from chimerax.cmd_line.tool import CommandLine

from Qt.QtGui import QFont, QFontMetrics

# change to control the size
new_size = 16

# get the command line tool object
cmd_line = CommandLine.get_singleton(session)

# make a copy of the command line's current font, but with
# larger/smaller text
new_font = QFont(cmd_line.tool_window.ui_area.font())
new_font.setPointSize(new_size)
cmd_line.tool_window.ui_area.setFont(new_font)

# need to adjust the size of the text box to be appropriate
# for the larger/smaller font
metrics = QFontMetrics(new_font)
min_height = int(1.1 * metrics.boundingRect("Qy").height() + 5)
cmd_line.text.setMinimumHeight(min_height)