import PySimpleGUI as sg

class keyboard():
  def __init__(self,font=('Arial',16)):
    self.font=font
    numberRow='1234567890'
    topRow='QWERTYUIOP'
    midRow='ASDFGHJKL'
    bottomRow='ZXCVBNM'
    keyboard_layout=[[sg.ReadButton(c, key=c, pad=(0, 0), size=(4, 2), font=self.font) for c in numberRow]+[sg.ReadButton('⌫', key='back', pad=(0, 0), size=(4, 2), font=self.font),sg.ReadButton('Esc', key='close', pad=(0, 0), size=(4, 2), font=self.font)],
                     [sg.T(' '*4)]+[sg.ReadButton(c, key=c, pad=(0, 0), size=(4, 2), font=self.font) for c in topRow],
                     [sg.T(' '*11)]+[sg.ReadButton(c, key=c, pad=(0, 0), size=(4, 2), font=self.font) for c in midRow],
                     [sg.T(' '*18)]+[sg.ReadButton(c, key=c, pad=(0, 0), size=(4, 2), font=self.font) for c in bottomRow]]

    self.window=sg.Window('keyboard', grab_anywhere=True, keep_on_top=True, no_titlebar=True).Layout(
      keyboard_layout).Finalize()
    self.hide()

  def _keyboardhandler(self):
    if self.event is not None:
      if self.event=='close':
        self.hide()
      elif len(self.event)==1:
        self.focus.Update(self.focus.Get()+self.event)
      elif self.event=='back':
        Text=self.focus.Get()
        if len(Text)>0:
          Text=Text[:-1]
          self.focus.Update(Text)

  def hide(self):
    self.visible=False
    self.window.Disappear()

  def show(self):
    self.visible=True
    self.window.Reappear()

  def togglevis(self):
    if self.visible:
      self.hide()
    else:
      self.show()

  def update(self,focus):
    self.event,_=self.window.ReadNonBlocking()
    self.focus=focus
    self._keyboardhandler()

  def close(self):
    self.window.CloseNonBlocking()


class GUI():
  def __init__(self):
    layout = [[sg.Text('Enter Text')],
          [sg.Input(size=(17, 1), key='input1',)],
          [sg.InputText(size=(17, 1), key='input2')],
          [sg.ReadButton('on-screen keyboard',key='keyboard')],
          [sg.ReadButton('close',key='close')]]

    self.mainWindow = sg.Window('On-screen test', grab_anywhere=False,no_titlebar=True).Layout(layout)
    self.keyboard=keyboard()
    self.focus=None


  def run(self):
    while True:
      for row in self.mainWindow.Rows:
        for element in row:
          if element.Type=='input' and element.TKEntry is not None and element.TKEntry is element.TKEntry.focus_get():
            self.focus=element
      event, values=self.mainWindow.ReadNonBlocking()
      self.keyboard.update(self.focus)
      if event=='keyboard':
        self.keyboard.togglevis()
      elif event=='close':
        break
    self.keyboard.close()
    self.mainWindow.CloseNonBlocking()

if __name__ == '__main__':
  app=GUI()
  app.run()