/**
* Moves this piece to a new position on the board.
*
* @param newRow The destination row.
* @param newColumn The destination column.
* @return <code>false</code> if the destination is not a legal board position, or if the piece is
* already moving.
*/
public boolean moveTo(int newRow, int newColumn) {
if (!board.isLegalPosition(newRow, newColumn)) return false;
if (moving) return false;
int startX = board.columnToX(column);
int startY = board.rowToY(row);
int finishX = board.columnToX(newColumn);
int finishY = board.rowToY(newRow);
int changeInX = finishX - startX;
int changeInY = finishY - startY;
Rectangle oldRect = getRectangle();
Rectangle newRect = new Rectangle(oldRect);
// compensate for squares being slightly different sizes
oldRect.width += 2;
newRect.width += 2;
oldRect.height += 2;
newRect.height += 2;
// Move smoothly towards new position
moving = true;
board.moveToTop(this);
int deltaRow = Math.abs(row - newRow);
int deltaColumn = Math.abs(column - newColumn);
int distance = Math.max(deltaRow, deltaColumn) + Math.min(deltaRow, deltaColumn) / 2;
int numberOfSteps = distance * FRAME_RATE / getSpeed();
for (int i = 1; i <= numberOfSteps; i++) {
oldRect.x = x;
oldRect.y = y;
x = startX + (i * changeInX) / numberOfSteps;
y = startY + (i * changeInY) / numberOfSteps;
newRect.x = x;
newRect.y = y;
board.getJPanel().paintImmediately(oldRect.union(newRect));
// redraw(oldRect.union(newRect));
try {
Thread.sleep(PAUSE_MS);
} catch (InterruptedException e) {
/* Deliberately empty */
}
}
moving = false;
if (canMoveTo(newRow, newColumn)) {
changePosition(newRow, newColumn);
}
redraw(oldRect.union(newRect));
return true;
}
/**
* 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);
}
/**
* Ensures that this piece will be drawn on top of any other pieces in the same location on the
* board.
*/
public void moveToTop() {
if (board != null) {
board.moveToTop(this);
}
}
