[FIXED] javafx column in tableview auto fit size

Issue

afaik The TableView in javafx have 2 column resize policies: CONSTRAINED_RESIZE_POLICY and UNCONSTRAINED_RESIZE_POLICY, but I want columns is resized to fit the content of theirs cells I think it's a simple problem in other platform (like datagridview in C#) but can not resolve

Solution

After 3 years I come back to this problem again, some suggestions are calculating the size of text of data in each cell (it's complicated depending on font size, font family, padding...)

But I realize that when I click on the divider on table header, it's resized fit to content as I want. So I dig into JavaFX source code I finally found resizeColumnToFitContent method in TableViewSkin, but it is protected method, we can resolve by reflection:

import com.sun.javafx.scene.control.skin.TableViewSkin;
import javafx.scene.control.Skin;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class GUIUtils {
    private static Method columnToFitMethod;

    static {
        try {
            columnToFitMethod = TableViewSkin.class.getDeclaredMethod("resizeColumnToFitContent", TableColumn.class, int.class);
            columnToFitMethod.setAccessible(true);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        }
    }

    public static void autoFitTable(TableView tableView) {
        tableView.getItems().addListener(new ListChangeListener<Object>() {
            @Override
            public void onChanged(Change<?> c) {
                for (Object column : tableView.getColumns()) {
                    try {
                        columnToFitMethod.invoke(tableView.getSkin(), column, -1);
                    } catch (IllegalAccessException | InvocationTargetException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }
}

Note that we call "tableView.getItems()" so we have to call this function after setItems()

Answered By - yelliver
Answer Checked By - Robin (JavaFixing Admin)