Got it, let's tackle your two Tkinter requirements step by step. I'll break down each feature with working code and explanations so you can follow along easily.

1. Mouse Wheel Vertical Scrolling for Multiple Text Areas #

By default, some Tkinter Text widgets might not respond to mouse wheel scrolling consistently across platforms, or you might want multiple text areas to scroll independently (or even in sync). Here's a straightforward implementation:

We'll create a reusable scroll handler function that adjusts the text widget's view based on the wheel input, then bind this function to each Text widget's <MouseWheel> event.

import tkinter as tk

def on_text_scroll(event, text_widget):
    # Normalize scroll delta across Windows/macOS/Linux
    delta = event.delta if hasattr(event, 'delta') else -event.num * 120
    text_widget.yview_scroll(int(-delta/120), "units")

root = tk.Tk()
root.title("Multiple Scrollable Text Areas")

# First Text Area
text1 = tk.Text(root, wrap="word")
text1.pack(side="left", fill="both", expand=True, padx=5, pady=5)
text1.bind("<MouseWheel>", lambda e: on_text_scroll(e, text1))
# Add sample content
for i in range(50):
    text1.insert("end", f"Line {i+1} for Text Area 1\n")

# Second Text Area
text2 = tk.Text(root, wrap="word")
text2.pack(side="right", fill="both", expand=True, padx=5, pady=5)
text2.bind("<MouseWheel>", lambda e: on_text_scroll(e, text2))
for i in range(50):
    text2.insert("end", f"Line {i+1} for Text Area 2\n")

root.mainloop()

Quick Notes: #

• The handler function fixes cross-platform scroll behavior (Windows uses event.delta, Linux relies on event.num).
• If you want the text areas to scroll in sync, just modify the handler to update both widgets instead of a single one.

2. Text Area with Left Line Number Sidebar (Synchronized Scrolling) #

To build a text area with a line number sidebar that scrolls perfectly in sync with the main text, we'll wrap both components in a container frame. We'll also dynamically update line numbers as the text changes and sync their scroll positions.

import tkinter as tk

class LineNumberText(tk.Frame):
    def __init__(self, parent, *args, **kwargs):
        super().__init__(parent)
        
        # Line number panel (disabled Text widget for clean alignment)
        self.line_numbers = tk.Text(self, width=4, padx=3, takefocus=0, border=0,
                                    background="#f0f0f0", state="disabled")
        self.line_numbers.pack(side="left", fill="y")
        
        # Main text area
        self.text = tk.Text(self, *args, **kwargs)
        self.text.pack(side="right", fill="both", expand=True)
        
        # Bind events for sync and line number updates
        self.text.bind("<MouseWheel>", self.on_scroll)
        self.text.bind("<Configure>", self.update_line_numbers)
        self.text.bind("<KeyRelease>", self.update_line_numbers)
        
        # Initialize line numbers
        self.update_line_numbers()
        
    def on_scroll(self, event):
        # Sync scroll position between text area and line numbers
        delta = event.delta if hasattr(event, 'delta') else -event.num * 120
        self.text.yview_scroll(int(-delta/120), "units")
        self.line_numbers.yview_scroll(int(-delta/120), "units")
        
    def update_line_numbers(self, event=None):
        # Refresh line count and update the sidebar
        line_count = self.text.get("1.0", "end-1c").count("\n") + 1
        
        self.line_numbers.config(state="normal")
        self.line_numbers.delete("1.0", "end")
        for line in range(1, line_count+1):
            self.line_numbers.insert("end", f"{line}\n")
        self.line_numbers.config(state="disabled")
        # Keep scroll positions aligned after update
        self.line_numbers.yview_moveto(self.text.yview()[0])

# Demo the custom widget
root = tk.Tk()
root.title("Text Area with Line Numbers")

text_panel = LineNumberText(root, wrap="word")
text_panel.pack(fill="both", expand=True, padx=5, pady=5)

# Add sample content
for i in range(100):
    text_panel.text.insert("end", f"This is line {i+1} of the main text area.\n")

root.mainloop()

Quick Notes: #

• The custom LineNumberText frame keeps everything organized and reusable.
• The line number panel uses a disabled Text widget to match the main text's vertical spacing automatically.
• Line numbers update whenever you type, resize the window, or scroll, so they're always accurate.

内容的提问来源于stack exchange，提问作者Syzio