Add the ability to read text from the system clipboard

EvoScientist/cli/clipboard.py

@@ -1,9 +1,16 @@
 """Clipboard utilities for EvoScientist TUI.
 
-Provides copy-on-select for the Textual TUI with three fallback methods:
+Provides copy-on-select and paste for the Textual TUI with fallback methods:
+
+Copy (3 methods):
   1. pyperclip  — preferred on local machines (uses pbcopy on macOS)
   2. Textual    — built-in app.copy_to_clipboard()
   3. OSC 52     — escape sequence for SSH / tmux remote sessions
+
+Paste (3 methods):
+  1. pyperclip  — preferred on local machines
+  2. Platform-native — pbpaste (macOS), xclip/xsel (Linux), PowerShell (Windows)
+  3. Textual    — built-in app.paste() on supported terminals
 """
 
 from __future__ import annotations
@@ -12,6 +19,8 @@ import base64
 import logging
 import os
 import pathlib
+import subprocess
+import sys
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
@@ -22,6 +31,61 @@ logger = logging.getLogger(__name__)
 _PREVIEW_MAX = 40
 
 
+# ── Platform-native clipboard read ────────────────────────────────
+
+
+def _paste_native() -> str | None:
+    """Read clipboard using platform-native commands.
+
+    Returns:
+        Clipboard text, or None if unavailable.
+    """
+    if sys.platform == "darwin":
+        # macOS: pbpaste
+        try:
+            result = subprocess.run(
+                ["pbpaste"],
+                capture_output=True,
+                text=True,
+                timeout=2,
+            )
+            if result.returncode == 0:
+                return result.stdout
+        except (subprocess.TimeoutExpired, FileNotFoundError, OSError):
+            pass
+    elif sys.platform == "win32":
+        # Windows: PowerShell Get-Clipboard
+        try:
+            result = subprocess.run(
+                ["powershell", "-command", "Get-Clipboard"],
+                capture_output=True,
+                text=True,
+                timeout=2,
+            )
+            if result.returncode == 0:
+                return result.stdout.rstrip("\r\n")
+        except (subprocess.TimeoutExpired, FileNotFoundError, OSError):
+            pass
+    else:
+        # Linux: try xclip, then xsel
+        for cmd in (
+            ["xclip", "-selection", "clipboard", "-o"],
+            ["xsel", "--clipboard", "--output"],
+        ):
+            try:
+                result = subprocess.run(
+                    cmd,
+                    capture_output=True,
+                    text=True,
+                    timeout=2,
+                )
+                if result.returncode == 0:
+                    return result.stdout
+            except (subprocess.TimeoutExpired, FileNotFoundError, OSError):
+                continue
+    return None
+
+
 # ── OSC 52 (remote / SSH / tmux) ──────────────────────────────────
 
 
@@ -118,3 +182,33 @@ def copy_selection_to_clipboard(app: App) -> None:
         severity="warning",
         timeout=3,
     )
+
+
+def get_clipboard_text() -> str | None:
+    """Read text from the system clipboard.
+
+    Tries multiple methods in priority order:
+      1. pyperclip (if installed)
+      2. Platform-native commands (pbpaste, xclip, PowerShell)
+
+    Returns:
+        Clipboard text, or None if unavailable or empty.
+    """
+    # 1. Try pyperclip first
+    try:
+        import pyperclip
+
+        text = pyperclip.paste()
+        if text:
+            return text
+    except ImportError:
+        pass
+    except Exception as exc:
+        logger.debug("pyperclip.paste() failed: %s", exc)
+
+    # 2. Try platform-native commands
+    text = _paste_native()
+    if text:
+        return text
+
+    return None

EvoScientist/cli/tui_interactive.py

@@ -199,7 +199,7 @@ def run_textual_interactive(
         from textual.events import MouseUp
         from textual.widgets import Input, Static
 
-        from .clipboard import copy_selection_to_clipboard
+        from .clipboard import copy_selection_to_clipboard, get_clipboard_text
         from .widgets import (
             LoadingWidget,
             ThinkingWidget,
@@ -285,6 +285,7 @@ def run_textual_interactive(
         """
         BINDINGS = [
             Binding("ctrl+c", "request_quit", "Quit", show=False),
+            Binding("ctrl+v", "paste_clipboard", "Paste", show=False),
             Binding("up", "edit_queued", show=False, priority=True),
             Binding("down", "down_delegate", show=False, priority=True),
             Binding("escape", "cancel_queued", show=False, priority=True),
@@ -1501,6 +1502,25 @@ def run_textual_interactive(
                     focused.action_move_down()
                     return
 
+        def action_paste_clipboard(self) -> None:
+            """Paste text from system clipboard into the input field."""
+            text = get_clipboard_text()
+            if not text:
+                self.notify(
+                    "Clipboard is empty or unavailable",
+                    severity="warning",
+                    timeout=2,
+                )
+                return
+
+            prompt = self.query_one("#prompt", Input)
+            # Insert at cursor position
+            pos = prompt.cursor_position
+            current = prompt.value
+            new_value = current[:pos] + text + current[pos:]
+            prompt.value = new_value
+            prompt.cursor_position = pos + len(text)
+
         def on_key(self, event: Any) -> None:
             comp_widget = self.query_one("#completions", Static)
             if not (comp_widget.display and self._comp_items):

tests/test_tui_widgets.py

@@ -453,5 +453,61 @@ class TestWidgetImports(unittest.TestCase):
             assert isinstance(cls, type), f"{cls} is not a class"
 
 
+class TestClipboardPaste(unittest.TestCase):
+    """Test clipboard paste functionality."""
+
+    def test_get_clipboard_text_import(self):
+        """get_clipboard_text should be importable."""
+        from EvoScientist.cli.clipboard import get_clipboard_text
+
+        assert callable(get_clipboard_text)
+
+    def test_paste_native_import(self):
+        """_paste_native should be importable."""
+        from EvoScientist.cli.clipboard import _paste_native
+
+        assert callable(_paste_native)
+
+    def test_paste_native_returns_string_or_none(self):
+        """_paste_native should return str or None."""
+        from EvoScientist.cli.clipboard import _paste_native
+
+        result = _paste_native()
+        assert result is None or isinstance(result, str)
+
+    def test_get_clipboard_text_with_pyperclip_mock(self):
+        """get_clipboard_text should use pyperclip when available."""
+        from unittest.mock import MagicMock, patch
+
+        mock_pyperclip = MagicMock()
+        mock_pyperclip.paste.return_value = "mocked text"
+
+        with patch.dict("sys.modules", {"pyperclip": mock_pyperclip}):
+            # Re-import to pick up the mock
+            from EvoScientist.cli import clipboard
+            import importlib
+
+            importlib.reload(clipboard)
+
+            result = clipboard.get_clipboard_text()
+            # pyperclip.paste was called
+            mock_pyperclip.paste.assert_called_once()
+            assert result == "mocked text"
+
+    def test_get_clipboard_text_fallback_to_native(self):
+        """get_clipboard_text should fall back to native when pyperclip unavailable."""
+        from unittest.mock import patch
+
+        with patch.dict("sys.modules", {"pyperclip": None}):
+            from EvoScientist.cli import clipboard
+            import importlib
+
+            importlib.reload(clipboard)
+
+            # Should not raise, returns None or string
+            result = clipboard.get_clipboard_text()
+            assert result is None or isinstance(result, str)
+
+
 if __name__ == "__main__":
     unittest.main()