Working with pop up canvases - python-3.x

Trying to create a pop up canvas that will pop up when I hit the certain key combination and then it will display images that can be scrolled through using the arrow keys and then closed out with the escape key. This is all going on top of a canvas that has a map drawn on it that I can use the the arrow keys to move around the map. Since I'm having many issues with this that are all pretty much interrelated I figured I would just asking them all with one post instead of doing separate posts, it may come in very handy to have all the information in one place for other people as well.
Currently, I have tried several approaches to solve the problem, I do see one other possible option just a couple minutes ago since I finally got online this morning but it didn't seem to want to work.
Question 1: Where do you form the pop up canvas? In the original
def __init__(self, parent):
or do you normally wait until the time of the switch over to the pop up to form the pop canvas? I have tried it both ways and have seen problems with both approaches. Forming it at the start up causes the pop up to pop up on the screen right from the get go. I have seen on effbot.org that supposedly using the state='hidden' attribute exists but when I try to use it all I get is an error that says I can only use 'disabled' or 'normal'.
Question 2: So how do you hide the popup until you want to use it, if you create the pop up at the start of the program versus waiting until the pop up key combo is pushed?
I have tried sizing the pop up to 0x0 but I still see single pixel on the screen until I hit the key combo.
I have tried waiting until key combo is hit to bring up the pop up and that works fine until I get ready to change to the second image.
On effbot.org I saw and have tried several different combinations to try to 'disable' without destroying(which I don't want to do) the canvas underneath when the pop up comes up. The trouble I have is when I go and push an arrow key the underneath canvas still has the focus and it moves the map instead of change the image on the pop up. I have tried several of the effbot combinations...
self.canvas.config(state='disabled')
self.canvaspopup = Canvas(self, width=800, height=614)
self.canvaspopup.pack_propagate(0)
self.canvaspopup.place(x=284,y=52)
self.png = Label(self.canvaspopup)
self.png.pack()
self.canvaspopup.focus_set()
I have also tried
self.canvas.bind('<FocusOut>')
self.canvaspopup.bind('<FocusIn>')
And still no luck, the underneath canvas still has the focus and I'm still moving the map instead of advancing the image in the pop up. I am guessing given it was on the Events and Bindings page on effbot.org that I saw FocusIn/Out being talked about that I should put that in the .bind statement and not in the .config.
Question 3: How do I get the pop up to take the focus, pretty much should only need keyboard focus and no mouse focus?
I know I want to keep the pop up handy as I want to be able to click on the underlying map in different locations and have the program go to the internet and pull up data for those locations so the pop up is something that will be used several times throughout any one run of the program. I know from what I've seen I can use
self.canvaspopup.destroy()
But this destroys the canvas so I would have to recreate it again. So if I put the pop up creation at the beginning of the program...I'm screwed and can't recreate it. Which leads right back to Question 2.
Definitely a mess. I have most everything working fine, its just the interaction, and knowing the proper way of handling this kind of situation that has me stumped.

Since you are using place, you can use place_forget to hide the popup. For the focus, you use focus_set.
Here's an example:
import tkinter as tk
class PopupCanvas(tk.Canvas):
def __init__(self, parent, *args, **kwargs):
tk.Canvas.__init__(self, parent, *args, **kwargs)
self.parent = parent
self.text_item=self.create_text(10, 10, anchor="nw")
self.bind("<Left>", self.handle_left)
self.bind("<Right>", self.handle_right)
self.bind("<Escape>", self.hide)
def handle_left(self, event=None):
self.itemconfigure(self.text_item, text="You clicked left")
def handle_right(self, event=None):
self.itemconfigure(self.text_item, text="You clicked right")
def show(self, event=None):
self.place(relx=.5, rely=.5, anchor="center")
self.focus_set()
def hide(self, event=None):
self.place_forget()
self.parent.focus_set()
root = tk.Tk()
label = tk.Label(root, text="Press 'p' to pop up a canvas, <escape> to hide it\n" +
"Press left and right arrows when the popup is visible")
canvas = tk.Canvas(root, width=400, height=400)
popup = PopupCanvas(canvas, width=200, height=200, background="pink")
label.pack(side="top", fill="x")
canvas.pack(side="top", fill="both", expand=True)
canvas.focus_set()
canvas.bind("<p>", popup.show)
root.mainloop()

Related

Why does a borderless Kivy Window shift content down and to the right?

Using Kivy, I want to remove the default border from the App window (removing the close, minimize and maximize buttons). Based on the Kivy docs, I want to set the borderless value of my Window to True. However, doing so moves the content of my window down and to the right, exposing the black background color on the top and left sides of the window.
Screenshot of Window with borderless=False
Screenshot of Window with borderless=True
In the above images, the white within the window is coming from the Window.clearcolor, and the black in the borderless=True image is what I want to remove, or overlay with the rest of my content.
In the following snippet I have removed all the code that makes up the inner widgets of the kivy App, replacing them with an empty GridLayout to show where the content will be.
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.core.window import Window
class MyApp(App):
def build(self):
self.title = 'My App'
Window.clearcolor = (1, 1, 1, 1)
Window.size = (300, 430)
Window.borderless = True # This is what is being changed
return GridLayout()
if __name__ == '__main__':
MyApp().run()
I have read the answers to similar questions regarding removing the default Kivy window border and how to position a borderless Kivy window.
Can anyone help diagnose how to shift the contents of my window back to the upper left corner when borderless is set to True?
Note: This is my first Stackoverflow question, please let me know how to improve it if need be!
Well, I'm not sure what the exact issue was, but after troubleshooting several different things within PyCharm (where my original project files were held), on a whim I tried opening the same project with Sublime and the issue is no longer present. When I run the identical code in Sublime, I get the intended result:
Beautiful! Just how I wanted it. =) I'm sure I somehow goofed up the Kivy settings in Pycharm somehow without realizing it, maybe something with the builder strings? I'm honestly at a loss. But I suppose if by any off chance someone else comes across this, switch up your IDE for a clean slate and give it another go.

Weird white Stripe appearing next to tkinter scrollbar

So while 'designing' my tkinter application i noticed this white stripe appearing next to the scrollbar there:
It is not disappearing when the scrollbar gets to an active state but it is definetly part of the Scrollbar itself because there is nothing under it in my programm which has a white background.
It seems to appear no matter if I use grid or pack. In this case I use grid - here the little extract of my code:
class App(Tk):
def __init__(self):
#other stuff
self.hvf=hvFrame(self,sticky=EW,showfocus=S,bg='white',padx=5,pady=5)
self.hvf.grid(row=1,column=0,columnspan=2,sticky=NSEW,pady=5,padx=(0,5))
sb=Scrollbar(self,orient=VERTICAL,command=self.hvf.yview,bd=0,highlightthickness=0)
sb.grid(row=1,column=2,sticky=NSEW,pady=5)
self.hvf.config(yscrollcommand=sb.set)
If you ned more, then here you go. (Should not be executable for you because you do not have the extras file but you should still be able to understand it.)
EDIT:
A little reproduceable example:
from tkinter import Tk,Frame,Scrollbar,VERTICAL,NS
root = Tk()
frame = Frame(root,height=300,width=500)
frame.grid(row=0,column=0,padx=(0,5),pady=5)
sb = Scrollbar(root,orient=VERTICAL)
sb.grid(row=0,column=1,sticky=NS,pady=5)
root.mainloop()
After testing a few things like changing the windows theme or changing the root and frame background to black the while line still comes up. I cannot be 100% sure but I believe this is due to fact that tkinter on Windows pulls the scrollbar design from Windows itself and it is simply part of that design. It may be a design choice to give the scroll bar some visual depth. That said you cannot do anything to change the design of the scrollbar within a Windows environment so you as stuck with this unless you write a custom scrollbar.
Example code:
import tkinter as tk
root = tk.Tk()
root['bg'] = 'black'
frame = tk.Frame(root, height=300, width=500, background='black')
frame.grid(row=0, column=0)
sb = tk.Scrollbar(root, orient=tk.VERTICAL)
sb.grid(row=0, column=1, sticky=tk.NS)
root.mainloop()
Results from overlay of white and black backgrounds:
Below is the code I use for a custom scrollbar (but did not write myself). You can find the post where I got the code here.

binding keyboard events tkinter

Still quite new at python , i'm learning tkinter.
I would like to use keyboard events rather than mouse events for some fonction.
However keyboard events do not work although mouse events do.
here is a very simple example of what is not working. Using button 1 with the mouse and pressing key 'z on the keyboard should do the same, but the keyboard does nothing. I have tried to read tkinter documentation but didn't find the answer.
thanks for your help
from tkinter import *
class Pipi(Frame):
def __init__(self,master=None):
Frame.__init__(self,width=400,height=400,bg='red')
self.pack()
self.bind("<z>",self.do)
self.bind("<Button-1>", self.do)
def do(self,event):
print('la vie est belle')
root=Tk()
Pipi(root)
root.mainloop()
This is due to Frame widget not having the focus. With the mouse event, it works seemingly different. There can be a couple of workarounds:
Grabbing the focus before the event happens
binding to something else
To achieve the first, simply add:
self.focus_set()
somewhere inside __init__.
To achieve the second, replace:
self.bind("<z>",self.do)
with:
self.master.bind('<z>', self.do)

Make a Toplevel window take up the entire monitor space?

I'm trying to make a tkinter Toplevel window to go full screen and take up the entire monitor space (going over the task bar as well). I am able to do this with the Tk() using the code: window.attributes("-fullscreen", True). But I know you can't have two instances of Tk() so I need to use a Toplevel and root.attributes("-fullscreen", True) does not work with Toplevel.
The code I have in place at the moment to make the Toplevel fullscreen is this:
window = Toplevel()
w = window.winfo_screenwidth()
h = window.winfo_screenheight()
window.geometry("%dx%d+0+0" % (w,h))
But this does not even go into a proper fullscreen mode as the left side of the interface does not reach the edge of the screen.
How can I get a Toplevel window to take up the entire space of the screen like a Tk() window can?
I found a work around to this issue. What I did was I set the Tk() interface to take up the entire screen, and I placed a frame on top of it and made it fit the Tk(). That way I could put the desired widgets on the frame and when I'm done, destroy the frame and reset the size of the Tk() frame.
This is a possible way to solve fullscreen trouble:
finestra1= Toplevel()
wf1= finestra1.winfo_screenwidth()
hf1= finestra1.winfo_screenheight()
A = str(wf1)
B = str(hf1)
finestra1.geometry(A+"x"+B)

Python Tkinter Clickable Text?

I'm wondering if there's a way to make clickable text in Tkinter. Maybe like you would see on a title screen of a game, and where you hover your mouse over the text and it changes color/hightlights itself. All I need the click to do is execute another function.
Are either of these things possible? Thanks!
you are looking for tkinter's events:
tk_widget.bind("<Button-1>",CALLBACK)
The call back needs to take an event argument which is a dictionary containing information about what triggered the event.
This can run into issues with widgets that overlap such as windows in a canvas or labels sometimes triggering the callback for the window behind it.
For hovering the mouse over a widget the event is called "<Enter>" and moving mouse out of widget region is called "<Leave>" for highlighting text effect, if you just want to capture a click anywhere on a window then on the root call root.bind_all("<Button-1>",CALLBACK)
source: http://infohost.nmt.edu/tcc/help/pubs/tkinter/web/index.html
http://infohost.nmt.edu/tcc/help/pubs/tkinter/web/events.html
example:
try:
import tkinter as tk
except ImportError:
import Tkinter as tk
def change_case(event=None):
new_text = str.swapcase(lab["text"])
lab.config(text=new_text)
def red_text(event=None):
lab.config(fg="red")
def black_text(event=None):
lab.config(fg="black")
root = tk.Tk()
lab = tk.Label(root,text="this is a test")
lab.bind("<Button-1>",change_case)
lab.bind("<Enter>",red_text)
lab.bind("<Leave>",black_text)
lab.grid()
root.mainloop()
hope this helps :)

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