java 通过单击列标题进行 SWT 表排序
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时间：2020-10-31 19:50:46 来源:igfitidea点击:
SWT Table Sorting by clicking the column header
提问by Venkatachalam Subramanian
In swt table- sorting works for Strings how to do sorting for Integer, Double and Date values. And this only works for String ascending. Can anyone suggest a better way to do it.
在 swt table-sorting 中，Strings 如何对 Integer、Double 和 Date 值进行排序。这仅适用于字符串升序。任何人都可以提出更好的方法来做到这一点。
TableItem item = new TableItem(table, SWT.NONE);
item.setText(new String[] { "1", "v", "1.1", "20/03/2013" });
item = new TableItem(table, SWT.NONE);
item.setText(new String[] { "10", "z", "1.5", "20/04/2013" });
item = new TableItem(table, SWT.NONE);
item.setText(new String[] { "3", "a", "1.3", "30/01/2013" });
Listener sortListener = new Listener() {
public void handleEvent(Event e) {
TableItem[] items = table.getItems();
Collator collator = Collator.getInstance(Locale.getDefault());
TableColumn column = (TableColumn) e.widget;
int index = column == tblclmnNumber ? 0 : 1;
for (int i = 1; i < items.length; i++) {
String value1 = items[i].getText(index);
for (int j = 0; j < i; j++) {
String value2 = items[j].getText(index);
if (collator.compare(value1, value2) < 0) {
String[] values = { items[i].getText(0),
items[i].getText(1), items[i].getText(2),
items[i].getText(3) };
items[i].dispose();
TableItem item = new TableItem(table, SWT.NONE, j);
item.setText(values);
items = table.getItems();
break;
}
}
}
table.setSortColumn(column);
}
};
tblclmnNumber.addListener(SWT.Selection, sortListener);
tblclmnName.addListener(SWT.Selection, sortListener);
tblclmnDeci.addListener(SWT.Selection, sortListener);
tblclmnDate.addListener(SWT.Selection, sortListener);
table.setSortColumn(tblclmnNumber);
table.setSortDirection(SWT.UP);
回答by Sorceror
I've modified the SWT snippet with sorting to show how is possible to sort columns with with different data types..
我已经通过排序修改了 SWT 片段，以展示如何对具有不同数据类型的列进行排序。
/*
* Table example snippet: sort a table by column
*
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
*
* @since 3.2
*/
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Date;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.TableItem;
public class SortTable {
private TableRow rows[] = new TableRow[] {
new TableRow(1, "aaa", new Date(1363784269000L)),
new TableRow(2, "abc", new Date(1367784269000L)),
new TableRow(3, "efc", new Date(1363584269000L)),
new TableRow(4, "ccc", new Date(1363734269000L)),
};
private Table table;
private TableColumn intColumn;
private TableColumn strColumn;
private TableColumn dateColumn;
public SortTable() {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
table = new Table(shell, SWT.BORDER);
table.setHeaderVisible(true);
intColumn = new TableColumn(table, SWT.NONE);
intColumn.setText("int");
intColumn.setWidth(50);
strColumn = new TableColumn(table, SWT.NONE);
strColumn.setText("string");
strColumn.setWidth(50);
dateColumn = new TableColumn(table, SWT.NONE);
dateColumn.setText("date");
dateColumn.setWidth(100);
updateTable();
Listener sortListener = new Listener() {
public void handleEvent(Event e) {
TableColumn column = (TableColumn) e.widget;
if (column == intColumn) Arrays.sort(rows, BY_VAL);
if (column == strColumn) Arrays.sort(rows, BY_STR);
if (column == dateColumn) Arrays.sort(rows, BY_DATE);
table.setSortColumn(column);
updateTable();
}
};
intColumn.addListener(SWT.Selection, sortListener);
strColumn.addListener(SWT.Selection, sortListener);
dateColumn.addListener(SWT.Selection, sortListener);
shell.setSize(shell.computeSize(SWT.DEFAULT, SWT.DEFAULT).x, 300);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
private void updateTable() {
table.removeAll();
for (TableRow row : rows) {
TableItem item = new TableItem(table, SWT.NONE);
item.setText(row.asString());
}
}
public final Comparator<TableRow> BY_VAL = new Comparator<TableRow>() {
@Override
public int compare(TableRow o1, TableRow o2) {
if (o1.val < o2.val) return -1;
if (o1.val > o2.val) return 1;
return 0;
}
};
public final Comparator<TableRow> BY_STR = new Comparator<TableRow>() {
@Override
public int compare(TableRow o1, TableRow o2) {
return o1.str.compareTo(o2.str);
}
};
public final Comparator<TableRow> BY_DATE = new Comparator<TableRow>() {
@Override
public int compare(TableRow o1, TableRow o2) {
return o1.date.compareTo(o2.date);
}
};
private class TableRow {
private int val;
private String str;
private Date date;
private SimpleDateFormat format = new SimpleDateFormat();
public TableRow(int val, String str, Date date) {
this.val = val;
this.str = str;
this.date = date;
}
public String[] asString() {
return new String[] {Integer.toString(val), str, format.format(date)};
}
}
public static void main(String[] args) {
new SortTable();
}
}
Summarizeit's totally up to programmer how will be columns in table sorted, because table just always wants array of String for a row whatever they mean..
总结一下这完全取决于程序员如何对表中的列进行排序，因为无论表的含义如何，表总是需要一行字符串的数组。
回答by pretzalcoatl
You can throw a comparator for the column in as data to the column, and then use it to sort. This keeps the sorting logic closer to the definition of the column itself.
您可以将列的比较器作为数据扔到列中，然后使用它进行排序。这使排序逻辑更接近于列本身的定义。
intColumn = new TableColumn(table, SWT.NONE);
intColumn.setText("int");
intColumn.setWidth(50);
intColumn.setData(new Comparator<TableItem>() {
@Override
public int compare(TableItem t1, TableItem t2) {
int i1 = Integer.parseInt(t1.getText(0));
int i2 = Integer.parseInt(t2.getText(0));
if (i1.val < i2.val) return -1;
if (i1.val > i2.val) return 1;
return 0;
}
};
strColumn = new TableColumn(table, SWT.NONE);
strColumn.setText("string");
strColumn.setWidth(50);
strColumn.setData(new Comparator<TableItem>() {
@Override
public int compare(TableItem t1, TableItem t2) {
return t1.getText(1).compareTo(t2.getText(1));
}
};
dateColumn = new TableColumn(table, SWT.NONE);
dateColumn.setText("date");
dateColumn.setWidth(100);
dateColumn.setData(new Comparator<TableItem>() {
@Override
public int compare(TableItem t1, TableItem t2) {
return Date.parse(t1.getText(2)).compareTo(Date.parse(t2.getText(2)));
}
};
Listener sortListener = e -> {
TableColumn sortColumn = table.getSortColumn();
TableColumn selectedColumn = (TableColumn) e.widget;
int dir = table.getSortDirection();
if (sortColumn == selectedColumn) {
dir = dir == SWT.UP ? SWT.DOWN : SWT.UP;
} else {
table.setSortColumn(selectedColumn);
dir = SWT.UP;
}
TableItem[] items = table.getItems();
final Comparator<TableItem> comparator = (Comparator<TableItem>) selectedColumn.getData();
for (int i = 1; i < items.length; i++) {
for (int j = 0; j < i; j++) {
if ((comparator.compare(items[i], items[j]) < 0 && dir == SWT.UP) || (comparator.compare(items[i], items[j]) > 0 && dir == SWT.DOWN)) {
String[] oldItem = new String[table.getColumnCount()];
for (int h = 0; h < table.getColumnCount(); h++) {
item[h] = items[i].getText(h);
}
items[i].dispose();
TableItem newItem = new TableItem(table, SWT.NONE, j);
newItem.setText(oldItem);
items = table.getItems();
break;
}
}
}
table.setSortDirection(dir);
};
