com.levigo.util.base.glazedlists.gui
Class AbstractTableComparatorChooser<E>

java.lang.Object
  com.levigo.util.base.glazedlists.gui.AbstractTableComparatorChooser<E>

Direct Known Subclasses:

TableComparatorChooser

public abstract class AbstractTableComparatorChooser<E>
extends Object

A TableComparatorChooser is a tool that allows the user to sort a table widget by clicking on the table's headers. It requires that the table has a SortedList as a source as the sorting on that list is used.

Author:

Kevin Maltby

Field Summary

static Object	MULTIPLE_COLUMN_KEYBOARD Emulate the sorting behaviour of SUN's TableSorter, by Philip Milne et.
static Object	MULTIPLE_COLUMN_MOUSE Sort multiple columns without use of the keyboard.
static Object	MULTIPLE_COLUMN_MOUSE_WITH_UNDO Sort multiple columns without use of the keyboard.
static Object	SINGLE_COLUMN Emulate the sorting behaviour of Windows Explorer and Mac OS X Finder.
protected SortedList<E>	sortedList the sorted list to choose the comparators for
protected Comparator<? super E>	sortedListComparator the potentially foreign comparator associated with the sorted list
protected com.levigo.util.base.internal.glazedlists.gui.SortingState	sortingState manage which columns are sorted and in which order

Constructor Summary

protected

AbstractTableComparatorChooser(SortedList<E> sortedList, TableFormat<? super E> tableFormat) Create a AbstractTableComparatorChooser that sorts the specified SortedList over the specified columns.

Method Summary

void	appendComparator(int column, int comparatorIndex, boolean reverse) Append the comparator specified by the column, comparator index and reverse parameters to the end of the sequence of comparators this AbstractTableComparatorChooser is sorting the SortedList by.
void	clearComparator() Clear all sorting state and set the SortedList to use its natural order.
Comparator	createComparatorForElement(Comparator<E> comparatorForColumn, int column) Creates a Comparator that can compare list elements given a Comparator that can compare column values for the specified column.
protected com.levigo.util.base.internal.glazedlists.gui.SortingState	createSortingState() Returns the object which models the current sorting state of all columns in the table.
void	dispose()
void	fromString(String stringEncoded) This class is capable of representing its own state with a String, to persist sorting state externally.
int	getColumnComparatorIndex(int column) Gets the index comparator in use for the specified column.
List<Comparator>	getComparatorsForColumn(int column) Gets the list of comparators for the specified column.
List<Integer>	getSortingColumns() Get the columns that the TableComparatorChooser is sorting by.
protected int	getSortingStyle(int column) Gets the sorting style currently applied to the specified column.
boolean	isColumnReverse(int column) Gets whether the comparator in use for the specified column is reverse.
protected void	rebuildComparator() Updates the comparator in use and applies it to the table.
protected void	redetectComparator(Comparator<? super E> currentComparator) Examines the current Comparator of the SortedList and adds icons to the table header renderers in response.
protected void	setTableFormat(TableFormat<? super E> tableFormat) Adjusts the TableFormat this comparator chooser uses when selecting comparators.
String	toString() Encode the current sorting state as a String.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

SINGLE_COLUMN

public static final Object SINGLE_COLUMN

Emulate the sorting behaviour of Windows Explorer and Mac OS X Finder.

Single clicks toggles between forward and reverse. If multiple comparators are available for a particular column, they will be cycled in order.

At most one column can be sorted at a time.

MULTIPLE_COLUMN_MOUSE

public static final Object MULTIPLE_COLUMN_MOUSE

Sort multiple columns without use of the keyboard. Single clicks cycle through comparators, double clicks clear all secondary sorts before performing the normal behaviour.

This is the original sorting strategy provided by Glazed Lists, with a limitation that it is impossible to clear a sort order that is already in place. It's designed to be used with multiple columns and multiple comparators per column.

The overall behaviour is as follows:

Click: sort this column. If it's already sorted, reverse the sort order. If its already reversed, sort using the column's next comparator in forward order. If there are no more comparators, go to the first comparator. If there are multiple sort columns, sort this column after those columns.

Double click: like a single click, but clear all sorting columns first.

MULTIPLE_COLUMN_MOUSE_WITH_UNDO

public static final Object MULTIPLE_COLUMN_MOUSE_WITH_UNDO

Sort multiple columns without use of the keyboard. Single clicks cycle through comparators. Single click on the last comparator of the primary sort column will clear the entire sort (for all columns).

This is an improvement over the original sorting strategy provided by Glazed Lists, since it gives a reasonable mechanism for clearing a sort order that is already in place. It's designed to be used with multiple columns and multiple comparators per column.

The overall behaviour is as follows:

Click: sort this column. If it's already sorted, reverse the sort order. If its already reversed, sort using the column's next comparator in forward order. If there are no more comparators, clear ALL column comparators. If there are multiple sort columns, sort this column after those columns.

MULTIPLE_COLUMN_KEYBOARD

public static final Object MULTIPLE_COLUMN_KEYBOARD

Emulate the sorting behaviour of SUN's TableSorter, by Philip Milne et. al.

This is not a direct adaptation since we choose to support potentially many Comparators per column, whereas TableSorter is limited to one.

For reference, this is TableSorter's behaviour, copied shamelessly from that project's source file:

Mouse-click: Clears the sorting gui of all other columns and advances the sorting gui of that column through three values: {NOT_SORTED, ASCENDING, DESCENDING} (then back to NOT_SORTED again).

SHIFT-mouse-click: Clears the sorting gui of all other columns and cycles the sorting gui of the column through the same three values, in the opposite order: {NOT_SORTED, DESCENDING, ASCENDING}.

CONTROL-mouse-click and CONTROL-SHIFT-mouse-click: as above except that the changes to the column do not cancel the statuses of columns that are already sorting - giving a way to initiate a compound sort.

See Also:

Table tutorial

sortedList

protected SortedList<E> sortedList

the sorted list to choose the comparators for

sortedListComparator

protected Comparator<? super E> sortedListComparator

the potentially foreign comparator associated with the sorted list

sortingState

protected com.levigo.util.base.internal.glazedlists.gui.SortingState sortingState

manage which columns are sorted and in which order

Constructor Detail

AbstractTableComparatorChooser

protected AbstractTableComparatorChooser(SortedList<E> sortedList,
                                         TableFormat<? super E> tableFormat)

Create a AbstractTableComparatorChooser that sorts the specified SortedList over the specified columns.

Method Detail

createSortingState

protected com.levigo.util.base.internal.glazedlists.gui.SortingState createSortingState()

Returns the object which models the current sorting state of all columns in the table.

rebuildComparator

protected void rebuildComparator()

Updates the comparator in use and applies it to the table.

setTableFormat

protected void setTableFormat(TableFormat<? super E> tableFormat)

Adjusts the TableFormat this comparator chooser uses when selecting comparators. Calling this method will clear any active sorting.

getComparatorsForColumn

public List<Comparator> getComparatorsForColumn(int column)

Gets the list of comparators for the specified column. The user is free to add comparators to this list or clear the list if the specified column cannot be sorted.

getSortingColumns

public List<Integer> getSortingColumns()

Get the columns that the TableComparatorChooser is sorting by.

Returns:

a List of Integers. The first Integer is the primary sorting column, the second is the secondary, etc. This list may be empty but never null.

getColumnComparatorIndex

public int getColumnComparatorIndex(int column)

Gets the index comparator in use for the specified column. This comparator may be retrieved using getComparatorsForColumn(int).

Returns:

the comparator index for the specified column, or -1 if that column is not being used to sort.

isColumnReverse

public boolean isColumnReverse(int column)

Gets whether the comparator in use for the specified column is reverse.

appendComparator

public void appendComparator(int column,
                             int comparatorIndex,
                             boolean reverse)

Append the comparator specified by the column, comparator index and reverse parameters to the end of the sequence of comparators this AbstractTableComparatorChooser is sorting the SortedList by.

Append implies that if this AbstractTableComparatorChooser is already sorting that list by another column, this comparator will only be used to break ties from that Comparator. If the table is already sorting by the specified column, it will be silently discarded.

Suppose we're currently not sorting the table, this method will cause the table to be sorted by the column specified. If we are sorting the table by some column c, this will sort by that column first and the column specified here second.

If this AbstractTableComparatorChooser doesn't support multiple column sort, this will replace the current Comparator rather than appending to it.

Parameters:

column - the column to sort by

comparatorIndex - the comparator to use, specify 0 for the default comparator.

reverse - whether to reverse the specified comparator.

clearComparator

public void clearComparator()

Clear all sorting state and set the SortedList to use its natural order.

redetectComparator

protected void redetectComparator(Comparator<? super E> currentComparator)

Examines the current Comparator of the SortedList and adds icons to the table header renderers in response.

To do this, clicks are injected into each of the corresponding ColumnClickTrackers.

getSortingStyle

protected int getSortingStyle(int column)

Gets the sorting style currently applied to the specified column.

createComparatorForElement

public Comparator createComparatorForElement(Comparator<E> comparatorForColumn,
                                             int column)

Creates a Comparator that can compare list elements given a Comparator that can compare column values for the specified column. This returns a Comparator that extracts the table values for the specified column and then delegates the actual comparison to the specified comparator.

toString

public String toString()

Encode the current sorting state as a String. This specially formatted String is ideal for persistence using any preferences API. The state of this AbstractTableComparatorChooser can be restored by passing the return value of this method to fromString(String).

Overrides:

toString in class Object

fromString

public void fromString(String stringEncoded)

This class is capable of representing its own state with a String, to persist sorting state externally. The format uses zero or more column specifications, separated by commas. Here are some valid examples:

String Representation	Description
"column 3"	Sort using the column at index 3, using that column's first comparator, in forward order
"column 3 reversed"	Sort using the column at index 3, using that column's first comparator, in reverse order
"column 3, column 1"	Sort using the column at index 3, using that column's first comparator, in forward order then by the column at index 1, using that column's first comparator, in forward order.
"column 3 comparator 2"	Sort using the column at index 3, using that column's comparator at index 2, in forward order
"column 3 comparator 2 reversed"	Sort using the column at index 3, using that column's comparator at index 2, in reverse order
"column 3 reversed, column 1 comparator 2, column 5 comparator 1 reversed, column 0"	Sort using the column at index 3, using that column's first comparator, in reverse order then by the column at index 1, using that column's comparator at index 2, in forward order then by the column at index 5, using that column's comparator at index 1, in reverse order then by the column at index 0, using that column's first comparator, in forward order.

More formally, the grammar for this String representation is as follows:
<COLUMN> = column <COLUMN INDEX> (comparator <COMPARATOR INDEX>)? (reversed)?
<COMPARATOR SPEC> = ( <COLUMN> (, <COLUMN>)* )?

dispose

public void dispose()