aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py
diff options
context:
space:
mode:
authornkozlovskiy <nmk@ydb.tech>2023-09-29 12:24:06 +0300
committernkozlovskiy <nmk@ydb.tech>2023-09-29 12:41:34 +0300
commite0e3e1717e3d33762ce61950504f9637a6e669ed (patch)
treebca3ff6939b10ed60c3d5c12439963a1146b9711 /contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py
parent38f2c5852db84c7b4d83adfcb009eb61541d1ccd (diff)
downloadydb-e0e3e1717e3d33762ce61950504f9637a6e669ed.tar.gz
add ydb deps
Diffstat (limited to 'contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py')
-rw-r--r--contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py189
1 files changed, 189 insertions, 0 deletions
diff --git a/contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py b/contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py
new file mode 100644
index 0000000000..83a4be1f8f
--- /dev/null
+++ b/contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py
@@ -0,0 +1,189 @@
+"""
+Key bindings, for scrolling up and down through pages.
+
+This are separate bindings, because GNU readline doesn't have them, but
+they are very useful for navigating through long multiline buffers, like in
+Vi, Emacs, etc...
+"""
+from __future__ import annotations
+
+from prompt_toolkit.key_binding.key_processor import KeyPressEvent
+
+__all__ = [
+ "scroll_forward",
+ "scroll_backward",
+ "scroll_half_page_up",
+ "scroll_half_page_down",
+ "scroll_one_line_up",
+ "scroll_one_line_down",
+]
+
+E = KeyPressEvent
+
+
+def scroll_forward(event: E, half: bool = False) -> None:
+ """
+ Scroll window down.
+ """
+ w = event.app.layout.current_window
+ b = event.app.current_buffer
+
+ if w and w.render_info:
+ info = w.render_info
+ ui_content = info.ui_content
+
+ # Height to scroll.
+ scroll_height = info.window_height
+ if half:
+ scroll_height //= 2
+
+ # Calculate how many lines is equivalent to that vertical space.
+ y = b.document.cursor_position_row + 1
+ height = 0
+ while y < ui_content.line_count:
+ line_height = info.get_height_for_line(y)
+
+ if height + line_height < scroll_height:
+ height += line_height
+ y += 1
+ else:
+ break
+
+ b.cursor_position = b.document.translate_row_col_to_index(y, 0)
+
+
+def scroll_backward(event: E, half: bool = False) -> None:
+ """
+ Scroll window up.
+ """
+ w = event.app.layout.current_window
+ b = event.app.current_buffer
+
+ if w and w.render_info:
+ info = w.render_info
+
+ # Height to scroll.
+ scroll_height = info.window_height
+ if half:
+ scroll_height //= 2
+
+ # Calculate how many lines is equivalent to that vertical space.
+ y = max(0, b.document.cursor_position_row - 1)
+ height = 0
+ while y > 0:
+ line_height = info.get_height_for_line(y)
+
+ if height + line_height < scroll_height:
+ height += line_height
+ y -= 1
+ else:
+ break
+
+ b.cursor_position = b.document.translate_row_col_to_index(y, 0)
+
+
+def scroll_half_page_down(event: E) -> None:
+ """
+ Same as ControlF, but only scroll half a page.
+ """
+ scroll_forward(event, half=True)
+
+
+def scroll_half_page_up(event: E) -> None:
+ """
+ Same as ControlB, but only scroll half a page.
+ """
+ scroll_backward(event, half=True)
+
+
+def scroll_one_line_down(event: E) -> None:
+ """
+ scroll_offset += 1
+ """
+ w = event.app.layout.current_window
+ b = event.app.current_buffer
+
+ if w:
+ # When the cursor is at the top, move to the next line. (Otherwise, only scroll.)
+ if w.render_info:
+ info = w.render_info
+
+ if w.vertical_scroll < info.content_height - info.window_height:
+ if info.cursor_position.y <= info.configured_scroll_offsets.top:
+ b.cursor_position += b.document.get_cursor_down_position()
+
+ w.vertical_scroll += 1
+
+
+def scroll_one_line_up(event: E) -> None:
+ """
+ scroll_offset -= 1
+ """
+ w = event.app.layout.current_window
+ b = event.app.current_buffer
+
+ if w:
+ # When the cursor is at the bottom, move to the previous line. (Otherwise, only scroll.)
+ if w.render_info:
+ info = w.render_info
+
+ if w.vertical_scroll > 0:
+ first_line_height = info.get_height_for_line(info.first_visible_line())
+
+ cursor_up = info.cursor_position.y - (
+ info.window_height
+ - 1
+ - first_line_height
+ - info.configured_scroll_offsets.bottom
+ )
+
+ # Move cursor up, as many steps as the height of the first line.
+ # TODO: not entirely correct yet, in case of line wrapping and many long lines.
+ for _ in range(max(0, cursor_up)):
+ b.cursor_position += b.document.get_cursor_up_position()
+
+ # Scroll window
+ w.vertical_scroll -= 1
+
+
+def scroll_page_down(event: E) -> None:
+ """
+ Scroll page down. (Prefer the cursor at the top of the page, after scrolling.)
+ """
+ w = event.app.layout.current_window
+ b = event.app.current_buffer
+
+ if w and w.render_info:
+ # Scroll down one page.
+ line_index = max(w.render_info.last_visible_line(), w.vertical_scroll + 1)
+ w.vertical_scroll = line_index
+
+ b.cursor_position = b.document.translate_row_col_to_index(line_index, 0)
+ b.cursor_position += b.document.get_start_of_line_position(
+ after_whitespace=True
+ )
+
+
+def scroll_page_up(event: E) -> None:
+ """
+ Scroll page up. (Prefer the cursor at the bottom of the page, after scrolling.)
+ """
+ w = event.app.layout.current_window
+ b = event.app.current_buffer
+
+ if w and w.render_info:
+ # Put cursor at the first visible line. (But make sure that the cursor
+ # moves at least one line up.)
+ line_index = max(
+ 0,
+ min(w.render_info.first_visible_line(), b.document.cursor_position_row - 1),
+ )
+
+ b.cursor_position = b.document.translate_row_col_to_index(line_index, 0)
+ b.cursor_position += b.document.get_start_of_line_position(
+ after_whitespace=True
+ )
+
+ # Set the scroll offset. We can safely set it to zero; the Window will
+ # make sure that it scrolls at least until the cursor becomes visible.
+ w.vertical_scroll = 0