Added color theme test

Author: PierreRaybaut

plotpy/tests/widgets/test_theme.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+#
+# Licensed under the terms of the BSD 3-Clause
+# (see guidata/LICENSE for details)
+
+"""
+Test dark/light theme switching
+"""
+
+import sys
+from typing import Literal
+
+import pytest
+from guidata import qthelpers as qth
+from guidata.tests.widgets.test_theme import TestWidget as GuidataTestWidget
+from qtpy import QtWidgets as QW
+
+from plotpy.builder import make
+from plotpy.config import update_plotpy_color_mode
+from plotpy.plot import PlotOptions, PlotWidget
+from plotpy.tests import data as ptd
+
+
+class TestWidget(GuidataTestWidget):
+    """Testing color mode switching for PlotPy and guidata widgets"""
+
+    SIZE = (1400, 600)
+
+    def __init__(self, default: Literal["light", "dark", "auto"] = qth.AUTO) -> None:
+        self.plot_widget: PlotWidget | None = None
+        super().__init__(default=default)
+
+    def setup_widgets(self):
+        """Setup widgets"""
+        super().setup_widgets()
+        options = PlotOptions(type="image", show_contrast=True)
+        self.plot_widget = widget = PlotWidget(self, options=options)
+        plot = self.plot_widget.get_plot()
+        item = make.image(ptd.gen_image4(300, 200))
+        plot.add_item(item)
+        plot.set_active_item(item, select=False)
+        widget.setSizePolicy(QW.QSizePolicy.Expanding, QW.QSizePolicy.Expanding)
+        self.grid_layout.addWidget(widget, 1, 2)
+
+    def change_color_mode(self, mode: str) -> None:
+        """Change color mode"""
+        super().change_color_mode(mode)
+        update_plotpy_color_mode()
+
+
+@pytest.mark.skipif(reason="Not suitable for automated testing")
+def test_dark_light_themes(
+    default: Literal["light", "dark", "auto"] | None = None,
+) -> None:
+    """Test dark/light theme switching"""
+    with qth.qt_app_context(exec_loop=True):
+        widget = TestWidget(default=qth.AUTO if default is None else default)
+        widget.show()
+
+
+if __name__ == "__main__":
+    test_dark_light_themes(None if len(sys.argv) < 2 else sys.argv[1])