====== tkinter ======
===== links =====

Basics: https://likegeeks.com/python-gui-examples-tkinter-tutorial/

Layout: https://zetcode.com/tkinter/layout/

grid: https://blog.tecladocode.com/tkinters-grid-geometry-manager/

Mixed layout: https://stackoverflow.com/a/38154650/15030988

Radiobutton Gruppen:
https://riptutorial.com/tkinter/example/30286/create-a-group-of-radiobuttons
https://stackoverflow.com/a/47162318/15030988

Buttons mit gemeinsamer click-Funktion: https://stackoverflow.com/a/6921225/15030988

MessageBox: https://docs.python.org/3/library/tkinter.messagebox.html

Neues Fenster: https://www.delftstack.com/de/howto/python-tkinter/how-to-create-a-new-window-with-a-button-in-tkinter/
===== Bildschirmgröße =====

  * winfo_screenwidth()
  * winfo_screenheight()

Fenster in Bildschirmmitte ausrichten: https://m.youtube.com/watch?v=gjU3Lx8XMS8

  * X=(screenwidth-windowwidth)/2
  * Y=(screenheight-windowheight)/2

die Position kann wie die Größe mit der geometry Methode gesetzt werden

  root = Tk()
  root.geometry("300x200+300+300") #WxH+X+Y

es kann auch nur die position verändert werden:

  root.geometry("+10+10")
===== Fenster als Klasse =====

<code python>
import tkinter as tk

class App:
  def __init__(self, window):
    window.geometry('350x200')
    frame = tk.Frame(window)
    frame.pack()
    self.button = tk.Button(frame, 
                         text="QUIT", fg="red",
                         command=frame.quit)
    self.button.pack(side=tk.LEFT)
    self.slogan = tk.Button(frame,
                         text="Hello",
                         command=self.write_slogan)
    self.slogan.pack(side=tk.LEFT)
  def write_slogan(self):
    print("Tkinter is easy to use!")
    
if __name__ == "__main__":
    root = tk.Tk()
    app = App(root)
    root.mainloop()
</code>

alternativ kann man auch direkt von der tk.Tk-Klasse ableiten, somit muss das Fenster nicht extern erzeugt werden

<code python>
class App(tk.Tk):
  def __init__(self):
    tk.Tk.__init__(self)
    self.geometry('350x200')
    frame = tk.Frame(self)
    ...
</code>

Das sollte aber nur bei Anwendungen gemacht werden die nur 1 Fenster nutzen. Bei mehreren Fenstern sollte die Fenstererstellung außerhalb der Klasse und nur das Füllen des Fensters innerhalb ablaufen.
===== Texteingabe =====

hier wird ein neuer Frame erzeugt um die Scrollbars an der Textbox auszurichten

ggf. mainframe (Eltern-Element) und txt_frm.grid anpassen (ggf. pack o.ä.)

<code python>
import tkinter as tk

class scrolltext(tk.Frame):
    def __init__(self,parent,width,height):
        tk.Frame.__init__(self, parent, width=width, height=height)
        # ensure a consistent GUI size
        self.grid_propagate(False)
        # implement stretchability
        self.grid_rowconfigure(0, weight=1)
        self.grid_columnconfigure(0, weight=1)
        
        self.txt = tk.Text(self, borderwidth=3, relief="sunken")
        self.txt.config(undo=True, wrap='none')#word
        self.txt.grid(row=0, column=0, sticky="nsew", padx=2, pady=2)
        
        #create vertical scrollbar
        self.vscrollb = tk.Scrollbar(self, command=self.txt.yview)
        self.vscrollb.grid(row=0, column=1, sticky='nsew')
        self.txt['yscrollcommand'] = self.vscrollb.set
        
        #create horizontal scrollbar
        self.hscrollb = tk.Scrollbar(self, orient='horizontal',command=self.txt.xview)
        self.hscrollb.grid(row=1, column=0, sticky='nsew')
        self.txt['xscrollcommand'] = self.hscrollb.set

    def focus(self):
        self.txt.focus()
    def getText(self):
        return self.txt.get("1.0", tk.END)
    def setText(self,text):
        self.txt.delete(1.0,"end")
        self.txt.insert(1.0, text)

if __name__ == "__main__":
    def clicked():
        print(txt.getText().splitlines())
        txt.setText("this is a special text")

    window = tk.Tk()
    window.geometry('350x200')
    window.title("Welcome to LikeGeeks app")

    txt=scrolltext(window, width=250,height=200)
    txt.pack(side = tk.LEFT,fill=tk.BOTH,expand=1)

    btn = tk.Button(window, text="Click Me", command=clicked)
    btn.pack(side=tk.RIGHT)

    txt.focus()

    window.mainloop()
</code>

https://stackoverflow.com/a/9662139/15030988

Beispiel mit yscrollcommand und zeilenweisem auslesen: https://stackoverflow.com/a/17747230/15030988
Horizontale scrollbar: https://stackoverflow.com/a/47954818/15030988
===== treeview =====
https://riptutorial.com/tkinter/example/31880/treeview--basic-example

https://www.askpython.com/python-modules/tkinter/tkinter-treeview-widget
===== PanedWindow =====

ein PanedWindow is ein Container für mindestens 2 Widgets mit einer verschiebbaren Begrenzung.

<code python>
m1 = tk.PanedWindow(window) 
m1.pack(fill = tk.BOTH, expand = 1)

button = tk.Button(m1,text="QUIT", fg="red")
m1.add(button, stretch="always") #always richtet automatisch aus, danach sind alle Felder gleich groß
    
button2 = tk.Button(m1,text="Hello")
m1.add(button2, stretch="always")

#setzen des Schiebereglers (optional, falls always nicht richtig ist)
m1.update()
m1.sash_place(0,400,0) #x-position 400 des ersten Widgets
</code>

https://stackoverflow.com/a/62032595/15030988

https://stackoverflow.com/a/27389064/15030988

===== Notebook =====

<code python>
tc = ttk.Notebook(master)
t1 = ttk.Frame(tc)
t2 = ttk.Frame(tc)
tc.add(t1, text ='Notebook tab1')
tc.add(t2, text ='Notebook tab2')
tc.pack(expand = 1, fill ="both")
</code>

https://www.educba.com/tkinter-notebook/


===== Beispiel-Gui =====

<code python>
from tkinter import Tk, RIGHT, BOTH, RAISED,X,Y,IntVar,BooleanVar,StringVar
from tkinter import messagebox
from tkinter.ttk import Label, Frame, Button, Entry, Checkbutton,Radiobutton, Notebook, Treeview, Style

class Example():

    def __init__(self,window):
        self.window=window
        self.initUI(window)

    def initUI(self,window):
        self.tc=Notebook(window)
        self.t1 = Frame(self.tc)
        self.t2 = Frame(self.tc)
        self.t3 = Frame(self.tc)
        self.tc.add(self.t1, text ='Tab1')
        self.tc.add(self.t2, text ='Tab2')
        self.tc.add(self.t3, text ='Tab3')
        self.tc.pack(fill=BOTH, expand=True)

        closeButton = Button(window, text="Close",command=window.destroy)
        closeButton.pack(side=RIGHT, padx=5, pady=5)
        okButton = Button(window, text="OK",command=lambda:messagebox.showinfo("OK pressed","Hello, you have successful pressed the OK-Button!\n\nEntry: %s CHK:%d RD:%s" % (self.e1.get(),self.chkvar1.get(),self.radvar1.get())))
        okButton.pack(side=RIGHT)
        mvButton = Button(window,text="move",command=lambda:window.geometry("+10+10"))
        mvButton.pack(side=RIGHT)

        self.filltabs()

    def filltabs(self):
        l1=Label(self.t1, text="Entry:")
        l1.grid(row=0,column=0)
        self.e1=Entry(self.t1)
        self.e1.grid(row=0,column=1)
        l2=Label(self.t1, text="Checkbutton:")
        l2.grid(row=1,column=0)
        self.chkvar1 = IntVar()
        self.chkvar1.set(1)
        c1=Checkbutton(self.t1, text='Choose', variable=self.chkvar1) #, onvalue=1,offvalue=0)
        c1.grid(row=1,column=1,sticky="W") #left justify

        l3=Label(self.t2,text="Radiobuttons")
        l3.grid(row=0,column=0,sticky="N")
        rf=Frame(self.t2)
        rf.grid(row=0,column=1)
        self.radvar1=StringVar()
        r1=Radiobutton(rf, text="Python", variable=self.radvar1, value="python")
        r1.pack(anchor="w") #untereinander linksbündig
        r2=Radiobutton(rf, text="PHP", variable=self.radvar1, value="php")
        r2.pack(anchor="w")

        self.tree1=Treeview(self.t3, columns=("Name", "Data")) # causes WIndow be bigger and hides buttonframe
        self.tree1.pack(fill=BOTH, expand=True)

        self.tree1.insert(parent='', index='end', iid=0, text="root", values=("First Col", "Second Col"))
        self.tree1.insert(parent=0, index='end', iid=1, text="child", values=("Hello", "Again"))

def main():

    root = Tk()
    root.geometry("400x300+300+300")
    root.title("testwindow")
    root.style = Style().theme_use("alt") # to show checkmarks in checkbutton and round radiobuttons
    app = Example(root)
    root.mainloop()


if __name__ == '__main__':
    main()
</code>