From 33613a85afc4b1481367fbe92a17ee59c240250b Mon Sep 17 00:00:00 2001
From: Sven Eisenhauer <sven@sven-eisenhauer.net>
Date: Fri, 10 Nov 2023 15:11:48 +0100
Subject: add new repo

---
 .../hjp5/examples/ButtonPanel.java                 | 154 +++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 Master/Reference Architectures and Patterns/hjp5/examples/ButtonPanel.java

(limited to 'Master/Reference Architectures and Patterns/hjp5/examples/ButtonPanel.java')

diff --git a/Master/Reference Architectures and Patterns/hjp5/examples/ButtonPanel.java b/Master/Reference Architectures and Patterns/hjp5/examples/ButtonPanel.java
new file mode 100644
index 0000000..2125aca
--- /dev/null
+++ b/Master/Reference Architectures and Patterns/hjp5/examples/ButtonPanel.java	
@@ -0,0 +1,154 @@
+/* ButtonPanel.java */
+
+import java.awt.*;
+import java.awt.event.*;
+import java.beans.*;
+import java.io.*;
+
+public class ButtonPanel
+extends Panel
+implements Serializable, ItemListener
+{
+  //---Instanzvariablen------------------------------------
+  protected CheckboxGroup cbg;
+  protected Checkbox[]    cb;
+  transient protected PropertyChangeSupport pcs;
+
+  //---Methoden--------------------------------------------
+  public ButtonPanel()
+  {
+    cbg = new CheckboxGroup();
+    cb = new Checkbox[0];
+    initTransientState();
+  }
+
+  //---Anzahl der RadioButtons-----------------------------
+  public void setButtonCnt(int cnt)
+  {
+    if (cnt != cb.length) {
+      int oldvalue = cb.length;
+      //Bisherige Buttons entfernen
+      if (cb.length > 0) {
+        removeAll();
+      }
+      cb = new Checkbox[cnt];
+      setLayout(new GridLayout(cnt, 1));
+      for (int i = 0; i < cnt; ++i) {
+        cb[i] = new Checkbox(
+          "RadioButton " + i,
+          cbg,
+          (i == 0 ? true : false)
+        );
+        cb[i].addItemListener(this); 
+        add(cb[i]);
+      }
+      //PropertyChangeEvents senden
+      pcs.firePropertyChange("buttonCnt", oldvalue, cnt);
+      if (cnt > 0) {
+        setSelected(0);
+      }
+      //Neu layouten 
+      setSize(getPreferredSize());
+      invalidate();
+      doLayout();
+      Container owner = getParent();
+      if (owner != null) {
+        owner.invalidate();
+        owner.doLayout();
+      }
+    }
+  }
+
+  public int getButtonCnt()
+  {
+    return cb.length;
+  }
+
+  //---Beschriftung der Buttons----------------------------
+  public void setLabel(int index, String label)
+  {
+    if (index >= 0 && index < cb.length) {
+      cb[index].setLabel(label);
+    }
+  }
+
+  public String getLabel(int index)
+  {
+    String ret = "***invalid index***";
+    if (index >= 0 && index < cb.length) {
+      ret = cb[index].getLabel();
+    }
+    return ret;
+  }
+
+  //---Selektiertes Element--------------------------------
+  public void setSelected(int index)
+  {
+    if (index >= 0 && index < cb.length) {
+      int oldvalue = getSelected();
+      cb[index].setState(true);
+      pcs.firePropertyChange("selected", oldvalue, index);
+    }
+  }
+
+  public int getSelected()
+  {
+    int ret = -1;
+    for (int i = 0; i < cb.length; ++i) {
+      if (cb[i].getState()) {
+        ret = i;
+        break;
+      }
+    }
+    return ret;
+  }
+
+  //---Verwaltung der PropertyChangeListener---
+  public void addPropertyChangeListener(
+    PropertyChangeListener l
+  )
+  {
+    pcs.addPropertyChangeListener(l);
+  }
+
+  public void removePropertyChangeListener(
+    PropertyChangeListener l
+  )
+  {
+    pcs.removePropertyChangeListener(l);
+  }
+
+  //---Reaktion auf Zustandsänderungen---------------------
+  public void itemStateChanged(ItemEvent event)
+  {
+    Checkbox changedcb = (Checkbox) event.getItemSelectable();
+    if (changedcb.getState()) {
+      for (int i = 0; i < cb.length; ++i) {
+        if (cb[i] == changedcb) {
+          pcs.firePropertyChange("selected", -1, i);
+          break;
+        }
+      }
+    }
+  }
+
+  //---Private Methoden------------------------------------
+  /**
+   * Initialisierung der nicht-persistenten Instanzvariablen.
+   */
+  private void initTransientState()
+  {
+    pcs = new PropertyChangeSupport(this);
+  }
+
+  /**
+   * Wird überlagert, um nach dem Deserialisieren den transienten
+   * Zustand zu initialisieren.
+   */
+  private void readObject(ObjectInputStream stream)
+  throws IOException, ClassNotFoundException
+  {
+    stream.defaultReadObject();
+    initTransientState();
+  }
+}
\ No newline at end of file
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