1 files changed, 70 insertions, 0 deletions
diff --git a/examples/prompts/custom-vi-operator-and-text-object.py b/examples/prompts/custom-vi-operator-and-text-object.py
new file mode 100755
index 0000000..7478afc
--- /dev/null
+++ b/examples/prompts/custom-vi-operator-and-text-object.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+"""
+Example of adding a custom Vi operator and text object.
+(Note that this API is not guaranteed to remain stable.)
+"""
+from prompt_toolkit import prompt
+from prompt_toolkit.enums import EditingMode
+from prompt_toolkit.key_binding import KeyBindings
+from prompt_toolkit.key_binding.bindings.vi import (
+    TextObject,
+    create_operator_decorator,
+    create_text_object_decorator,
+)
+
+
+def main():
+    # We start with a `Registry` of default key bindings.
+    bindings = KeyBindings()
+
+    # Create the decorators to be used for registering text objects and
+    # operators in this registry.
+    operator = create_operator_decorator(bindings)
+    text_object = create_text_object_decorator(bindings)
+
+    # Create a custom operator.
+
+    @operator("R")
+    def _(event, text_object):
+        "Custom operator that reverses text."
+        buff = event.current_buffer
+
+        # Get relative start/end coordinates.
+        start, end = text_object.operator_range(buff.document)
+        start += buff.cursor_position
+        end += buff.cursor_position
+
+        text = buff.text[start:end]
+        text = "".join(reversed(text))
+
+        event.app.current_buffer.text = buff.text[:start] + text + buff.text[end:]
+
+    # Create a text object.
+
+    @text_object("A")
+    def _(event):
+        "A custom text object that involves everything."
+        # Note that a `TextObject` has coordinates, relative to the cursor position.
+        buff = event.current_buffer
+        return TextObject(
+            -buff.document.cursor_position,  # The start.
+            len(buff.text) - buff.document.cursor_position,
+        )  # The end.
+
+    # Read input.
+    print('There is a custom text object "A" that applies to everything')
+    print('and a custom operator "r" that reverses the text object.\n')
+
+    print("Things that are possible:")
+    print("-  Riw    - reverse inner word.")
+    print("-  yA     - yank everything.")
+    print("-  RA     - reverse everything.")
+
+    text = prompt(
+        "> ", default="hello world", key_bindings=bindings, editing_mode=EditingMode.VI
+    )
+    print("You said: %s" % text)
+
+
+if __name__ == "__main__":
+    main()