move callback to scatter_widget

src/cell_gater/widgets/scatter_widget.py

@@ -0,0 +1,47 @@
+from typing import Any
+
+from qtpy.QtCore import Qt
+from qtpy.QtWidgets import (
+    QComboBox,
+    QLabel,
+    QSizePolicy,
+    QVBoxLayout,
+    QWidget,
+)
+
+from cell_gater.model.data_model import DataModel
+
+
+class ScatterWidget(QWidget):
+    """Widget for a scatter plot with markers on the x axis and any dtype column on the y axis."""
+
+    def __init__(self, model: DataModel) -> None:
+        super().__init__()
+
+        self.setLayout(QVBoxLayout())
+        self.setSizePolicy(QSizePolicy.Minimum, QSizePolicy.Maximum)
+        self._model = model
+
+        # Dropdown of samples once directory is loaded
+        selection_label = QLabel("Select sample:")
+        self.sample_selection_dropdown = QComboBox()
+        if len(self.model.samples) > 0:
+            self.sample_selection_dropdown.addItems(self.model.samples)
+        self.sample_selection_dropdown.currentTextChanged.connect(self._on_sample_changed)
+
+        self.layout().addWidget(selection_label, 4, 0, Qt.AlignCenter)
+        self.layout().addWidget(self.sample_selection_dropdown, 4, 1)
+
+    def _on_sample_changed(self):
+        pass
+
+    def _set_samples_dropdown(self, event: Any) -> None:
+        """Set the items for the samples dropdown QComboBox."""
+        if (region_props := self.model.regionprops_df) is not None:
+            self.model.samples = list(region_props["sample_id"].cat.categories)
+
+            # New directory loaded so we reload the dropdown items
+            self.sample_selection_dropdown.clear()
+            if len(self.model.samples) > 0:
+                self.sample_selection_dropdown.addItems([None])
+                self.sample_selection_dropdown.addItems(self.model.samples)