How to add ComboBox as a cell editor in scala.swing.Table?

Question

I'm trying to add ComboBox as a Column Cell Editor for each cell in a second column in Scala Swing application and struggle to do. Following code shows what I have tried so far, please help me to change the code to achieve the task.

import swing._
import javax.swing.JComboBox
import javax.swing.table.AbstractTableModel
import javax.swing.DefaultCellEditor

//////////////////////////////////////////////////////////////////////////////////////////////////
class MyModel(var cells: Array[Array[Any]], val columns: Array[Any] ) extends AbstractTableModel {
  def getRowCount(): Int = cells.length

  def getColumnCount(): Int = columns.length

  def getValueAt(row: Int, col: Int): AnyRef = cells(row)(col).asInstanceOf[AnyRef]

  override def getColumnClass(column: Int) = getValueAt(0, column).getClass

  override def isCellEditable(row: Int, column: Int) = if (column == 0) false else true

  override def setValueAt(value: Any, row: Int, col: Int) {
    cells(row)(col) = value
    fireTableCellUpdated(row, col)
  }

  override def getColumnName(column: Int): String = columns(column).toString
}

//////////////////////////////////////////////////////////////////////////////////////////////////
class TestTable extends ScrollPane {
  final val columns: Array[Any] = Array[Any]( "Column1", "Column2" )

  final val Col1Data: Array[Any] = Array[Any]( "Col1_Data",
      "Col2_Data", "Col3_Data", "Col4_Data", "Col5_Data", "Col6_Data"
  )

  var modelarr = Array.ofDim[Any](Col1Data.length, columns.length)

  for (i <- 0 until Col1Data.length) {
    modelarr(i)(0) = Col1Data(i)
    // Have tried to set it to 1/"Value2"
    modelarr(i)(1) = "Value2"
  }

  val table = new Table( modelarr, columns ) {

    val mymodel = new MyModel(modelarr, columns)
    model = mymodel

    val Col1 = peer.getColumnModel.getColumn( 1 )
    val cb = new JComboBox[String](Array("Value1", "Value2", "Value3"))
    Col1.setCellEditor( new DefaultCellEditor( cb ) )
  }

  viewportView = table
}

//////////////////////////////////////////////////////////////////////////////////////////////////
object MyCombo extends SimpleSwingApplication {

  override def main(args: Array[String]) = super.main(args)

  var mytable = new TestTable

  def top = new MainFrame {
    title = "Table Test"
    contents = mytable
  }
}

Update:

Just found similair question: How to embed a (working) Button in a Swing Table in Scala? Will try suggested approach.

score 1 · Accepted Answer · edited May 23 '17 at 11:45

Thanks Nickal for hints. My own solution is a modified version of original code and posting only changes here.

Modified import block:

import scala.swing._
import scala.swing.Swing._
import javax.swing._
import javax.swing.table.{TableCellEditor, AbstractTableModel}
import java.awt.{Component => AWTComponent}

Added two traits to be able to mix java classes in new class:

//////////////////////////////////////////////////////////////////////////////////////////////////
trait AbstractCellEditorTrait extends AbstractCellEditor

//////////////////////////////////////////////////////////////////////////////////////////////////
trait TableCellEditorTrait extends TableCellEditor

//////////////////////////////////////////////////////////////////////////////////////////////////
class comboboxEditor(val currentValue: AnyRef) extends AbstractCellEditorTrait with TableCellEditorTrait {
  private val cb  = new ComboBox(Array("Value1", "Value2", "Value3"))
  cb.selection.item = currentValue.toString

  def getCellEditorValue: AnyRef = cb.selection.item.asInstanceOf[AnyRef]

  def getTableCellEditorComponent(tab: JTable, value: AnyRef, isSelected: Boolean, row: Int, col: Int): AWTComponent = {
    cb.peer.asInstanceOf[AWTComponent]
  }
}

Modified code wich sets an cell editor in TestTable class (3 lines of code starting with val Col1 = peer.g are replaced with code below):

  override def editor(row: Int, col: Int): TableCellEditor = {
    if (col == 1) 
      new comboboxEditor(mymodel.getValueAt(row, col))
    else 
      super.editor(row, col)
    }

It wasn't clear to me why you have the traits `AbstractCellEditorTrait` and `TableCellEditorTrait`. I tried your example (thanks), but didn't need them. — Core, Jan 23 '16 at 22:11

Core · Answer 2 · 2016-01-23T23:32:34.207

Building on e_z's code, I separated out a BaseEditor abstract class for the common code since eventually I needed to also implement isCellEditable. In the sub-class of BaseEditor you need an instance of editor that is your component and to implement getCellEditorValue.

  abstract class BaseEditor extends AbstractCellEditor with TableCellEditor {
    protected val editor: Component  // scala.swing.Component

    override def isCellEditable(e: EventObject): Boolean= {
      if (super.isCellEditable(e)) {
        e match {
          case me: java.awt.event.MouseEvent => me.getClickCount >= 2
          case ke: java.awt.event.KeyEvent => 
            // F2 not working, for some reason keypress arrives as ActionEvent
            ke.getKeyCode == java.awt.event.KeyEvent.VK_F2  
          case ae: java.awt.event.ActionEvent => false // ignore for now
          case x => false  // otherwise ignore
        }
      } else false
    }

    def getTableCellEditorComponent(table: JTable, value: AnyRef,
                                    selected: Boolean, row: Int, col: Int): AWTComponent= {
      editor.peer.asInstanceOf[AWTComponent]
    }

  }

  // example extending BaseEditor and custom StringData object
  case class StringData(s: String)
  class TextFieldEditor(current: StringData) extends BaseEditor {
    protected val editor= new TextField(current.s)

    def getCellEditorValue: AnyRef= StringData(editor.text)
  }

How to add ComboBox as a cell editor in scala.swing.Table?

2 Answers2