JavaFX网格窗格和内容大小

Question

I've been trying to get a GridPane's content to behave regarding auto-size but I'm relatively new to JavaFX, so I've not had any success. Basically, each column is what appears to me to be a completely random size, and I have no idea how to make them grow correctly. If I try to set column constraints, the content sometimes disappears completely, sometimes it's just sized completely arbitrarily. Trying to bind preferred width to anything else also fails to work. I'm sure the error is mine, though. Here's my code (the contentHolder is a ScrollPane with vGrow set to ALWAYS):

    int row = 1;
    GridPane gridPane = new GridPane();
    for (List<IndexObject> stepList : search) {
        Label itemLabel = new Label();
        itemLabel.setText(String.valueOf(row));

        TreeItem<String> treeRoot = new TreeItem<>(stepList.get(0).getPath());
        for (int line = 1; line < stepList.size(); line++) {
            treeRoot.getChildren().add(new TreeItem<>(stepList.get(line).getPath()));
        }
        TreeView treeView = new TreeView();
        treeView.setShowRoot(true);
        treeView.setRoot(treeRoot);
        treeRoot.setExpanded(true);

        IndexObject lastObject = stepList.get(stepList.size() - 1);

        TextArea output = new TextArea();
        output.setText(lastObject.prettyPrint());

        gridPane.addRow(row, itemLabel, treeView, output);
        row++;
    }
    contentHolder.setContent(gridPane);

Everything up to the contentHolder is defined in fxml. Here's what it looks like. No entry has anywhere near the height that is automatically assigned, but all the widths are too small. What am I missing?

Answer 1

The answer is that the scroll pane does not automatically resize until you make it:

<ScrollPane VBox.vgrow="ALWAYS" fitToWidth="true">

at which point everything works as expected.