Add Flet desktop client

Client/App.py

@@ -0,0 +1,167 @@
+"""What the window's parts share: the config, the current Source (local or
+server), toasts, dialogs and the login flow. Changing the source (Settings,
+logging in or out) tells every listener to reload."""
+
+from typing import Callable, Optional
+
+import flet as ft
+
+from Core import AppConfig, ChipButton, LoadSessionToken, NotificationStyle, Palette, SaveSessionToken
+from Sources import MakeSource, ServerSource, Source, SourceError
+
+
+class App:
+    def __init__(self, Page: ft.Page, Config: AppConfig):
+        self.Page = Page
+        self.Config = Config
+        self.Picker = ft.FilePicker()  # registers itself with the page
+        self.Source: Source = MakeSource(Config)
+        self.ConnectError = ""  # why the server couldn't be reached, shown instead of the file list
+        self.DialogOpen = False  # keyboard shortcuts pause while a dialog is up
+        self.Listeners: list[Callable[[], None]] = []  # run after the source changes
+
+    # --- Source -----------------------------------------------------------
+
+    def Connect(self) -> None:
+        """(Re)builds the source from Config and, for a server, checks it's
+        there and whether the saved login still works. Listeners reload."""
+        if isinstance(self.Source, ServerSource):
+            self.Source.Close()
+        Token = LoadSessionToken(self.Config.ServerUrl) if self.Config.Mode == "Server" and self.Config.RememberLogin else ""
+        self.Source = MakeSource(self.Config, Token)
+        self.ConnectError = ""
+        if isinstance(self.Source, ServerSource):
+            try:
+                self.Source.Connect()
+            except SourceError as Error:
+                self.ConnectError = str(Error)
+            if Token and self.Source.User is None and not self.ConnectError:
+                SaveSessionToken(self.Config.ServerUrl, "")
+                self.Notify("Your saved login ended (the server restarted?). Browsing as Guest.", "warning")
+        self.Changed()
+
+    def Changed(self) -> None:
+        for Listener in self.Listeners:
+            Listener()
+
+    @property
+    def Server(self) -> Optional[ServerSource]:
+        return self.Source if isinstance(self.Source, ServerSource) else None
+
+    def HandleError(self, Error: SourceError, Doing: str = "") -> None:
+        """A toast, plus the login dialog when the server wants a login."""
+        Text = f"{Doing}: {Error}" if Doing else str(Error)
+        if Error.Status == 401 and self.Server is not None:
+            if self.Server.User is not None:  # the session ended under us
+                self.Server.Logout()
+                SaveSessionToken(self.Config.ServerUrl, "")
+                self.Changed()
+            self.ShowLoginDialog(Reason=Text)
+            return
+        self.Notify(Text, "error")
+
+    # --- Login ------------------------------------------------------------
+
+    def ShowLoginDialog(self, Reason: str = "") -> None:
+        Server = self.Server
+        if Server is None:
+            return
+        UsernameField = ft.TextField(label="Username", value=self.Config.Username, autofocus=not self.Config.Username)
+        PasswordField = ft.TextField(label="Password", password=True, can_reveal_password=True,
+                                     autofocus=bool(self.Config.Username))
+        RememberSwitch = ft.Switch(label="Stay logged in", value=self.Config.RememberLogin)
+        ErrorText = ft.Text("", color=Palette.Red, size=12, visible=False)
+
+        def DoLogin(e=None) -> None:
+            Username = (UsernameField.value or "").strip()
+            if not Username or not PasswordField.value:
+                return
+            try:
+                Server.Login(Username, PasswordField.value)
+            except SourceError as Error:
+                ErrorText.value = str(Error)
+                ErrorText.visible = True
+                ErrorText.update()
+                return
+            self.Config.Username = Username
+            self.Config.RememberLogin = RememberSwitch.value
+            self.Config.Save()
+            SaveSessionToken(self.Config.ServerUrl, Server.Token if RememberSwitch.value else "")
+            self.Close()
+            self.Notify(f"Logged in as {Username}.", "success")
+            self.Changed()
+
+        UsernameField.on_submit = lambda e: PasswordField.focus()
+        PasswordField.on_submit = DoLogin
+        Content = [ft.Text(Server.Url, color=Palette.Overlay0, size=12)]
+        if Reason:
+            Content.append(ft.Text(Reason, color=Palette.Yellow, size=13))
+        Content += [UsernameField, PasswordField, RememberSwitch, ErrorText]
+        self.ShowDialog("Log in", ft.Column(Content, tight=True, spacing=12), [
+            ChipButton("Cancel", lambda e: self.Close()),
+            ChipButton("Log in", DoLogin),
+        ], Width=380)
+
+    def Logout(self) -> None:
+        if self.Server is None:
+            return
+        self.Server.Logout()
+        SaveSessionToken(self.Config.ServerUrl, "")
+        self.Notify("Logged out. Browsing as Guest.", "info")
+        self.Changed()
+
+    # --- UI helpers -------------------------------------------------------
+
+    def Notify(self, Text: str, Kind: str = "info") -> None:
+        Background, Accent = NotificationStyle(Kind)
+        self.Page.show_dialog(ft.SnackBar(
+            content=ft.Text(Text, color=Accent),
+            bgcolor=Background,
+            shape=ft.RoundedRectangleBorder(radius=4, side=ft.BorderSide(1, Accent)),
+            open=True,
+        ))
+
+    def ShowDialog(self, Title: str, Content: ft.Control, Actions: list[ft.Control], Width: int = 440) -> None:
+        self.DialogOpen = True
+        self.Page.show_dialog(ft.AlertDialog(
+            title=Title,
+            content=ft.Container(Content, width=Width),
+            actions=Actions,
+            on_dismiss=lambda e: setattr(self, "DialogOpen", False),
+        ))
+
+    def Close(self) -> None:
+        self.DialogOpen = False
+        self.Page.pop_dialog()
+
+    def Confirm(self, Title: str, Text: str, OnYes: Callable[[], None], YesText: str = "Delete") -> None:
+        def Yes(e) -> None:
+            self.Close()
+            OnYes()
+
+        self.ShowDialog(Title, ft.Text(Text), [
+            ChipButton("Cancel", lambda e: self.Close()),
+            ChipButton(YesText, Yes, Accent=Palette.Red),
+        ])
+
+    def AskName(self, Title: str, Value: str, SelectEnd: int, OnDone: Callable[[str], None],
+                ActionText: str = "Create", Note: str = "", RequireChange: bool = True) -> None:
+        """A one-field dialog with the name's stem preselected, like SaraFem's.
+        RequireChange: an unchanged name does nothing (Rename)."""
+        NameField = ft.TextField(value=Value, autofocus=True,
+                                 selection=ft.TextSelection(base_offset=0, extent_offset=SelectEnd))
+
+        def Done(e=None) -> None:
+            NewName = (NameField.value or "").strip()
+            self.Close()
+            if NewName and (NewName != Value or not RequireChange):
+                OnDone(NewName)
+
+        NameField.on_submit = Done
+        Content: ft.Control = NameField
+        if Note:
+            Content = ft.Column([NameField, ft.Text(Note, color=Palette.Overlay0, size=12)], tight=True, spacing=8)
+        self.ShowDialog(Title, Content, [
+            ChipButton("Cancel", lambda e: self.Close()),
+            ChipButton(ActionText, Done),
+        ], Width=380)