1 files changed, 104 insertions, 0 deletions
diff --git a/src/prompt_toolkit/cursor_shapes.py b/src/prompt_toolkit/cursor_shapes.py
new file mode 100644
index 0000000..453b72c
--- /dev/null
+++ b/src/prompt_toolkit/cursor_shapes.py
@@ -0,0 +1,104 @@
+from __future__ import annotations
+
+from abc import ABC, abstractmethod
+from enum import Enum
+from typing import TYPE_CHECKING, Any, Callable, Union
+
+from prompt_toolkit.enums import EditingMode
+from prompt_toolkit.key_binding.vi_state import InputMode
+
+if TYPE_CHECKING:
+    from .application import Application
+
+__all__ = [
+    "CursorShape",
+    "CursorShapeConfig",
+    "SimpleCursorShapeConfig",
+    "ModalCursorShapeConfig",
+    "DynamicCursorShapeConfig",
+    "to_cursor_shape_config",
+]
+
+
+class CursorShape(Enum):
+    # Default value that should tell the output implementation to never send
+    # cursor shape escape sequences. This is the default right now, because
+    # before this `CursorShape` functionality was introduced into
+    # prompt_toolkit itself, people had workarounds to send cursor shapes
+    # escapes into the terminal, by monkey patching some of prompt_toolkit's
+    # internals. We don't want the default prompt_toolkit implementation to
+    # interfere with that. E.g., IPython patches the `ViState.input_mode`
+    # property. See: https://github.com/ipython/ipython/pull/13501/files
+    _NEVER_CHANGE = "_NEVER_CHANGE"
+
+    BLOCK = "BLOCK"
+    BEAM = "BEAM"
+    UNDERLINE = "UNDERLINE"
+    BLINKING_BLOCK = "BLINKING_BLOCK"
+    BLINKING_BEAM = "BLINKING_BEAM"
+    BLINKING_UNDERLINE = "BLINKING_UNDERLINE"
+
+
+class CursorShapeConfig(ABC):
+    @abstractmethod
+    def get_cursor_shape(self, application: Application[Any]) -> CursorShape:
+        """
+        Return the cursor shape to be used in the current state.
+        """
+
+
+AnyCursorShapeConfig = Union[CursorShape, CursorShapeConfig, None]
+
+
+class SimpleCursorShapeConfig(CursorShapeConfig):
+    """
+    Always show the given cursor shape.
+    """
+
+    def __init__(self, cursor_shape: CursorShape = CursorShape._NEVER_CHANGE) -> None:
+        self.cursor_shape = cursor_shape
+
+    def get_cursor_shape(self, application: Application[Any]) -> CursorShape:
+        return self.cursor_shape
+
+
+class ModalCursorShapeConfig(CursorShapeConfig):
+    """
+    Show cursor shape according to the current input mode.
+    """
+
+    def get_cursor_shape(self, application: Application[Any]) -> CursorShape:
+        if application.editing_mode == EditingMode.VI:
+            if application.vi_state.input_mode == InputMode.INSERT:
+                return CursorShape.BEAM
+            if application.vi_state.input_mode == InputMode.REPLACE:
+                return CursorShape.UNDERLINE
+
+        # Default
+        return CursorShape.BLOCK
+
+
+class DynamicCursorShapeConfig(CursorShapeConfig):
+    def __init__(
+        self, get_cursor_shape_config: Callable[[], AnyCursorShapeConfig]
+    ) -> None:
+        self.get_cursor_shape_config = get_cursor_shape_config
+
+    def get_cursor_shape(self, application: Application[Any]) -> CursorShape:
+        return to_cursor_shape_config(self.get_cursor_shape_config()).get_cursor_shape(
+            application
+        )
+
+
+def to_cursor_shape_config(value: AnyCursorShapeConfig) -> CursorShapeConfig:
+    """
+    Take a `CursorShape` instance or `CursorShapeConfig` and turn it into a
+    `CursorShapeConfig`.
+    """
+    if value is None:
+        return SimpleCursorShapeConfig()
+
+    if isinstance(value, CursorShape):
+        return SimpleCursorShapeConfig(value)
+
+    return value