Swing Hacks

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Chapter 3, Tables and Trees

#26 Search Through JTables Easily

HACK

searchButton.addActionListener(searchListener);

searchField.addActionListener(searchListener);

Finishing Touches

You’ve got the bare bones down, but there are a few things you’ll want to

add to make everything a little more functional. Here are a couple of ideas.

Listen to inner table updates. If the inner table model changes, you need to

know about it. Otherwise, your search results will not jive with the inner

table model. The simple solution is to add a

TableModelListener to the inner

table to rebuild the index, and then rerun the search against the new index.

Here’s the code:

private class TableModelHandler implements TableModelListener {

public void tableChanged(TableModelEvent e) {

// If we're not searching, just pass the event along.

if (!isSearching( )) {

clearSearchingState( );

reindex( );

fireTableChanged(e);

return;

}

// Something has happened to the data that may

// have invalidated the search.

reindex( );

search(searchString);

fireTableDataChanged( );

}

}

You should consider extending this hack if you have serious performance

considerations. You could narrow down the area of the table that changed

to fire more accurate events to the table.

Clear search results for blank search. When users search with an empty

string, they typically expect that to clear the search. The easiest way to do

this is to check for an empty string in the search method. If they search with

an empty string, clear the search and rerun the method that indexes all of

the inner table model without a search:

public void search(String searchString){

if (searchString == null || searchString.equals("")){

clearSearchingState( );

fireTableDataChanged( );

return;

}

//rest of search method

}