treat cases for empty databases

Author: Fernando Cezar

main.py

@@ -1,4 +1,3 @@
-import json
 import os
 import random
 import sys
@@ -41,7 +40,6 @@ def __init__(self, message):
         self.layout.addWidget(self.button)
 
 
-# Subclass QMainWindow to customize your application's main window
 class MainWindow(QMainWindow):
     def __init__(self):
         super().__init__()
@@ -100,26 +98,27 @@ def draw_register_situation_screen(self):
     def draw_situation_quiz_screen(self):
         self.situation_quiz_widget = SituationQuiz()
         self.situation_quiz_widget.cancel_button.clicked.connect(self.start_screen)
-        self.situation_quiz_widget.answer_button.clicked.connect(
-            lambda: self.check_situation_answer(self.situation_quiz_widget)
-        )
-        buttons = [
-            self.situation_quiz_widget.cancel_button,
-            self.situation_quiz_widget.answer_button,
-        ]
+        buttons = [self.situation_quiz_widget.cancel_button]
+        if hasattr(self.situation_quiz_widget, "answer_button"):
+            self.situation_quiz_widget.answer_button.clicked.connect(
+                lambda: self.check_situation_answer(self.situation_quiz_widget)
+            )
+            buttons.append(self.situation_quiz_widget.answer_button)
         self._draw_screen(self.situation_quiz_widget, buttons)
 
     def draw_choose_quiz_screen(self):
         self.choose_drug_widget = ChooseDrugQuiz()
         self.choose_drug_widget.cancel_button.clicked.connect(self.start_screen)
-        self.choose_drug_widget.start_button.clicked.connect(
-            lambda: self.draw_quiz_screen(self.choose_drug_widget.combo_options.currentText(), quiz_type="choose")
-        )
-        buttons = [
-            self.choose_drug_widget.cancel_button,
-            self.choose_drug_widget.start_button,
-        ]
-
+        buttons = [self.choose_drug_widget.cancel_button]
+        if hasattr(self.choose_drug_widget, "start_button"):
+            self.choose_drug_widget.start_button.clicked.connect(
+                lambda: self.draw_quiz_screen(
+                    self.choose_drug_widget.combo_options.currentText(),
+                    quiz_type="choose"
+                )
+            )
+            buttons.append(self.choose_drug_widget.answer_button)
+        
         self._draw_screen(self.choose_drug_widget, buttons)
 
     def draw_quiz_screen(self, drug, quiz_type):
@@ -135,6 +134,10 @@ def save_content(self, widget):
 
     def random_quiz(self):
         current_content = read_current_drugs()
+        if not current_content:
+            self.answer_window = AnswerWindow("No substances registered. Please register some substances first.")
+            self.answer_window.show()
+            return
         random_item = random.choice(list(current_content.keys()))
         self.draw_quiz_screen(random_item, "random")
 

widgets/screens.py

@@ -179,7 +179,18 @@ def __init__(self):
         current_situations = read_current_situations()
         current_drugs = read_current_drugs()
         current_drugs = list(current_drugs.keys())
+        if not current_situations or not current_drugs:
+            self.draw_empty()
+        else:
+            self.draw_question(current_situations, current_drugs)
+
+        self.cancel_button = QPushButton("Cancel")
 
+    def draw_empty(self):
+        self.addWidget(QLabel("No situations or substances registered!"), 1, 0)
+        self.addWidget(QLabel("Register situations and substances on the home screen"), 2, 0)
+    
+    def draw_question(self, current_situations, current_drugs):
         random_item = random.choice(current_situations)
         self.correct_answer = random_item[1]
 
@@ -195,7 +206,7 @@ def __init__(self):
         self.addWidget(self.drugs_box, 1, 1)
 
         self.answer_button = QPushButton("Answer")
-        self.cancel_button = QPushButton("Cancel")
+
 
     def answer(self):
         answer = self.drugs_box.currentData()
@@ -243,10 +254,19 @@ def __init__(self):
         super().__init__()
         all_options = read_current_drugs()
         options = list(all_options.keys())
+        if not options:
+            self.draw_empty()
+        else:
+            self.draw_question(options)
 
+        self.cancel_button = QPushButton("Cancel")
+    
+    def draw_empty(self):
+        self.addWidget(QLabel("No substances registered!\nRegister substances on the home screen"))
+    
+    def draw_options(self, options):
         self.combo_options = QComboBox()
         self.combo_options.addItems(options)
         self.addWidget(self.combo_options)
 
         self.start_button = QPushButton("Start quiz")
-        self.cancel_button = QPushButton("Cancel")