Repaint/Refreshing AWT components

Question

Hi there,
I'm writing a chess game and for the GUI I've added 8x8 panels into a frame with a grid layout. Currently I'm just using labels for the pieces, in the middle of panels. I'm having a problem updating my GUI after a move has been made - a call to repaint() does nothing. I'm just using basic AWT.
I've also tried removeAllComponents() of the frame and adding them again with the updated data, but nothing happens - I just lose all my panels. Can anyone help please?
Many thanks!

Answer 1

scsi-boy :
I want to have a more general method of refreshing the
graphics so that later if/when I 'upgrade' to using
images (or whatever) instead of labels I can simplyi believe my suggestion is certainly compatible with that.
adapt it. I would think that calling setText for the
Labels would mean that I would have to give the
location of the panel as a parameter somewhere, and
would also have to remove the label where the piece
was previously (ie if a knight moves, I'd have to
target its destination to setText and remove it from
where it was).here is what i would do, please note that this will work with a variety
of implementations including using all Graphics later on or whatever.
// here we have a bunch of constants that represent the possible status
// of board postions
final int EMPTY_SPACE = 0;
final int B_KING = 1;
final int W_KING = 2;
final int B_QUEEN = 3;
final int W_QUEEN = 5;
final int B_BISHOP = 6;
final int W_BISHOP = 7;
final int B_KNIGHT = 8;
final int W_KNIGHT = 9;
final int B_ROOK = 10;
final int W_ROOK = 11;
final int B_PAWN = 12;
final int W_PAWN = 13;
// the game board is used to store the status of all the postitions in
// a game
int[][] gameBoard;
// the game display is the array of Labels that we use to present the
// board in our GUI
Label[][] gameDisplay;
// in the constructor;
gameBoard = new int[8][8];
for(int i=0;i<gameBoard.length;i++){
  for(int j=0;i<8;j++){
    gameBoard[i][j] = EMPTY_SPACE;
// here is where you would add the various pieces to gameBoard...
gameDisplay = new Label[8][8];
  Now wherever you interaction and logic are you can use a method. You
  can call this method repaint(); so that it will be compatible with
  what you do later.
public void repaint(){
  for(int i=0;i<gameBoard.length;i++){
    for(int j=0;j<8;j++){
      switch(gameBoard[i][j]){
        case B_KING:
          gameDisplayj].setText("Black King");
break;
case W_KING:
gameDisplay[i]j].setText("White King");
break;
case B_QUEEN:
gameDisplay[i]j].setText("Black Queen");
break;
// and so on and so forth... until
default:
gameDisplay[i]j].setText("");
anyway the above code is just a sample of how you can build this so you
can seperate out your logic from your GUI so you can change your GUI
later without hassle.
finally i would ask how are you changing the text on the screen. are you
creating new Labels and sticking them in the Panels? i suspect something
like this... don't do that. two reasons, one as you may have noticed it
doesn't work that way or you have to use some sort of hack to get it to
work and two it's more efficient in terms of memory and speed if you
re-use the awt ot Swing components by making use of methods such as
setText rather than creating new objects each time.
i hope you find this helpful.