问题
I am using this below piece of code:
class CountryTreeCellRenderer implements TreeCellRenderer {
private JLabel label;
CountryTreeCellRenderer() {
label = new JLabel();
}
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
Object o = ((DefaultMutableTreeNode) value).getUserObject();
if (o instanceof Country) {
Country country = (Country) o;
label.setIcon(new ImageIcon(country.getFlagIcon()));
label.setText(country.getName());
} else {
label.setIcon(null);
label.setText("" + value);
}
return label;
}
}
Since I am passing/returning a label, so on selecting any component in the JTree
, no selection color is coming.
I tried to use:
JComponent comp = (JComponent) super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
comp.setOpaque(true);
if(selected)
comp.setBackground(Color.RED);
But if I return comp
, then the output of the tree is not coming as expected.
How to resolve the same?
I did not implement any Editor for the same.
回答1:
Please take a look at the source code of the DefaultTreeCellRenderer, which extends JLabel
as well and is perfectly capable of setting a background color. I copy-pasted the relevant lines below:
if (selected)
{
super.setBackground(getBackgroundSelectionColor());
setForeground(getTextSelectionColor());
if (hasFocus)
setBorderSelectionColor(UIManager.getLookAndFeelDefaults().
getColor("Tree.selectionBorderColor"));
else
setBorderSelectionColor(null);
}
else
{
super.setBackground(getBackgroundNonSelectionColor());
setForeground(getTextNonSelectionColor());
setBorderSelectionColor(null);
}
回答2:
Yes it worked as explained by Robin by bit of change basically
if(selected){
label.setBackground(Color.YELLOW);
label.setForeground(Color.GREEN);
}else
{
label.setBackground(Color.WHITE);
label.setForeground(Color.BLACK);
//setBorderSelectionColor(null);
}
enough
来源:https://stackoverflow.com/questions/9051463/jtree-treecellrenderer-raising-issue-on-showing-the-selection-color