First, I am new to programming and this is my first major assignment in java and programming in general so if I am doing some incredibly stupid please tell me so I can correct the bad habit.
Anyway to the problem, I am currently trying to create a gridLayout that has a variable number of rows which will be filled with a label that has text that comes from a file. My problem is specifically on gridLayout were the labels that I do add and are constants seem to be disappearing into one giant cell. So far none of the reasearch I have done has lead to anything so I thought I may as well pose the question.
public void fillTimetablePane(JPanel pane){
int noOfRows = pref.getNoOFPeriods()+1;
pane.setLayout(new GridLayout(noOfRows,4));
pane.setBorder(BorderFactory.createLineBorder(Color.black));
JLabel label = new JLabel();
int i=0;
while (i<4){
switch (i) {
case 0: label.setText("Lesson");
break;
case 1: label.setText("Period");
break;
case 2: label.setText("Room");
break;
case 3: label.setText("Teacher");
break;
}
i++;
pane.add(label);
}
}
here is an image of what happens when I add run the following code: http://www.freeimagehosting.net/1hqn2
public void fillTimetablePane(JPanel pane){
int noOfRows = pref.getNoOFPeriods()+1;
pane.setLayout(new GridLayout(noOfRows,4));
pane.setBorder(BorderFactory.createLineBorder(Color.black));
//JLabel label = new JLabel(); // from here
int i=0; // V
while (i<4){ // V
JLabel label = new JLabel(); // to here
switch (i) {
case 0: label.setText("Lesson");
break;
case 1: label.setText("Period");
break;
case 2: label.setText("Room");
break;
case 3: label.setText("Teacher");
break;
}
i++;
pane.add(label);
}
}
Ok, why is it not working in your case but works fine in my case? The problem is that you add your label 4 times and change the text inbetween. In a Layout, a single component can only be existing once. So what happens is that when you add your label a second/third/fourth time, its location in the grid will be updated and not added again.
In my case, I actually create a new JLabel
in every iteration of the loop and therefore adding a different label to the JPanel
.
Hope this is clear enough. Just ask if something is not clear.