如何使TreeViewer单元格的一部分变为粗体？

Question

我目前想要编写一个基于JFace的Eclipse编辑器TreeViewer.我添加了一个CellLabelProvider到TreeViewer.如果我直接在粗体字体的update方法中设置单元格的CellLabelProvider字体,则标签显示为粗体.

但我只希望标签的一部分显示为粗体.所以我将StyleRanges应用于单元格.'StyleRange的选定颜色完美无缺,但将a的字体设置StyleRange为粗体,似乎不起作用.

为什么这样,我该如何解决？

Answer 1

根据greg-449的规定,基本上你可以创建你的Font并将其设置为粗体:

  class BoldFontStyler extends Styler {                                                                  
    @Override
    public void applyStyles(final TextStyle textStyle)
    {
        FontDescriptor boldDescriptor = FontDescriptor.createFrom(new FontData()).setStyle(SWT.BOLD);
        Font boldFont = boldDescriptor.createFont(Display.getCurrent());
        textStyle.font = boldFont;
    }
}

然后你可以把它应用到你的StyledString内心#getStyledText().

我不确定这是可移植的,我只是在我的Linux机器上测试过.

一个完整的例子(只需将其附加到a Part):

package com.ebotlution.c4ids.comms.ui;

import javax.annotation.PostConstruct;

import org.eclipse.jface.resource.FontDescriptor;
import org.eclipse.jface.viewers.ColumnLabelProvider;
import org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider;
import org.eclipse.jface.viewers.ILabelProviderListener;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.StyledString;
import org.eclipse.jface.viewers.StyledString.Styler;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.TreeViewerColumn;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.TextStyle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.TreeColumn;

class BoldFontStyler extends Styler {
    @Override
    public void applyStyles(final TextStyle textStyle)
    {
        FontDescriptor boldDescriptor = FontDescriptor.createFrom(new FontData()).setStyle(SWT.BOLD);
        Font boldFont = boldDescriptor.createFont(Display.getCurrent());
        textStyle.font = boldFont;
    }
}

class NormalColumnLabelProvider extends ColumnLabelProvider {
    @Override
    public String getText(Object element) {
        return (element).toString().split(" ")[0];
    }
}

class BoldColumnLabelProvider extends DelegatingStyledCellLabelProvider {
    static final Styler BOLD_FONT_STYLER = new BoldFontStyler();

    public BoldColumnLabelProvider() {
        super(new IStyledLabelProvider() {
            @Override
            public Image getImage(Object element) {
                return null;
            }

            @Override
            public StyledString getStyledText(Object element) {
                return new StyledString((element).toString().split(" ")[1], BOLD_FONT_STYLER);
            }

            @Override
            public void addListener(ILabelProviderListener listener) {}

            @Override
            public void dispose() {}

            @Override
            public boolean isLabelProperty(Object element, String property) {
                return false;
            }

            @Override
            public void removeListener(ILabelProviderListener listener) {}
        });
    }
}

class MyContentProvider implements ITreeContentProvider {

    static final Object[] EMPTY_ARRAY = new Object[0];

    Object[] data;

    @Override
    public void dispose() {}

    @Override
    public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
        data = (Object[]) newInput;
    }

    @Override
    public Object[] getElements(Object inputElement) {
        return data;
    }

    @Override
    public Object[] getChildren(Object parentElement) {
        return EMPTY_ARRAY;
    }

    @Override
    public Object getParent(Object element) {
        return null;
    }

    @Override
    public boolean hasChildren(Object element) {
        return false;
    }
}

public class BoldColumnTreeViewerEx {

    TreeViewer treeViewer;

    @PostConstruct
    public void createControls(Composite parent) {
        treeViewer = new TreeViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
        treeViewer.setUseHashlookup(true);
        treeViewer.setContentProvider(new MyContentProvider());
        // Do all your stuff
        // [...]

        TreeViewerColumn normalCol = createTreeViewerColumn("Normal Column");
        normalCol.setLabelProvider(new NormalColumnLabelProvider());

        TreeViewerColumn boldCol = createTreeViewerColumn("Bold Column");
        boldCol.setLabelProvider(new BoldColumnLabelProvider());

        treeViewer.setInput(new String[] { "Hello Dude", "SWT JFace" });
        treeViewer.expandAll();
    }

    private TreeViewerColumn createTreeViewerColumn(String title) {
        TreeViewerColumn viewerColumn = new TreeViewerColumn(treeViewer, SWT.NONE);
        TreeColumn column = viewerColumn.getColumn();
        column.setText(title);
        column.setWidth(100);
        return viewerColumn;
    }
}

Answer 2

您可能需要使用基于StyledCellLabelProvider.

DelegatingStyledCellLabelProvider最容易使用，因为您只需要提供一个实现DelegatingStyledCellLabelProvider.IStyledLabelProvider. 其中关键的方法是

public StyledString getStyledText(Object element);

StyledString它可以让你只为每个对象返回一个。