From ff4f9d4a9cd6b724bfea2fedf850c835ee80c1c1 Mon Sep 17 00:00:00 2001
From: Michael Bayne <mdb@threerings.net>
Date: Mon, 7 Feb 2005 03:37:39 +0000
Subject: [PATCH] A helper that makes it easy to wire up scrollbars or a
 scrollbox to a virtual media panel.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3334 542714f4-19e9-0310-aa3c-eee0fc999fb1
---
 .../threerings/media/VirtualRangeModel.java   | 96 +++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 src/java/com/threerings/media/VirtualRangeModel.java

diff --git a/src/java/com/threerings/media/VirtualRangeModel.java b/src/java/com/threerings/media/VirtualRangeModel.java
new file mode 100644
index 000000000..aab1676e9
--- /dev/null
+++ b/src/java/com/threerings/media/VirtualRangeModel.java
@@ -0,0 +1,96 @@
+//
+// $Id$
+//
+// Narya library - tools for developing networked games
+// Copyright (C) 2002-2004 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/narya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.media;
+
+import java.awt.Rectangle;
+
+import javax.swing.BoundedRangeModel;
+import javax.swing.DefaultBoundedRangeModel;
+
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+
+import com.threerings.media.util.MathUtil;
+
+/**
+ * Provides a {@link BoundedRangeModel} interface to a virtual media panel
+ * so that it can easily be wired up to scroll bars or other scrolling
+ * controls.
+ */
+public class VirtualRangeModel
+    implements ChangeListener
+{
+    /**
+     * Creates a virtual media panel range model that will interact with
+     * the supplied virtual media panel.
+     */
+    public VirtualRangeModel (VirtualMediaPanel panel)
+    {
+        _panel = panel;
+
+        // listen to our range models and scroll our badself
+        _horizRange.addChangeListener(this);
+        _vertRange.addChangeListener(this);
+    }
+
+    /**
+     * Informs the virtual range model the extent of the area over which
+     * we can scroll.
+     */
+    public void setScrollableArea (int x, int y, int width, int height)
+    {
+        Rectangle vbounds = _panel.getViewBounds();
+        int hmax = x + width, vmax = y + height, value =
+            MathUtil.bound(x, _horizRange.getValue(), hmax - vbounds.width);
+        _horizRange.setRangeProperties(value, vbounds.width, x, hmax, false);
+        value = MathUtil.bound(y, _vertRange.getValue(), vmax - vbounds.height);
+        _vertRange.setRangeProperties(value, vbounds.height, y, vmax, false);
+    }
+
+    /**
+     * Returns a range model that controls the scrollability of the scene
+     * in the horizontal direction.
+     */
+    public BoundedRangeModel getHorizModel ()
+    {
+        return _horizRange;
+    }
+
+    /**
+     * Returns a range model that controls the scrollability of the scene
+     * in the vertical direction.
+     */
+    public BoundedRangeModel getVertModel ()
+    {
+        return _vertRange;
+    }
+
+    // documentation inherited from interface ChangeListener
+    public void stateChanged (ChangeEvent e)
+    {
+        _panel.setViewLocation(_horizRange.getValue(), _vertRange.getValue());
+    }
+
+    protected VirtualMediaPanel _panel;
+    protected BoundedRangeModel _horizRange = new DefaultBoundedRangeModel();
+    protected BoundedRangeModel _vertRange = new DefaultBoundedRangeModel();
+}