Got it, let's figure out how to get multi-selection comment toggling working in QScintilla. I’ve built this feature before, so here’s a practical, tested approach with code you can adapt to your existing implementation:

Core Approach #

The key here is to handle each selected block individually—QScintilla’s default comment commands only target the active selection by default. We’ll cover two robust methods: one that leverages QScintilla’s native lexer-aware logic (best for most cases) and a custom line-based toggle for full control over comment syntax.

Method 1: Lexer-Aware Native Toggle (Recommended) #

This method uses QScintilla’s built-in SCI_COMMENTTOGGLE command, which automatically adapts to your active lexer (e.g., // for C++, # for Python). We just need to loop through each selected block, set it as the active selection, toggle comments, then restore the user’s original cursor position.

from PyQt5.Qsci import QsciScintilla

def toggle_multiselect_comments(self):
    # Replace with your QScintilla widget instance
    editor = self.your_scintilla_widget
    
    # Save original cursor/anchor to avoid disrupting the user's workflow
    original_cursor = editor.cursorPosition()
    original_anchor = editor.anchor()
    
    # Process selections in reverse order to prevent position shifts when modifying text
    for i in reversed(range(editor.selections())):
        # Set the current selection to the i-th selected block
        start = editor.selectionNStart(i)
        end = editor.selectionNEnd(i)
        editor.setSelection(start, end)
        
        # Trigger native comment toggle (uses the lexer's built-in comment rules)
        editor.SendScintilla(QsciScintilla.SCI_COMMENTTOGGLE)
    
    # Restore the original cursor position and anchor
    editor.setCursorPosition(original_cursor)
    editor.setAnchor(original_anchor)

Key Details: #

• Reverse Order Processing: Modifying upper lines first can shift the position of lower selections. Processing from bottom to top avoids this issue entirely.
• Lexer Compatibility: Works with any QScintilla lexer out of the box—no hardcoding comment syntax needed.
• State Preservation: Saving and restoring the cursor/anchor ensures the user doesn’t lose their place after the toggle.

Method 2: Custom Line-Based Toggle (For Full Control) #

If you need custom comment syntax (e.g., non-standard languages or project-specific rules), use this line-by-line approach. It checks each line in the selected blocks and toggles comments manually.

def toggle_custom_multiselect_comments(self):
    editor = self.your_scintilla_widget
    # Replace with your desired comment prefix (e.g., "# " for Python, "-- " for Lua)
    comment_prefix = "// "
    comment_len = len(comment_prefix)
    
    # Get all selections, reversed to avoid position shifts
    selections = [
        (editor.selectionNStart(i), editor.selectionNEnd(i)) 
        for i in range(editor.selections())
    ]
    selections.reverse()
    
    for start_pos, end_pos in selections:
        # Convert cursor positions to line numbers
        start_line = editor.lineFromPosition(start_pos)
        end_line = editor.lineFromPosition(end_pos)
        
        # Process each line in the selected range
        for line_num in range(start_line, end_line + 1):
            line_start = editor.positionFromLine(line_num)
            line_text = editor.text(line_num)
            
            # Check if the line is already commented (ignoring leading whitespace)
            is_commented = line_text.lstrip().startswith(comment_prefix.strip())
            
            if is_commented:
                # Remove the comment prefix
                comment_start_idx = line_text.find(comment_prefix)
                if comment_start_idx != -1:
                    new_line = line_text[:comment_start_idx] + line_text[comment_start_idx + comment_len:]
                    editor.replaceLine(line_num, new_line)
            else:
                # Add the comment prefix at the start of the line
                editor.insertAt(comment_prefix, line_start)

Key Details: #

• Custom Syntax Support: Ideal for niche languages or projects with unique comment rules.
• Line-Level Control: Toggles comments for entire lines even if only part of the line is selected (adjust the logic if you want to target only the selected text).

Integrate with a Keyboard Shortcut #

Bind the toggle function to a familiar shortcut like Ctrl+/ to make it accessible:

from PyQt5.QtGui import QKeySequence
from PyQt5.QtWidgets import QShortcut

# Bind Ctrl+/ to trigger the comment toggle
shortcut = QShortcut(QKeySequence("Ctrl+/"), self)
shortcut.activated.connect(self.toggle_multiselect_comments)

内容的提问来源于stack exchange，提问作者BPL