Canvas 扩展或增加水平滚动条宽度

我使用下面的代码来组合两个画布

public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
shell.setText("Canvas Test");

Composite mainComp = new Composite(shell, SWT.NONE);
GridLayout layout = new GridLayout(2, false);

layout.horizontalSpacing = 0;

mainComp.setLayout(layout);
mainComp.setLayoutData(new GridData(SWT.BEGINNING, SWT.TOP, true, true));

final Canvas hwCanvas = new Canvas(mainComp, SWT.NO_REDRAW_RESIZE | SWT.V_SCROLL);
hwCanvas.setForeground(display.getSystemColor(SWT.COLOR_WHITE));
hwCanvas.setBackground(display.getSystemColor(SWT.COLOR_BLACK));
hwCanvas.setLayoutData(new GridData(SWT.BEGINNING, SWT.TOP, false, true));
hwCanvas.getVerticalBar().setVisible(false);

final Canvas traceCanvas = new Canvas(mainComp, SWT.NO_REDRAW_RESIZE | SWT.H_SCROLL | SWT.V_SCROLL);
traceCanvas.setForeground(display.getSystemColor(SWT.COLOR_WHITE));
traceCanvas.setBackground(display.getSystemColor(SWT.COLOR_BLACK));
traceCanvas.setLayoutData(new GridData(SWT.BEGINNING, SWT.TOP, true, true));

shell.open();
while (!shell.isDisposed()) {
    if (!display.readAndDispatch()) {
    display.sleep();
    }
}
display.dispose();

}

是否可以按此处所示增加水平滚动条的宽度（长度）

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尝试将滚动条移动到包含两个画布组件的组件上，这样水平滚动条就可以控制两个画布组件的总宽度：

Composite mainComp = new Composite(shell, SWT.H_SCROLL | SWT.V_SCROLL);
:
final Canvas hwCanvas = new Canvas(mainComp, SWT.NO_REDRAW_RESIZE);
:
final Canvas traceCanvas = new Canvas(mainComp, SWT.NO_REDRAW_RESIZE);

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是的，我可以这样做，但如果我隐藏第二个画布的水平滚动条，并将水平滚动条添加到主组合中，那么当我滚动主组合的水平滚动条时，它会同时滚动第一个和第二个画布。我不想滚动第一个画布及其内容。我想冻结第一张画布，第二张画布只能滚动。我误解了你原来的问题。你是说当第二个画布的水平滚动条没有画布本身那么宽时？