Swing Hacks

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Chapter 3, Tables and Trees

#26 Search Through JTables Easily

HACK

Decorating the TableModel

Start by creating a class called TableSearcher that implements TableModel.

Next, create a simple decorator (or wrapper) that implements all of the

TableModel

methods and forwards the calls to the inner model. Depending

on your IDE, you may be able to automate the process (IntelliJ IDEA does it

for me). You’ll have to modify a few of the methods, but most are going to

remain unchanged. You don’t have to touch the

getColumnName( ) and

getColumnClass( ) methods, for example. Just forward them to the inner

TableModel:

public String getColumnName(int column) {

return tableModel.getColumnName(column);

}

public Class getColumnClass(int column) {

return tableModel.getColumnClass(column);

}

The getColumnCount( ) method is slightly different in that you have to check

if the

TableModel is null. This is because the table calls getColumnCount( )

first and calls other column methods only if there are valid columns. Here is

the code with the

null check:

public int getColumnCount( ) {

return (tableModel == null) ? 0 : tableModel.getColumnCount( );

}

Creating Logical Links to the Inner Table Model

Now, you need to introduce the idea of links between the inner table model

and this table model. Create a

Collection called rowToModelIndex. In it,

you’ll store

Integers corresponding to the inner table model row number, at

the index that corresponds to this table model’s row. So, if the fifth row in

the inner model is the first row in this model, you would store an

Integer

value of 5 as the first in the rowtoModelIndex.

This method clears the searching state by making a one-to-one mapping of

the inner table model to this table model:

private void clearSearchingState( ){

searchString = null;

rowToModelIndex.clear( );

for (int t=0; t<tableModel.getRowCount( ); t++){

rowToModelIndex.add(new Integer(t));

}

}

Now, you need to change the row reference methods to indirect through the

row to model index before hitting the inner table model: