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/*******************************************************************************
* Copyright (c) 2000, 2018 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
*******************************************************************************/
package org.eclipse.swt.custom;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;
/**
* This Layout stacks all the controls one on top of the other and resizes all controls
* to have the same size and location.
* The control specified in topControl is visible and all other controls are not visible.
* Users must set the topControl value to flip between the visible items and then call
* layout() on the composite which has the StackLayout.
*
* <p> Here is an example which places ten buttons in a stack layout and
* flips between them:
*
* <pre><code>
* public static void main(String[] args) {
* Display display = new Display();
* Shell shell = new Shell(display);
* shell.setLayout(new GridLayout());
*
* final Composite parent = new Composite(shell, SWT.NONE);
* parent.setLayoutData(new GridData(GridData.FILL_BOTH));
* final StackLayout layout = new StackLayout();
* parent.setLayout(layout);
* final Button[] bArray = new Button[10];
* for (int i = 0; i < 10; i++) {
* bArray[i] = new Button(parent, SWT.PUSH);
* bArray[i].setText("Button "+i);
* }
* layout.topControl = bArray[0];
*
* Button b = new Button(shell, SWT.PUSH);
* b.setText("Show Next Button");
* final int[] index = new int[1];
* b.addListener(SWT.Selection, new Listener(){
* public void handleEvent(Event e) {
* index[0] = (index[0] + 1) % 10;
* layout.topControl = bArray[index[0]];
* parent.layout();
* }
* });
*
* shell.open();
* while (shell != null && !shell.isDisposed()) {
* if (!display.readAndDispatch())
* display.sleep();
* }
* }
* </code></pre>
*
* @see <a href="http://www.eclipse.org/swt/snippets/#stacklayout">StackLayout snippets</a>
* @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: LayoutExample</a>
* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
*/
public class StackLayout extends Layout {
/**
* marginWidth specifies the number of points of horizontal margin
* that will be placed along the left and right edges of the layout.
*
* The default value is 0.
*/
public int marginWidth = 0;
/**
* marginHeight specifies the number of points of vertical margin
* that will be placed along the top and bottom edges of the layout.
*
* The default value is 0.
*/
public int marginHeight = 0;
/**
* topControl the Control that is displayed at the top of the stack.
* All other controls that are children of the parent composite will not be visible.
*/
public Control topControl;
@Override
protected Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache) {
Control children[] = composite.getChildren();
int maxWidth = 0;
int maxHeight = 0;
for (int i = 0; i < children.length; i++) {
Point size = children[i].computeSize(wHint, hHint, flushCache);
maxWidth = Math.max(size.x, maxWidth);
maxHeight = Math.max(size.y, maxHeight);
}
int width = maxWidth + 2 * marginWidth;
int height = maxHeight + 2 * marginHeight;
if (wHint != SWT.DEFAULT) width = wHint;
if (hHint != SWT.DEFAULT) height = hHint;
return new Point(width, height);
}
@Override
protected boolean flushCache(Control control) {
return true;
}
@Override
protected void layout(Composite composite, boolean flushCache) {
Control children[] = composite.getChildren();
Rectangle rect = composite.getClientArea();
rect.x += marginWidth;
rect.y += marginHeight;
rect.width -= 2 * marginWidth;
rect.height -= 2 * marginHeight;
for (int i = 0; i < children.length; i++) {
children[i].setBounds(rect);
children[i].setVisible(children[i] == topControl);
}
}
String getName () {
String string = getClass ().getName ();
int index = string.lastIndexOf ('.');
if (index == -1) return string;
return string.substring (index + 1, string.length ());
}
/**
* Returns a string containing a concise, human-readable
* description of the receiver.
*
* @return a string representation of the layout
*/
@Override
public String toString () {
String string = getName ()+" {";
if (marginWidth != 0) string += "marginWidth="+marginWidth+" ";
if (marginHeight != 0) string += "marginHeight="+marginHeight+" ";
if (topControl != null) string += "topControl="+topControl+" ";
string = string.trim();
string += "}";
return string;
}
}
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