# Copyright 2016 The TensorFlow Authors. All Rights Reserved.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

# ==============================================================================

"""Curses-Based Command-Line Interface of TensorFlow Debugger (tfdbg)."""

from __future__ import absolute_import

from __future__ import division

from __future__ import print_function

import collections

import curses

from curses import textpad

import signal

import sys

from six.moves import xrange # pylint: disable=redefined-builtin

from tensorflow.python.debug.cli import base_ui

from tensorflow.python.debug.cli import command_parser

from tensorflow.python.debug.cli import debugger_cli_common

from tensorflow.python.debug.cli import tensor_format

def _get_command_from_line_attr_segs(mouse_x, attr_segs):

"""Attempt to extract command from the attribute segments of a line.

Args:

mouse_x: (int) x coordinate of the mouse event.

attr_segs: (list) The list of attribute segments of a line from a

RichTextLines object.

Returns:

(str or None) If a command exists: the command as a str; otherwise, None.

"""

for seg in attr_segs:

if seg[0] <= mouse_x < seg[1]:

attributes = seg[2] if isinstance(seg[2], list) else [seg[2]]

for attr in attributes:

if isinstance(attr, debugger_cli_common.MenuItem):

return attr.content

class CursesUI(base_ui.BaseUI):

"""Curses-based Command-line UI.

In this class, the methods with the prefix "_screen_" are the methods that

interact with the actual terminal using the curses library.

"""

CLI_TERMINATOR_KEY = 7 # Terminator key for input text box.

CLI_TAB_KEY = ord("\t")

REGEX_SEARCH_PREFIX = "/"

TENSOR_INDICES_NAVIGATION_PREFIX = "@"

# Possible Enter keys. 343 is curses key code for the num-pad Enter key when

# num lock is off.

CLI_CR_KEYS = [ord("\n"), ord("\r"), 343]

_SCROLL_REFRESH = "refresh"

_SCROLL_UP = "up"

_SCROLL_DOWN = "down"

_SCROLL_HOME = "home"

_SCROLL_END = "end"

_SCROLL_TO_LINE_INDEX = "scroll_to_line_index"

_FOREGROUND_COLORS = {

"white": curses.COLOR_WHITE,

"red": curses.COLOR_RED,

"green": curses.COLOR_GREEN,

"yellow": curses.COLOR_YELLOW,

"blue": curses.COLOR_BLUE,

"cyan": curses.COLOR_CYAN,

"magenta": curses.COLOR_MAGENTA,

"black": curses.COLOR_BLACK,

}

_BACKGROUND_COLORS = {

"white": curses.COLOR_WHITE,

"black": curses.COLOR_BLACK,

}

# Font attribute for search and highlighting.

_SEARCH_HIGHLIGHT_FONT_ATTR = "black_on_white"

_ARRAY_INDICES_COLOR_PAIR = "black_on_white"

_ERROR_TOAST_COLOR_PAIR = "red_on_white"

_INFO_TOAST_COLOR_PAIR = "blue_on_white"

_STATUS_BAR_COLOR_PAIR = "black_on_white"

def __init__(self, on_ui_exit=None):

"""Constructor of CursesUI.

Args:

on_ui_exit: (Callable) Callback invoked when the UI exits.

"""

base_ui.BaseUI.__init__(self, on_ui_exit=on_ui_exit)

self._screen_init()

self._screen_refresh_size()

# TODO(cais): Error out if the size of the screen is too small.

# Initialize some UI component size and locations.

self._init_layout()

self._command_history_store = debugger_cli_common.CommandHistory()

# Active list of command history, used in history navigation.

# _command_handler_registry holds all the history commands the CLI has

# received, up to a size limit. _active_command_history is the history

# currently being navigated in, e.g., using the Up/Down keys. The latter

# can be different from the former during prefixed or regex-based history

# navigation, e.g., when user enter the beginning of a command and hit Up.

self._active_command_history = []

# Pointer to the current position in the history sequence.

# 0 means it is a new command being keyed in.

self._command_pointer = 0

self._command_history_limit = 100

self._pending_command = ""

# State related to screen output.

self._output_pad = None

self._output_pad_row = 0

self._output_array_pointer_indices = None

self._curr_unwrapped_output = None

self._curr_wrapped_output = None

# Register signal handler for SIGINT.

signal.signal(signal.SIGINT, self._interrupt_handler)

self.register_command_handler(

"mouse",

self._mouse_mode_command_handler,

"Get or set the mouse mode of this CLI: (on|off)",

prefix_aliases=["m"])

def _init_layout(self):

"""Initialize the layout of UI components.

Initialize the location and size of UI components such as command textbox

and output region according to the terminal size.

"""

# NamedTuple for rectangular locations on screen

self.rectangle = collections.namedtuple("rectangle",

"top left bottom right")

# Height of command text box

self._command_textbox_height = 2

self._title_row = 0

# Top row index of the output pad.

# A "pad" is a curses object that holds lines of text and not limited to

# screen size. It can be rendered on the screen partially with scroll

# parameters specified.

self._output_top_row = 1

# Number of rows that the output pad has.

self._output_num_rows = (

self._max_y - self._output_top_row - self._command_textbox_height - 1)

# Row index of scroll information line: Taking into account the zero-based

# row indexing and the command textbox area under the scroll information

# row.

self._output_scroll_row = self._max_y - 1 - self._command_textbox_height

# Tab completion bottom row.

self._candidates_top_row = self._output_scroll_row - 4

self._candidates_bottom_row = self._output_scroll_row - 1

# Maximum number of lines the candidates display can have.

self._candidates_max_lines = int(self._output_num_rows / 2)

self.max_output_lines = 10000

# Regex search state.

self._curr_search_regex = None

self._unwrapped_regex_match_lines = []

# Size of view port on screen, which is always smaller or equal to the

# screen size.

self._output_pad_screen_height = self._output_num_rows - 1

self._output_pad_screen_width = self._max_x - 1

self._output_pad_screen_location = self.rectangle(

top=self._output_top_row,

left=0,

bottom=self._output_top_row + self._output_num_rows,

right=self._output_pad_screen_width)

def _screen_init(self):

"""Screen initialization.

Creates curses stdscr and initialize the color pairs for display.

"""

self._stdscr = curses.initscr()

self._command_window = None

# Prepare color pairs.

curses.start_color()

self._color_pairs = {}

color_index = 0

for fg_color in self._FOREGROUND_COLORS:

for bg_color in self._BACKGROUND_COLORS:

color_index += 1

curses.init_pair(color_index, self._FOREGROUND_COLORS[fg_color],

self._BACKGROUND_COLORS[bg_color])

color_name = fg_color

if bg_color != "black":

color_name += "_on_" + bg_color

self._color_pairs[color_name] = curses.color_pair(color_index)

# A_BOLD or A_BLINK is not really a "color". But place it here for

# convenience.

self._color_pairs["bold"] = curses.A_BOLD

self._color_pairs["blink"] = curses.A_BLINK

self._color_pairs["underline"] = curses.A_UNDERLINE

# Default color pair to use when a specified color pair does not exist.

self._default_color_pair = self._color_pairs["white"]

def _screen_launch(self, enable_mouse_on_start):

"""Launch the curses screen."""

curses.noecho()

curses.cbreak()

self._stdscr.keypad(1)

self._mouse_enabled = enable_mouse_on_start

self._screen_set_mousemask()

self._screen_create_command_window()

def _screen_create_command_window(self):

"""Create command window according to screen size."""

if self._command_window:

del self._command_window

self._command_window = curses.newwin(

self._command_textbox_height, self._max_x - len(self.CLI_PROMPT),

self._max_y - self._command_textbox_height, len(self.CLI_PROMPT))

def _screen_refresh(self):

self._stdscr.refresh()

def _screen_terminate(self):

"""Terminate the curses screen."""

self._stdscr.keypad(0)

curses.nocbreak()

curses.echo()

curses.endwin()

# Remove SIGINT handler.

signal.signal(signal.SIGINT, signal.SIG_DFL)

def run_ui(self,

init_command=None,

title=None,

title_color=None,

enable_mouse_on_start=True):

"""Run the CLI: See the doc of base_ui.BaseUI.run_ui for more details."""

self._screen_launch(enable_mouse_on_start=enable_mouse_on_start)

# Optional initial command.

if init_command is not None:

self._dispatch_command(init_command)

if title is not None:

self._title(title, title_color=title_color)

# CLI main loop.

exit_token = self._ui_loop()

if self._on_ui_exit:

self._on_ui_exit()

self._screen_terminate()

return exit_token

def get_help(self):

return self._command_handler_registry.get_help()

def _screen_create_command_textbox(self, existing_command):

"""Create command textbox on screen.

Args:

existing_command: (str) A command string to put in the textbox right

after its creation.

"""

# Display the tfdbg prompt.

self._stdscr.addstr(self._max_y - self._command_textbox_height, 0,

self.CLI_PROMPT, curses.A_BOLD)

self._stdscr.refresh()

self._command_window.clear()

# Command text box.

self._command_textbox = textpad.Textbox(

self._command_window, insert_mode=True)

# Enter existing command.

self._auto_key_in(existing_command)

def _ui_loop(self):

"""Command-line UI loop.

Returns:

An exit token of arbitrary type. The token can be None.

"""

while True:

# Enter history command if pointer is in history (> 0):

if self._command_pointer > 0:

existing_command = self._active_command_history[-self._command_pointer]

else:

existing_command = self._pending_command

self._screen_create_command_textbox(existing_command)

command, terminator, pending_command_changed = self._get_user_command()

if not command and terminator != self.CLI_TAB_KEY:

continue

if terminator in self.CLI_CR_KEYS or terminator == curses.KEY_MOUSE:

exit_token = self._dispatch_command(command)

if exit_token is not None:

return exit_token

elif terminator == self.CLI_TAB_KEY:

tab_completed = self._tab_complete(command)

self._pending_command = tab_completed

self._cmd_ptr = 0

elif pending_command_changed:

self._pending_command = command

return

def _get_user_command(self):

"""Get user command from UI.

Returns:

command: (str) The user-entered command.

terminator: (str) Terminator type for the command.

If command is a normal command entered with the Enter key, the value

will be the key itself. If this is a tab completion call (using the

Tab key), the value will reflect that as well.

pending_command_changed: (bool) If the pending command has changed.

Used during command history navigation.

"""

# First, reset textbox state variables.

self._textbox_curr_terminator = None

self._textbox_pending_command_changed = False

command = self._screen_get_user_command()

command = self._strip_terminator(command)

return (command, self._textbox_curr_terminator,

self._textbox_pending_command_changed)

def _screen_get_user_command(self):

return self._command_textbox.edit(validate=self._on_textbox_keypress)

def _strip_terminator(self, command):

if not command:

return command

for v in self.CLI_CR_KEYS:

if v < 256:

command = command.replace(chr(v), "")

return command.strip()

def _screen_refresh_size(self):

self._max_y, self._max_x = self._stdscr.getmaxyx()

def _dispatch_command(self, command):

"""Dispatch user command.

Args:

command: (str) Command to dispatch.

Returns:

An exit token object. None value means that the UI loop should not exit.

A non-None value means the UI loop should exit.

"""

if command in self.CLI_EXIT_COMMANDS:

# Explicit user command-triggered exit: EXPLICIT_USER_EXIT as the exit

# token.

return debugger_cli_common.EXPLICIT_USER_EXIT

if command:

self._command_history_store.add_command(command)

if (command.startswith(self.REGEX_SEARCH_PREFIX) and

self._curr_unwrapped_output):

if len(command) > len(self.REGEX_SEARCH_PREFIX):

# Command is like "/regex". Perform regex search.

regex = command[len(self.REGEX_SEARCH_PREFIX):]

self._curr_search_regex = regex

self._display_output(self._curr_unwrapped_output, highlight_regex=regex)

elif self._unwrapped_regex_match_lines:

# Command is "/". Continue scrolling down matching lines.

self._display_output(

self._curr_unwrapped_output,

is_refresh=True,

highlight_regex=self._curr_search_regex)

self._command_pointer = 0

self._pending_command = ""

return

elif command.startswith(self.TENSOR_INDICES_NAVIGATION_PREFIX):

indices_str = command[1:].strip()

if indices_str:

try:

indices = command_parser.parse_indices(indices_str)

omitted, line_index, _, _ = tensor_format.locate_tensor_element(

self._curr_wrapped_output, indices)

if not omitted:

self._scroll_output(

self._SCROLL_TO_LINE_INDEX, line_index=line_index)

except Exception as e: # pylint: disable=broad-except

self._error_toast(str(e))

else:

self._error_toast("Empty indices.")

return

try:

prefix, args, output_file_path = self._parse_command(command)

except SyntaxError as e:

self._error_toast(str(e))

return

if not prefix:

# Empty command: take no action. Should not exit.

return

screen_info = {"cols": self._max_x}

exit_token = None

if self._command_handler_registry.is_registered(prefix):

try:

screen_output = self._command_handler_registry.dispatch_command(

prefix, args, screen_info=screen_info)

except debugger_cli_common.CommandLineExit as e:

exit_token = e.exit_token

else:

screen_output = debugger_cli_common.RichTextLines([

self.ERROR_MESSAGE_PREFIX + "Invalid command prefix \"%s\"" % prefix

])

# Clear active command history. Until next up/down history navigation

# occurs, it will stay empty.

self._active_command_history = []

if exit_token is not None:

return exit_token

self._display_output(screen_output)

if output_file_path:

try:

screen_output.write_to_file(output_file_path)

self._info_toast("Wrote output to %s" % output_file_path)

except Exception: # pylint: disable=broad-except

self._error_toast("Failed to write output to %s" % output_file_path)

self._command_pointer = 0

self._pending_command = ""

def _screen_gather_textbox_str(self):

"""Gather the text string in the command text box.

Returns:

(str) the current text string in the command textbox, excluding any

return keys.

"""

txt = self._command_textbox.gather()

return txt.strip()

def _on_textbox_keypress(self, x):

"""Text box key validator: Callback of key strokes.

Handles a user's keypress in the input text box. Translates certain keys to

terminator keys for the textbox to allow its edit() method to return.

Also handles special key-triggered events such as PgUp/PgDown scrolling of

the screen output.

Args:

x: (int) Key code.

Returns:

(int) A translated key code. In most cases, this is identical to the

input x. However, if x is a Return key, the return value will be

CLI_TERMINATOR_KEY, so that the text box's edit() method can return.

Raises:

TypeError: If the input x is not of type int.

"""

if not isinstance(x, int):

raise TypeError("Key validator expected type int, received type %s" %

type(x))

if x in self.CLI_CR_KEYS:

# Make Enter key the terminator

self._textbox_curr_terminator = x

return self.CLI_TERMINATOR_KEY

elif x == self.CLI_TAB_KEY:

self._textbox_curr_terminator = self.CLI_TAB_KEY

return self.CLI_TERMINATOR_KEY

elif x == curses.KEY_PPAGE:

self._scroll_output(self._SCROLL_UP)

return x

elif x == curses.KEY_NPAGE:

self._scroll_output(self._SCROLL_DOWN)

return x

elif x == curses.KEY_HOME:

self._scroll_output(self._SCROLL_HOME)

return x

elif x == curses.KEY_END:

self._scroll_output(self._SCROLL_END)

return x

elif x in [curses.KEY_UP, curses.KEY_DOWN]:

# Command history navigation.

if not self._active_command_history:

hist_prefix = self._screen_gather_textbox_str()

self._active_command_history = (

self._command_history_store.lookup_prefix(

hist_prefix, self._command_history_limit))

if self._active_command_history:

if x == curses.KEY_UP:

if self._command_pointer < len(self._active_command_history):

self._command_pointer += 1

elif x == curses.KEY_DOWN:

if self._command_pointer > 0:

self._command_pointer -= 1

else:

self._command_pointer = 0

self._textbox_curr_terminator = x

# Force return from the textbox edit(), so that the textbox can be

# redrawn with a history command entered.

return self.CLI_TERMINATOR_KEY

elif x == curses.KEY_RESIZE:

# Respond to terminal resize.

self._screen_refresh_size()

self._init_layout()

self._screen_create_command_window()

self._redraw_output()

# Force return from the textbox edit(), so that the textbox can be

# redrawn.

return self.CLI_TERMINATOR_KEY

elif x == curses.KEY_MOUSE and self._mouse_enabled:

try:

_, mouse_x, mouse_y, _, mouse_event_type = self._screen_getmouse()

except curses.error:

mouse_event_type = None

if mouse_event_type == curses.BUTTON1_RELEASED:

command = self._fetch_hyperlink_command(mouse_x, mouse_y)

if command:

self._auto_key_in(command)

self._textbox_curr_terminator = x

return self.CLI_TERMINATOR_KEY

else:

# Mark the pending command as modified.

self._textbox_pending_command_changed = True

# Invalidate active command history.

self._command_pointer = 0

self._active_command_history = []

return x

def _screen_getmouse(self):

return curses.getmouse()

def _redraw_output(self):

if self._curr_unwrapped_output is not None:

self._display_main_menu(self._curr_unwrapped_output)

self._display_output(self._curr_unwrapped_output, is_refresh=True)

def _fetch_hyperlink_command(self, mouse_x, mouse_y):

output_top = self._output_top_row

if self._main_menu_pad:

output_top += 1

if mouse_y == self._output_top_row and self._main_menu_pad:

# Click was in the menu bar.

return _get_command_from_line_attr_segs(mouse_x,

self._main_menu.font_attr_segs[0])

else:

absolute_mouse_y = mouse_y + self._output_pad_row - output_top

if absolute_mouse_y in self._curr_wrapped_output.font_attr_segs:

return _get_command_from_line_attr_segs(

mouse_x, self._curr_wrapped_output.font_attr_segs[absolute_mouse_y])

def _title(self, title, title_color=None):

"""Display title.

Args:

title: (str) The title to display.

title_color: (str) Color of the title, e.g., "yellow".

"""

# Pad input title str with "-" and space characters to make it pretty.

self._title_line = "--- %s " % title

if len(self._title_line) < self._max_x:

self._title_line += "-" * (self._max_x - len(self._title_line))

self._screen_draw_text_line(

self._title_row, self._title_line, color=title_color)

def _auto_key_in(self, command):

"""Automatically key in a command to the command Textbox.

Args:

command: The command, as a string.

"""

for c in command:

self._command_textbox.do_command(ord(c))

def _screen_draw_text_line(self, row, line, attr=curses.A_NORMAL, color=None):

"""Render a line of text on the screen.

Args:

row: (int) Row index.

line: (str) The line content.

attr: curses font attribute.

color: (str) font foreground color name.

Raises:

TypeError: If row is not of type int.

"""

if not isinstance(row, int):

raise TypeError("Invalid type in row")

if len(line) > self._max_x:

line = line[:self._max_x]

color_pair = (self._default_color_pair if color is None else

self._color_pairs[color])

self._stdscr.addstr(row, 0, line, color_pair | attr)

self._screen_refresh()

def _screen_new_output_pad(self, rows, cols):

"""Generate a new pad on the screen.

Args:

rows: (int) Number of rows the pad will have: not limited to screen size.

cols: (int) Number of columns the pad will have: not limited to screen

size.

Returns:

A curses textpad object.

"""

return curses.newpad(rows, cols)

def _screen_display_output(self, output):

"""Actually render text output on the screen.

Wraps the lines according to screen width. Pad lines below according to

screen height so that the user can scroll the output to a state where

the last non-empty line is on the top of the screen. Then renders the

lines on the screen.

Args:

output: (RichTextLines) text lines to display on the screen. These lines

may have widths exceeding the screen width. This method will take care

of the wrapping.

Returns:

(List of int) A list of line indices, in the wrapped output, where there

are regex matches.

"""

# Wrap the output lines according to screen width.

self._curr_wrapped_output, wrapped_line_indices = (

debugger_cli_common.wrap_rich_text_lines(output, self._max_x - 1))

# Append lines to curr_wrapped_output so that the user can scroll to a

# state where the last text line is on the top of the output area.

self._curr_wrapped_output.lines.extend([""] * (self._output_num_rows - 1))

# Limit number of lines displayed to avoid curses overflow problems.

if self._curr_wrapped_output.num_lines() > self.max_output_lines:

self._curr_wrapped_output = self._curr_wrapped_output.slice(

0, self.max_output_lines)

self._curr_wrapped_output.lines.append("Output cut off at %d lines!" %

self.max_output_lines)

self._curr_wrapped_output.font_attr_segs[self.max_output_lines] = [

(0, len(output.lines[-1]), "magenta")

]

self._display_main_menu(self._curr_wrapped_output)

(self._output_pad, self._output_pad_height,

self._output_pad_width) = self._display_lines(self._curr_wrapped_output,

self._output_num_rows)

# The indices of lines with regex matches (if any) need to be mapped to

# indices of wrapped lines.

return [

wrapped_line_indices[line]

for line in self._unwrapped_regex_match_lines

]

def _display_output(self, output, is_refresh=False, highlight_regex=None):

"""Display text output in a scrollable text pad.

This method does some preprocessing on the text lines, render them on the

screen and scroll to the appropriate line. These are done according to regex

highlighting requests (if any), scroll-to-next-match requests (if any),

and screen refresh requests (if any).

TODO(cais): Separate these unrelated request to increase clarity and

maintainability.

Args:

output: A RichTextLines object that is the screen output text.

is_refresh: (bool) Is this a refreshing display with existing output.

highlight_regex: (str) Optional string representing the regex used to

search and highlight in the current screen output.

"""

if not output:

return

if highlight_regex:

try:

output = debugger_cli_common.regex_find(

output, highlight_regex, font_attr=self._SEARCH_HIGHLIGHT_FONT_ATTR)

except ValueError as e:

self._error_toast(str(e))

return

if not is_refresh:

# Perform new regex search on the current output.

self._unwrapped_regex_match_lines = output.annotations[

debugger_cli_common.REGEX_MATCH_LINES_KEY]

else:

# Continue scrolling down.

self._output_pad_row += 1

else:

self._curr_unwrapped_output = output

self._unwrapped_regex_match_lines = []

# Display output on the screen.

wrapped_regex_match_lines = self._screen_display_output(output)

# Now that the text lines are displayed on the screen scroll to the

# appropriate line according to previous scrolling state and regex search

# and highlighting state.

if highlight_regex:

next_match_line = -1

for match_line in wrapped_regex_match_lines:

if match_line >= self._output_pad_row:

next_match_line = match_line

break

if next_match_line >= 0:

self._scroll_output(

self._SCROLL_TO_LINE_INDEX, line_index=next_match_line)

else:

# Regex search found no match >= current line number. Display message

# stating as such.

self._toast("Pattern not found", color=self._ERROR_TOAST_COLOR_PAIR)

elif is_refresh:

self._scroll_output(self._SCROLL_REFRESH)

else:

self._output_pad_row = 0

self._scroll_output(self._SCROLL_HOME)

def _display_lines(self, output, min_num_rows):

"""Display RichTextLines object on screen.

Args:

output: A RichTextLines object.

min_num_rows: (int) Minimum number of output rows.

Returns:

1) The text pad object used to display the main text body.

2) (int) number of rows of the text pad, which may exceed screen size.

3) (int) number of columns of the text pad.

Raises:

ValueError: If input argument "output" is invalid.

"""

if not isinstance(output, debugger_cli_common.RichTextLines):

raise ValueError(

"Output is required to be an instance of RichTextLines, but is not.")

self._screen_refresh()

# Number of rows the output area will have.

rows = max(min_num_rows, len(output.lines))

# Size of the output pad, which may exceed screen size and require

# scrolling.

cols = self._max_x - 1

# Create new output pad.

pad = self._screen_new_output_pad(rows, cols)

for i in xrange(len(output.lines)):

if i in output.font_attr_segs:

self._screen_add_line_to_output_pad(

pad, i, output.lines[i], color_segments=output.font_attr_segs[i])

else:

self._screen_add_line_to_output_pad(pad, i, output.lines[i])

return pad, rows, cols

def _display_main_menu(self, output):

"""Display main menu associated with screen output, if the menu exists.

Args:

output: (debugger_cli_common.RichTextLines) The RichTextLines output from

the annotations field of which the menu will be extracted and used (if

the menu exists).

"""

if debugger_cli_common.MAIN_MENU_KEY in output.annotations:

self._main_menu = output.annotations[

debugger_cli_common.MAIN_MENU_KEY].format_as_single_line(

prefix="| ", divider=" | ", enabled_item_attrs=["underline"])

self._main_menu_pad = self._screen_new_output_pad(1, self._max_x - 1)

# The unwrapped menu line may exceed screen width, in which case it needs

# to be cut off.

wrapped_menu, _ = debugger_cli_common.wrap_rich_text_lines(

self._main_menu, self._max_x - 2)

self._screen_add_line_to_output_pad(

self._main_menu_pad,

0,

wrapped_menu.lines[0],

color_segments=(wrapped_menu.font_attr_segs[0]

if 0 in wrapped_menu.font_attr_segs else None))

else:

self._main_menu = None

self._main_menu_pad = None

def _screen_add_line_to_output_pad(self, pad, row, txt, color_segments=None):

"""Render a line in a text pad.

Assumes: segments in color_segments are sorted in ascending order of the

beginning index.

Note: Gaps between the segments are allowed and will be fixed in with a

default color.

Args:

pad: The text pad to render the line in.

row: Row index, as an int.

txt: The text to be displayed on the specified row, as a str.

color_segments: A list of 3-tuples. Each tuple represents the beginning

and the end of a color segment, in the form of a right-open interval:

[start, end). The last element of the tuple is a color string, e.g.,

"red".

Raisee:

TypeError: If color_segments is not of type list.

"""

if not color_segments:

pad.addstr(row, 0, txt, self._default_color_pair)

return

if not isinstance(color_segments, list):

raise TypeError("Input color_segments needs to be a list, but is not.")

all_segments = []

all_color_pairs = []

# Process the beginning.

if color_segments[0][0] == 0:

pass

else:

all_segments.append((0, color_segments[0][0]))

all_color_pairs.append(self._default_color_pair)

for (curr_start, curr_end, curr_attrs), (next_start, _, _) in zip(

color_segments, color_segments[1:] + [(len(txt), None, None)]):

all_segments.append((curr_start, curr_end))

if not isinstance(curr_attrs, list):

curr_attrs = [curr_attrs]

curses_attr = curses.A_NORMAL

for attr in curr_attrs:

if (self._mouse_enabled and

isinstance(attr, debugger_cli_common.MenuItem)):

curses_attr |= curses.A_UNDERLINE

else:

curses_attr |= self._color_pairs.get(attr, self._default_color_pair)

all_color_pairs.append(curses_attr)

if curr_end < next_start:

# Fill in the gap with the default color.

all_segments.append((curr_end, next_start))

all_color_pairs.append(self._default_color_pair)

# Finally, draw all the segments.

for segment, color_pair in zip(all_segments, all_color_pairs):

if segment[1] < self._max_x:

pad.addstr(row, segment[0], txt[segment[0]:segment[1]], color_pair)

def _screen_scroll_output_pad(self, pad, viewport_top, viewport_left,

screen_location_top, screen_location_left,

screen_location_bottom, screen_location_right):

pad.refresh(viewport_top, viewport_left, screen_location_top,

screen_location_left, screen_location_bottom,

screen_location_right)

def _scroll_output(self, direction, line_index=None):

"""Scroll the output pad.

Args:

direction: _SCROLL_REFRESH, _SCROLL_UP, _SCROLL_DOWN, _SCROLL_HOME or

_SCROLL_END, _SCROLL_TO_LINE_INDEX

line_index: (int) Specifies the zero-based line index to scroll to.

Applicable only if direction is _SCROLL_TO_LINE_INDEX.

Raises:

ValueError: On invalid scroll direction.

TypeError: If line_index is not int and direction is

_SCROLL_TO_LINE_INDEX.

"""

if not self._output_pad:

# No output pad is present. Do nothing.

return

if direction == self._SCROLL_REFRESH:

pass

elif direction == self._SCROLL_UP:

# Scroll up

if self._output_pad_row - 1 >= 0:

self._output_pad_row -= 1

elif direction == self._SCROLL_DOWN:

# Scroll down

if self._output_pad_row + 1 < (

self._output_pad_height - self._output_pad_screen_height):

self._output_pad_row += 1

elif direction == self._SCROLL_HOME:

# Scroll to top

self._output_pad_row = 0

elif direction == self._SCROLL_END:

# Scroll to bottom

self._output_pad_row = (

self._output_pad_height - self._output_pad_screen_height - 1)

elif direction == self._SCROLL_TO_LINE_INDEX:

if not isinstance(line_index, int):

raise TypeError("Invalid line_index type (%s) under mode %s" %

(type(line_index), self._SCROLL_TO_LINE_INDEX))

self._output_pad_row = line_index

else:

raise ValueError("Unsupported scroll mode: %s" % direction)

# Actually scroll the output pad: refresh with new location.

output_pad_top = self._output_pad_screen_location.top

if self._main_menu_pad:

output_pad_top += 1

self._screen_scroll_output_pad(self._output_pad, self._output_pad_row, 0,

output_pad_top,

self._output_pad_screen_location.left,

self._output_pad_screen_location.bottom,

self._output_pad_screen_location.right)

self._screen_render_menu_pad()

self._scroll_info = self._compile_ui_status_summary()

self._screen_draw_text_line(