Better folder organization

src/download_window.py

@@ -0,0 +1,117 @@
+from PyQt5 import uic
+from PyQt5.QtCore import Qt, pyqtSlot, pyqtSignal
+from PyQt5.QtWidgets import QWidget
+from threads import DownloadThread, ThreadStatus
+from utilities import pop_up, resource_path
+from constants import Constants, Messages
+
+
+Ui_Download_window, _ = uic.loadUiType(
+    resource_path("download_db_window.ui")
+)
+
+
+class DownloadWindow(QWidget, Ui_Download_window):
+    """Subclass QWidget and Ui_Download_window. It is the window displayed during the database download."""
+
+    complete = pyqtSignal()
+    closed = pyqtSignal()
+
+    def __init__(self):
+        """Initialize the window."""
+        super().__init__()
+        self.setupUi(self)
+        self.setWindowFlags(
+            # Qt.Window                |
+            Qt.CustomizeWindowHint   |
+            Qt.WindowTitleHint       |
+            Qt.WindowCloseButtonHint |
+            Qt.WindowStaysOnTopHint
+        )
+
+        self._no_internet_msg = pop_up(self, title=Messages.NO_CONNECTION,
+                                       text=Messages.NO_CONNECTION_MSG,
+                                       connection=self.close)
+
+        self._bad_db_download_msg = pop_up(self, title=Messages.BAD_DOWNLOAD,
+                                           text=Messages.BAD_DOWNLOAD_MSG,
+                                           connection=self.close)
+
+        self._slow_conn_msg = pop_up(self, title=Messages.SLOW_CONN,
+                                     text=Messages.SLOW_CONN_MSG,
+                                     connection=self.close)
+
+        self._download_thread = DownloadThread()
+        self._download_thread.finished.connect(self._wait_close)
+        self._download_thread.progress.connect(self._display_progress)
+        self._download_thread.speed_progress.connect(self._display_speed)
+        self.closed.connect(self._download_thread.set_exit)
+        self.cancel_btn.clicked.connect(self._terminate_process)
+
+    def start_download(self):
+        """Start the download thread."""
+        self._download_thread.start()
+
+    def _download_format_str(self, n):
+        """Return a well-formatted string with the downloaded MB."""
+        return f"Downloaded: {n} MB"
+
+    @pyqtSlot(float)
+    def _display_speed(self, speed):
+        """Display the download speed."""
+        ret = "Speed: "
+        if speed == Constants.ZERO_INITIAL_SPEED:
+            ret += "Calculating..."
+        elif speed == 0.0:
+            ret += "VERY SLOW"
+        elif speed == Constants.ZERO_FINAL_SPEED:
+            ret = ""
+        else:
+            ret += f"{speed} MB/s"
+        self.speed_lbl.setText(ret)
+
+    @pyqtSlot(int)
+    def _display_progress(self, progress):
+        """Display the downloaded MB."""
+        if progress != Constants.EXTRACTING_CODE:
+            self.status_lbl.setText(self._download_format_str(progress))
+        elif progress == Constants.EXTRACTING_CODE:
+            self.status_lbl.setText(Constants.EXTRACTING_MSG)
+
+    def show(self):
+        """Extends QWidget.show. Set downloaded MB and speed to zero."""
+        self._display_progress(0)
+        self._display_speed(Constants.ZERO_INITIAL_SPEED)
+        super().show()
+
+    def _stop_thread(self):
+        """Ask the download thread to stop."""
+        if self._download_thread.isRunning():
+            self.closed.emit()
+            self._download_thread.wait()
+
+    @pyqtSlot()
+    def _terminate_process(self):
+        """Terminate the download thread and close."""
+        self._stop_thread()
+        self.close()
+
+    @pyqtSlot()
+    def _wait_close(self):
+        """Decide the action based on the download thread status and close."""
+        if self._download_thread.status is ThreadStatus.OK:
+            self.complete.emit()
+            self.close()
+        elif self._download_thread.status is ThreadStatus.NO_CONNECTION_ERR:
+            self._no_internet_msg.show()
+        elif self._download_thread.status is ThreadStatus.BAD_DOWNLOAD_ERR:
+            self._bad_db_download_msg.show()
+        elif self._download_thread.status is ThreadStatus.SLOW_CONN_ERR:
+            self._slow_conn_msg.show()
+        else:
+            self.close()
+
+    def reject(self):
+        """Extends QWidget.reject. Terminate the download thread."""
+        self._stop_thread()
+        super().reject()