# The tkinter Package

Reference:

* [Docs](https://docs.python.org/3/library/tkinter.html)
* [Index of Tutorials](https://wiki.python.org/moin/TkInter)
* [An unofficial, but most helpful, guide](https://www.tutorialspoint.com/python/python_gui_programming.htm):
  * [`Button`](https://www.tutorialspoint.com/python/tk_button.htm)
  * [`CheckButton`](https://www.tutorialspoint.com/python/tk_checkbutton.htm)
  * [`Entry`](https://www.tutorialspoint.com/python/tk_entry.htm)
  * [`ListBox`](https://www.tutorialspoint.com/python/tk_listbox.htm)
  * [`Message`](https://www.tutorialspoint.com/python/tk_message.htm)
  * [`RadioButton`](https://www.tutorialspoint.com/python/tk_radiobutton.htm)
  * [`MessageBox`](https://www.tutorialspoint.com/python/tk_messagebox.htm)
  * [`Menu`](https://www.tutorialspoint.com/python/tk_menu.htm)

The `tkinter` package provides an application with a graphical user interface capable of being run on a personal computer.

## Installation

The `tkinter` package is most likely already pre-installed in your Python installation.

## Usage

Usage example:

```python
import tkinter

#
# INITIALIZE A NEW GUI WINDOW
#

window = tkinter.Tk()

#
# INITIALIZE SOME USER INTERFACE COMPONENTS
#

# MESSAGE

my_message = tkinter.Message(text="Hi. Welcome to my Example GUI Application!", width=1000)

# ENTRY (TEXT INPUT) WITH LABEL

my_label = tkinter.Label(text="Input something here:")
entry_value = tkinter.StringVar()
my_entry = tkinter.Entry(textvariable=entry_value)

# RADIO BUTTONS

my_radio_label = tkinter.Label(text="Please selection one of the following options:")
my_radio_value = tkinter.StringVar()
my_radio_a = tkinter.Radiobutton(text="Option A", value="A", variable=my_radio_value)
my_radio_b = tkinter.Radiobutton(text="Option B", value="B", variable=my_radio_value)
my_radio_c = tkinter.Radiobutton(text="Option C", value="C", variable=my_radio_value)

# CHECKBUTTONS

my_checkbox_group_label = tkinter.Label(text="Please check one or more of the following boxes:")
my_checkbox_a_val = tkinter.StringVar()
my_checkbox_a = tkinter.Checkbutton(text="Box A", variable=my_checkbox_a_val)
my_checkbox_b_val = tkinter.StringVar()
my_checkbox_b = tkinter.Checkbutton(text="Box B", variable=my_checkbox_b_val)
my_checkbox_c_val = tkinter.StringVar()
my_checkbox_c = tkinter.Checkbutton(text="Box C", variable=my_checkbox_c_val)

# LISTBOX (DROPDOWN SELECT)

my_select_label = tkinter.Label(text="Please select an item from the dropdown:")
my_select = tkinter.Listbox()
my_select.insert(1, "First Item")
my_select.insert(2, "Second Item")
my_select.insert(3, "Third Item")
my_select.insert(4, "Fourth Item")
my_select.insert(5, "Fifth Item")
my_select.insert(6, "Sixth Item")

# BUTTON

def handle_button_click():
    print("------------------------------")
    print("NICE. YOU CLICKED THE BUTTON")
    print("THE ENTRY'S INPUT VALUE IS:", my_entry.get())
    print("THE SELECTED RADIO BUTTON'S VALUE IS:", my_radio_value.get())
    print("THE CHECKBOX ON/OFF VALUES FOR A, B, C, RESPECTIVELY, ARE:", [my_checkbox_a_val.get(), my_checkbox_b_val.get(), my_checkbox_c_val.get()])
    print("THE SELECTED DROPDOWN ITEM IS:", my_select.get(my_select.curselection()))

my_button = tkinter.Button(text="Click Me", command=handle_button_click)

#
# BIND THE INDIVIDUAL COMPONENTS TO THE GUI WINDOW (PACK)
# ... THEN LAUNCH THE GUI WINDOW (MAINLOOP)
#

my_message.pack()

my_label.pack()
my_entry.pack()

my_radio_label.pack()
my_radio_a.pack()
my_radio_b.pack()
my_radio_b.pack()

my_checkbox_group_label.pack()
my_checkbox_a.pack()
my_checkbox_b.pack()
my_checkbox_c.pack()

my_select_label.pack()
my_select.pack()

my_button.pack()

window.mainloop()
```

![a screencast of using the program. a desktop window comes up. the user inputs some values and selects some things. then upon button click the terminal outputs the values of all selected items](https://github.com/prof-rossetti/nyu-info-2335-201805/raw/master/notes/programming-languages/python/packages/img/tkinter-demo.gif)