| /******************************************************************************* |
| * Copyright (c) 2000, 2015 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| * Alex Blewitt <alex.blewitt@gmail.com> - replace new Boolean with Boolean.valueOf - https://bugs.eclipse.org/470344 |
| *******************************************************************************/ |
| package org.eclipse.compare; |
| |
| import org.eclipse.swt.custom.SashForm; |
| import org.eclipse.swt.widgets.Composite; |
| import org.eclipse.swt.widgets.Control; |
| import org.eclipse.swt.widgets.Sash; |
| |
| /** |
| * The Splitter adds support for nesting to a SashForm. |
| * <P> |
| * If Splitters are nested directly: |
| * <UL> |
| * <LI>changing the visibility of a child may propagate upward to the parent Splitter if the child |
| * is the last child to become invisible or the first to become visible.</LI> |
| * <LI>maximizing a child makes it as large as the topmost enclosing Splitter</LI> |
| * </UL> |
| * |
| * @since 2.1 |
| */ |
| public class Splitter extends SashForm { |
| |
| private static final String VISIBILITY= "org.eclipse.compare.internal.visibility"; //$NON-NLS-1$ |
| |
| /** |
| * Constructs a new instance of this class given its parent |
| * and a style value describing its behavior and appearance. |
| * <p> |
| * The style value is either one of the style constants defined in |
| * class <code>SWT</code> which is applicable to instances of this |
| * class, or must be built by <em>bitwise OR</em>'ing together |
| * (that is, using the <code>int</code> "|" operator) two or more |
| * of those <code>SWT</code> style constants. The class description |
| * lists the style constants that are applicable to the class. |
| * Style bits are also inherited from superclasses. |
| * </p> |
| * |
| * @param parent a widget which will be the parent of the new instance (cannot be null) |
| * @param style the style of widget to construct |
| * |
| * @exception IllegalArgumentException <ul> |
| * <li>ERROR_NULL_ARGUMENT - if the parent is null</li> |
| * </ul> |
| * @exception org.eclipse.swt.SWTException <ul> |
| * <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li> |
| * </ul> |
| */ |
| public Splitter(Composite parent, int style) { |
| super(parent, style); |
| } |
| |
| /** |
| * Sets the visibility of the given child in this Splitter. If this change |
| * affects the visibility state of the whole Splitter, and if the Splitter |
| * is directly nested in one or more Splitters, this method recursively |
| * propagates the new state upward. |
| * |
| * @param child the child control for which the visibility is changed |
| * @param visible the new visibility state |
| */ |
| public void setVisible(Control child, boolean visible) { |
| |
| boolean wasEmpty= isEmpty(); |
| |
| child.setVisible(visible); |
| child.setData(VISIBILITY, Boolean.valueOf(visible)); |
| |
| if (wasEmpty != isEmpty()) { |
| // recursively walk up |
| Composite parent= getParent(); |
| if (parent instanceof Splitter) { |
| Splitter sp= (Splitter) parent; |
| sp.setVisible(this, visible); |
| sp.layout(); |
| } |
| } else { |
| layout(); |
| } |
| } |
| |
| /* |
| * Recursively calls setMaximizedControl for all direct parents that are itself |
| * Splitters. |
| */ |
| @Override |
| public void setMaximizedControl(Control control) { |
| if (control == null || control == getMaximizedControl()) |
| super.setMaximizedControl(null); |
| else |
| super.setMaximizedControl(control); |
| |
| // recursively walk upward |
| Composite parent= getParent(); |
| if (parent instanceof Splitter) |
| ((Splitter) parent).setMaximizedControl(this); |
| |
| layout(true); |
| } |
| |
| /* |
| * Returns true if Splitter has no children or if all children are invisible. |
| */ |
| private boolean isEmpty() { |
| Control[] controls= getChildren(); |
| for (Control control : controls) |
| if (isVisible(control)) |
| return false; |
| return true; |
| } |
| |
| /* |
| * Returns the visibility state of the given child control. If the control is a |
| * Sash, this method always returns false. |
| */ |
| private boolean isVisible(Control child) { |
| if (child instanceof Sash) |
| return false; |
| Object data= child.getData(VISIBILITY); |
| if (data instanceof Boolean) |
| return ((Boolean)data).booleanValue(); |
| return true; |
| } |
| } |