Method GetHyperlink

src/textfile_gui.cpp:284–327

* Get the hyperlink at the given position. * @param pt The point to check. * @returns The hyperlink at the given position, or nullptr if there is no hyperlink. */

 * @returns The hyperlink at the given position, or nullptr if there is no hyperlink.
 */
const TextfileWindow::Hyperlink *TextfileWindow::GetHyperlink(Point pt) const
{
	if (this->links.empty()) return nullptr;

	/* Which line was clicked. */
	const int clicked_row = this->GetRowFromWidget(pt.y, WID_TF_BACKGROUND, WidgetDimensions::scaled.frametext.top, GetCharacterHeight(FS_MONO)) + this->GetScrollbar(WID_TF_VSCROLLBAR)->GetPosition();

	int visible_line = 0;
	auto it = std::ranges::find_if(this->lines, [&visible_line, clicked_row](const Line &l) {
		visible_line += l.num_lines;
		return (visible_line - l.num_lines) <= clicked_row && visible_line > clicked_row;
	});
	if (it == this->lines.cend()) return nullptr;

	size_t line_index = it - this->lines.cbegin();
	size_t subline = clicked_row - (visible_line - it->num_lines);
	Debug(misc, 4, "TextfileWindow check hyperlink: clicked_row={}, line_index={}, line.top={}, subline={}", clicked_row, line_index, visible_line - it->num_lines, subline);

	/* Find hyperlinks in this line. */
	std::vector<const Hyperlink *> found_links;
	for (const auto &link : this->links) {
		if (link.line == line_index) found_links.push_back(&link);
	}
	if (found_links.empty()) return nullptr;

	/* Build line layout to figure out character position that was clicked. */
	const Line &line = this->lines[line_index];
	Layouter layout(line.text, line.wrapped_width == 0 ? INT32_MAX : line.wrapped_width, FS_MONO);
	assert(subline < layout.size());
	ptrdiff_t char_index = layout.GetCharAtPosition(pt.x - WidgetDimensions::scaled.frametext.left, subline);
	if (char_index < 0) return nullptr;
	Debug(misc, 4, "TextfileWindow check hyperlink click: line={}, subline={}, char_index={}", line_index, subline, char_index);

	/* Found character index in line, check if any links are at that position. */
	for (const Hyperlink *link : found_links) {
		Debug(misc, 4, "Checking link from char {} to {}", link->begin, link->end);
		if (static_cast<size_t>(char_index) >= link->begin && static_cast<size_t>(char_index) < link->end) {
			Debug(misc, 4, "Returning link with destination: {}", link->destination);
			return link;
		}
	}

	return nullptr;
}

/**
 * Append the new location to the history, so the user can go back.