chore: import upstream snapshot with attribution

python/samples/02-agents/harness/console/components/text_input.py

@@ -0,0 +1,102 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""Text input widget with inline prompt for the harness console."""
+
+from __future__ import annotations
+
+from textual import on
+from textual.app import ComposeResult
+from textual.containers import Horizontal
+from textual.message import Message
+from textual.reactive import reactive
+from textual.widget import Widget
+from textual.widgets import Input, Label
+
+
+class HarnessTextInput(Widget):
+    """Text input widget with a prompt label on the left.
+
+    Displays a prompt (e.g., "> ") followed by a borderless input field.
+    Sits between the two mode-colored horizontal rules.
+
+    Attributes:
+        prompt: The prompt text displayed on the left (e.g., "> ").
+        placeholder: Placeholder text shown when the input is empty.
+    """
+
+    prompt: reactive[str] = reactive("> ")
+    placeholder: reactive[str] = reactive("")
+
+    class Submitted(Message):
+        """Message sent when the input is submitted.
+
+        Attributes:
+            value: The submitted text value.
+        """
+
+        def __init__(self, value: str) -> None:
+            """Initialize the Submitted message.
+
+            Args:
+                value: The submitted text value.
+            """
+            self.value = value
+            super().__init__()
+
+    def compose(self) -> ComposeResult:
+        """Compose the prompt label and input field.
+
+        Yields:
+            A horizontal container with the prompt and input field.
+        """
+        with Horizontal(classes="prompt-container"):
+            yield Label(self.prompt, classes="prompt-label", id="prompt-label")
+            yield Input(placeholder=self.placeholder, classes="input-field", id="input-field")
+
+    def watch_prompt(self, new_prompt: str) -> None:
+        """Update the prompt label when the prompt attribute changes.
+
+        Args:
+            new_prompt: The new prompt text.
+        """
+        try:
+            label = self.query_one("#prompt-label", Label)
+            label.update(new_prompt)
+        except Exception:
+            pass
+
+    def watch_placeholder(self, new_placeholder: str) -> None:
+        """Update the input placeholder when the placeholder attribute changes.
+
+        Args:
+            new_placeholder: The new placeholder text.
+        """
+        try:
+            input_field = self.query_one("#input-field", Input)
+            input_field.placeholder = new_placeholder
+        except Exception:
+            # Input doesn't exist yet (before compose), ignore
+            pass
+
+    @on(Input.Submitted)
+    def on_input_submitted(self, event: Input.Submitted) -> None:
+        """Handle input submission.
+
+        Clears the input field and posts a Submitted message with the value.
+
+        Args:
+            event: The Input.Submitted event.
+        """
+        value = event.value
+        event.input.clear()
+        self.post_message(self.Submitted(value))
+
+    def focus_input(self) -> None:
+        """Focus the input field."""
+        input_field = self.query_one(".input-field", Input)
+        input_field.focus()
+
+    def clear_input(self) -> None:
+        """Clear the input field."""
+        input_field = self.query_one(".input-field", Input)
+        input_field.clear()