/**
* Continues dragging a piece.
*
* @see java.awt.event.MouseMotionListener#mouseDragged(java.awt.event.MouseEvent)
*/
@Override
public void mouseDragged(MouseEvent e) {
int x;
int y;
if (pieceBeingDragged == null) return;
// Don't allow drag outside board boundaries
int maxX = board.columnToX(board.getColumns() - 1);
int maxY = board.rowToY(board.getRows() - 1);
x = e.getX() - board.getCellWidth() / 2;
if (x < 0) {
x = 0;
} else {
if (x > maxX) x = maxX;
}
y = e.getY() - board.getCellHeight() / 2;
if (y < 0) {
y = 0;
} else {
if (y > maxY) y = maxY;
}
pieceBeingDragged.x = x;
pieceBeingDragged.y = y;
// Track mouse movement
pieceBeingDragged.setChanged();
pieceBeingDragged.notifyObservers();
}
/**
* When the mouse button is pressed over a draggable piece, begins the dragging process. Only
* one piece can be dragged at a time.
*
* @see java.awt.event.MouseListener#mousePressed(java.awt.event.MouseEvent)
*/
@Override
public void mousePressed(MouseEvent e) {
board.setSelectedSquare(board.yToRow(e.getY()), board.xToColumn(e.getX()));
Piece chosenPiece = board.findPiece(e.getX(), e.getY());
if (chosenPiece == null) {
return;
}
if (chosenPiece.isSelectable()) {
board.setSelectedPiece(chosenPiece);
}
if (pieceBeingDragged != null) {
return; // can only drag one piece at a time
}
if (!chosenPiece.draggable) {
return;
}
pieceBeingDragged = chosenPiece;
board = pieceBeingDragged.board;
pieceBeingDragged.moving = true;
board.moveToTop(pieceBeingDragged);
}
/**
* Terminates the drag process, putting the dragged piece in the nearest square.
*
* @see java.awt.event.MouseListener#mouseReleased(java.awt.event.MouseEvent)
*/
@Override
public void mouseReleased(MouseEvent e) {
if (pieceBeingDragged == null) return;
Rectangle oldRect = pieceBeingDragged.getRectangle();
Rectangle newRect = oldRect;
int newRow = board.yToRow(pieceBeingDragged.y + board.getCellHeight() / 2);
int newColumn = board.xToColumn(pieceBeingDragged.x + board.getCellWidth() / 2);
if (pieceBeingDragged.canMoveTo(newRow, newColumn)) {
pieceBeingDragged.changePosition(newRow, newColumn);
}
pieceBeingDragged.moving = false;
newRect = pieceBeingDragged.getRectangle();
pieceBeingDragged.redraw(pieceBeingDragged.enlarge(oldRect.union(newRect)));
board.dragEvent.reportEvent(pieceBeingDragged);
pieceBeingDragged = null;
}