Get the number of rows in a JavaFX GridPane?

Question

I initialized a GridPane through SceneBuilder and inside the controller I want to conditionally add a row to the GridPane. I do not want to store an int for how many rows I initialized, I want to be able to get the number of rows from the GridPane object. Is that possible?

score 11 · Accepted Answer · edited Sep 01 '15 at 09:51

11

Hej j will, try this method:

private int getRowCount(GridPane pane) {
        int numRows = pane.getRowConstraints().size();
        for (int i = 0; i < pane.getChildren().size(); i++) {
            Node child = pane.getChildren().get(i);
            if (child.isManaged()) {
                Integer rowIndex = GridPane.getRowIndex(child);
                if(rowIndex != null){
                    numRows = Math.max(numRows,rowIndex+1);
                }
            }
        }
        return numRows;
    }

This worked for me.

Patrick

edited Sep 01 '15 at 09:51

Michael Stauffer

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answered Dec 24 '13 at 21:06

Patrick

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2

Isn't rowIndex and rowEnd same numbers? Both are obtained with GridPane.getRowIndex(child). – Xdg Jan 03 '15 at 13:51
Yeah this doesn't work when I prorammatically add rows to a gridpane it still shows the initial row count, so it has issues – user176495 May 01 '17 at 04:16
I could have a valid GridPane with a non-empty set of rows, then call getRowConstraints() which is a list, call clear() to clear this list to remove all constraints and then when I call your getRowCount() get a return value of 0 even though the grid still has the same number of rows. – Graham Seed Jun 06 '23 at 16:21

score 7 · Answer 2 · answered Oct 01 '16 at 13:30

7

In my case I used Java Reflections ( GridPane.java has private method getNumberOfRows() ):

Method method = gridPane.getClass().getDeclaredMethod("getNumberOfRows");
method.setAccessible(true);
Integer rows = (Integer) method.invoke(gridPane);

answered Oct 01 '16 at 13:30

Vova Perebykivskyi

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this works after I have added rows in code otherwise all I get is the initial allocation, which is dumb, poor form from the designers of the GridPane class – user176495 May 01 '17 at 04:19

score 3 · Answer 3 · answered Dec 10 '17 at 10:51

3

With java 9, you can do this:

myGridPane.getRowCount();

answered Dec 10 '17 at 10:51

Muzib

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I believe this returns the row index of the element with the largest row index, so if you have gaps between rows, this doesn't return the number of rows. – Jack J Aug 23 '20 at 20:46

score 0 · Answer 4 · answered Feb 20 '20 at 20:25

0

This works for me

GridPane.getRowConstraints().size()

answered Feb 20 '20 at 20:25

Tarkhan

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Get the number of rows in a JavaFX GridPane?

4 Answers4