[cp-patches] FYI: Prevent multiple lines in JTextField

[Meskauskas Audrius]

JTextField is always a single line component. In GNU Classpath, it is 
possible to make it multi line by setting or pasting the line with line 
feeds. While this is highly impressive, the Sun's implementation never 
does this, replacing the line feeds by spaces instead. The unwanted 
resizing of the component generally does not look well in the 
applications that do not expect this.

The simplest way to reach the identical behaviour is to override setText 
and replaceSelection, replacing (if present) line feeds and carriage 
returns by spaces.

2005-11-15  Audrius Meskauskas  <address@hidden>

* javax/swing/JTextField.java (setText, replaceSelection, filterString): 
New methods.

Index: javax/swing/JTextField.java
===================================================================
RCS file: /cvsroot/classpath/classpath/javax/swing/JTextField.java,v
retrieving revision 1.26
diff -u -r1.26 JTextField.java
--- javax/swing/JTextField.java 31 Oct 2005 16:22:51 -0000      1.26
+++ javax/swing/JTextField.java 15 Nov 2005 10:09:24 -0000
@@ -511,4 +511,45 @@
     // javax.swing.text.FieldView.
     return horizontalVisibility;
   }
+  
+  /**
+   * JTextField is a single line component. The method replaces the line
+   * feeds by spaces.
+   */
+  public void replaceSelection(String content)
+  {
+    super.replaceSelection(filterString(content));
+  }
+  
+  /**
+   * JTextField is a single line component. The method replaces the line
+   * feeds by spaces.
+   */
+  public void setText(String content)
+  {
+    super.setText(filterString(content));
+  }
+  
+  /**
+   * Replaces line feeds and carriage returns by spaces.
+   * 
+   * @param content
+   */
+  String filterString(String content)
+  {
+    if (content.indexOf('\n') >= 0 || content.indexOf('\r') >= 0)
+      {
+        StringBuilder b = new StringBuilder(content);
+        char c;
+        for (int i = 0; i < b.length(); i++)
+          {
+            c = b.charAt(i);
+            if (c == '\n' || c == '\r')
+              b.setCharAt(i, ' ');
+          }
+        return b.toString();
+      }
+    else
+      return content;
+  }
 }