spacr.qt.widgets.colour_picker

The one colour picker the GUI uses, with the platform dialog turned off.

WHY THIS MODULE EXISTS AT ALL

QColorDialog.getColor defaults to the platform’s colour chooser. On a GNOME desktop with xdg-desktop-portal running, that is not a Qt widget at all: Qt asks the portal, the portal starts (or wakes) the GTK implementation over D-Bus, and the dialog can be slow to appear. Every colour picker in the tree was reached through an unguarded getColor — six of them, none passing DontUseNativeDialog.

Qt’s own dialog opens immediately, looks the same on every platform, and follows the application palette — which the GTK one does not, so the option is a consistency win as well as a speed one.

The portal round trip cannot be reproduced headless: an offscreen Qt never asks the portal, so no test in this suite can observe the stall or its absence. The restyle work itself is free (set_line_style 0.000 s on a 1,200 point plot) so the wait is in the dialog — and “the portal is what the wait is” is a named, checkable hypothesis to be confirmed on a real display, not something this file proves. What IS proven here, by tests/qt/test_colour_picker.py, is that no call site can ask for the platform dialog any more.

USE IT INSTEAD OF QColorDialog.getColor. That is the whole point: an option that has to be remembered at every call site is an option that will be forgotten at the seventh. The grep test enforces it.

Functions

pick_colour(→ PySide6.QtGui.QColor)

Ask the user for a colour, using Qt's own dialog.

Module Contents

spacr.qt.widgets.colour_picker.pick_colour(parent: PySide6.QtWidgets.QWidget | None = None, initial: PySide6.QtGui.QColor | str | None = None, title: str | None = None) → PySide6.QtGui.QColor[source]

Ask the user for a colour, using Qt’s own dialog.

Parameters:

  • parent – dialog parent, as for QColorDialog.getColor().

  • initial – the colour to open on — a QColor, a string Qt understands ("#ff0000", "red"), or None for white.

  • title – window title; Qt’s default when omitted.

Returns:

the chosen QColor, or an invalid QColor when the user cancelled.

Returning an invalid colour rather than None is deliberate: every existing call site already tests colour.isValid() before using it, so adopting this helper is a one-line change at each and cannot silently turn a cancel into a colour.