Reflector

term.py

#!/usr/bin/env python

import sys
from code import InteractiveConsole
from io import StringIO

from rich.syntax import Syntax
from textual.app import App, ComposeResult, RenderResult
from textual.containers import Container, Horizontal
from textual.widget import Widget
from textual.widgets import Footer, Header, RichLog, TextArea


class Reflector(Widget):
    CSS = """
    #input {
        padding: 1 2 1 2;
        border: none;
    }
    #output {
        padding: 1 2 1 2;
    }
    #input-container {
        border: solid;
        height: 0.4fr;
        margin: 0 2 1 2;
    }
    #output-container {
        border: solid;
        margin: 1 2 1 2;
        height: 0.6fr;
    }
    """

    BINDINGS = [
        ("ctrl+enter,ctrl+r", "eval", "eval"),
        ("ctrl+n", "dir", "namespace"),
        ("ctrl+l", "clear_output", "clear"),
        ("ctrl+u", "clear_input", "clear input"),
    ]

    def render(self) -> RenderResult:
        self.header = Header(id="header", icon="🐍")
        self.input = TextArea.code_editor(id="input", language="python")
        self.input_container = Container(
            self.input, id="input-container", placeholder="^⏎ to evaluate"
        )
        self.output = RichLog(id="output", markup=True, highlight=True)
        self.output_container = Container(self.output, id="output-container")
        self.footer = Footer(id="footer")

        yield self.header
        yield self.output_container
        yield self.input_container
        yield self.footer

    def on_mount(self) -> None:
        self.title = "Reflector"
        self.sub_title = self.app.title
        self.footer.show_command_palette = False
        self.input_container.border_title = "Input"
        self.output_container.border_title = "Output"
        self.namespace = {"app": self, "__builtins__": __builtins__}
        self.repl = InteractiveConsole(locals=self.namespace)
        self.input.focus()

    def action_dir(self) -> None:
        self.action_eval("dir()")

    def action_clear_output(self) -> None:
        self.output.clear()

    def action_clear_input(self) -> None:
        self.input.text = ""

    def action_eval(self, code="") -> None:
        if not code:
            code = self.input.text
            if not code:
                return

        split_code = code.split("\n")
        self.output.write(Syntax(f">>> {split_code[0]}", "python", indent_guides=True))

        if len(split_code) > 1:
            for line in split_code[1:]:
                self.output.write(Syntax(f"... {line}", "python", indent_guides=True))
            self.output.write(Syntax("... ", "python", indent_guides=True))

        old_stdout, old_stderr = sys.stdout, sys.stderr
        sys.stdout, sys.stderr = StringIO(), StringIO()
        self.repl.push(code + "\n")
        captured_output = sys.stdout.getvalue().strip()
        captured_error = sys.stderr.getvalue().strip()

        if captured_output:
            self.output.write(Syntax(captured_output, "python", indent_guides=True))
        if captured_error:
            self.output.write(Syntax(captured_error, "python", indent_guides=True))

        sys.stdout, sys.stderr = old_stdout, old_stderr
        self.input.text = ""
        self.input.focus()


class TerminalApp(App):
    def compose(self):
        yield Reflector()


if __name__ == "__main__":
    app = TerminalApp()
    app.run()