refactor: add instanceof check

Author: aterai

CellEditorInputVerifier/src/java/example/MainPanel.java

@@ -23,18 +23,20 @@
 public final class MainPanel extends JPanel {
   private MainPanel() {
     super(new BorderLayout());
+    JTextField field1 = new JTextField();
+    initBorderAndAlignment(field1);
+    Document doc1 = field1.getDocument();
+    if (doc1 instanceof AbstractDocument) {
+      ((AbstractDocument) doc1).setDocumentFilter(new IntegerDocumentFilter());
+    }
 
-    JTextField textField1 = new JTextField();
-    initBorderAndAlignment(textField1);
-    ((AbstractDocument) textField1.getDocument()).setDocumentFilter(new IntegerDocumentFilter());
-
-    JTextField textField2 = new JTextField();
-    initBorderAndAlignment(textField2);
-    textField2.setInputVerifier(new IntegerInputVerifier());
+    JTextField field2 = new JTextField();
+    initBorderAndAlignment(field2);
+    field2.setInputVerifier(new IntegerInputVerifier());
 
-    JFormattedTextField textField3 = new JFormattedTextField();
-    initBorderAndAlignment(textField3);
-    textField3.setFormatterFactory(new NumberFormatterFactory());
+    JFormattedTextField field3 = new JFormattedTextField();
+    initBorderAndAlignment(field3);
+    field3.setFormatterFactory(new NumberFormatterFactory());
 
     String[] columnNames = {"Default", "DocumentFilter", "InputVerifier", "JFormattedTextField"};
     TableModel model = new DefaultTableModel(columnNames, 10) {
@@ -45,12 +47,14 @@ private MainPanel() {
     JTable table = new JTable(model) {
       @Override public Component prepareEditor(TableCellEditor editor, int row, int column) {
         Component c = super.prepareEditor(editor, row, column);
-        ((JComponent) c).setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
+        if (c instanceof JComponent) {
+          ((JComponent) c).setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
+        }
         return c;
       }
     };
-    table.getColumnModel().getColumn(1).setCellEditor(new DefaultCellEditor(textField1));
-    table.getColumnModel().getColumn(2).setCellEditor(new DefaultCellEditor(textField2) {
+    table.getColumnModel().getColumn(1).setCellEditor(new DefaultCellEditor(field1));
+    table.getColumnModel().getColumn(2).setCellEditor(new DefaultCellEditor(field2) {
       @Override public boolean stopCellEditing() {
         JComponent editor = (JComponent) getComponent();
         boolean isEditValid = editor.getInputVerifier().verify(editor);
@@ -59,7 +63,7 @@ private MainPanel() {
         return isEditValid && super.stopCellEditing();
       }
     });
-    table.getColumnModel().getColumn(3).setCellEditor(new DefaultCellEditor(textField3) {
+    table.getColumnModel().getColumn(3).setCellEditor(new DefaultCellEditor(field3) {
       @Override public boolean stopCellEditing() {
         JFormattedTextField editor = (JFormattedTextField) getComponent();
         boolean isEditValid = editor.isEditValid();

DeleteKeyBeep/src/java/example/MainPanel.java

@@ -22,17 +22,18 @@ public final class MainPanel extends JPanel {
   private MainPanel() {
     super(new GridLayout(2, 1));
     JTextField field = new JTextField(12);
-
-    ((AbstractDocument) field.getDocument()).setDocumentFilter(new SizeFilter());
-    // ((AbstractDocument) field.getDocument()).setDocumentFilter(new DocumentSizeFilter(5));
+    Document doc = field.getDocument();
+    if (doc instanceof AbstractDocument) {
+      ((AbstractDocument) doc).setDocumentFilter(new SizeFilter());
+      // ((AbstractDocument) doc).setDocumentFilter(new DocumentSizeFilter(5));
+    }
 
     ActionMap am = field.getActionMap();
+    String delPrev = DefaultEditorKit.deletePrevCharAction; // "delete-previous";
+    am.put(delPrev, new SilentDeleteTextAction(delPrev, am.get(delPrev)));
 
-    String key = DefaultEditorKit.deletePrevCharAction; // "delete-previous";
-    am.put(key, new SilentDeleteTextAction(key, am.get(key)));
-
-    key = DefaultEditorKit.deleteNextCharAction; // "delete-next";
-    am.put(key, new SilentDeleteTextAction(key, am.get(key)));
+    String delNext = DefaultEditorKit.deleteNextCharAction; // "delete-next";
+    am.put(delNext, new SilentDeleteTextAction(delNext, am.get(delNext)));
 
     add(makeTitledPanel("Default", new JTextField()));
     add(makeTitledPanel("Override delete-previous, delete-next beep", field));
@@ -72,7 +73,7 @@ private static void createAndShowGui() {
 }
 
 class SilentDeleteTextAction extends TextAction {
-  private final Action deleteAction;
+  private final transient Action deleteAction;
 
   protected SilentDeleteTextAction(String name, Action deleteAction) {
     super(name);

FIFODocument/src/java/example/MainPanel.java

@@ -27,7 +27,10 @@ private MainPanel() {
     textArea1.setEditable(false);
 
     JTextArea textArea2 = new JTextArea();
-    ((AbstractDocument) textArea2.getDocument()).setDocumentFilter(new FifoDocumentFilter());
+    Document doc2 = textArea2.getDocument();
+    if (doc2 instanceof AbstractDocument) {
+      ((AbstractDocument) doc2).setDocumentFilter(new FifoDocumentFilter());
+    }
 
     Timer timer = new Timer(200, e -> {
       String s = LocalDateTime.now(ZoneId.systemDefault()).toString();

LastLineEditableTextArea/src/java/example/MainPanel.java

@@ -25,8 +25,10 @@ private MainPanel() {
     JTextArea textArea = new JTextArea();
     textArea.setMargin(new Insets(2, 5, 2, 2));
     textArea.setText(MESSAGE + NonEditableLineDocumentFilter.PROMPT);
-    ((AbstractDocument) textArea.getDocument()).setDocumentFilter(new NonEditableLineDocumentFilter());
-
+    Document doc = textArea.getDocument();
+    if (doc instanceof AbstractDocument) {
+      ((AbstractDocument) doc).setDocumentFilter(new NonEditableLineDocumentFilter());
+    }
     add(new JScrollPane(textArea));
     setPreferredSize(new Dimension(320, 240));
   }

NonEditableLine/src/java/example/MainPanel.java

@@ -25,11 +25,13 @@ private MainPanel() {
     JTextArea textArea = new JTextArea();
     textArea.setText("Non editable lines\naaa bbb ccc ddd eee\n1234567890\n1234567890987654321");
     DocumentFilter filter = new NonEditableLineDocumentFilter(maskRange);
-    ((AbstractDocument) textArea.getDocument()).setDocumentFilter(filter);
+    Document doc = textArea.getDocument();
+    if (doc instanceof AbstractDocument) {
+      ((AbstractDocument) doc).setDocumentFilter(filter);
+    }
+    Highlighter highlighter = textArea.getHighlighter();
+    Element root = doc.getDefaultRootElement();
     try {
-      Highlighter highlighter = textArea.getHighlighter();
-      Document doc = textArea.getDocument();
-      Element root = doc.getDefaultRootElement();
       for (int i = 0; i < maskRange; i++) { // root.getElementCount(); i++) {
         Element elm = root.getElement(i);
         highlighter.addHighlight(elm.getStartOffset(), elm.getEndOffset() - 1, highlightPainter);

NumericTextField/src/java/example/MainPanel.java

@@ -21,23 +21,25 @@
 public final class MainPanel extends JPanel {
   private MainPanel() {
     super(new BorderLayout());
+    JTextField field1 = new JTextField("1000");
+    field1.setHorizontalAlignment(SwingConstants.RIGHT);
+    field1.setInputVerifier(new IntegerInputVerifier());
+
+    JTextField field2 = new JTextField();
+    field2.setDocument(new IntegerDocument());
+    field2.setText("2000");
+
+    JTextField field3 = new JTextField();
+    Document doc = field3.getDocument();
+    if (doc instanceof AbstractDocument) {
+      ((AbstractDocument) doc).setDocumentFilter(new IntegerDocumentFilter());
+    }
+    field3.setText("3000");
 
-    JTextField textField1 = new JTextField("1000");
-    textField1.setHorizontalAlignment(SwingConstants.RIGHT);
-    textField1.setInputVerifier(new IntegerInputVerifier());
-
-    JTextField textField2 = new JTextField();
-    textField2.setDocument(new IntegerDocument());
-    textField2.setText("2000");
-
-    JTextField textField3 = new JTextField();
-    ((AbstractDocument) textField3.getDocument()).setDocumentFilter(new IntegerDocumentFilter());
-    textField3.setText("3000");
-
-    JFormattedTextField textField4 = new JFormattedTextField();
-    textField4.setFormatterFactory(new NumberFormatterFactory());
-    textField4.setHorizontalAlignment(SwingConstants.RIGHT);
-    textField4.setValue(4000);
+    JFormattedTextField field4 = new JFormattedTextField();
+    field4.setFormatterFactory(new NumberFormatterFactory());
+    field4.setHorizontalAlignment(SwingConstants.RIGHT);
+    field4.setValue(4000);
 
     JSpinner spinner = new JSpinner(new SpinnerNumberModel(0, 0, Integer.MAX_VALUE, 1));
     ((JSpinner.NumberEditor) spinner.getEditor()).getFormat().setGroupingUsed(false);
@@ -46,19 +48,19 @@ private MainPanel() {
     Box box = Box.createVerticalBox();
     box.setBorder(BorderFactory.createTitledBorder("TextField"));
     box.add(new JLabel("InputVerifier"));
-    box.add(textField1);
+    box.add(field1);
     box.add(Box.createVerticalStrut(10));
 
     box.add(new JLabel("Custom Document"));
-    box.add(textField2);
+    box.add(field2);
     box.add(Box.createVerticalStrut(10));
 
     box.add(new JLabel("DocumentFilter"));
-    box.add(textField3);
+    box.add(field3);
     box.add(Box.createVerticalStrut(10));
 
     box.add(new JLabel("FormatterFactory"));
-    box.add(textField4);
+    box.add(field4);
     box.add(Box.createVerticalStrut(10));
 
     JPanel p = new JPanel(new BorderLayout(5, 5));
@@ -178,12 +180,12 @@ class IntegerDocumentFilter extends DocumentFilter {
     fb.replace(offset, length, text, attrs);
   }
 
-  private static void checkInput(String proposedValue, int offset) throws BadLocationException {
-    if (!proposedValue.isEmpty()) {
+  private static void checkInput(String value, int offset) throws BadLocationException {
+    if (!value.isEmpty()) {
       try {
-        Integer.parseInt(proposedValue);
+        Integer.parseInt(value);
       } catch (NumberFormatException ex) {
-        throw (BadLocationException) new BadLocationException(proposedValue, offset).initCause(ex);
+        throw (BadLocationException) new BadLocationException(value, offset).initCause(ex);
       }
     }
   }

PageInputForPagination/src/java/example/MainPanel.java

@@ -71,9 +71,13 @@ private MainPanel() {
     KeyStroke enter = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0);
     field.getInputMap(JComponent.WHEN_FOCUSED).put(enter, "Enter");
     field.getActionMap().put("Enter", enterAction);
-    ((AbstractDocument) field.getDocument()).setDocumentFilter(new IntegerDocumentFilter());
+    Document doc = field.getDocument();
+    if (doc instanceof AbstractDocument) {
+      ((AbstractDocument) doc).setDocumentFilter(new IntegerDocumentFilter());
+    }
 
-    Stream.of(first, prev, next, last).forEach(b -> b.addActionListener(this::updateCurrentPageIndex));
+    Stream.of(first, prev, next, last)
+        .forEach(b -> b.addActionListener(this::updateCurrentPageIndex));
 
     new TableUpdateTask(2020, itemsPerPage).execute();
 
@@ -242,7 +246,8 @@ protected int load(int current, int size) throws InterruptedException {
 
   // private int load(Statement stat, int current, int limit) throws SQLException {
   //   List<Object[]> result = new ArrayList<>(limit);
-  //   String q = String.format("select * from moz_bookmarks limit %d offset %d", limit, current - 1);
+  //   String q = String.format(
+  //       "select * from moz_bookmarks limit %d offset %d", limit, current - 1);
   //   ResultSet rs = stat.executeQuery(q);
   //   int i = current;
   //   while (rs.next() && !isCancelled()) {