JavaFX: GridPane Overview

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The

GridPane
class creates a JavaFX layout pane which places controls based on a column and row position. The grid contained in this layout is not predefined. It creates columns and rows as each control is added. This allows the grid to be completely flexible in its design.

Nodes can be placed in each cell of the grid and can span multiple cells either vertically or horizontally. By default the rows and columns will be sized to fit their content - that is the widest child node defines the column width and the tallest child node the row height. 

Import Statement

import javafx.scene.layout.GridPane;

Constructors

The

GridPane
class has one constructor which does not accept any arguments:
GridPane playerGrid = new GridPane();

Useful Methods

Child nodes are added to the

GridPane
using the add method specifying the node to be added with the column and row index:
 //Place the Text control in column 1, row 8
Text rank4 = new Text("4");
playerGrid.add(rank4, 0,7);

Note: The column and row index starts at 0. So the first cell positioned at column 1, row 1 has an index of 0, 0.

Child nodes can also span multiple columns or rows. This can be specified in the

add
method by adding the number of columns and rows to span to the end of the arguments passed:
//Here the Text control is spanning 4 columns and 1 row
Text title = new Text("Top Scorers in English Premier League");
playerGrid.add(title, 0,0,4,1);

Child nodes contained within the

GridPane
can have their alignment along the horizontal or vertical axis by using the
setHalignment
and
setValignment
methods:
 GridPane.setHalignment(goals4, HPos.CENTER);

Note: The

VPos
enum contains four constant values to define the vertical position:
BASELINE
,
BOTTOM
,
CENTER
and
TOP
. The
HPos
enum only contains three values for the horizontal position:
CENTER
,
LEFT
and
RIGHT

The padding of child nodes can also be set by using the

setPadding
method. This method takes the child node being set and
Insets
object defining the padding:
 //set the padding for all the cells in the GridPane
playerGrid.setPadding(new Insets(0, 10, 0, 10));

The spacing between the columns and rows can be defined by using the

setHgap
and
setVgap
methods:
 playerGrid.setHgap(10);
playerGrid.setVgap(10);

The

setGridLinesVisible
method can be very useful in seeing where the grid lines are being drawn:
 playerGrid.setGridLinesVisible(true);

Usage Tips

If two nodes are set to be displayed in the same cell then they will overlap in the JavaFX scene. 

Columns and rows can be set to a preferred width and height through the use of

RowConstraints
and
ColumnConstraints
. These are separate classes that can be used to control the size. Once defined they are added to the
GridPane
by using the
getRowConstraints().addAll
and
getColumnConstraints().addAll
methods.
GridPane
objects can be styled using JavaFX CSS. All the CSS properties defined under
Region
can be used.

To see the

GridPane
layout in action have a look at the GridPane Example Program. It shows how to place
Text
controls in a table format by defining uniform rows and columns.