/*
* Copyright (c) 2010, 2014, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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package javafx.scene;
import javafx.beans.
DefaultProperty;
import javafx.beans.property.
BooleanProperty;
import javafx.beans.property.
BooleanPropertyBase;
import javafx.collections.
ObservableList;
import javafx.geometry.
Bounds;
import java.util.
Collection;
/**
* A {@code Group} node contains an ObservableList of children that
* are rendered in order whenever this node is rendered.
* <p>
* A {@code Group} will take on the collective bounds of its children and is
* not directly resizable.
* <p>
* Any transform, effect, or state applied to a {@code Group} will be applied
* to all children of that group. Such transforms and effects will NOT be included
* in this Group's layout bounds, however if transforms and effects are set
* directly on children of this Group, those will be included in this Group's layout bounds.
* <p>
* By default, a {@code Group} will "auto-size" its managed resizable
* children to their preferred sizes during the layout pass to ensure that Regions
* and Controls are sized properly as their state changes. If an application
* needs to disable this auto-sizing behavior, then it should set {@link #autoSizeChildren}
* to {@code false} and understand that if the preferred size of the children
* change, they will not automatically resize (so buyer beware!).
*
* <p>Group Example:</p>
*
<PRE>
import javafx.scene.*;
import javafx.scene.paint.*;
import javafx.scene.shape.*;
import java.lang.Math;
Group g = new Group();
for (int i = 0; i < 5; i++) {
Rectangle r = new Rectangle();
r.setY(i * 20);
r.setWidth(100);
r.setHeight(10);
r.setFill(Color.RED);
g.getChildren().add(r);
}
</PRE>
* @since JavaFX 2.0
*/
@
DefaultProperty("children")
public class
Group extends
Parent {
/**
* Constructs a group.
*/
public
Group() { }
/**
* Constructs a group consisting of children.
*
* @param children children.
*/
public
Group(
Node...
children) {
getChildren().
addAll(
children);
}
/**
* Constructs a group consisting of the given children.
*
* @param children children of the group
* @throws NullPointerException if the specified collection is null
* @since JavaFX 8.0
*/
public
Group(
Collection<
Node>
children) {
getChildren().
addAll(
children);
}
/**
* Controls whether or not this {@code Group} will automatically resize any
* managed resizable children to their preferred sizes
* during the layout pass. If set to {@code false}, then the application is
* responsible for setting the size of this Group's resizable children, otherwise
* such nodes may end up with a zero width/height and will not be visible.
* This variable has no effect on content nodes which are not resizable (Shape, Text, etc).
*
* @defaultValue true
*/
private
BooleanProperty autoSizeChildren;
public final void
setAutoSizeChildren(boolean
value){
autoSizeChildrenProperty().
set(
value);
}
public final boolean
isAutoSizeChildren() {
return
autoSizeChildren == null ? true :
autoSizeChildren.
get();
}
public final
BooleanProperty autoSizeChildrenProperty() {
if (
autoSizeChildren == null) {
autoSizeChildren = new
BooleanPropertyBase(true) {
@
Override
protected void
invalidated() {
requestLayout();
}
@
Override
public
Object getBean() {
return
Group.this;
}
@
Override
public
String getName() {
return "autoSizeChildren";
}
};
}
return
autoSizeChildren;
}
/**
* Gets the list of children of this {@code Group}.
* @return the list of children of this {@code Group}.
*/
@
Override public
ObservableList<
Node>
getChildren() {
return super.getChildren();
}
/**
* @treatAsPrivate implementation detail
* @deprecated This is an internal API that is not intended for use and will be removed in the next version
*/
@
Deprecated
@
Override
protected
Bounds impl_computeLayoutBounds() {
layout(); // Needs to done prematurely, as we otherwise don't know the bounds of the children
return super.impl_computeLayoutBounds();
}
/**
* Group defines the preferred width as simply being the width of its layout bounds, which
* in turn is simply the sum of the positions & widths of all of its children. That is,
* the preferred width is the one that it is at, because a Group cannot be resized.
*
* Note: as the layout bounds in autosize Group depend on the Group to be already laid-out,
* this call will do the layout of the Group if necessary.
*
* @param height This parameter is ignored by Group
* @return The layout bounds width
*/
@
Override
public double
prefWidth(double
height) {
if (
isAutoSizeChildren()) {
layout();
}
final double
result =
getLayoutBounds().
getWidth();
return
Double.
isNaN(
result) ||
result < 0 ? 0 :
result;
}
/**
* Group defines the preferred height as simply being the height of its layout bounds, which
* in turn is simply the sum of the positions & heights of all of its children. That is,
* the preferred height is the one that it is at, because a Group cannot be resized.
*
* Note: as the layout bounds in autosize Group depend on the Group to be already laid-out,
* this call will do the layout of the Group if necessary.
*
* @param width This parameter is ignored by Group
* @return The layout bounds height
*/
@
Override
public double
prefHeight(double
width) {
if (
isAutoSizeChildren()) {
layout();
}
final double
result =
getLayoutBounds().
getHeight();
return
Double.
isNaN(
result) ||
result < 0 ? 0 :
result;
}
@
Override
public double
minHeight(double
width) {
return
prefHeight(
width);
}
@
Override
public double
minWidth(double
height) {
return
prefWidth(
height);
}
/**
* Group implements layoutChildren such that each child is resized to its preferred
* size, if the child is resizable. Non-resizable children are simply left alone.
* If {@link #autoSizeChildren} is false, then Group does nothing in this method.
*/
@
Override protected void
layoutChildren() {
if (
isAutoSizeChildren()) {
super.layoutChildren();
}
}
}