[gui][patch] various fixes in swing text painting

[graydon hoare <graydon at redhat dot com>]

hi,

this patch improves the swing text components' ability to cope with 
focus transfers, caret movement, and the painting of multiple lines and 
tabs in general. I've committed it to java-gui-branch.

-graydon

2004-11-11  Graydon Hoare  <graydon@redhat.com>

	* javax/swing/plaf/basic/BasicTextUI.java:
	Listen to focus events, indicate focus via caret.
	* javax/swing/text/GapContent.java (getString): Return substring.
	* javax/swing/text/PlainDocument.java (reindex): New method.
	(createDefaultRoot): Call it.
	(insertUpdate): Likewise.
	(removeUpdate): Likewise.
	* javax/swing/text/Utilities.java (drawTabbedText): Always advance
	on tab and newline, even if no painting happens.

--- javax/swing/plaf/basic/BasicTextUI.java	10 Nov 2004 07:19:49 -0000	1.4.16.16
+++ javax/swing/plaf/basic/BasicTextUI.java	11 Nov 2004 07:48:35 -0000
@@ -45,6 +45,8 @@
 import java.awt.Point;
 import java.awt.Rectangle;
 import java.awt.Shape;
+import java.awt.event.FocusEvent;
+import java.awt.event.FocusListener;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 
@@ -228,9 +230,20 @@
     caret.setBlinkRate(defaults.getInt(prefix + ".caretBlinkRate"));
   }
 
+  private FocusListener focuslistener = new FocusListener() {
+      public void focusGained(FocusEvent e) 
+      {
+        textComponent.repaint();
+      }
+      public void focusLost(FocusEvent e)
+      {
+        textComponent.repaint();
+      }
+    };
+
   protected void installListeners()
   {
-    // Do nothing here.
+    textComponent.addFocusListener(focuslistener);
   }
 
   protected String getKeymapName()
@@ -328,7 +341,7 @@
 
   protected void uninstallListeners()
   {
-    // Do nothing here.
+    textComponent.removeFocusListener(focuslistener);
   }
 
   protected void uninstallKeyboardActions()
@@ -367,7 +380,7 @@
 
     rootView.paint(g, getVisibleEditorRect());
 
-    if (caret != null)
+    if (caret != null && textComponent.hasFocus())
       caret.paint(g);
   }
 
--- javax/swing/text/GapContent.java	16 Jun 2004 10:06:47 -0000	1.2.8.2
+++ javax/swing/text/GapContent.java	11 Nov 2004 07:48:35 -0000
@@ -93,7 +93,7 @@
 
   public String getString(int where, int len) throws BadLocationException
   {
-    return buf.toString();
+    return buf.substring(where, where+len);
   }
 
   public void getChars(int where, int len, Segment txt)
--- javax/swing/text/PlainDocument.java	20 Jun 2004 15:27:41 -0000	1.1.52.3
+++ javax/swing/text/PlainDocument.java	11 Nov 2004 07:48:35 -0000
@@ -37,6 +37,8 @@
 
 package javax.swing.text;
 
+import java.util.ArrayList;
+
 public class PlainDocument extends AbstractDocument
 {
   private static final long serialVersionUID = 4758290289196893664L;
@@ -59,14 +61,53 @@
     rootElement = createDefaultRoot();
   }
 
-  protected AbstractDocument.AbstractElement createDefaultRoot()
+  protected void reindex()
+  {
+    Element[] lines;
+    try 
+      {
+        String str = content.getString(0, content.length());
+
+        ArrayList elts = new ArrayList();
+        int j = 0;
+        for (int i = str.indexOf('\n', 0); i != -1; i = str.indexOf('\n', i+1))
+          {
+            elts.add(createLeafElement(rootElement, null, j, i));
+            j = i;
+          }
+        
+        if (j < content.length())
+          elts.add(createLeafElement(rootElement, null, j, content.length()));
+        
+        lines = new Element[elts.size()];
+        for (int i = 0; i < elts.size(); ++i)
+          lines[i] = (Element) elts.get(i);
+        
+      }
+    catch (BadLocationException e)
   {
-    BranchElement rootElement =
-      (BranchElement) createBranchElement(null, null);
-    Element[] lines = new Element[1];
+        lines = new Element[1];
     lines[0] = createLeafElement(rootElement, null, 0, 1);
-    rootElement.replace(0, 0, lines);
-    return rootElement;
+      }
+
+    ((BranchElement) rootElement).replace(0, rootElement.getElementCount(), lines);
+  }
+
+  protected AbstractDocument.AbstractElement createDefaultRoot()
+  {
+    rootElement = createBranchElement(null, null);
+    reindex();
+    return (AbstractElement) rootElement;
+  }
+
+  protected void insertUpdate(DefaultDocumentEvent chng, AttributeSet attr)
+  {
+    reindex();
+  }
+
+  protected void removeUpdate(DefaultDocumentEvent chng)
+  {
+    reindex();
   }
 
   public Element getDefaultRootElement()
--- javax/swing/text/Utilities.java	4 Oct 2004 16:45:49 -0000	1.1.2.6
+++ javax/swing/text/Utilities.java	11 Nov 2004 07:48:35 -0000
@@ -98,11 +98,13 @@
     for (int offset = s.offset; offset < (s.offset + s.count); ++offset)
       {
         char c = buffer[offset];
-        if (len > 0 && (c == '\t' || c == '\n'))
+        if (c == '\t' || c == '\n')
           {
+            if (len > 0) {
 	    g.drawChars(buffer, pos, len, pixelX, pixelY + ascent);            
             pixelX += pixelWidth;
             pixelWidth = 0;
+            }
             pos = offset+1;
             len = 0;
           }