Method getKeyFromMouse

src/gui/PianoView.cpp:328–372

gets the key from the given mouse-position ! \brief Get the key from the mouse position in the piano display * * First we determine it roughly by the position of the point given in * white key widths from our start. We then add in any black keys that * might have been skipped over (they take a key number, but no 'white * key' space). We then add in our starting key number. * * We the

 *  \param _p The point that the mouse was pressed.
 */
int PianoView::getKeyFromMouse( const QPoint & _p ) const
{
	int offset = _p.x() % PW_WHITE_KEY_WIDTH;
	if( offset < 0 ) offset += PW_WHITE_KEY_WIDTH;
	int key_num = ( _p.x() - offset) / PW_WHITE_KEY_WIDTH;

	for( int i = 0; i <= key_num; ++i )
	{
		if ( Piano::isBlackKey( m_startKey+i ) )
		{
			++key_num;
		}
	}
	for( int i = 0; i >= key_num; --i )
	{
		if ( Piano::isBlackKey( m_startKey+i ) )
		{
			--key_num;
		}
	}

	key_num += m_startKey;

	// is it a black key?
	if( _p.y() < PIANO_BASE + PW_BLACK_KEY_HEIGHT )
	{
		// then do extra checking whether the mouse-cursor is over
		// a black key
		if( key_num > 0 && Piano::isBlackKey( key_num-1 ) &&
			offset <= ( PW_WHITE_KEY_WIDTH / 2 ) -
					( PW_BLACK_KEY_WIDTH / 2 ) )
		{
			--key_num;
		}
		if( key_num < NumKeys - 1 && Piano::isBlackKey( key_num+1 ) &&
			offset >= ( PW_WHITE_KEY_WIDTH -
					PW_BLACK_KEY_WIDTH / 2 ) )
		{
			++key_num;
		}
	}

	// some range-checking-stuff
	return tLimit( key_num, 0, NumKeys - 1 );
}