app_explorer.py

from framework import BaseApp
import os
import lcd

# import uos

S_IFDIR = 0o040000  # directory


# noinspection PyPep8Naming
def S_IFMT(mode):
    """Return the portion of the file's mode that describes the
    file type.
    """
    return mode & 0o170000


# noinspection PyPep8Naming
def S_ISDIR(mode):
    """Return True if mode is from a directory."""
    return S_IFMT(mode) == S_IFDIR


def sizeof_fmt(num, suffix='B'):
    for unit in ['', 'K', 'M', 'G', 'T', 'P', 'E', 'Z']:
        if abs(num) < 1024.0:
            return "%3.1f%s%s" % (num, unit, suffix)
        num /= 1024.0
    return "%.1f%s%s" % (num, 'Yi', suffix)


class ExplorerApp(BaseApp):
    def __init__(self, system):
        super(ExplorerApp, self).__init__(system)
        self.current_offset = 0
        self.current_selected_index = 0
        self.__initialized = False

    def __lazy_init(self):
        current_dir_files = os.listdir("/sd/")
        self.current_dir_file_info_list = []
        for file_name in current_dir_files:
            info = {}
            info["file_name"] = file_name
            try:
                f_stat = os.stat('/sd/' + file_name)
                info["stat"] = f_stat
            except Exception as e:
                info["stat"] = None
                print(
                    "----- error when calling os.stat() ----- file_name =", file_name, e)
            self.current_dir_file_info_list.append(info)
        print(self.current_dir_file_info_list)
        self.__initialized = True

    def on_top_button_changed(self, state):
        if state == "pressed":
            self.current_selected_index += 1
            if self.current_selected_index >= len(self.current_dir_file_info_list):
                self.current_selected_index = 0
            if self.current_selected_index >= 7:
                self.current_offset = self.current_selected_index - 6
            else:
                self.current_offset = 0
            print("current_selected=", self.current_selected_index,
                  "current_offset=", self.current_offset)
            self.invalidate_drawing()

    def on_draw(self):
        if not self.__initialized:
            self.__lazy_init()
        x_offset = 4
        y_offset = 6
        lcd.clear()
        print("progress 0")
        for i in range(self.current_offset, len(self.current_dir_file_info_list)):
            # gc.collect()
            print("progress 1")
            file_info = self.current_dir_file_info_list[i]
            file_name = file_info["file_name"]
            f_stat = file_info["stat"]
            if f_stat != None:
                if S_ISDIR(f_stat[0]):
                    file_name = file_name + '/'
                file_readable_size = sizeof_fmt(f_stat[6])
                lcd.draw_string(lcd.width() - 50, y_offset,
                                file_readable_size, lcd.WHITE, lcd.BLUE)
            is_current = self.current_selected_index == i
            line = "%s %d %s" % ("->" if is_current else "  ", i, file_name)
            lcd.draw_string(x_offset, y_offset, line, lcd.WHITE, lcd.RED)
            # gc.collect()
            print("progress 2")
            y_offset += 18
            if y_offset > lcd.height():
                print("y_offset > height(), break")
                break
            print("progress 3")