text/display_boot_message

#!/bin/sh
# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Converts and displays UTF-8 based text message file from
# /usr/share/chromeos-assets/text/boot_messages/${locale}/${message}.txt .
# Uses pango-view to convert from txt to png, then frecon to render png on
# frame buffer.

# Default conversion parameters (can be overridden by environment variables)
# Note pango-view and frecon uses different color code format (#rrggbb vs
# 0xrrggbb), so we use format 'rrggbb' in IMAGE_BACKGROUND_RGB and not
# allowing common names.
: ${IMAGE_BACKGROUND_RGB:=202124}
: ${IMAGE_FONT_NAME:=sans-serif}
: ${IMAGE_FONT_SIZE:=22}
: ${IMAGE_MARGIN_SIZE:=5}
: ${IMAGE_TEXT_COLOR:=White}
: ${MESSAGE_BASE_PATH:=/usr/share/chromeos-assets/text/boot_messages}
: ${ASSETS_IMAGE_PATH:=/usr/share/chromeos-assets/images}
: ${SPINNER_IMAGE_BASE:=/usr/share/chromeos-assets/images/spinner/48x48}
: ${SPINNER_INTERVAL:=100}
: ${PROGRESS_BAR_WIDTH:=2}
: ${PROGRESS_BAR_RGB:=d0d0d0}
: ${DISPLAY_INDICATOR_FILE:=/run/boot_message_displayed}
: ${LOGGER_TAG:=display_boot_message}
: ${MESSAGE_OPTIONS:=""}

isatty() {
  local path="$1"
  [ -t 0 ] <"${path}"
}

create_temp_output() {
  # File extension (.png) is required for render engine (pango-view) to decide
  # output format.
  mktemp --suffix .png
}

# Prints width of given PNG file.
get_png_width() {
  local input="$1"
  local width
  # Get image width (the 17~20 bytes of PNG file in big-endian).
  width="$(dd if="${input}" bs=1 count=4 skip=16 2>/dev/null | od -A n -t x1)"
  echo "$(( 0x$(echo "${width}" | sed 's/ //g') ))"
}

# Converts a text file to PNG file by pango-view without further postprocessing.
txt_to_png() {
  local input="$1"
  local output="$2"
  local locale="$3"
  local option="$4"
  pango-view -q --output="${output}" \
    --dpi=72 --align=left --hinting=full \
    --margin="${IMAGE_MARGIN_SIZE}"\
    --font="${IMAGE_FONT_NAME} ${IMAGE_FONT_SIZE}" \
    --foreground="${IMAGE_TEXT_COLOR}" \
    --background="#${IMAGE_BACKGROUND_RGB}" \
    --language="${locale}" \
    ${option} "${input}"
}

# Converts a message file to PNG format to fit into given size.
message_to_png() {
  local input="$1"
  local output="$2"
  local locale="$3"
  local max_size_file="$4"
  local extra_options="$5"

  txt_to_png "${input}" "${output}" "${locale}" "${extra_options}"

  # We prefer a "left-aligned text image on center of screen, with text
  # wrapped by margin of its background image (max_size_file)". However if a
  # --width is assigned to pango-view, it will always pad (by text align
  # direction) to specified width, even if the image is smaller. That creates an
  # image which is always aligned to left of background, not on center. To fix
  # that, we first create the file, compare the width, and assign --width only
  # if we need wrapping.
  if [ -f "${max_size_file}" ]; then
    local max_width="$(get_png_width "${max_size_file}")"
    local width="$(get_png_width "${output}")"
    if [ "${max_width}" -gt 0 -a "${width}" -gt "${max_width}" ]; then
      extra_options="${extra_options} --width=${max_width}"
      txt_to_png "${input}" "${output}" "${locale}" "${extra_options}"
    fi
  fi
}

# Returns if given message needs spinner animation.
need_spinner() {
  local message="$1"

  case "${message}" in
    enter_dev2 | leave_dev | self_repair | update_firmware | power_wash | \
        show_spinner | wipe | update_detachable_base_firmware | \
        update_touchpad_firmware | update_touchscreen_firmware | \
        update_firmware_slow_extra_warning | update_fwupd_firmware)
      return 0
      ;;
    *)
      # Default: don't show spinner for unknown messages
      return 1
  esac
}

# Returns true if given message requires frecon to be restarted.
need_frecon_restart() {
  local message="$1"

  # Restart frecon if needs spinner.
  if need_spinner "${message}"; then
    return 0
  fi
  # Restart frecon if not running.
  if ! pgrep frecon > /dev/null; then
    return 0
  fi
  # Restart frecon if /run/frecon/vt0 does not exist.
  if ! isatty /run/frecon/vt0; then
    return 0
  fi
  # Do not restart frecon for the next messages:
  case "${message}" in update_arc_data_snapshot)
    return 1
    ;;
    *)
    return 0
  esac
}

# Renders given images to screen.
render_images() {
  local rc=0
  local message="$1"
  local file="$2"
  local spiner_offset=""
  local spinner_file="${SPINNER_IMAGE_BASE}"*01.png

  # Keep a copy of file in temp folder and never delete so it won't be removed
  # before the renderer (frecon running in background) is ready.
  # This is required for factory wiping that file lives on stateful partition.
  # It will be removed only when system reboots.
  local image_file="$(create_temp_output)"
  cp -f "${file}" "${image_file}"

  # Put spinner in left of centered message file, with a padding of 1/2 spinner
  # image width (offset is calculated from the default location, which puts
  # spinner in center).
  local spinner_offset_x=-"$(( $(get_png_width "${image_file}") / 2 +
                               $(get_png_width ${spinner_file}) ))"

  # TODO(hungte) Figure out a way to render using OSC in frecon if there is
  # already a frecon instance running.
  # Stop any running frecon instance.
  touch "${DISPLAY_INDICATOR_FILE}"

  # By default frecon would exit after all images are displayed unless there
  # is --loop-start or --enable-vts. Most boot-time messages need to keep the
  # display until reboot so we want to always add --enable-vts.

  local params="--enable-vts \
    --clear 0x${IMAGE_BACKGROUND_RGB} \
    --frame-interval 0 \
    --scale=0 \
    --enable-vt1 \
    --no-login \
    --enable-osc \
    --pre-create-vts \
    ${ASSETS_IMAGE_PATH}/boot_message.png \
    ${image_file}"

  # Frecon requires all options specified before image files.
  if need_spinner "${message}"; then
    params="\
      --loop-offset ${spinner_offset_x},0 \
      --loop-interval ${SPINNER_INTERVAL} \
      --loop-start 2 \
      ${params} \
      ${SPINNER_IMAGE_BASE}*.png"
  fi

  if need_frecon_restart "${message}"; then
    logger -t "${LOGGER_TAG}" "Kill frecon and display message: ${message}"
    pkill -9 frecon

    frecon --daemon ${params}
    simulate_tty
  else
    logger -t "${LOGGER_TAG}" "Display message: ${message}"

    update_image "${ASSETS_IMAGE_PATH}/boot_message.png"
    update_image "${image_file}"
  fi

  return ${rc}
}

# Shows an arbitrary text file.
show_text_file() {
  local message="$1"
  local locale="$2"
  local file="$3"
  local options="$4"
  local rc

  # Some systems run the rendering in background (for example, frecon) and we
  # don't know when the file will be accessed; so keep the file undeleted until
  # next boot.
  local output="$(create_temp_output)"
  message_to_png "${file}" "${output}" "${locale}" \
    "${ASSETS_IMAGE_PATH}/boot_message.png" "${options}" &&
  render_images "${message}" "${output}" || rc=$?
  rm -f "${output}"
  return ${rc}
}

# Shows a predefined and localized message from ${MESSAGE_BASE_PATH}.
show_message() {
  local message="$1"
  local locales="$2"
  local options="${MESSAGE_OPTIONS}"
  local rc=0
  local locale file

  for locale in ${locales}; do
    file="${MESSAGE_BASE_PATH}/${locale}/${message}.txt"
    [ -f "${file}" ] || continue
    show_text_file "${message}" "${locale}" "${file}" "${options}" || rc=$?
    return ${rc}
  done
  # If none of given locales have this message, return as failure.
  logger -t "${LOGGER_TAG}" \
    "Couldn't find message ${message} in '${locales}'; not displaying anything."
  return 1
}

# Shows a PNG image file or text markup file.
show_file() {
  local message="$1"
  local file="$2"

  case "${file}" in
    *.png)
      render_images "${message}" "${file}"
      ;;

    *)
      show_text_file "${message}" "" "${file}" "--markup"
      ;;
  esac
}

# Draw a box using frecon box drawing escape sequences.
draw_box() {
  local width="$1"
  local height="$2"
  local color="$3"
  local offset_x="$4"
  local offset_y="$5"

  # Bail out if the frecon terminal doesn't exist.
  isatty /run/frecon/vt0 || return 1

  printf '\033]box:color=0x%s;size=%u,%u;offset=%d,%d;scale=0\033\\' \
    "${color}" "${width}" "${height}" "${offset_x}" "${offset_y}" \
    > /run/frecon/vt0
}

# Show image using frecon image showing escape sequences.
update_image() {
  local image_file="$1"

  isatty /run/frecon/vt0 || return 1

  printf '\033]image:file=%s;color=%s;scale=0\033\\' "${image_file}" \
    "0x${IMAGE_BACKGROUND_RGB}" > /run/frecon/vt0
}

# Updates the progress bar. This requires frecon to already be set up, e.g. by
# previously invoking display_boot_message to show a message.
update_progress() {
  local progress="$1"

  # Draw the frame. The calculations below size the bar to be half the width of
  # the maximum message width, and 20 times as wide as high. The bar should show
  # below the message, so it's offset by 5 times its height to the bottom.
  local width="$(get_png_width "${ASSETS_IMAGE_PATH}/boot_message.png")"
  local bar_width="$(( width / ${PROGRESS_BAR_WIDTH} ))"
  local bar_height="$(( width / 40 ))"
  local bar_offset_y="$(( bar_height * 5 ))"

  # The frame is created by a solid rectangle of the full bar dimension,
  # overlayed with a slightly smaller rectangle in background color (2 pixels on
  # each edge) to punch out the interior.
  draw_box "${bar_width}" "${bar_height}" \
    "${PROGRESS_BAR_RGB}" "0" "${bar_offset_y}"
  draw_box "$(( bar_width - 4 ))" "$(( bar_height - 4 ))" \
    "${IMAGE_BACKGROUND_RGB}" "0" "${bar_offset_y}"

  # Draw the progress bar.
  if [ "$((progress))" -lt 0 ]; then
    progress=0
  fi
  if [ "$((progress))" -gt 100 ]; then
    progress=100
  fi

  # The progress rectangle itself is slightly smaller than the frame (2 pixels
  # on each edge), and needs to be offset to the left so it doesn't show at the
  # center of the bar, but aligned with the left edge.
  local progress_width="$(( ((bar_width - 8) * progress) / 100 ))"
  local progress_offset=-"$(( (bar_width - 8 - progress_width) / 2 ))"
  draw_box "${progress_width}" "$(( bar_height - 8 ))" \
    "${PROGRESS_BAR_RGB}" "${progress_offset}" "${bar_offset_y}"
}

# Simulate the TTY1 for text output (for example, progress bar).
# Some legacy scripts may create a broken TTY1 so we want to delete that if
# it is not a character device. Note the vtN in /run/frecon starts from 0.
simulate_tty() {
  local i="" frecon_vt="/run/frecon/vt" tty=""
  for i in 1 2 3; do
    tty="/dev/tty$((i + 1))"
    if isatty "${frecon_vt}${i}" && ! isatty "${tty}"; then
      rm -f "${tty}"
      ln -sf "${frecon_vt}${i}" "${tty}"
    fi
  done
}

action() {
  local action="$1"
  case "${action}" in
    # Restores frecon when the boot message should be cleared.
    restore_frecon)
      if [ -f "${DISPLAY_INDICATOR_FILE}" ]; then
        logger -t "${LOGGER_TAG}" "Kill and restore frecon."
        rm "${DISPLAY_INDICATOR_FILE}"
        pkill -9 frecon || true
        if is_developer_end_user; then
          # Restore frecon with the same arguments as boot-splash.conf
          frecon --daemon --enable-osc --enable-vts --pre-create-vts
        fi
      fi
      ;;
    *)
      return 1
      ;;
  esac
}

usage() {
  cat <<EOL >&2
Usage: $0 [MESSAGE LOCALES | show_file FILE | show_spinner FILE |
           update_progress PERCENTAGE |
           action [clear_indicator | restore_frecon] ]"
EOL
  exit 1
}

main() {
  [ "$#" = "2" ] || usage

  case "$1" in
    show_file|show_spinner)
      show_file "$1" "$2"
      ;;
    update_progress)
      update_progress "$2"
      ;;
    action)
      action "$2"
      ;;
    *)
      show_message "$1" "$2"
      ;;
  esac
}

set -e
main "$@"