3.13/site-packages"
+    PYQT6_PATH="${pyqt6StorePath}/lib/python3.12/site-packages"
-    PYQT6_SIP_PATH="${pyqt6SipStorePath}/lib/python3.13/site-packages"
+    PYQT6_SIP_PATH="${pyqt6SipStorePath}/lib/python3.12/site-packages"
 
     PATCH="$PATCH:$RPDFUZZ_PATH"
     PATCH="$PATCH:$QDRKSTYLE_PATH"
@@ -128,8 +127,8 @@ stdenv.mkDerivation {
 
     export PATCH
 
-    # install all dev and extras
+    # Install deps
-    uv sync --dev --all-extras
+    uv lock
 
   '';
 }

piker/brokers/binance/venues.py

@@ -220,10 +220,7 @@ class FutesPair(Pair):
                 assert pair == self.pair  # sanity
                 return f'{expiry}'
 
-            case (
+            case 'PERPETUAL':
-                'PERPETUAL'
-                | 'TRADIFI_PERPETUAL'
-            ):
                 return 'PERP'
 
             case '':
@@ -252,10 +249,7 @@ class FutesPair(Pair):
         margin: str = self.marginAsset
 
         match ctype:
-            case (
+            case 'PERPETUAL':
-                'PERPETUAL'
-                | 'TRADIFI_PERPETUAL'
-            ):
                 return f'{margin}M'
 
             case (

piker/ui/_style.py

@@ -182,7 +182,7 @@ class DpiAwareFont:
         # always going to hit that error in range mapping from inches:
         # float to px size: int.
         self._font_inches = inches
-        font_size = math.floor(inches * pdpi)
+        font_size = math.floor(inches * dpi)
 
         log.debug(
             f"screen:{screen.name()}\n"

pyproject.toml

@@ -85,6 +85,9 @@ uis = [
     # TODO: make sure the levenshtein shit compiles on nix..
     # rapidfuzz = {extras = ["speedup"], version = "^0.18.0"}
     "rapidfuzz >=3.2.0, <4.0.0",
+    "qdarkstyle >=3.0.2, <4.0.0",
+    "pyqt6 >=6.7.0, <7.0.0",
+    "pyqtgraph",
 
     # for consideration,
     # - 'visidata'
@@ -115,10 +118,6 @@ dev = [
 
     # ?from git, see below.
     "xonsh",
-    "qdarkstyle >=3.0.2, <4.0.0",
-    "pyqt6 >=6.7.0, <7.0.0",
-    "pyqtgraph",
-
 ]
 
 [tool.pytest.ini_options]

snippets/qt_screen_info.py

@@ -32,6 +32,7 @@ Resource list for mucking with DPIs on multiple screens:
 
 '''
 
+from pyqtgraph import QtGui
 from PyQt6 import (
     QtCore,
     QtWidgets,
@@ -42,7 +43,6 @@ from PyQt6.QtCore import (
     QSize,
     QRect,
 )
-from pyqtgraph import QtGui
 
 # Proper high DPI scaling is available in Qt >= 5.6.0. This attibute
 # must be set before creating the application

tests/test_dpi_font.py

@@ -1,36 +0,0 @@
-import pytest
-from piker.ui._style import DpiAwareFont
-
-
-class MockScreen:
-    def __init__(self, pdpi, ldpi, name="MockScreen"):
-        self._pdpi = pdpi
-        self._ldpi = ldpi
-        self._name = name
-
-    def physicalDotsPerInch(self):
-        return self._pdpi
-
-    def logicalDotsPerInch(self):
-        return self._ldpi
-
-    def name(self):
-        return self._name
-
-
-@pytest.mark.parametrize(
-    "pdpi, ldpi, expected_px",
-    [
-        (96, 96, 9),       # normal DPI
-        (169, 96, 15),     # HiDPI
-        (120, 96, 10),     # mid-DPI
-    ]
-)
-def test_font_px_size(pdpi, ldpi, expected_px):
-    font = DpiAwareFont()
-    font.configure_to_dpi(screen=MockScreen(pdpi, ldpi))
-
-    px = font.px_size
-    print(f"{pdpi}x{ldpi} DPI -> Computed pixel size: {px}")
-
-    assert px == expected_px