how to retrieve all visible table section header views

Question

is there a way to get all the section header views that are visible?

something similar to UITableView\'s visibleCells instance method..

Answer 1

The solution by Benjamin Wheeler is a great Swift solution. I fixed an issue in it due to new Swift syntax, and modified it to match the .visibleCells property provided by the default UITableView implementation.

extension UITableView {

    /// The table section headers that are visible in the table view. (read-only)
    ///
    /// The value of this property is an array containing UITableViewHeaderFooterView objects, each representing a visible cell in the table view.
    ///
    /// Derived From: [http://stackoverflow.com/a/31029960/5191100](http://stackoverflow.com/a/31029960/5191100)
    var visibleSectionHeaders: [UITableViewHeaderFooterView] {
        get {
            var visibleSects = [UITableViewHeaderFooterView]()

            for sectionIndex in indexesOfVisibleSections() {
                if let sectionHeader = self.headerViewForSection(sectionIndex) {
                    visibleSects.append(sectionHeader)
                }
            }

            return visibleSects
        }
    }

    private func indexesOfVisibleSections() -> Array {
        // Note: We can't just use indexPathsForVisibleRows, since it won't return index paths for empty sections.
        var visibleSectionIndexes = Array()

        for (var i = 0; i < self.numberOfSections; i++) {
            var headerRect: CGRect?
            // In plain style, the section headers are floating on the top,
            // so the section header is visible if any part of the section's rect is still visible.
            // In grouped style, the section headers are not floating,
            // so the section header is only visible if it's actual rect is visible.
            if (self.style == .Plain) {
                headerRect = self.rectForSection(i)
            } else {
                headerRect = self.rectForHeaderInSection(i)
            }

            if headerRect != nil {
                // The "visible part" of the tableView is based on the content offset and the tableView's size.
                let visiblePartOfTableView: CGRect = CGRect(
                    x: self.contentOffset.x,
                    y: self.contentOffset.y,
                    width: self.bounds.size.width,
                    height: self.bounds.size.height
                )

                if (visiblePartOfTableView.intersects(headerRect!)) {
                    visibleSectionIndexes.append(i)
                }
            }
        }

        return visibleSectionIndexes
    }
}