FEAT: Continue work on ratio selection widget.

faslr/model/ratio.py

@@ -1,22 +1,69 @@
 """
 Module that contains base classes for ratio selections, e.g., development factor or a priori loss ratio selections.
 """
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from pandas import DataFrame
+
+from faslr.model.average import FAverageBox
+
+from PyQt6.QtCore import Qt
+
+from PyQt6.QtGui import QStandardItemModel
 
 from PyQt6.QtWidgets import (
-    QWidget
+    QPushButton,
+    QWidget,
+    QVBoxLayout
 )
 
 
 class FRatioSelectionWidget(QWidget):
-    def __init__(self):
+    def __init__(
+            self,
+            ratios: DataFrame = None,
+            averages: DataFrame = None
+    ):
         """
         Containing widget for FRatioSelectionModel/View.
         """
         super().__init__()
 
-    def open_average_box(self):
+        # Main layout.
+        self.layout = QVBoxLayout()
+        self.setLayout(self.layout)
 
-        pass
+        # Space above the table(s) where we can put auxiliary buttons, such as one to add averages.
+        self.tool_space = QWidget()
+        self.tool_layout = QVBoxLayout()
+        self.tool_space.setLayout(self.tool_layout)
+        self.add_average_button = QPushButton("Available Averages")
+
+        # Dialog box to select averages.
+        self.average_box = FAverageBox(data=averages)
 
+        self.tool_layout.addWidget(
+            self.add_average_button,
+            alignment=Qt.AlignmentFlag.AlignRight
+        )
 
+        self.layout.addWidget(self.tool_space)
 
+        self.add_average_button.clicked.connect(self.open_average_box) #noqa
+
+
+    def open_average_box(self):
+
+        self.average_box.show()
+
+
+class FRatioSelectionModel(QStandardItemModel):
+    def __init__(
+            self,
+            ratios: DataFrame
+    ):
+        super().__init__()
+        pass