Make inner classes protected...

[mlaggner]

... to avoid copying the whole content of the inner class when creating subclasses

e.g. where I found an example https://github.com/JFormDesigner/FlatLaf/blob/master/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTableHeaderUI.java#L255

[mlaggner]

another similar example would be private helper methods like FlatComboBoxUI.getDisabledBackground() which I had to re-implement in the subclass just to adopt the paint method a bit

[DevCharly]

I'm willing to open FlatLaf as much as possible, but I'm not sure whether opening FlatTableCellHeaderRenderer is a good idea. This class is not a general header renderer. It is only used when sort icon position is not on right side. And it always delegates to the default header renderer.

What's your use case for subclassing FlatTableCellHeaderRenderer ?

[mlaggner]

the problem here was that I use glazedlists for my tables and glazedlists needs a component which implements the interface SortableRenderer as header renderer to inject the sort icon into the header. So my idea was to

private static class MyHeaderRenderer extends FlatTableCellHeaderRenderer  implements SortableRenderer {
...
}

to achieve this without the need to copy the whole inner class.

Creating sub-themes on your theme would be much easier if we could use as much code as possible (protected). Just my personal opinion

[DevCharly]

Implemented a little app to test Glazed Lists with FlatLaf (in commit 212c553) and the table header sort icons work out of the box (without a custom header renderer and without FlatTableCellHeaderRenderer involved):

Top/bottom/left positioned sort arrows did not work, but is fixed in 211030b (enable with UIManager.put( "TableHeader.sortIconPosition", "top" );. This commit also changes how class FlatTableCellHeaderRenderer is internally used. Default renderer of JTableHeader is no longer changed permanently. Only temporary while painting.

Little "problem" is that this uses non-HiDPI icons from Glazed Lists. It is possible to replace them with TableComparatorChooser.setIconPath( "path" ) (see

FlatLaf/flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/glazedlists/FlatGlazedListsTest.java

Line 70 in 212c553

TableComparatorChooser.setIconPath( "resources/windowsxp" );

), but this supports only PNGs.

Is your plan/idea to use SortableRenderer to replace glazedlists icons with FlatLaf icons?

This is probably difficult because the only method of the interface is void setSortIcon(Icon sortIcon) and does not have any information about the column or sort direction.

Would be easy if Glazed Lists would provide a TableComparatorChooser.setIcons(Icon[] icons) method. As workaround you could use reflection to set field TableComparatorChooser.icons.

BTW the recommended way to implement custom header renderer, which works with all look and feels, is:

private static class MyHeaderRenderer implements TableCellRenderer {
    private final TableCellRenderer delegate;

    MyHeaderRenderer( TableCellRenderer delegate ) {
        this.delegate = delegate;
    }

    @Override
    public Component getTableCellRendererComponent( JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column ) {
        Component c = delegate.getTableCellRendererComponent( table, value, isSelected, hasFocus, row, column );
        // TODO do some modifications
        return c;
    }
}

// install own header renderer
JTableHeader header = itemsTable.getTableHeader();
header.setDefaultRenderer( new MyHeaderRenderer( header.getDefaultRenderer() ) );

Still don't think that it is necessary to copy code from FlatTableCellHeaderRenderer or subclass it, but I'm open for arguments...

Regarding other private methods/fields/classes: I plan to review them soon and will make them protected where it may be useful...

[mlaggner]

wow, even more that I could imagine! thanks!

[mlaggner]

Is your plan/idea to use SortableRenderer to replace glazedlists icons with FlatLaf icons?

yes this would be the next step.

initially I created a header renderer which is able to display an icon instead of text AND the sort icon (so I need basically 2 JLabels). Something like

[DevCharly]

@mlaggner wrote:

another similar example would be private helper methods like FlatComboBoxUI.getDisabledBackground() which I had to re-implement in the subclass just to adopt the paint method a bit

I've reviewed all private methods and made them protected/public where it might be useful for subclasses in commit ea2412d. Also made some changes to FlatComboBoxUI and FlatSpinnerUI, which now have protected getBackground(boolean enabled) and getForeground(boolean enabled) methods.

[mlaggner]

thanks, will review my "patches" as soon as 0.37 is released.
And with your help about Glazedlists I was able to reimplement a TableComparatorChooser (mostly copied code, because I avoid using dirty reflection) with SVG sort icons

[nseven404]

Not working! :( Help me!

[DevCharly]

Did you enable table sorting?
E.g. invoking JTable.setAutoCreateRowSorter(true)?
This is the code used in the FlatLaf Demo (on "Data components" tab; click on column header to sort column):

FlatLaf/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DataComponentsPanel.java

Line 296 in 368fbcd

table1.setAutoCreateRowSorter(true);

[nseven404]

Thanks you very much! I want to add an icon down on the header table bar, what should I do?

[DevCharly]

Here is a great article that gives many details about how to sort JTable:
https://www.codejava.net/java-se/swing/6-techniques-for-sorting-jtable-you-should-know