import sys
from PyQt5.QtWidgets import QApplication, QDialog, QLineEdit, QLabel, QWidget, QPushButton, QMessageBox, QComboBox, QDialogButtonBox, QShortcut
from PyQt5 import uic
from PyQt5.QtGui import QKeySequence
from PyQt5.QtCore import Qt, QEvent, QObject, QTimer

sys_path = sys.path[0].replace("\\", "/")

ui_file_path = sys_path + "/DialogModifyText.ui"

def modify_string(string, index, new_char):
    string_list = list(string)
    string_list[index] = new_char
    modified_string = ''.join(string_list)
    return modified_string

def chr_adjust(old_chr, dif : int) :
    new_chr = old_chr
    if old_chr == '+':
        new_chr = '-'
    elif old_chr == '-':
        new_chr = '+'
    elif dif > 0:
        new_chr    =  chr(ord(old_chr) + 1)
        if new_chr > '9' :
            new_chr = '0' 
    else :
        new_chr    =  chr(ord(old_chr) - 1)
        if new_chr < '0' :
            new_chr = '9'
    return new_chr

class DialogModifyText(QDialog):
    def __init__(self, main_window, parent=None):
        super(DialogModifyText, self).__init__(parent)
        # Load UI file
        uic.loadUi(ui_file_path, self)        
        
        self.Text            = "2019-09-10 10:22:23"
        self.select_bit      = 0
        self.main_window     = main_window

        self.setWindowTitle("参数修改")
        self.setWindowFlag(Qt.FramelessWindowHint)
        self.buttonBox.button(QDialogButtonBox.Ok).setText('确定')
        self.buttonBox.button(QDialogButtonBox.Cancel).setText('取消')
        
        self.buttonBox.clicked.connect(self.dialog_button_ok_clicked)

        modify_text = self.Text
        self.update_modify_info(modify_text, "缺省多字符修改")
        
        #让定时器周期刷修改字符串, 防止出现焦点切换时选中消失的情况
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.timeout_modify_string_refresh)
        self.timer.start(100)
    
        #定义4个快捷键, Key_Enter, Key_Escape经常被各类程序模块使用, 用Key_End, 与Key_Home来代替
        QShortcut(QKeySequence(Qt.Key_Up), self, activated=self.key_increase_parameter)
        QShortcut(QKeySequence(Qt.Key_Down), self, activated=self.key_decrease_parameter)
        QShortcut(QKeySequence(Qt.Key_PageDown), self, activated=self.key_enter_process)
        QShortcut(QKeySequence(Qt.Key_PageUp), self, activated=self.key_escape_process)
        QShortcut(QKeySequence(Qt.Key_End), self, activated=self.key_enter_process)
        QShortcut(QKeySequence(Qt.Key_Home), self, activated=self.key_escape_process)

    @property
    def value(self):
        return self.Text
    
    def timeout_modify_string_refresh(self) :
        line_modify : QLineEdit = self.lineEdit
        modify_str : str = line_modify.text()
        self.update_modify_string(modify_str)

    def update_modify_info(self, modify_str, caption : str) :
        if hasattr(self, "label") :
            label : QLabel = self.label
            label.setText(caption)
        self.update_modify_string(modify_str)
        
    def update_modify_string(self, modify_str : str) :
        line_modify : QLineEdit = self.lineEdit
        line_modify.setText(modify_str)

        if self.select_bit < len(modify_str) :
            if modify_str[self.select_bit] == ' ':
               self.key_enter_process()

        # 设置选择从第self.select_bit个字符开始，长度为1
        line_modify.setSelection(self.select_bit, 1)
        
    def key_increase_parameter(self):
        line_modify : QLineEdit = self.lineEdit
        text : str = line_modify.text()
        if self.select_bit < len(text) :
            old_chr    =  text[self.select_bit]
            new_chr    =  chr_adjust(old_chr, 1)
            new_modify_text = modify_string(text, self.select_bit, new_chr)
            self.update_modify_string(new_modify_text)
        
    def key_decrease_parameter(self):
        line_modify : QLineEdit = self.lineEdit
        text : str = line_modify.text()
        if self.select_bit < len(text) :
            old_chr    =  text[self.select_bit]
            new_chr    =  chr_adjust(old_chr, -1)
            new_modify_text = modify_string(text, self.select_bit, new_chr)
            self.update_modify_string(new_modify_text)

    def key_enter_process(self):
        line_modify : QLineEdit = self.lineEdit
        text : str = line_modify.text()

        if self.select_bit < len(text) - 1:
            self.select_bit += 1
            if not str.isdigit(text[self.select_bit]) :
                self.key_enter_process()
            else :
                self.update_modify_string(text)
        else :
            self.buttonBox.button(QDialogButtonBox.Ok).click()
        
    def key_escape_process(self):
        self.buttonBox.button(QDialogButtonBox.Cancel).click()

    def dialog_button_ok_clicked(self, button):
        if button == self.buttonBox.button(QDialogButtonBox.Ok) :
            line_modify : QLineEdit = self.lineEdit
            self.Text = line_modify.text()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    dialog = DialogModifyText(None)    
    dialog.show()
    dialog.exec_()
    sys.exit(0)