How do you make a slide show in Guizero/tkinter?

Question

I am trying to make a slide show in python 3 with Guizero. I cant seem to make the next and back button work with time reset.

from guizero import *
app = App(bg='#121212',title='Guizero - slide show',width=500,height=500)

#list of images
images = ["img1.jpg", "img2.png", "img3.jpg", "img4.jpg"]

#sets what slide to start with
current_slide=0

#changes current slide displayed
def slideShow():
    global current_slide
    if len(images)-1>current_slide:
        current_slide+=1
        picture.image=images[current_slide]
    
    else:
        current_slide=0
        picture.image=images[current_slide]

#Function runs to change slide on button push
def slide_change(Change):
    global current_slide
    current_slide+=Change
    picture.image=images[current_slide]


#starter image    
picture = Picture(app, image=images[0])
#set picture size    
picture.width=app.width-100
picture.height=app.height-100


#Time based loop
picture.repeat(2000, slideShow)


#Buttons to change slides 
Back_button = PushButton(app, text='Back',command = lambda:slide_change(-1))
Back_button.text_color='white'

Next_button = PushButton(app, text='Next',command = lambda:slide_change(1))
Next_button.text_color='white'


app.display()

What I'm trying to do

1. Move between slides on button press
2. Reset time after slide change ( 2 seconds per slide)

What I'm using

1. Python 3.7.9
2. Guizero 1.3.0

Answer 1

from guizero import *
app = App(bg='#121212',title='Guizero - slide show',width=500,height=500)

#list of images
images = ["img1.jpg", "img2.png", "img3.jpg", "img4.jpg"]

#sets what slide to start with
current_slide=0
time_per_slide=2000

#changes current slide displayed
def slideShow():
    global current_slide
    if len(images)-1>current_slide:
        current_slide+=1
        picture.image=images[current_slide] 
    else:
        current_slide=0
        picture.image=images[current_slide]

#Function runs to change slide on button push
def nextImage():
    global current_slide
    if current_slide < len(images)-1: 
            current_slide+=1     
    else: 
        current_slide=0
    picture.image=images[current_slide]
    app.cancel(slideShow)
    #Restarts slide show
    picture.repeat(time_per_slide, slideShow)
    

def previousImage():
    global current_slide
    if current_slide > 0:
      current_slide-=1      
    
    else:
        current_slide=len(images)-1    
    picture.image=images[current_slide]
    app.cancel(slideShow)
    #Restarts slide show
    picture.repeat(time_per_slide, slideShow)
    
    
#starter image    
picture = Picture(app, image=images[0])
#set picture size    
picture.width=app.width-100
picture.height=app.height-100


#Time based loop
picture.repeat(time_per_slide, slideShow)


#Buttons to change slides 
Back_button = PushButton(app, text='Back', command =previousImage)
Back_button.text_color='white'


Next_button = PushButton(app, text='Next',command =nextImage)
Next_button.text_color='white'

app.when_closed=quit
app.display()