colordropper.py

"""
    Color Eyedropper

    Author: Israel Dryer
    Modified: 2020-06-29

    Instructions:
        > Hover over the color you want to inspect.
        > Scroll the mouse wheel to zoom in or out.
        > Left-click to save color to clipboard and exit the program.
        > Right-click to toggle between HEX and RGB color formats.

    NOTES: There is a bug in Tkinter that prevents the Tk clipboard from transferring to the system
    clipboard when the window is destroyed, at least on Windows. There are a few work-arounds for 
    this, but none of them worked for me. Thus, I am forced to use pyperclip to implement this 
    functionality when the window is destroyed. ---> https://bugs.python.org/issue23760
"""
import tkinter as tk
from tkinter import ttk
from PIL import ImageGrab, ImageTk, Image
import pyperclip

class ColorDropper(tk.Tk):

    def __init__(self):
        super().__init__()
        self.wm_attributes('-fullscreen', 'true')
        self.canvas = tk.Canvas(self, cursor='plus')
        self.img_data = ImageGrab.grab()
        self.img = ImageTk.PhotoImage(self.img_data)
        self.mode = 'rgb'
        self.zoom = 2
        self.canvas.create_image(0, 0, image=self.img, anchor='nw')
        self.canvas.pack(fill='both', expand='yes')

        # event binding
        self.bind("<Motion>", self.on_motion)
        self.bind("<Button-1>", self.on_left_click)
        self.bind("<Button-3>", self.on_right_click)
        self.bind("<MouseWheel>", self.on_mouse_scroll) 

        # initial setup
        self.snip = None
        self.box_data = None
        self.box_img = None        
        self.after(50, self.show_toplevel)               

    def on_mouse_scroll(self, event):
        delta = event.delta / -120
        if delta > 0 and self.zoom < 10:
            self.zoom += delta
        elif delta < 0 and self.zoom > 0:
            self.zoom += delta
        self.on_motion()

    def on_left_click(self, event):
        color = self.snip.color_var.get()
        pyperclip.copy(color)
        self.destroy()
        
    def on_right_click(self, event):
        """Callback for right-click event. Toggle between hex and rgb color mode"""
        self.mode = 'hex' if self.mode == 'rgb' else 'rgb'
        self.on_motion()

    def on_motion(self, event=None):
        """Callback for mouse motion"""
        # get current mouse position
        x, y = self.winfo_pointerxy()
        # move snip window
        self.snip.geometry(f'+{x+50}+{y-25}')
        # update the snip image
        bbox = (x-self.zoom, y-self.zoom, x+self.zoom+1, y+self.zoom+1)
        self.box_data = self.img_data.crop(bbox).resize((50, 50), Image.BOX)
        self.box_img = ImageTk.PhotoImage(self.box_data)
        self.snip.canvas.create_image(0, 0, image=self.box_img, anchor='nw') 
        # update color text
        text_color = self.get_colors()
        self.snip.canvas.create_text(25, 25, text='+', fill=text_color)        

    def get_colors(self):
        """Extract the color from the target pixel"""
        if self.mode == 'rgb':
            r, g, b = self.box_data.getpixel((25, 25))
            rgb_color = f'({r},{g},{b})'
            self.snip.color_var.set(rgb_color)
            offset = 255 - max(r, g, b)
        else:
            r, g, b = self.box_data.getpixel((25, 25))
            hex_color = f'#{255-r:0>2x}{255-g:0>2x}{255-b:0>2x}'
            self.snip.color_var.set(hex_color)
            offset = 255 - max(r, g, b)
        return f'#{offset:0>2x}{offset:0>2x}{offset:0>2x}'

    def show_toplevel(self):
        """Display the toplevel Snip widget"""
        self.snip = Snip(self)
        self.on_motion()

    
class Snip(tk.Toplevel):

    def __init__(self, master):
        super().__init__(master, cursor='plus')
        self.transient(master)
        self.overrideredirect(True)
        self.geometry('180x50')
        self.lift()
        self.canvas = tk.Canvas(self, height=50, width=50)
        self.canvas.create_text(10, 10, text='+', fill='white')
        self.color_var = tk.StringVar()
        self.color_lbl = tk.Label(self, textvariable=self.color_var, font='-size 14')

        # add widget to window
        self.canvas.pack(side='left', fill='both')
        self.color_lbl.pack(side='left', fill='both', expand='yes')

if __name__ == "__main__":

    e = ColorDropper()
    e.mainloop()