Added example with a custom Vi operator and text object.

1 files changed, 64 insertions, 0 deletions

diff --git a/examples/custom-vi-operator-and-text-object.py b/examples/custom-vi-operator-and-text-object.py
new file mode 100755
index 00000000..dfe3a0ab
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+++ b/examples/custom-vi-operator-and-text-object.py
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+#!/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 __future__ import unicode_literals
+from prompt_toolkit import prompt
+from prompt_toolkit.key_binding.defaults import load_default_key_bindings_for_prompt
+from prompt_toolkit.key_binding.bindings.vi import create_operator_decorator, create_text_object_decorator, TextObject
+from prompt_toolkit.enums import EditingMode
+
+
+def main():
+    # We start with a `Registry` of default key bindings.
+    registry = load_default_key_bindings_for_prompt()
+
+    # Create the decorators to be used for registering text objects and
+    # operators in this registry.
+    operator = create_operator_decorator(registry)
+    text_object = create_text_object_decorator(registry)
+
+    # 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.cli.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 coordinatens, 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_registry=registry, editing_mode=EditingMode.VI)
+    print('You said: %s' % text)
+
+
+if __name__ == '__main__':
+    main()