消耗Vaadin Gridlayout中的可用空间，但考虑换行 [英] Consume available space in Vaadin Gridlayout, but consider line breaks

问题描述

我使用Vaadin的GridLayout来可视化某些标题和值标签.GridLayout有2列和几行.标题标签在左侧，而其相关的值标签在右侧.

I use Vaadin's GridLayout for visualization of some title and value labels. The GridLayout has 2 columns and several rows. Title labels are on the left side and their associated value labels on the right.

我希望第一列占用尽可能少的空间，第二列应该占用浏览器窗口的所有刷新空间.如果值标签需要的空间超过可用空间，则必须换行.

I want the first column to consume as less space as possible and the second column should occupy all the remining space of the browser's window. If a value label requires more space than available then it must break the line.

我试图玩 setColumnExpandRatio().如果我确定第二列的以下比率(并省略第一列的比率规范)，那么一切都按要求工作，除了具有非常大文本内容的值标签不会在行尾中断.相反，会出现一个水平滚动条:

I tried to play with setColumnExpandRatio(). If I determine following ratio for the second column (and omit a ratio specification for the first column) then everything works as requested except the fact that value labels with very large textual content don't break at the line's end. Instead, a horizontal scroll bar appears:

public class MyPanel extends GridLayout
{
   public MyPanel()
   {
       setWidth("100%");
       setMargin(true);
       setSpacing(true);

       buildView();
   }

   public void buildView()
   {
       removeAllComponents();
       setColumns(2);
       setColumnExpandRatio(1, 1);
       ...
       titleLabel.setWidth(null);
       valueLabel.setWidth(null);

       addComponent(titleLabel);
       addComponent(valueLabel);

       setComponentAlignment(titleLabel, Alignment.TOP_RIGHT);
   }
}

如果我还为第一列指定比率，那么第一列会消耗比实际需要更多的空间.

If I also specify a ratio for the first column then the first column consumes more space than really needed.

我如何实现我的要求?

推荐答案

Label 的内容仅在 Label 具有定义的宽度时才换行.考虑一下:如果宽度是不确定的，那么即使在换行时如何确定宽度呢?此处的解决方案非常简单，只需将 valueLabel 的宽度设置为"100％" .实际上，它比这更简单.默认情况下，新的 Label 实例的宽度为100％，因此您只需删除将宽度设置为 null 的行即可.

The contents of a Label only wrap if the Label has a defined width. Think about it: if the width is undefined, how should it even be determined when to wrap the text? The solution here is as simple as setting the width of valueLabel to "100%". Actually, it's even more simple than that. A fresh Label instance is 100%-wide by default, so you can just remove the line where you are setting the width to null.

这是一个用于测试它的示例 UI 类:

Here's an example UI class to test it with:

public class MyUI extends UI {

    @Override
    protected void init(VaadinRequest request) {

        GridLayout layout = new GridLayout();
        layout.setWidth("100%");
        layout.setColumns(2);
        layout.setColumnExpandRatio(1, 1);

        Label label1 = new Label("Lorem ipsum");
        Label label2 = new Label(
                "Lorem ipsum dolor sit amet, consectetur adipiscing elit. "
                        + "Morbi augue sapien, tempus ac mattis ut, iaculis a erat. "
                        + "Ut vitae ante metus. Pellentesque vitae rutrum lacus, id volutpat tellus. "
                        + "Duis eget ultricies metus. "
                        + "Vestibulum ac nibh eget velit pretium semper et eget est. "
                        + "Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. "
                        + "Curabitur nec rutrum tellus. Curabitur vel urna a nunc cursus congue. "
                        + "Vestibulum pellentesque mi in leo luctus, sit amet auctor enim ornare. "
                        + "Proin in mauris convallis, vestibulum nisi sed, consectetur dolor. "
                        + "Vestibulum ultricies metus ut nulla gravida, eget dapibus turpis fringilla. "
                        + "Mauris hendrerit felis non aliquam elementum. "
                        + "Phasellus ut purus ut urna consequat commodo. "
                        + "Cras semper ac augue quis rutrum. "
                        + "Nunc tristique magna sit amet congue faucibus.");

        layout.addComponent(label1);
        layout.addComponent(label2);

        label1.setWidth(null);
        label2.setWidth("100%"); // I'm being explicit, but you can just as well leave this out if you like

        setContent(layout);
    }
}

这篇关于消耗Vaadin Gridlayout中的可用空间，但考虑换行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！