micropython-micro-gui/gui/demos/dropdown_var.py

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2.2 KiB
Python

# dropdown_var.py micro-gui demo of Dropdown widget with changeable elements
# Released under the MIT License (MIT). See LICENSE.
# Copyright (c) 2024 Peter Hinch
# hardware_setup must be imported before other modules because of RAM use.
import hardware_setup # Create a display instance
from gui.core.ugui import Screen, Window, ssd
from gui.widgets import Label, Button, CloseButton, Dropdown
from gui.core.writer import CWriter
# Font for CWriter
import gui.fonts.font10 as font
from gui.core.colors import *
def newtext(): # Create new listbox entries
strings = ("Iron", "Copper", "Lead", "Zinc")
n = 0
while True:
yield strings[n]
n = (n + 1) % len(strings)
ntxt = newtext() # Instantiate the generator
class BaseScreen(Screen):
def __init__(self):
super().__init__()
wri = CWriter(ssd, font, GREEN, BLACK, verbose=False)
col = 2
row = 2
self.els = ["Hydrogen", "Helium", "Neon", "Argon", "Krypton", "Xenon", "Radon"]
self.dd = Dropdown(
wri,
row,
col,
elements=self.els,
dlines=5, # Show 5 lines
bdcolor=GREEN,
callback=self.ddcb,
)
row += 30
self.lbl = Label(wri, row, col, self.dd.width, bdcolor=RED)
b = Button(wri, 2, 120, text="del", callback=self.delcb)
b = Button(wri, b.mrow + 2, 120, text="add", callback=self.addcb)
b = Button(wri, b.mrow + 10, 120, text="h2", callback=self.gocb, args=("Hydrogen",))
b = Button(wri, b.mrow + 2, 120, text="fe", callback=self.gocb, args=("Iron",))
CloseButton(wri)
def gocb(self, _, txt): # Go button callback: Move currency to specified entry
self.dd.textvalue(txt)
def addcb(self, _): # Add button callback
self.els.append(next(ntxt)) # Append a new entry
self.dd.update()
def delcb(self, _): # Delete button callback
del self.els[self.dd.value()] # Delete current entry
self.dd.update()
def ddcb(self, dd):
if hasattr(self, "lbl"):
self.lbl.value(dd.textvalue())
def after_open(self):
self.lbl.value(self.dd.textvalue())
def test():
print("Dropdown demo.")
Screen.change(BaseScreen)
test()