Add signals list, search bar, picture display

main.py

@@ -1,9 +1,12 @@
 import sys
 import os
+from pandas import read_csv
 from PyQt5.QtWidgets import (QMainWindow,
-                             QApplication,)
+                             QApplication,
+                             QMessageBox,)
 from PyQt5.QtGui import QPixmap
 from PyQt5 import uic
+from PyQt5.QtCore import QFileInfo
 
 qt_creator_file = "main_window.ui"
 
@@ -13,9 +16,47 @@ class MyApp(QMainWindow, Ui_MainWindow):
     def __init__(self):
         super().__init__()
         self.setupUi(self)
+        self.show()
+        self.load_db()
+        self.display_signals()
+        self.search_bar.textChanged.connect(self.display_signals)
+        self.result_list.itemSelectionChanged.connect(self.display_spectrogram)
+
+    def load_db(self):
+        try:
+            db = read_csv(os.path.join('Data', 'db.csv'), 
+                      sep = '*',
+                      header = None,
+                      prefix = 'signal_')
+        except FileNotFoundError:
+            self.signal_names = ''
+            self.search_bar.setDisabled(True)
+            box = QMessageBox(self)
+            box.setStyleSheet("""
+                color:#FFFFFF;
+            """)
+            box.setWindowTitle("No database")
+            box.setText("No database available.\n"
+                "Go to Updates->Download database.")
+            box.show()
+        else:
+            self.signal_names = db['signal_0']
+
+    def display_signals(self):
+        self.result_list.clear()
+        for signal in self.signal_names:
+            if self.search_bar.text().lower() in signal.lower():
+                self.result_list.addItem(signal)
+
+    def display_spectrogram(self):
+        spectrogram_name = self.result_list.currentItem().text()
+        path_spectr = os.path.join("Data", "Spectra", spectrogram_name + ".jpg")
+        if not QFileInfo(path_spectr).exists():
+            path_spectr = os.path.join("icons_imgs", "image_not_found.png")
+        self.spectrogram.setPixmap(QPixmap(path_spectr))
+
 
 if __name__ == '__main__':
     my_app = QApplication(sys.argv)
     w = MyApp()
-    w.show()
     sys.exit(my_app.exec_())