Created TimedPath to factor out code common to paths that effect

themselves in a fixed period of time.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1688 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/util/LinePath.java

@@ -1,5 +1,5 @@
 //
-// $Id: LinePath.java,v 1.9 2002/06/18 22:25:33 mdb Exp $
+// $Id: LinePath.java,v 1.10 2002/09/17 03:59:05 mdb Exp $
 
 package com.threerings.media.util;
 
@@ -11,13 +11,12 @@ import java.awt.Point;
 import com.samskivert.util.StringUtil;
 
 import com.threerings.media.Log;
-import com.threerings.media.util.MathUtil;
 
 /**
  * The line path is used to cause a pathable to go from point A to point B
  * in a certain number of milliseconds.
  */
-public class LinePath implements Path
+public class LinePath extends TimedPath
 {
     /**
      * Constructs a line path between the two specified points that will
@@ -34,29 +33,9 @@ public class LinePath implements Path
      */
     public LinePath (Point source, Point dest, long duration)
     {
-        // sanity check some things
+        super(duration);
-        if (duration <= 0) {
-            String errmsg = "Requested path with illegal duration (<=0) " +
-                "[duration=" + duration + "]";
-            throw new IllegalArgumentException(errmsg);
-        }
-
         _source = source;
         _dest = dest;
-        _duration = duration;
-    }
-
-    // documentation inherited
-    public void init (Pathable pable, long timestamp)
-    {
-        // give the pable a chance to perform any starting antics
-        pable.pathBeginning();
-
-        // make a note of when we started
-        _startStamp = timestamp;
-
-        // update our position to the start of the path
-        tick(pable, timestamp);
     }
 
     // documentation inherited
@@ -83,12 +62,6 @@ public class LinePath implements Path
         return false;
     }
 
-    // documentation inherited
-    public void fastForward (long timeDelta)
-    {
-        _startStamp += timeDelta;
-    }
-
     // documentation inherited
     public void paint (Graphics2D gfx)
     {
@@ -97,11 +70,11 @@ public class LinePath implements Path
     }
 
     // documentation inherited
-    public String toString ()
+    protected void toString (StringBuffer buf)
     {
-        return "[src=" + StringUtil.toString(_source) +
+        super.toString(buf);
-            ", dest=" + StringUtil.toString(_dest) +
+        buf.append(", src=").append(StringUtil.toString(_source));
-            ", duration=" + _duration + "ms]";
+        buf.append(", dest=").append(StringUtil.toString(_dest));
     }
 
     /**
@@ -125,10 +98,4 @@ public class LinePath implements Path
     /** A temporary point used when computing our position along the
      * path. */
     protected Point _tpos = new Point();
-
-    /** The time at which we started along the path. */
-    protected long _startStamp;
-
-    /** The duration that we're to spend following the path. */
-    protected long _duration;
 }

src/java/com/threerings/media/util/TimedPath.java

@@ -0,0 +1,71 @@
+//
+// $Id: TimedPath.java,v 1.1 2002/09/17 03:59:05 mdb Exp $
+
+package com.threerings.media.util;
+
+/**
+ * A base class for path implementations that endeavor to move their
+ * pathables along a path in a specified number of milliseconds.
+ */
+public abstract class TimedPath implements Path
+{
+    /**
+     * Configures the timed path with the duration in which it must
+     * traverse its path.
+     */
+    public TimedPath (long duration)
+    {
+        // sanity check some things
+        if (duration <= 0) {
+            String errmsg = "Requested path with illegal duration (<=0) " +
+                "[duration=" + duration + "]";
+            throw new IllegalArgumentException(errmsg);
+        }
+
+        _duration = duration;
+    }
+
+    // documentation inherited
+    public void init (Pathable pable, long timestamp)
+    {
+        // give the pable a chance to perform any starting antics
+        pable.pathBeginning();
+
+        // make a note of when we started
+        _startStamp = timestamp;
+
+        // update our position to the start of the path
+        tick(pable, timestamp);
+    }
+
+    // documentation inherited
+    public void fastForward (long timeDelta)
+    {
+        _startStamp += timeDelta;
+    }
+
+    /**
+     * Generates a string representation of this instance.
+     */
+    public String toString ()
+    {
+        StringBuffer buf = new StringBuffer("[");
+        toString(buf);
+        return buf.append("]").toString();
+    }
+
+    /**
+     * An extensible method for generating a string representation of this
+     * instance.
+     */
+    protected void toString (StringBuffer buf)
+    {
+        buf.append("duration=").append(_duration).append("ms");
+    }
+
+    /** The duration that we're to spend following the path. */
+    protected long _duration;
+
+    /** The time at which we started along the path. */
+    protected long _startStamp;
+}