JAVAFX BASICS - Introduction to Java Programming: Comprehensive Version - page 552

14.19

✓ ✓

How do you create an Image from a URL or a filename?

Check

14.20

Point

How do you create an ImageView from an Image , or directly from a file or a URL?

14.21

Can you set an Image to multiple ImageView ? Can you display the same ImageView
multiple times?

14.10 Layout Panes
JavaFX provides many types of panes for automatically laying out nodes in a desired
location and size.

Key
Point

JavaFX provides many types of panes for organizing nodes in a container, as shown in
Table 14.1. You have used the layout panes Pane , StackPane , and HBox in the preceding
sections for containing nodes. This section introduces the panes in more details.

VideoNote
Use layout panes

T ABLE 14.1 Panes fo r Containing and Organizing Nodes

Class Description

Base class for layout panes. It contains the getChildren() method for
returning a list of nodes in the pane.

Pane

StackPane Places the nodes on top of each other in the center of the pane.

FlowPane Places the nodes row-by-row horizontally or column-by-column vertically.

Places the nodes in the cells in a two-dimensional grid.

GridPane

BorderPane Places the nodes in the top, right, bottom, left, and center regions.

HBox Places the nodes in a single row.

VBox Places the nodes in a single column.

You have used the Pane in Listing 14.4, ShowCircle.java. A Pane is usually used as a
canvas for displaying shapes. Pane is the base class for all specialized panes. You have used
a specialized pane StackPane in Listing 14.3, ButtonInPane.java. Nodes are placed in the
center of a StackPane . Each pane contains a list for holding nodes in the pane. This list is an
instance of ObservableList , which can be obtained using pane's getChildren() method.
You can use the add(node) method to add an element to the list, use addAll(node1,
node2, ...) to add a variable number of nodes to the pane.

ObservableList
getChildren()

14.10.1 FlowPane
FlowPane arranges the nodes in the pane horizontally from left to right or vertically
from top to bottom in the order in which they were added. When one row or one column
is filled, a new row or column is started. You can specify the way the nodes are placed
horizontally or vertically using one of two constants: Orientation.HORIZONTAL or
Orientation.VERTICAL . You can also specify the gap between the nodes in pixels. The
class diagram for FlowPane is shown in Figure 14.15.
Data fields alignment , orientation , hgap , and vgap are binding properties. Each
binding property in JavaFX has a getter method (e.g., getHgap() ) that returns its value, a
setter method (e.g., sethGap(double) ) for setting a value, and a getter method that returns
the property itself (e.g., hGapProperty() ). For a data field of ObjectProperty<T> type,
the value getter method returns a value of type T and the property getter method returns a
property value of type ObjectProperty<T> .