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This is a backport of OpenJFX 8 to run on Java 7.
The newest version!
/*
* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package javafx.scene;
import java.util.Collection;
import javafx.beans.DefaultProperty;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.BooleanPropertyBase;
import javafx.collections.ObservableList;
/**
* A {@code Group} node contains an ObservableList of children that
* are rendered in order whenever this node is rendered.
*
* A {@code Group} will take on the collective bounds of its children and is
* not directly resizable.
*
* 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.
*
* 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!).
*
*
Group Example:
*
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);
}
* @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 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 getChildren() {
return super.getChildren();
}
@Override
protected double computePrefWidth(double height) {
if (isAutoSizeChildren()) {
return super.computePrefWidth(height);
} else {
return getLayoutBounds().getWidth();
}
}
@Override
protected double computePrefHeight(double width) {
if (isAutoSizeChildren()) {
return super.computePrefHeight(width);
} else {
return getLayoutBounds().getHeight();
}
}
/**
* 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.
*
* @param height This parameter is ignored by Group
* @return The layout bounds width
*/
@Override public double prefWidth(double height) {
return getLayoutBounds().getWidth();
}
/**
* 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.
*
* @param width This parameter is ignored by Group
* @return The layout bounds height
*/
@Override public double prefHeight(double width) {
return getLayoutBounds().getHeight();
}
@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();
}
}
}