Merge pull request SKCraft#82 from seebs/master

Avoid pathological failure mode when trimming lines.
jensz12 · Aug 3, 2015 · 40555cc · 40555cc
2 parents 454aa32 + 2a50a19
commit 40555cc
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Showing 2 changed files with 46 additions and 28 deletions.
diff --git a/launcher/src/main/java/com/skcraft/launcher/swing/MessageLog.java b/launcher/src/main/java/com/skcraft/launcher/swing/MessageLog.java
@@ -111,21 +111,29 @@ public void clear() {
      * @param line line
      * @param attributes attribute set, or null for none
      */
-    public void log(String line, AttributeSet attributes) {
+    public void log(final String line, AttributeSet attributes) {
+        final Document d = document;
+        final JTextComponent t = textComponent;
         if (colorEnabled) {
             if (line.startsWith("(!!)")) {
                 attributes = highlightedAttributes;
             }
         }
+        final AttributeSet a = attributes;
 
-        try {
-            int offset = document.getLength();
-            document.insertString(offset, line,
-                    (attributes != null && colorEnabled) ? attributes : defaultAttributes);
-            textComponent.setCaretPosition(document.getLength());
-        } catch (BadLocationException ble) {
-
-        }
+        SwingUtilities.invokeLater(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    int offset = d.getLength();
+                    d.insertString(offset, line,
+                            (a != null && colorEnabled) ? a : defaultAttributes);
+                    t.setCaretPosition(d.getLength());
+                } catch (BadLocationException ble) {
+
+                }
+            }
+        });
     }
 
     /**

diff --git a/launcher/src/main/java/com/skcraft/launcher/util/LimitLinesDocumentListener.java b/launcher/src/main/java/com/skcraft/launcher/util/LimitLinesDocumentListener.java
@@ -21,6 +21,7 @@
 public class LimitLinesDocumentListener implements DocumentListener {
     private int maximumLines;
     private boolean isRemoveFromStart;
+    private volatile boolean isRemoving;
 
     /**
      * Specify the number of lines to be stored in the Document. Extra lines
@@ -34,6 +35,7 @@ public LimitLinesDocumentListener(int maximumLines,
                                       boolean isRemoveFromStart) {
         setLimitLines(maximumLines);
         this.isRemoveFromStart = isRemoveFromStart;
+        this.isRemoving = false;
     }
 
     /**
@@ -54,12 +56,15 @@ public void insertUpdate(final DocumentEvent e) {
         // Changes to the Document can not be done within the listener
         // so we need to add the processing to the end of the EDT
 
-        SwingUtilities.invokeLater(new Runnable() {
-            @Override
-            public void run() {
-                removeLines(e);
-            }
-        });
+        if (!this.isRemoving) {
+            this.isRemoving = true;
+            SwingUtilities.invokeLater(new Runnable() {
+                @Override
+                public void run() {
+                    removeLines(e);
+                }
+            });
+        }
     }
 
     @Override
@@ -74,20 +79,25 @@ private void removeLines(DocumentEvent e) {
         // The root Element of the Document will tell us the total number
         // of line in the Document.
 
-        Document document = e.getDocument();
-        Element root = document.getDefaultRootElement();
-
-        while (root.getElementCount() > maximumLines) {
-            if (isRemoveFromStart) {
-                removeFromStart(document, root);
-            } else {
-                removeFromEnd(document, root);
+        try {
+            Document document = e.getDocument();
+            Element root = document.getDefaultRootElement();
+            int excess = root.getElementCount() - maximumLines;
+
+            if (excess > 0) {
+                if (isRemoveFromStart) {
+                    removeFromStart(document, root, excess);
+                } else {
+                    removeFromEnd(document, root);
+                }
             }
+        } finally {
+            this.isRemoving = false;
         }
     }
 
-    private void removeFromStart(Document document, Element root) {
-        Element line = root.getElement(0);
+    private void removeFromStart(Document document, Element root, int excess) {
+        Element line = root.getElement(excess - 1);
         int end = line.getEndOffset();
 
         try {
@@ -101,14 +111,14 @@ private void removeFromEnd(Document document, Element root) {
         // We use start minus 1 to make sure we remove the newline
         // character of the previous line
 
-        Element line = root.getElement(root.getElementCount() - 1);
+        Element line = root.getElement(maximumLines);
         int start = line.getStartOffset();
-        int end = line.getEndOffset();
+        int end = root.getEndOffset();
 
         try {
             document.remove(start - 1, end - start);
         } catch (BadLocationException ble) {
             System.out.println(ble);
         }
     }
-}
+}