Textual Modes 實戰：Workspace 切換、畫面生命週期與路由測試

work 模式                 inspect 模式
┌──────────────────┐     ┌──────────────────┐
│ Detail（若已開啟） │     │ InspectScreen    │
├──────────────────┤     └──────────────────┘
│ WorkScreen       │
└──────────────────┘

uv init textual-workspaces
cd textual-workspaces
uv add 'textual==8.2.8'
uv add --dev pytest pytest-asyncio

from dataclasses import dataclass
from typing import cast

from textual.app import App, ComposeResult
from textual.screen import Screen
from textual.widgets import Button, Footer, Input, Label, Static


@dataclass
class ProjectState:
    project: str = "拍拍君工具箱"


class WorkspaceScreen(Screen):
    """Counters make lifecycle behavior observable in tests."""

    def __init__(self) -> None:
        super().__init__()
        self.mount_count = 0
        self.resume_count = 0
        self.suspend_count = 0

    @property
    def owner(self) -> "WorkspaceApp":
        return cast("WorkspaceApp", self.app)

    def on_mount(self) -> None:
        self.mount_count += 1
        self.refresh_summary()

    def on_screen_resume(self) -> None:
        self.resume_count += 1
        self.refresh_summary()

    def on_screen_suspend(self) -> None:
        self.suspend_count += 1

    def refresh_summary(self) -> None:
        self.query_one("#summary", Static).update(
            f"目前專案：{self.owner.state.project}"
        )


class WorkScreen(WorkspaceScreen):
    def compose(self) -> ComposeResult:
        yield Label("工作台：Ctrl+2 切到檢查器")
        yield Static("", id="summary", markup=False)
        yield Input(placeholder="切換模式後仍保留的備註", id="note")
        yield Footer()


class InspectScreen(WorkspaceScreen):
    def compose(self) -> ComposeResult:
        yield Label("檢查器：Ctrl+1 回工作台")
        yield Static("", id="summary", markup=False)
        yield Input(value=self.owner.state.project, id="project")
        yield Button("套用專案名稱", id="apply", variant="primary")
        yield Footer()

    def on_button_pressed(self, event: Button.Pressed) -> None:
        if event.button.id != "apply":
            return
        project = self.query_one("#project", Input).value.strip()
        if not project:
            self.notify("專案名稱不能空白", severity="warning")
            return
        self.owner.state.project = project
        self.refresh_summary()


class WorkspaceApp(App[None]):
    DEFAULT_MODE = "work"
    MODES = {"work": WorkScreen, "inspect": InspectScreen}
    BINDINGS = [
        ("ctrl+1", "route('work')", "工作台"),
        ("ctrl+2", "route('inspect')", "檢查器"),
        ("ctrl+q", "quit", "結束"),
    ]
    CSS = """
    WorkspaceScreen { padding: 1 2; }
    Label, Static { margin-bottom: 1; }
    Input { margin-bottom: 1; }
    """

    def __init__(self) -> None:
        super().__init__()
        self.state = ProjectState()

    async def action_route(self, mode: str) -> bool:
        if mode not in self.MODES:
            self.notify("未知工作區", severity="warning")
            return False
        if mode == self.current_mode:
            return False
        await self.switch_mode(mode)
        return True


if __name__ == "__main__":
    WorkspaceApp().run()

uv run python workspace_app.py

MODES = {"work": WorkScreen, "inspect": InspectScreen}

import pytest
from textual.screen import Screen
from textual.widgets import Input, Static

from workspace_app import InspectScreen, WorkScreen, WorkspaceApp


@pytest.mark.asyncio
async def test_mode_preserves_widget_and_lifecycle():
    app = WorkspaceApp()
    async with app.run_test(size=(90, 26)) as pilot:
        work = app.screen
        assert app.current_mode == "work"
        assert isinstance(work, WorkScreen)
        note = work.query_one("#note", Input)
        note.value = "拍拍君還沒寫完"
        resumed = work.resume_count
        await pilot.press("ctrl+2")
        await pilot.pause()
        assert isinstance(app.screen, InspectScreen)
        assert work.suspend_count >= 1
        await pilot.press("ctrl+1")
        await pilot.pause()
        assert app.screen is work
        assert work.query_one("#note", Input) is note
        assert note.value == "拍拍君還沒寫完"
        assert work.mount_count == 1
        assert work.resume_count > resumed


@pytest.mark.asyncio
async def test_shared_state_refreshes_without_losing_note():
    app = WorkspaceApp()
    async with app.run_test(size=(90, 26)) as pilot:
        work = app.screen
        work.query_one("#note", Input).value = "本地 buffer"
        await app.action_route("inspect")
        await pilot.pause()
        app.screen.query_one("#project", Input).value = "拍拍醬報表"
        await pilot.click("#apply")
        assert app.state.project == "拍拍醬報表"
        await app.action_route("work")
        await pilot.pause()
        assert str(work.query_one("#summary", Static).content) == (
            "目前專案：拍拍醬報表"
        )
        assert work.query_one("#note", Input).value == "本地 buffer"


@pytest.mark.asyncio
async def test_router_rejects_unknown_and_same_mode():
    app = WorkspaceApp()
    async with app.run_test() as pilot:
        work = app.screen
        resumed = work.resume_count
        assert not await app.action_route("missing")
        assert not await app.action_route("work")
        await pilot.pause()
        assert app.screen is work
        assert work.resume_count == resumed


@pytest.mark.asyncio
async def test_each_mode_keeps_its_own_stack():
    app = WorkspaceApp()
    async with app.run_test() as pilot:
        work = app.screen
        detail = Screen()
        await app.push_screen(detail)
        await pilot.pause()
        assert app.screen is detail
        await app.action_route("inspect")
        await pilot.pause()
        assert len(app.screen_stack) == 1
        await app.action_route("work")
        await pilot.pause()
        assert app.screen is detail
        assert len(app.screen_stack) == 2
        await app.pop_screen()
        await pilot.pause()
        assert app.screen is work