SWT(JFace)体验之模拟BorderLayout布局

SWT中没有AWT的BorderLayout布局管理器。下面是SWT下的自定义实现：

BorderLayout.java

复制代码 代码如下:

package swt_jface.demo2;

import org.eclipse.swt.SWT;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.graphics.Rectangle;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Control;

import org.eclipse.swt.widgets.Layout;

public class BorderLayout extends Layout {

public static final int NORTH = 0;

public static final int SOUTH = 1;

public static final int CENTER = 2;

public static final int EAST = 3;

public static final int WEST = 4;

public static class BorderData {

public int region = CENTER;

public BorderData() {

}

public BorderData(int region) {

this.region = region;

}

}

public Control[] controls = new Control[5];

Point[] sizes;

int width;

int height;

protected Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache) {

if (sizes == null || flushCache == true)

refreshSizes(composite.getChildren());

int w = wHint;

int h = hHint;

if (w == SWT.DEFAULT) w = width;

if (h == SWT.DEFAULT) h = height;

return new Point(w, h);

}

protected void layout(Composite composite, boolean flushCache) {

if (flushCache || sizes == null)

refreshSizes(composite.getChildren());

Rectangle clientArea = composite.getClientArea();

if (controls[NORTH] != null) {

controls[NORTH].setBounds(

clientArea.x,

clientArea.y,

clientArea.width,

sizes[NORTH].y);

}

if (controls[SOUTH] != null) {

controls[SOUTH].setBounds(

clientArea.x,

clientArea.y + clientArea.height - sizes[SOUTH].y,

clientArea.width,

sizes[SOUTH].y);

}

if (controls[WEST] != null) {

controls[WEST].setBounds(

clientArea.x,

clientArea.y + sizes[www.devze.comNORTH].y,

sizes[WEST].x,

clientArea.height - sizes[NORTH].y - sizes[SOUTH].y);

}

if (controls[EAST] != null) {

controls[EAST].setBounds(

clientArea.x + clientArea.width - sizwww.devze.comes[EAST].x,

clientArea.y + sizes[NORTH].y,

sizes[EAST].x,

clientArea.height - sizes[NORTH].y - sizes[SOUTH].y);

}

if (controls[CENTER] != null) {

controls[CENTER].setBounds(

clientArea.x + sizes[WEST].x,

clientArea.y + sizes[NORTH].y,

clientArea.width - sizes[WEST].x - sizes[EAST].x,

clientA开发者_JAVA教程rea.height - sizes[NORTH].y - sizes[SOUTH].y);

}

}

private void refreshSizes(Control[] children) {

for (int i = 0; i < children.length; i++) {

Object layoutData = children[i].getLayoutwww.devze.comData();

if (layoutData == null || (!(layoutData instanceof BorderData)))

continue;

BorderData borderData = (BorderData) layoutData;

if (borderData.region < 0 || borderData.region > 4) // Invalid.

continue;

controls[borderData.region] = children[i];

}

width = 0;

height = 0;

if (sizes == null)

sizes = new Point[5];

for (int i = 0; i < controls.length; i++) {

Control contro编程客栈l = controls[i];

if (control == null) {

sizes[i] = new Point(0, 0);

} else {

sizes[i] = control.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);

}

}

width = Math.max(width, sizes[NORTH].x);

width = Math.max(width, sizes[WEST].x + sizes[CENTER].x + sizes[EAST].x);

width = Math.max(width, sizes[SOUTH].x);

height = Math.max(Math.max(sizes[WEST].y, sizes[EAST].y), sizes[CENTER].y)

+ sizes[NORTH].y

+ sizes[SOUTH].y;

}

}

测试代码：

BorderLayoutSample.java

复制代码 代码如下:

package swt_jface.demo2;

import org.eclipse.swt.SWT;

import org.eclipse.swt.widgets.Button;

import org.eclipse.swt.widgets.Display;

import org.eclipse.swt.widgets.Shell;

import org.eclipse.swt.widgets.Text;

public class BorderLayoutSample {

Display display = new Display();

Shell shell = new Shell(display);

public BorderLayoutSample() {

shell.setLayout(new BorderLayout());

Button buttonWest = new Button(shell, SWT.PUSH);

buttonWest.setText("West");

buttonWest.setLayoutData(new BorderLayout.BorderData(BorderLayout.WEST));

Button buttonEast = new Button(shell, SWT.PUSH);

buttonEast.setText("East");

buttonEast.setLa编程客栈youtData(new BorderLayout.BorderData(BorderLayout.EAST));

Button buttonNorth = new Button(shell, SWT.PUSH);

buttonNorth.setText("North");

buttonNorth.setLayoutData(new BorderLayout.BorderData(BorderLayout.NORTH));

Button buttonSouth = new Button(shell, SWT.PUSH);

buttonSouth.setText("South");

buttonSouth.setLayoutData(new BorderLayout.BorderData(BorderLayout.SOUTH));

Text text = new Text(shell, SWT.MULTI | SWT.BORDER | SWT.V_SCROLL | SWT.H_SCROLL);

text.setText("Center");

text.setLayoutData(new BorderLayout.BorderData(BorderLayout.CENTER));

shell.pack();

shell.open();

while (!shell.isDisposed()) {

if (!display.readAndDispatch()) {

display.sleep();

}

}

display.dispose();

}

public static void main(String[] args) {

new BorderLayoutSample();

}

}