/* * Copyright (c) 2011, 2017, 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.layout; import com.sun.javafx.scene.layout.PaneHelper; import javafx.beans.DefaultProperty; import javafx.collections.ObservableList; import javafx.scene.Node; /** * Base class for layout panes which need to expose the children list as public * so that users of the subclass can freely add/remove children. *
* This class may be used directly in cases where absolute positioning of children * is required since it does not perform layout beyond resizing resizable children * to their preferred sizes. It is the application's responsibility to position the * children since the pane leaves the positions alone during layout. * For example: *
{@code * Pane canvas = new Pane(); * canvas.setStyle("-fx-background-color: black;"); * canvas.setPrefSize(200,200); * Circle circle = new Circle(50,Color.BLUE); * circle.relocate(20, 20); * Rectangle rectangle = new Rectangle(100,100,Color.RED); * rectangle.relocate(70,70); * canvas.getChildren().addAll(circle,rectangle); * }*
* Note: if an application needs children to be kept aligned within a parent (centered, * positioned at top-left, etc), it should use a {@link javafx.scene.layout.StackPane StackPane} * instead.
* ** Pane resizes each managed child regardless of the child's visible property value; * unmanaged children are ignored for all layout calculations.
* ** A pane's parent will resize the pane within the pane's resizable range * during layout. By default the pane computes this range based on its content * as outlined in the table below: *
* *width | height | |
---|---|---|
minimum | *left plus right insets. | *top plus bottom insets. |
preferred | *width required to encompass each child at its current x location and preferred width. | *height required to encompass each child at its current y location and preferred height. |
maximum | *Double.MAX_VALUE | Double.MAX_VALUE |
* A pane's unbounded maximum width and height are an indication to the parent that * it may be resized beyond its preferred size to fill whatever space is assigned to it. *
* Pane provides properties for setting the size range directly. These * properties default to the sentinel value Region.USE_COMPUTED_SIZE, however the * application may set them to other values as needed: *
* pane.setPrefSize(500,400);
*
* Applications may restore the computed values by setting these properties back
* to Region.USE_COMPUTED_SIZE.
* * Pane does not clip its content by default, so it is possible that children's * bounds may extend outside its own bounds, either if children are positioned * at negative coordinates or the pane is resized smaller than its preferred size.
* * @since JavaFX 2.0 */ @DefaultProperty("children") public class Pane extends Region { static { PaneHelper.setPaneAccessor(new PaneHelper.PaneAccessor() { }); } static void setConstraint(Node node, Object key, Object value) { if (value == null) { node.getProperties().remove(key); } else { node.getProperties().put(key, value); } if (node.getParent() != null) { node.getParent().requestLayout(); } } static Object getConstraint(Node node, Object key) { if (node.hasProperties()) { Object value = node.getProperties().get(key); if (value != null) { return value; } } return null; } { // To initialize the class helper at the begining each constructor of this class PaneHelper.initHelper(this); } /** * Creates a Pane layout. */ public Pane() { super(); } /** * Creates a Pane layout. * @param children The initial set of children for this pane. * @since JavaFX 8.0 */ public Pane(Node... children) { super(); getChildren().addAll(children); } /** * * @return modifiable list of children. */ @Override public ObservableList