Method HandleMouseButtonEvent

src/SFGUI/Scale.cpp:67–124

}

void Scale::HandleMouseButtonEvent( sf::Mouse::Button button, bool press, int x, int y ) {
	if( button != sf::Mouse::Button::Left ) {
		return;
	}

	if( m_drag_offset ) {
		m_drag_offset.reset();
		m_dragging = false;
	}

	if( !GetAllocation().contains( sf::Vector2f( sf::Vector2( x, y ) ) ) ) {
		return;
	}

	if( press ) {
		if( !GetSliderRect().contains( sf::Vector2f( sf::Vector2( x, y ) ) - GetAllocation().position ) ) {
			Adjustment::Ptr adjustment( GetAdjustment() );

			auto minor_step = adjustment->GetMinorStep();
			auto range = adjustment->GetUpper() - adjustment->GetLower();
			auto steps = range / minor_step;
			auto needed_steps = 0.f;

			auto trough_position = 0.f;
			auto trough_length = 0.f;

			if( GetOrientation() == Orientation::HORIZONTAL ) {
				trough_position = static_cast<float>( x ) - ( GetAllocation().position.x + GetSliderRect().size.x / 2.f );
				trough_length = GetAllocation().size.x - GetSliderRect().size.x;
			}

			if( GetOrientation() == Orientation::VERTICAL ) {
				trough_position = static_cast<float>( y ) - ( GetAllocation().position.y + GetSliderRect().size.y / 2.f );
				trough_length = GetAllocation().size.y - GetSliderRect().size.y;
			}

			trough_position = std::min( trough_position, trough_length );

			auto trough_ratio = trough_position / trough_length;

			for( ; needed_steps < steps; needed_steps += 1.f ) {
				if( ( 1.f / steps ) * needed_steps > trough_ratio ) {
					break;
				}
			}

			needed_steps = std::max( needed_steps - 1.f, 0.f );

			adjustment->SetValue( needed_steps * minor_step );
		}

		m_dragging = true;
		m_drag_offset.reset( new sf::Vector2f(
				static_cast<float>( x ) - ( GetAllocation().position.x + GetSliderRect().position.x + GetSliderRect().size.x / 2.f ),
				static_cast<float>( y ) - ( GetAllocation().position.y + GetSliderRect().position.y + GetSliderRect().size.y / 2.f )
		) );
	}
}