def clear_line(self):
"""
Entirely deletes the current line. This is useful if it needs to be redrawn,
for instance if the window has been resized.
"""
# Calculate where the beginning of the line is (in terms of line wrapping).
lines = (len(self.last_line) + len(self.input_buffer) - self.cursor_position) // context.window_size[1]
if lines > 0:
write(ansi.CUU(lines)) # Go to the line where the buffer starts.
write(ansi.CUB(context.window_size[1]) + ansi.ED(0)) # Delete all after the caret.
def cursor_back(self, adjust_internal_cursor=True):
"""
Moves the on-screen caret back one position, going up to the previous line if needed.
:param adjust_internal_cursor: Whether the internal cursor should be updated accordingly.
This should always be True unless you have a very good reason not to do so.
"""
if self.cursor_position + 1 <= len(self.input_buffer):
if not self.caret_at_sol():
write(ansi.CUB())
else:
write(ansi.CUU() + ansi.CUF(context.window_size[1]))
if adjust_internal_cursor:
self.cursor_position += 1
def cursor_forward(self, adjust_internal_cursor=True):
"""
Moves the on-screen caret forward one position, going down to the next line if needed.
:param adjust_internal_cursor: Whether the internal cursor should be updated accordingly.
This should always be True unless you have a very good reason not to do so.
"""
if self.cursor_position > 0:
if not self.caret_at_eol():
write(ansi.CUF())
else:
write(ansi.CUD() + ansi.CUB(context.window_size[1]))
if adjust_internal_cursor:
self.cursor_position -= 1
def relative_caret_move(x, y):
"""
Move the caret relatively to its current position.
:param x: The number of lines to move. Negative numbers go upwards.
:param y: The number of columns to move. Negative numbers go backwards.
"""
command = b""
if x > 0:
command += ansi.CUU(x)
if x < 0:
command += ansi.CUD(-x)
if y > 0:
command += ansi.CUF(y)
if y < 0:
command += ansi.CUB(-y)
if command:
write(command)