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author | Devtools Arcadia <arcadia-devtools@yandex-team.ru> | 2022-02-07 18:08:42 +0300 |
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committer | Devtools Arcadia <arcadia-devtools@mous.vla.yp-c.yandex.net> | 2022-02-07 18:08:42 +0300 |
commit | 1110808a9d39d4b808aef724c861a2e1a38d2a69 (patch) | |
tree | e26c9fed0de5d9873cce7e00bc214573dc2195b7 /contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py | |
download | ydb-1110808a9d39d4b808aef724c861a2e1a38d2a69.tar.gz |
intermediate changes
ref:cde9a383711a11544ce7e107a78147fb96cc4029
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.py | 187 |
1 files changed, 187 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 00000000000..4a43ff585ac --- /dev/null +++ b/contrib/python/prompt-toolkit/py3/prompt_toolkit/key_binding/bindings/scroll.py @@ -0,0 +1,187 @@ +""" +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 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 |