Method HandleAbsolutePositionChange

src/SFGUI/Canvas.cpp:300–341

}

void Canvas::HandleAbsolutePositionChange() {
	auto position = Widget::GetAbsolutePosition();

	auto parent = GetParent();

	sf::Vector2f parent_position( 0.f, 0.f );

	while( parent ) {
		if( parent->GetName() == "Viewport" ) {
			// Try to get the first ancestor of the viewport that is not a viewport itself.
			// Add up all allocations while searching.
			Container::PtrConst viewport_parent = parent->GetParent();

			while( viewport_parent && viewport_parent->GetName() == "Viewport" ) {
				parent_position += viewport_parent->GetAllocation().position;

				viewport_parent = viewport_parent->GetParent();
			}

			if( !viewport_parent || ( viewport_parent->GetName() == "Viewport" ) ) {
				parent_position = sf::Vector2f( 0.f, 0.f );
				break;
			}

			parent_position += viewport_parent->GetAbsolutePosition();
			parent_position += parent->GetAllocation().position;

			break;
		}

		parent = parent->GetParent();
	}

	m_custom_viewport->SetDestinationOrigin(
		sf::Vector2f(
			std::floor( parent_position.x + position.x + .5f ),
			std::floor( parent_position.y + position.y + .5f )
		)
	);

	Invalidate();
}

const std::string& Canvas::GetName() const {
	static const std::string name( "Canvas" );