Region Capture

## Why it matters

A full-page extraction of 400 links is noise when you only want 18 from the nav menu. Drag a box around the nav. Extract once. Export. Done. Selecting by geometry works everywhere without needing to read HTML or class names. No Inspector open, no CSS knowledge required.

It's also faster than building a complex filter. If you need just the footer links or the sidebar's "related articles" block, region capture is the quickest path.

## How it works

Region capture is a geometric filter. Every link gets tested against your rectangle. If any part of the link overlaps the box you drew, it's in the capture. Wrapped inline text links, which break across lines, get handled correctly without special cases.

You open the region mode, drag a rectangle on the page with your mouse, and Scalpel Links collects every link inside. The popup shows you the count and a preview. You can draw again to refine the region, or accept it and export.

The region stays persistent. Close the popup and re-open it, and the region is still there at the same position with the same links. A badge on the tab shows you a region is pending, so you don't forget it's active.

## What does not matter

Region capture doesn't read page structure. It doesn't know that something is a "nav" or a "sidebar". It only cares about geometry: the rectangle you drew. This is actually a strength, because it works on any layout. You don't need CSS class names or semantic HTML tags.

Also, the region doesn't update if the page reloads or if elements shift. It stays fixed to the coordinates where you drew it. If the page layout changes, you clear the region and draw a new one.

## Code example

// Scalpel Links stores the region as pixel coordinates
const region = {
  x: 120,
  y: 300,
  width: 400,
  height: 250
};

// Every link's bounding rect is tested against the region
function linkIsInRegion(linkElement, region) {
  const rect = linkElement.getBoundingClientRect();
  
  // Check if the link's rectangle overlaps the region
  return !(
    rect.right < region.x ||
    rect.left > region.x + region.width ||
    rect.bottom < region.y ||
    rect.top > region.y + region.height
  );
}

// Example: a link in the footer
const footerLink = document.querySelector('a[href="/contact"]');
const isInRegion = linkIsInRegion(footerLink, region);
// => true (footer link overlaps the box)
Copy

## How Scalpel Links shows it

Open Scalpel Links and look for the "Region" button in the popup toolbar. Click it, then drag a box on the page. Every link inside the box is highlighted. The popup counts them and shows a preview. Click "Clear" to reset if you want the full page again, or export to download just the links in your region.