add participant.py for entry window, update main.py to be application entry

main.py

@@ -0,0 +1,12 @@
+import sys
+
+from PyQt5.QtWidgets import QApplication
+
+from modules.participant import Participant
+
+if __name__ == '__main__':
+    app = QApplication(sys.argv)
+    window = Participant()
+    window.setWindowTitle("3Dots")
+    window.show()
+    sys.exit(app.exec_())

modules/participant.py

@@ -0,0 +1,83 @@
+from PyQt5.QtWidgets import (
+    QWidget,
+    QVBoxLayout,
+    QLineEdit,
+    QComboBox,
+    QPushButton,
+    QFormLayout,
+    QMessageBox,
+    QSpacerItem,
+    QSizePolicy,
+    QHBoxLayout,
+    QGroupBox,
+    QSpinBox
+)
+
+from PyQt5.QtCore import Qt
+
+
+class Participant(QWidget):
+    def __init__(self):
+        super().__init__()
+
+        main_layout = QVBoxLayout()
+        main_layout.addSpacerItem(
+            QSpacerItem(20, 40, QSizePolicy.Minimum, QSizePolicy.Expanding))
+
+        forms_container = QGroupBox()
+        forms_container.setFixedSize(600, 500)
+
+        forms_layout = QFormLayout()
+
+        # Identifier
+        self.identifier_input = QLineEdit()
+        self.identifier_input.setPlaceholderText("Enter Identifier")
+        forms_layout.addRow("Participant Identifier:", self.identifier_input)
+
+        # Age
+        self.age_input = QSpinBox()
+        self.age_input.setRange(0, 120)
+        forms_layout.addRow("Participant Age (0-120):", self.age_input)
+
+        # Sex
+        self.sex_input = QComboBox()
+        self.sex_input.addItems(["Select", "Male", "Female", "Other"])
+        forms_layout.addRow("Sex:", self.sex_input)
+
+        # Begin button
+        self.begin_button = QPushButton("Begin")
+        self.begin_button.clicked.connect(self.on_begin_clicked)
+        forms_layout.addWidget(self.begin_button)
+
+        box_layout = QVBoxLayout()
+        box_layout.setAlignment(Qt.AlignCenter)
+        box_layout.addLayout(forms_layout)
+        forms_container.setLayout(box_layout)
+
+        centered_layout = QHBoxLayout()
+        centered_layout.addStretch()
+        centered_layout.addWidget(forms_container, alignment=Qt.AlignCenter)
+        centered_layout.addStretch()
+
+        main_layout.addLayout(centered_layout)
+        main_layout.addSpacerItem(
+            QSpacerItem(20, 40, QSizePolicy.Minimum, QSizePolicy.Expanding))
+
+        self.setLayout(main_layout)
+
+    def on_begin_clicked(self):
+        """Handler for begin button"""
+        # include logic for saving participant data to file here also
+        identifier = self.identifier_input.text().strip()
+        age = self.age_input.value()
+        sex = self.sex_input.currentText()
+
+        if not identifier:
+            QMessageBox.warning(
+                self, 'Input Error', 'Please enter a Participant Identifier.')
+        elif sex == 'Select':
+            QMessageBox.warning(
+                self, 'Input Error', 'Please select your sex.')
+        else:
+            QMessageBox.information(
+                self, 'Success', f'Participant Registered: {identifier}, Age: {age}, Sex: {sex}')