GUI_multiple_threads_sleep_freeze.py

'''
May 2017
@author: Burkhard A. Meier
'''
#======================
# imports
#======================
import tkinter as tk
from tkinter import ttk
from tkinter import scrolledtext
from tkinter import Menu
from tkinter import messagebox as msg
from tkinter import Spinbox
from time import  sleep         
import Ch04_Code.ToolTip as tt

from threading import Thread

GLOBAL_CONST = 42

#=====================================================
class OOP():
    def __init__(self):         # Initializer method
        # Create instance
        self.win = tk.Tk()   
        
        # Add a title       
        self.win.title("Python GUI")      
        self.create_widgets()

    # Button callback
    def click_me(self): 
        self.action.configure(text='Hello ' + self.name.get() + 
                              ' ' + self.number_chosen.get())
        # Non-threaded code with sleep freezes the GUI
        for idx in range(10):
            sleep(5)
            self.scrol.insert(tk.INSERT, str(idx) + '\n')
            
            

    # Spinbox callback 
    def _spin(self):
        value = self.spin.get()
        print(value)
        self.scrol.insert(tk.INSERT, value + '\n')
        
    # GUI Callback  
    def checkCallback(self, *ignored_args):
        # only enable one checkbutton
        if self.chVarUn.get(): self.check3.configure(state='disabled')
        else:                  self.check3.configure(state='normal')
        if self.chVarEn.get(): self.check2.configure(state='disabled')
        else:                  self.check2.configure(state='normal') 
        
    # Radiobutton Callback
    def radCall(self):
        radSel = self.radVar.get()
        if   radSel == 0: self.mighty2.configure(text='Blue')
        elif radSel == 1: self.mighty2.configure(text='Gold')
        elif radSel == 2: self.mighty2.configure(text='Red')          
        
    # update progressbar in callback loop
    def run_progressbar(self):
        self.progress_bar["maximum"] = 100
        for i in range(101):
            sleep(0.05)
            self.progress_bar["value"] = i   # increment progressbar
            self.progress_bar.update()       # have to call update() in loop
        self.progress_bar["value"] = 0       # reset/clear progressbar  
    
    def start_progressbar(self):
        self.progress_bar.start()
        
    def stop_progressbar(self):
        self.progress_bar.stop()
     
    def progressbar_stop_after(self, wait_ms=1000):    
        self.win.after(wait_ms, self.progress_bar.stop)        

    def usingGlobal(self):
        global GLOBAL_CONST
        print(GLOBAL_CONST)
        GLOBAL_CONST = 777
        print(GLOBAL_CONST)

    def method_in_a_thread(self):
        print('Hi, how are you?')

                    
    # Exit GUI cleanly
    def _quit(self):
        self.win.quit()
        self.win.destroy()
        exit() 
                  
    #####################################################################################       
    def create_widgets(self):    
        tabControl = ttk.Notebook(self.win)          # Create Tab Control
        
        tab1 = ttk.Frame(tabControl)            # Create a tab 
        tabControl.add(tab1, text='Tab 1')      # Add the tab
        tab2 = ttk.Frame(tabControl)            # Add a second tab
        tabControl.add(tab2, text='Tab 2')      # Make second tab visible
        
        tabControl.pack(expand=1, fill="both")  # Pack to make visible
        
        # LabelFrame using tab1 as the parent
        mighty = ttk.LabelFrame(tab1, text=' Mighty Python ')
        mighty.grid(column=0, row=0, padx=8, pady=4)
        
        # Modify adding a Label using mighty as the parent instead of win
        a_label = ttk.Label(mighty, text="Enter a name:")
        a_label.grid(column=0, row=0, sticky='W')
     
        # Adding a Textbox Entry widget
        self.name = tk.StringVar()
        self.name_entered = ttk.Entry(mighty, width=24, textvariable=self.name)
        self.name_entered.grid(column=0, row=1, sticky='W')               
        
        # Adding a Button
        self.action = ttk.Button(mighty, text="Click Me!", command=self.click_me)   
        self.action.grid(column=2, row=1)                                
        
        ttk.Label(mighty, text="Choose a number:").grid(column=1, row=0)
        number = tk.StringVar()
        self.number_chosen = ttk.Combobox(mighty, width=14, textvariable=number, state='readonly')
        self.number_chosen['values'] = (1, 2, 4, 42, 100)
        self.number_chosen.grid(column=1, row=1)
        self.number_chosen.current(0)
        
        # Adding a Spinbox widget
        self.spin = Spinbox(mighty, values=(1, 2, 4, 42, 100), width=5, bd=9, command=self._spin) # using range
        self.spin.grid(column=0, row=2, sticky='W') # align left
        
        # Using a scrolled Text control    
        scrol_w = 40; scrol_h = 10                  # increase sizes
        self.scrol = scrolledtext.ScrolledText(mighty, width=scrol_w, height=scrol_h, wrap=tk.WORD)
        self.scrol.grid(column=0, row=3, sticky='WE', columnspan=3)                    
        
        for child in mighty.winfo_children():       # add spacing to align widgets within tabs
            child.grid_configure(padx=4, pady=2) 
         
        #=====================================================================================
        # Tab Control 2 ----------------------------------------------------------------------
        self.mighty2 = ttk.LabelFrame(tab2, text=' The Snake ')
        self.mighty2.grid(column=0, row=0, padx=8, pady=4)
        
        # Creating three checkbuttons
        chVarDis = tk.IntVar()
        check1 = tk.Checkbutton(self.mighty2, text="Disabled", variable=chVarDis, state='disabled')
        check1.select()
        check1.grid(column=0, row=0, sticky=tk.W)                   
        
        chVarUn = tk.IntVar()
        check2 = tk.Checkbutton(self.mighty2, text="UnChecked", variable=chVarUn)
        check2.deselect()
        check2.grid(column=1, row=0, sticky=tk.W)                   
        
        chVarEn = tk.IntVar()
        check3 = tk.Checkbutton(self.mighty2, text="Enabled", variable=chVarEn)
        check3.deselect()
        check3.grid(column=2, row=0, sticky=tk.W)                     
        
        # trace the state of the two checkbuttons
        chVarUn.trace('w', lambda unused0, unused1, unused2 : self.checkCallback())    
        chVarEn.trace('w', lambda unused0, unused1, unused2 : self.checkCallback())   
        
        
        # First, we change our Radiobutton global variables into a list
        colors = ["Blue", "Gold", "Red"]   
        
        # create three Radiobuttons using one variable
        self.radVar = tk.IntVar()
        
        # Next we are selecting a non-existing index value for radVar
        self.radVar.set(99)                                 
         
        # Now we are creating all three Radiobutton widgets within one loop
        for col in range(3):                             
            curRad = tk.Radiobutton(self.mighty2, text=colors[col], variable=self.radVar, 
                                    value=col, command=self.radCall)          
            curRad.grid(column=col, row=1, sticky=tk.W)             # row=6
            # And now adding tooltips
            tt.create_ToolTip(curRad, 'This is a Radiobutton control')
                
        # Add a Progressbar to Tab 2
        self.progress_bar = ttk.Progressbar(tab2, orient='horizontal', length=286, mode='determinate')
        self.progress_bar.grid(column=0, row=3, pady=2)         
             
        # Create a container to hold buttons
        buttons_frame = ttk.LabelFrame(self.mighty2, text=' ProgressBar ')
        buttons_frame.grid(column=0, row=2, sticky='W', columnspan=2)        
        
        # Add Buttons for Progressbar commands
        ttk.Button(buttons_frame, text=" Run Progressbar   ", command=self.run_progressbar).grid(column=0, row=0, sticky='W')  
        ttk.Button(buttons_frame, text=" Start Progressbar  ", command=self.start_progressbar).grid(column=0, row=1, sticky='W')  
        ttk.Button(buttons_frame, text=" Stop immediately ", command=self.stop_progressbar).grid(column=0, row=2, sticky='W')  
        ttk.Button(buttons_frame, text=" Stop after second ", command=self.progressbar_stop_after).grid(column=0, row=3, sticky='W')  
         
        for child in buttons_frame.winfo_children():  
            child.grid_configure(padx=2, pady=2) 
         
        for child in self.mighty2.winfo_children():  
            child.grid_configure(padx=8, pady=2) 
            
        # Creating a Menu Bar
        menu_bar = Menu(self.win)
        self.win.config(menu=menu_bar)
        
        # Add menu items
        file_menu = Menu(menu_bar, tearoff=0)
        file_menu.add_command(label="New")
        file_menu.add_separator()
        file_menu.add_command(label="Exit", command=self._quit)
        menu_bar.add_cascade(label="File", menu=file_menu)
        
        # Display a Message Box
        def _msgBox():
            msg.showinfo('Python Message Info Box', 'A Python GUI created using tkinter:\nThe year is 2017.')  
            
        # Add another Menu to the Menu Bar and an item
        help_menu = Menu(menu_bar, tearoff=0)
        help_menu.add_command(label="About", command=_msgBox)   # display messagebox when clicked
        menu_bar.add_cascade(label="Help", menu=help_menu)
        
        # Change the main windows icon
        self.win.iconbitmap('pyc.ico')
        
        # It is not necessary to create a tk.StringVar() 
        # strData = tk.StringVar()
        strData = self.spin.get()
        print("Spinbox value: " + strData)
        
        # call function
        self.usingGlobal()
        
        self.name_entered.focus()     

        # Add Tooltips -----------------------------------------------------
        # Add a Tooltip to the Spinbox
        tt.create_ToolTip(self.spin, 'This is a Spinbox control')   
                
        # Add Tooltips to more widgets
        tt.create_ToolTip(self.name_entered, 'This is an Entry control')  
        tt.create_ToolTip(self.action, 'This is a Button control')                      
        tt.create_ToolTip(self.scrol, 'This is a ScrolledText control')
                 
#======================
# Start GUI
#======================
oop = OOP()

# Running methods in Threads
run_thread = Thread(target=oop.method_in_a_thread)

oop.win.mainloop()