Hi David,
I can take a look at this and create a JBS issue if you have not already
created one.
Regards
Prasanta
On 14-Feb-20 7:16 PM, David Polock wrote:
Hello,
this is my first post on the mailing list – please point me tot he
right places, if i’m off topic.
I have an issue with tab stops in a JTextArea. The behaviour is very
similar to the bug JDK-8187957, which was fixed for JDK10. I’m using
JDK11 and see the same (wrong) behaviour in my code.
After some tests i could confirm, that the bug was fixed for a
JTextArea without line wrapping. But calling
JTextArea::setLineWrap(true) leads again to the false behaviour.
So in a next step I cloned the git Source repository and examined the
patch for the Bug. Besides adding a testcase (TestTabSize.java) the
fix is changing some float calculation to int:
================================================
commit 0da4c70d2d542d8ff37ee34e4878829af696b694
Author: Prasanta Sadhukhan <[email protected]>
Date: Tue Nov 14 10:32:31 2017 +0530
8187957: Tab Size does not work correctly in JTextArea
Reviewed-by: ssadetsky, serb
diff --git
a/src/java.desktop/share/classes/javax/swing/text/PlainView.java
b/src/java.desktop/share/classes/javax/swing/text/PlainView.java
index 9d1b4fc..6aabc24 100644
--- a/src/java.desktop/share/classes/javax/swing/text/PlainView.java
+++ b/src/java.desktop/share/classes/javax/swing/text/PlainView.java
@@ -646,7 +646,7 @@ public class PlainView extends View implements
TabExpander {
if (tabSize == 0) {
return x;
}
- float ntabs = (x - tabBase) / tabSize;
+ int ntabs = (int) ((x - tabBase) / tabSize);
return tabBase + ((ntabs + 1) * tabSize);
}
================================================
So in PlainView.java one line was changed. I can see in the source
code, that the same (false) line exists in the class WrappedPlainView
– which is used as the rendering class, when setLineWrap(true) was called.
I think the same fix should be applied to the WrappedPlainView. I
could not confirm this fix, because i’m not able to easily build /
change the java.desktop module.
The issue is reproducible with the following code (adopted from the
mentioned bug):
------------- BEGIN CODE ------------------
public class TabTestJFrame extends javax.swing.JFrame {
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextArea jTextArea1;
public TabTestJFrame() {
initComponents();
jTextArea1.setTabSize( 8 );
}
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
setDefaultCloseOperation( javax.swing.WindowConstants.EXIT_ON_CLOSE );
jTextArea1.setFont( new java.awt.Font( "Monospaced", 0, 10 ) );
jTextArea1.setLineWrap( true ); // use WrappedPlainView as renderer
jTextArea1.setText(
"#################################################\n# Some
Text\t\t\t\t\t#\n# Some Other Much Longer
Text\t\t\t#\n#################################################" );
jScrollPane1.setViewportView( jTextArea1 );
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(
getContentPane() );
getContentPane().setLayout( layout );
layout.setHorizontalGroup( layout.createParallelGroup(
javax.swing.GroupLayout.Alignment.LEADING ).addGroup(
layout.createSequentialGroup()
.addContainerGap().addComponent( jScrollPane1,
javax.swing.GroupLayout.DEFAULT_SIZE, 446, Short.MAX_VALUE
).addContainerGap() ) );
layout.setVerticalGroup( layout.createParallelGroup(
javax.swing.GroupLayout.Alignment.LEADING )
.addGroup(
layout.createSequentialGroup().addContainerGap().addComponent(
jScrollPane1 ).addContainerGap() ) );
pack();
}
public static void main( String args[] ) {
System.out.println( "Java Version: " + System.getProperty(
"java.specification.version" ) );
java.awt.EventQueue.invokeLater( () -> {
new TabTestJFrame().setVisible( true );
} );
}
}
------------- END CODE ------------------
So my question: Can somebody easily confirm the problem? And if the
answer is yes, what are the next steps (creating a bug report – but
who and how ;-) ?)
Best regards,
David
