java - jtreeのjcheckboxからの複数のITEM_STATE_CHANGEDイベント

Question

誰か、私に説明してください、それがどのように機能するか。コードは次のとおりです。

package checkboxtree;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseEvent;
import java.util.EventObject;
import java.util.Vector;

import javax.swing.AbstractCellEditor;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;

public class CheckBoxNodeTreeSample {
  public static void main(String args[]) {
    JFrame frame = new JFrame("CheckBox Tree");

    CheckBoxNode accessibilityOptions[] = {
        new CheckBoxNode(
            "Move system caret with focus/selection changes", false),
        new CheckBoxNode("Always expand alt text for images", true) };
    CheckBoxNode browsingOptions[] = {
        new CheckBoxNode("Notify when downloads complete", true),
        new CheckBoxNode("Disable script debugging", true),
        new CheckBoxNode("Use AutoComplete", true),
        new CheckBoxNode("Browse in a new process", false) };
    Vector accessVector = new NamedVector("Accessibility",
        accessibilityOptions);
    Vector browseVector = new NamedVector("Browsing", browsingOptions);
    Object rootNodes[] = { accessVector, browseVector };
    Vector rootVector = new NamedVector("Root", rootNodes);
    JTree tree = new JTree(rootVector);

    CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();
    tree.setCellRenderer(renderer);

    tree.setCellEditor(new CheckBoxNodeEditor(tree));
    tree.setEditable(true);

    JScrollPane scrollPane = new JScrollPane(tree);
    frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
    frame.setSize(300, 150);
    frame.setVisible(true);
  }
}

class CheckBoxNodeRenderer implements TreeCellRenderer {
  private JCheckBox leafRenderer = new JCheckBox();

  private DefaultTreeCellRenderer nonLeafRenderer = new DefaultTreeCellRenderer();

  Color selectionBorderColor, selectionForeground, selectionBackground,
      textForeground, textBackground;

  protected JCheckBox getLeafRenderer() {
    return leafRenderer;
  }

  public CheckBoxNodeRenderer() {
    Font fontValue;
    fontValue = UIManager.getFont("Tree.font");
    if (fontValue != null) {
      leafRenderer.setFont(fontValue);
    }
    Boolean booleanValue = (Boolean) UIManager
        .get("Tree.drawsFocusBorderAroundIcon");
    leafRenderer.setFocusPainted((booleanValue != null)
        && (booleanValue.booleanValue()));

    selectionBorderColor = UIManager.getColor("Tree.selectionBorderColor");
    selectionForeground = UIManager.getColor("Tree.selectionForeground");
    selectionBackground = UIManager.getColor("Tree.selectionBackground");
    textForeground = UIManager.getColor("Tree.textForeground");
    textBackground = UIManager.getColor("Tree.textBackground");
  }

  public Component getTreeCellRendererComponent(JTree tree, Object value,
      boolean selected, boolean expanded, boolean leaf, int row,
      boolean hasFocus) {

    Component returnValue;
    if (leaf) {

      String stringValue = tree.convertValueToText(value, selected,
          expanded, leaf, row, false);
      leafRenderer.setText(stringValue);
      leafRenderer.setSelected(false);

      leafRenderer.setEnabled(tree.isEnabled());

      if (selected) {
        leafRenderer.setForeground(selectionForeground);
        leafRenderer.setBackground(selectionBackground);
      } else {
        leafRenderer.setForeground(textForeground);
        leafRenderer.setBackground(textBackground);
      }

      if ((value != null) && (value instanceof DefaultMutableTreeNode)) {
        Object userObject = ((DefaultMutableTreeNode) value)
            .getUserObject();
        if (userObject instanceof CheckBoxNode) {
          CheckBoxNode node = (CheckBoxNode) userObject;
          leafRenderer.setText(node.getText());
          System.out.println("setting state");
          System.out.println(node.getText());
          System.out.println(node.isSelected());
          leafRenderer.setSelected(node.isSelected());
        }
      }
      returnValue = leafRenderer;
    } else {
      returnValue = nonLeafRenderer.getTreeCellRendererComponent(tree,
          value, selected, expanded, leaf, row, hasFocus);
    }
    return returnValue;
  }
}

class CheckBoxNodeEditor extends AbstractCellEditor implements TreeCellEditor {

  CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();
  public static int clickCount = 0;

  ChangeEvent changeEvent = null;

  JTree tree;

  public CheckBoxNodeEditor(JTree tree) {
    this.tree = tree;
  }

  public Object getCellEditorValue() {
      System.out.println("getCellEditorValue method called!");
    JCheckBox checkbox = renderer.getLeafRenderer();
    CheckBoxNode checkBoxNode = new CheckBoxNode(checkbox.getText(),
        checkbox.isSelected());
    return checkBoxNode;
  }

  public boolean isCellEditable(EventObject event) {

      System.out.println("isCellEditable method called");

      boolean returnValue = false;
    if (event instanceof MouseEvent) {
      MouseEvent mouseEvent = (MouseEvent) event;
      TreePath path = tree.getPathForLocation(mouseEvent.getX(),
          mouseEvent.getY());
      if (path != null) {
        Object node = path.getLastPathComponent();
        if ((node != null) && (node instanceof DefaultMutableTreeNode)) {
          DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) node;
          Object userObject = treeNode.getUserObject();
          returnValue = ((treeNode.isLeaf()) && (userObject instanceof CheckBoxNode));
        }
      }
    }
    return returnValue;
  }

  public Component getTreeCellEditorComponent(JTree tree, Object value,
      boolean selected, boolean expanded, boolean leaf, int row) {

      System.out.println("getTreeCellEditorComponent method called!");

      System.out.println(String.valueOf(clickCount++));

    Component editor = renderer.getTreeCellRendererComponent(tree, value,
        true, expanded, leaf, row, true);

    // editor always selected / focused
    ItemListener itemListener = new ItemListener() {
      public void itemStateChanged(ItemEvent itemEvent) {
          JCheckBox item = (JCheckBox)itemEvent.getItem();
          System.out.println(itemEvent.paramString());
          System.out.println("item "+item.getText()+" state Changed!");

          if (stopCellEditing()) {
              fireEditingStopped();
          }
      }
    };
    if (editor instanceof JCheckBox) {
      ((JCheckBox) editor).addItemListener(itemListener);
    }

    return editor;
  }
}

class CheckBoxNode {
  String text;

  boolean selected;

  public CheckBoxNode(String text, boolean selected) {
    this.text = text;
    this.selected = selected;
  }

  public boolean isSelected() {
    return selected;
  }

  public void setSelected(boolean newValue) {
    selected = newValue;
  }

  public String getText() {
    return text;
  }

  public void setText(String newValue) {
    text = newValue;
  }

  public String toString() {
    return getClass().getName() + "[" + text + "/" + selected + "]";
  }
}

class NamedVector extends Vector {
  String name;

  public NamedVector(String name) {
    this.name = name;
  }

  public NamedVector(String name, Object elements[]) {
    this.name = name;
    for (int i = 0, n = elements.length; i < n; i++) {
      add(elements[i]);
    }
  }

  public String toString() {
    return "[" + name + "]";
  }
}

そしてここに出力があります：

isCellEditable method called
getTreeCellEditorComponent method called!
0
setting state
Use AutoComplete
true
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=DESELECTED
item Use AutoComplete state Changed!
getCellEditorValue method called!
setting state
Use AutoComplete
false
setting state
Use AutoComplete
false
setting state
Use AutoComplete
false

isCellEditable method called
getTreeCellEditorComponent method called!
1
setting state
Use AutoComplete
false
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=SELECTED
item Use AutoComplete state Changed!
getCellEditorValue method called!
setting state
Use AutoComplete
true
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=SELECTED
item Use AutoComplete state Changed!
setting state
Use AutoComplete
true
setting state
Use AutoComplete
true

isCellEditable method called
getTreeCellEditorComponent method called!
2
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=checkboxtree.CheckBoxNode[Use AutoComplete/true]],stateChange=DESELECTED
item checkboxtree.CheckBoxNode[Use AutoComplete/true] state Changed!
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=checkboxtree.CheckBoxNode[Use AutoComplete/true]],stateChange=DESELECTED
item checkboxtree.CheckBoxNode[Use AutoComplete/true] state Changed!
setting state
Use AutoComplete
true
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=SELECTED
item Use AutoComplete state Changed!
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=SELECTED
item Use AutoComplete state Changed!
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=DESELECTED
item Use AutoComplete state Changed!
getCellEditorValue method called!
setting state
Use AutoComplete
false
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=DESELECTED
item Use AutoComplete state Changed!
ITEM_STATE_CHANGED,item=javax.swing.JCheckBox[,40,84,129x24,invalid,alignmentX=0.0,alignmentY=0.5,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@b179c3,flags=296,maximumSize=,minimumSize=,preferredSize=,defaultIcon=,disabledIcon=,disabledSelectedIcon=,margin=javax.swing.plaf.InsetsUIResource[top=2,left=2,bottom=2,right=2],paintBorder=false,paintFocus=false,pressedIcon=,rolloverEnabled=true,rolloverIcon=,rolloverSelectedIcon=,selectedIcon=,text=Use AutoComplete],stateChange=DESELECTED
item Use AutoComplete state Changed!
setting state
Use AutoComplete
false
setting state
Use AutoComplete
false

getCellEditorValueメソッドの後にgetTreeCellRendererComponentメソッドが3回呼び出される理由がわかりません。

そして、 JCheckboxを複数クリックすると、なぜJCheckboxが非常に多くのITEM_STATE_CHANGEDイベントを生成するのでしょうか。

score 1 · Accepted Answer

レンダラーに関して：

getTreeCellRendererComponentへの呼び出しの数は制御できません（内部のペイントメカニズムが必要であると判断した場合は常にツリー全体で使用されます）

編集者に関して：

getTreeCellEditorComponentを呼び出すたびに、新しいリスナーを作成して登録しています...選択状態の変更についてすべて通知されます
itemListenerは、選択を変更すると2回呼び出されます（選択/選択解除に対してそれぞれ1回）
選択状態の初期設定も2回発生する可能性があるため、リスナーごとにクリックごとに合計4つのイベントが発生します。
編集を停止するためのロジックが少し多すぎます。super.stopCellEditingを呼び出すと、すでにeditingStoppedが起動されます:-)

ItemListenerの代わりにActionListenerを使用することを検討してください。

java - jtreeのjcheckboxからの複数のITEM_STATE_CHANGEDイベント

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