CardLayout.java (show): Rewrote.

2003-01-15  Scott Gilbertson  <scottg@mantatest.com>

	* java/awt/CardLayout.java (show): Rewrote.
	(gotoComponent): Removed `target' argument.  Simplified code.
	Don't pre-compute `choice' unless `what' is FIRST or LAST.
	Changed all callers.
	(NONE): Removed.

From-SVN: r61357

1 files changed, 26 insertions, 21 deletions

diff --git a/libjava/java/awt/CardLayout.java b/libjava/java/awt/CardLayout.java
index 10ffa2e..1900a60 100644
--- a/libjava/java/awt/CardLayout.java
+++ b/libjava/java/awt/CardLayout.java
@@ -1,6 +1,6 @@
 // CardLayout.java - Card-based layout engine
 
-/* Copyright (C) 1999, 2000, 2002  Free Software Foundation
+/* Copyright (C) 1999, 2000, 2002, 2003  Free Software Foundation
 
 This file is part of GNU Classpath.
 
@@ -110,7 +110,7 @@ public class CardLayout implements LayoutManager2, Serializable
    */
   public void first (Container parent)
   {
-    gotoComponent (parent, FIRST, null);
+    gotoComponent (parent, FIRST);
   }
 
   /** Return this layout manager's horizontal gap.  */
@@ -154,7 +154,7 @@ public class CardLayout implements LayoutManager2, Serializable
    */
   public void last (Container parent)
   {
-    gotoComponent (parent, LAST, null);
+    gotoComponent (parent, LAST);
   }
 
   /**
@@ -210,7 +210,7 @@ public class CardLayout implements LayoutManager2, Serializable
    */
   public void next (Container parent)
   {
-    gotoComponent (parent, NEXT, null);
+    gotoComponent (parent, NEXT);
   }
 
   /** Get the preferred layout size of the container.
@@ -228,7 +228,7 @@ public class CardLayout implements LayoutManager2, Serializable
    */
   public void previous (Container parent)
   {
-    gotoComponent (parent, PREV, null);
+    gotoComponent (parent, PREV);
   }
 
   /** Remove the indicated component from this layout manager.
@@ -273,7 +273,21 @@ public class CardLayout implements LayoutManager2, Serializable
   {
     Object target = tab.get (name);
     if (target != null)
-      gotoComponent (parent, NONE, (Component) target);
+      {
+	int num = parent.ncomponents;
+	// This is more efficient than calling getComponents().
+	Component[] comps = parent.component;
+	for (int i = 0; i < num; ++i)
+	  {
+	    if (comps[i].isVisible())
+	      {
+		if (target == comps[i])
+		  return;
+		comps[i].setVisible (false);
+	      }
+	  }
+	((Component) target).setVisible (true);
+      }
   }
 
   /**
@@ -286,9 +300,11 @@ public class CardLayout implements LayoutManager2, Serializable
     return getClass ().getName () + "[" + hgap + "," + vgap + "]";
   }
 
-  // This implements first(), last(), next(), and previous().
-  private void gotoComponent (Container parent, int what,
-			      Component target)
+  /** This implements first(), last(), next(), and previous().
+   * @param parent The parent container
+   * @param what The type of goto: FIRST, LAST, NEXT or PREV
+   */
+  private void gotoComponent (Container parent, int what)
   {
     synchronized (parent.getTreeLock ())
       {
@@ -301,19 +317,9 @@ public class CardLayout implements LayoutManager2, Serializable
 	  choice = 0;
 	else if (what == LAST)
 	  choice = num - 1;
-	else if (what >= 0)
-	  choice = what;
 
 	for (int i = 0; i < num; ++i)
 	  {
-	    // If TARGET is set then we are looking for a specific
-	    // component.
-	    if (target != null)
-	      {
-		if (target == comps[i])
-		  choice = i;
-	      }
-
 	    if (comps[i].isVisible ())
 	      {
 		if (what == NEXT)
@@ -335,7 +341,7 @@ public class CardLayout implements LayoutManager2, Serializable
 		    return;
 		  }
 		comps[i].setVisible (false);
-
+ 
 		if (choice >= 0)
 		  break;
 	      }
@@ -403,7 +409,6 @@ public class CardLayout implements LayoutManager2, Serializable
   private int LAST = 1;
   private int NEXT = 2;
   private int PREV = 3;
-  private int NONE = 4;
 
   // These constants are used by the private getSize method.
   private int MIN = 0;