这是显示问题的简单可执行代码段。
使用ExpandBar时,期望的结果是在折叠或展开时调整窗口大小。它可以在Mac上正常运行,但不能在Linux上运行。
看起来 ExpandListener 在折叠/展开实际发生之前已被调用,因此 pack()的大小不正确。
异步执行仅仅是使它在Mac上运行的绷带,但是在Linux上却行不通。
import org.eclipse.swt.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.events.ExpandEvent;
import org.eclipse.swt.events.ExpandListener;
public class ExpandBarExample {
public static void main(String[] args) {
Shell shell = new Shell(SWT.DIALOG_TRIM | SWT.MIN
| SWT.APPLICATION_MODAL);
shell.setLayout(new FormLayout());
shell.setText("Expand Bar");
final ExpandBar bar = new ExpandBar(shell, SWT.NONE);
FormData fd = new FormData();
fd.top = new FormAttachment(0);
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
fd.bottom = new FormAttachment(100);
bar.setLayoutData(fd);
bar.addExpandListener(new ExpandListener() {
public void itemCollapsed(ExpandEvent arg0) {
Display.getCurrent().asyncExec(new Runnable() {
public void run() {
bar.getShell().pack();
}
});
}
public void itemExpanded(ExpandEvent arg0) {
bar.getShell().pack();
Display.getCurrent().asyncExec(new Runnable() {
public void run() {
bar.getShell().pack();
}
});
}
});
Composite composite = new Composite(bar, SWT.NONE);
fd = new FormData();
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
composite.setLayoutData(fd);
FormLayout layout = new FormLayout();
layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8;
composite.setLayout(layout);
Label label = new Label(composite, SWT.NONE);
label.setText("This is Bar 1");
ExpandItem item1 = new ExpandItem(bar, SWT.NONE, 0);
item1.setText("Bar 1");
item1.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
item1.setControl(composite);
item1.setExpanded(true);
composite = new Composite(bar, SWT.NONE);
fd = new FormData();
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
composite.setLayoutData(fd);
layout = new FormLayout();
layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8;
composite.setLayout(layout);
label = new Label(composite, SWT.NONE);
label.setText("This is Bar2");
ExpandItem item2 = new ExpandItem(bar, SWT.NONE, 1);
item2.setText("Bar 2");
item2.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
item2.setControl(composite);
item2.setExpanded(true);
composite = new Composite(bar, SWT.NONE);
fd = new FormData();
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
composite.setLayoutData(fd);
layout = new FormLayout();
layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8;
composite.setLayout(layout);
label = new Label(composite, SWT.NONE);
label.setText("This is Bar3");
ExpandItem item3 = new ExpandItem(bar, SWT.NONE, 2);
item3.setText("Bar 3");
item3.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
item3.setControl(composite);
item3.setExpanded(true);
bar.setSpacing(6);
shell.pack();
shell.open();
Display display = shell.getDisplay();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}
最佳答案
我对这种解决方案不满意,但是它可行。
绝对是XXX解决方案
无需再费周折
import org.eclipse.swt.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.events.ExpandEvent;
import org.eclipse.swt.events.ExpandListener;
public class ExpandBarExample {
public static void main(String[] args) {
Shell shell = new Shell(SWT.DIALOG_TRIM | SWT.MIN
| SWT.APPLICATION_MODAL);
shell.setLayout(new FormLayout());
shell.setText("Expand Bar");
final ExpandBar bar = new ExpandBar(shell, SWT.NONE);
FormData fd = new FormData();
fd.top = new FormAttachment(0);
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
fd.bottom = new FormAttachment(100);
bar.setLayoutData(fd);
bar.addExpandListener(new ExpandListener() {
private void resize(final ExpandEvent event, final boolean expand){
final Display display = Display.getCurrent();
new Thread(new Runnable() {
public void run() {
final int[] orgSize = new int[1];
final int[] currentSize = new int[1];
final Object lock = new Object();
if (display.isDisposed() || bar.isDisposed()){
return;
}
display.syncExec(new Runnable() {
public void run() {
if (bar.isDisposed() || bar.getShell().isDisposed()){
return;
}
synchronized(lock){
bar.getShell().pack(true);
orgSize[0] = bar.getShell().getSize().y;
currentSize[0] = orgSize[0];
}
}
});
while (currentSize[0] == orgSize[0]){
if (display.isDisposed() || bar.isDisposed()){
return;
}
display.syncExec(new Runnable() {
public void run() {
synchronized(lock){
if (bar.isDisposed() || bar.getShell().isDisposed()){
return;
}
currentSize[0] = bar.getShell().getSize().y;
if (currentSize[0] != orgSize[0]){
return;
}
else{
bar.getShell().layout(true);
bar.getShell().pack(true);
}
}
}
});
}
}
}).start();
}
public void itemCollapsed(ExpandEvent event) {
resize(event, false);
}
public void itemExpanded(ExpandEvent event) {
resize(event, true);
}
});
Composite composite = new Composite(bar, SWT.NONE);
fd = new FormData();
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
composite.setLayoutData(fd);
FormLayout layout = new FormLayout();
layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8;
composite.setLayout(layout);
Label label = new Label(composite, SWT.NONE);
label.setText("This is Bar 1");
ExpandItem item1 = new ExpandItem(bar, SWT.NONE, 0);
item1.setText("Bar 1");
item1.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
item1.setControl(composite);
item1.setExpanded(true);
composite = new Composite(bar, SWT.NONE);
fd = new FormData();
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
composite.setLayoutData(fd);
layout = new FormLayout();
layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8;
composite.setLayout(layout);
label = new Label(composite, SWT.NONE);
label.setText("This is Bar2");
ExpandItem item2 = new ExpandItem(bar, SWT.NONE, 1);
item2.setText("Bar 2");
item2.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
item2.setControl(composite);
item2.setExpanded(true);
composite = new Composite(bar, SWT.NONE);
fd = new FormData();
fd.left = new FormAttachment(0);
fd.right = new FormAttachment(100);
composite.setLayoutData(fd);
layout = new FormLayout();
layout.marginLeft = layout.marginTop = layout.marginRight = layout.marginBottom = 8;
composite.setLayout(layout);
label = new Label(composite, SWT.NONE);
label.setText("This is Bar3");
ExpandItem item3 = new ExpandItem(bar, SWT.NONE, 2);
item3.setText("Bar 3");
item3.setHeight(composite.computeSize(SWT.DEFAULT, SWT.DEFAULT).y);
item3.setControl(composite);
item3.setExpanded(true);
bar.setSpacing(6);
shell.pack();
shell.open();
Display display = shell.getDisplay();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
}
如果有人想知道它在做什么并且不想看代码。
基本上, ExpandListener 会查看 shell 的原始高度,并向 shell pack()发出syncExec,直到 shell 实际更改大小为止。一个非常繁忙的等待方法。