feat(accent colors): added helper function to get all accent colors

bec_widgets/utils/colors.py

@@ -1,6 +1,8 @@
+from __future__ import annotations
+
 import itertools
 import re
-from typing import Literal
+from typing import TYPE_CHECKING, Literal
 
 import bec_qthemes
 import numpy as np
@@ -10,6 +12,9 @@ from pydantic_core import PydanticCustomError
 from qtpy.QtGui import QColor
 from qtpy.QtWidgets import QApplication
 
+if TYPE_CHECKING:
+    from bec_qthemes._main import AccentColors
+
 
 def get_theme_palette():
     if QApplication.instance() is None or not hasattr(QApplication.instance(), "theme"):
@@ -19,6 +24,16 @@ def get_theme_palette():
     return bec_qthemes.load_palette(theme)
 
 
+def get_accent_colors() -> AccentColors | None:
+    """
+    Get the accent colors for the current theme. These colors are extensions of the color palette
+    and are used to highlight specific elements in the UI.
+    """
+    if QApplication.instance() is None or not hasattr(QApplication.instance(), "theme"):
+        return None
+    return QApplication.instance().theme.accent_colors
+
+
 def _theme_update_callback():
     """
     Internal callback function to update the theme based on the system theme.

bec_widgets/widgets/bec_progressbar/bec_progressbar.py

@@ -6,6 +6,7 @@ from qtpy.QtGui import QColor, QPainter, QPainterPath
 from qtpy.QtWidgets import QApplication, QLabel, QVBoxLayout, QWidget
 
 from bec_widgets.utils.bec_widget import BECWidget
+from bec_widgets.utils.colors import get_accent_colors
 
 
 class BECProgressBar(BECWidget, QWidget):
@@ -26,7 +27,7 @@ class BECProgressBar(BECWidget, QWidget):
         super().__init__(client=client, config=config, gui_id=gui_id)
         QWidget.__init__(self, parent=parent)
 
-        accent_colors = QApplication.instance().theme.accent_colors
+        accent_colors = get_accent_colors()
 
         # internal values
         self._oversampling_factor = 50

bec_widgets/widgets/figure/plots/waveform/waveform.py

@@ -16,6 +16,7 @@ from qtpy.QtWidgets import QApplication, QWidget
 
 from bec_widgets.qt_utils.error_popups import SafeSlot as Slot
 from bec_widgets.utils import Colors, EntryValidator
+from bec_widgets.utils.colors import get_accent_colors
 from bec_widgets.utils.linear_region_selector import LinearRegionWrapper
 from bec_widgets.widgets.figure.plots.plot_base import BECPlotBase, SubplotConfig
 from bec_widgets.widgets.figure.plots.waveform.waveform_curve import (
@@ -108,7 +109,7 @@ class BECWaveform(BECPlotBase):
         self.scan_item = None
         self._roi_region = None
         self.roi_select = None
-        self._accent_colors = QApplication.instance().theme.accent_colors
+        self._accent_colors = get_accent_colors()
         self._x_axis_mode = {
             "name": None,
             "entry": None,