更改JTable的选择行为以仅选择行或列中可变数量的单元格 [英] Alter selection behavior for a JTable to only select a variable number of cells in a row or column
问题描述
我有一个JTable，可以在其中启用行或列选择之间进行更改.此功能效果很好，但我希望能够确定在当前所选单元格旁边突出显示的单元格数量.当前，选择整个行或整个列.我试图添加一个ListSelectionModel来实现此功能，但它只允许选择整个行或整个列.以下是示例图片:
I have a JTable in which I alter between having row or column selection enabled. This feature works well but I want to be able to determine the number of cells which are highlighted adjacent to the currently selected cell. Currently, either the entire row or column is selected. I have tried to add a ListSelectionModel to implement this functionality but it only allows for either an entire row or column to be selected. Here are example images:
和
ADJACENTSELECTION默认情况下设置为2，所以我想在启用rowSelection时突出显示所选单元格左右两侧的2个单元格，或者当rowSelection为false时突出显示所选单元格上下的2个单元格.任何帮助将不胜感激.这是我的代码:
ADJACENTSELECTION is by default set to two so I'd like to highlight the 2 cells to the right and left of the selected cell when rowSelection is enabled or 2 cells above and below the selected cell when rowSelection is false. Any help would be greatly appreciated. Here is my code:
package selectionTest;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.KeyStroke;
import javax.swing.border.Border;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.table.DefaultTableModel;
public class App {
private void display() {
JFrame f = new JFrame("Demo");
JPanel gui = new JPanel(new BorderLayout());
GridTable gridTable = new GridTable(25, 25);
gui.add(gridTable, BorderLayout.CENTER);
f.add(gui);
f.setBackground(Color.BLUE);
gui.setBackground(Color.WHITE);
f.setLocationByPlatform(true);
f.pack();
f.setSize(500, 600);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new App().display();
}
});
}
}
class GridTable extends JTable {
static int ADJACENTSELECTION = 2;
boolean rowSelection = false;
int rows, cols;
public GridTable(int rows, int cols) {
this.rows = rows;
this.cols = cols;
this.setModel(new DefaultTableModel(rows, cols));
this.setShowGrid(true);
Border blackline = BorderFactory.createLineBorder(Color.black);
this.setBorder(blackline);
this.setGridColor(Color.black);
ActionMap map = this.getActionMap();
Action action = switchOrientation();
String keyStrokeAndKey = "control O";
KeyStroke keyStroke = KeyStroke.getKeyStroke(keyStrokeAndKey);
this.getInputMap().put(keyStroke, keyStrokeAndKey);
this.getActionMap().put(keyStrokeAndKey, action);
this.getSelectionModel().addListSelectionListener(new ListSelectionListener() {
public void valueChanged(ListSelectionEvent event) {
int row = getSelectedRow();
int column = getSelectedColumn();
if (rowSelection) {
setRowSelectionInterval(Math.max(0, row - ADJACENTSELECTION), Math.min(row, row + ADJACENTSELECTION));
} else {
setColumnSelectionInterval(Math.max(0, column - ADJACENTSELECTION), Math.min(column, column + ADJACENTSELECTION));
}
}
});
}
private AbstractAction switchOrientation() {
AbstractAction switchOrientation = new AbstractAction() {
@Override
public void actionPerformed(ActionEvent e) {
rowSelection = !rowSelection;
setColumnSelectionAllowed(rowSelection);
setRowSelectionAllowed(!rowSelection);
}
};
return switchOrientation;
}
}
推荐答案
您已经快到了，只需执行几个额外的步骤，就可以更新选择侦听器以仅突出显示特定的单元格:
You are almost there, just a couple of extra steps and you can update the selection listener to only highlight specific cells:
-
通过在
GridTable方法中添加this.setCellSelectionEnabled(true);允许选择特定的单元格:
Allow for selection of specific cells by adding
this.setCellSelectionEnabled(true);to yourGridTablemethod:
public GridTable(int rows, int cols) {
this.setCellSelectionEnabled(true);
//...
确保SelectionInterval范围/值正确:
make sure that the SelectionInterval ranges/values are correct:
if (rowSelection == true){
//Correct using `getRowCount()` for selection range
setRowSelectionInterval(Math.max(0, row - ADJACENTSELECTION), Math.min(getRowCount()-1, row + ADJACENTSELECTION));
}
else{
//Correct using `getColumnCount()` for selection range
setColumnSelectionInterval(Math.max(0, column - ADJACENTSELECTION), Math.min(getColumnCount()-1, column + ADJACENTSELECTION));
}
确保在更新选择时不会触发选择事件再次发生.您可以通过使用布尔值来跟踪选择事件来做到这一点:
Make sure that when you update the selection that it does not trigger the selection event to happen again. You can do this by using a boolean to track the selection event:
this.getSelectionModel().addListSelectionListener(new ListSelectionListener(){
//Use this to track changes
boolean initial = true;
//...
public void valueChanged(ListSelectionEvent e){
if (initial){
int column = getSelectedColumn();
int row = getSelectedRow();
//...
最后，将它们放在一起，这是全选侦听器(并且不要忘记将this.setCellSelectionEnabled(true);添加到GridTable中):
Finally, putting it all together, this is the full selection listener (And don't forget to add this.setCellSelectionEnabled(true); to GridTable):
this.getSelectionModel().addListSelectionListener(new ListSelectionListener(){
//Use this to track changes
boolean initial = true;
public void valueChanged(ListSelectionEvent e){
//Only change value on first select (This prevents the below from triggering itself)
if (initial){
int column = getSelectedColumn();
int row = getSelectedRow();
initial = false;
if (rowSelection == true){
setRowSelectionInterval(Math.max(0, row - ADJACENTSELECTION), Math.min(getRowCount()-1, row + ADJACENTSELECTION));
}
else{
setColumnSelectionInterval(Math.max(0, column - ADJACENTSELECTION), Math.min(getColumnCount()-1, column + ADJACENTSELECTION));
}
}
//Set the value back once a selection is complete
else{
initial = true;
}
}
});
这将突出显示选定的单元格，并在选择的两侧显示两个单元格
This will highlight the selected cell, and two cells either side of the selection
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