When I set the GridLayout to the JPanel and then add something, it is added subsequently in the "text order" (from left to right, from top to bottom). But I want to add an element to a specific cell (in the i-th row in the j-th column). Is it possible?
No, you can't add components at a specific cell. What you can do is add empty JPanel objects and hold on to references to them in an array, then add components to them in any order you want.
Something like:
int i = 3;
int j = 4;
JPanel[][] panelHolder = new JPanel[i][j];
setLayout(new GridLayout(i,j));
for(int m = 0; m < i; m++) {
for(int n = 0; n < j; n++) {
panelHolder[m][n] = new JPanel();
add(panelHolder[m][n]);
}
}
Then later, you can add directly to one of the JPanel objects:
panelHolder[2][3].add(new JButton("Foo"));