From ddc7f53dd8398442e2025d11330fa8dfe2f8dd35 Mon Sep 17 00:00:00 2001
From: jprocter <jprocter@compbio.dundee.ac.uk>
Date: Sat, 1 Sep 2012 13:08:27 +0100
Subject: [PATCH] JAL-1161 JAL-1160 implement custom mousewheel listener and
 increased scroll increment for annotation panel

---
 src/jalview/gui/AnnotationLabels.java |    1 +
 src/jalview/gui/AnnotationPanel.java  |   83 ++++++++++++++++++++++++++++++---
 2 files changed, 77 insertions(+), 7 deletions(-)

diff --git a/src/jalview/gui/AnnotationLabels.java b/src/jalview/gui/AnnotationLabels.java
index 319dcf4..533b22c 100755
--- a/src/jalview/gui/AnnotationLabels.java
+++ b/src/jalview/gui/AnnotationLabels.java
@@ -115,6 +115,7 @@ public class AnnotationLabels extends JPanel implements MouseListener,
 
     addMouseListener(this);
     addMouseMotionListener(this);
+    addMouseWheelListener(ap.annotationPanel);
   }
 
   public AnnotationLabels(AlignViewport av)
diff --git a/src/jalview/gui/AnnotationPanel.java b/src/jalview/gui/AnnotationPanel.java
index df29464..411c244 100755
--- a/src/jalview/gui/AnnotationPanel.java
+++ b/src/jalview/gui/AnnotationPanel.java
@@ -32,8 +32,8 @@ import jalview.renderer.AwtRenderPanelI;
  * @version $Revision$
  */
 public class AnnotationPanel extends JPanel implements AwtRenderPanelI,
-        MouseListener, MouseMotionListener, ActionListener,
-        AdjustmentListener
+        MouseListener, MouseWheelListener, MouseMotionListener,
+        ActionListener, AdjustmentListener, Scrollable
 {
   final String HELIX = "Helix";
 
@@ -95,6 +95,8 @@ public class AnnotationPanel extends JPanel implements AwtRenderPanelI,
 
   public final AnnotationRenderer renderer;
 
+  private MouseWheelListener[] _mwl;
+
   /**
    * Creates a new AnnotationPanel object.
    *
@@ -116,6 +118,10 @@ public class AnnotationPanel extends JPanel implements AwtRenderPanelI,
     addMouseMotionListener(this);
     ap.annotationScroller.getVerticalScrollBar()
             .addAdjustmentListener(this);
+    // save any wheel listeners on the scroller, so we can propagate scroll events to them.
+    _mwl = ap.annotationScroller.getMouseWheelListeners();
+    // and then set our own listener to consume all mousewheel events
+    ap.annotationScroller.addMouseWheelListener(this);
     renderer = new AnnotationRenderer();
   }
 
@@ -125,15 +131,78 @@ public class AnnotationPanel extends JPanel implements AwtRenderPanelI,
     renderer = new AnnotationRenderer();
   }
 
-  /**
-   * DOCUMENT ME!
-   *
-   * @param evt
-   *          DOCUMENT ME!
+  @Override
+  public void mouseWheelMoved(MouseWheelEvent e)
+  {
+    if (e.isShiftDown())
+    {
+      e.consume();
+      if (e.getWheelRotation() > 0)
+      {
+        ap.scrollRight(true);
+      }
+      else
+      {
+        ap.scrollRight(false);
+      }
+    }
+    else
+    {
+      // TODO: find the correct way to let the event bubble up to ap.annotationScroller
+      for (MouseWheelListener mwl : _mwl)
+      {
+        if (mwl != null)
+        {
+          mwl.mouseWheelMoved(e);
+        }
+        if (e.isConsumed())
+        {
+          break;
+        }
+      }
+    }
+  }
+
+  @Override
+  public Dimension getPreferredScrollableViewportSize()
+  {
+    return getPreferredSize();
+  }
+
+  @Override
+  public int getScrollableBlockIncrement(Rectangle visibleRect,
+          int orientation, int direction)
+  {
+    return 30;
+  }
+
+  @Override
+  public boolean getScrollableTracksViewportHeight()
+  {
+    return false;
+  }
+
+  @Override
+  public boolean getScrollableTracksViewportWidth()
+  {
+    return true;
+  }
+
+  @Override
+  public int getScrollableUnitIncrement(Rectangle visibleRect,
+          int orientation, int direction)
+  {
+    return 30;
+  }
+
+  /*
+   * (non-Javadoc)
+   * @see java.awt.event.AdjustmentListener#adjustmentValueChanged(java.awt.event.AdjustmentEvent)
    */
   @Override
   public void adjustmentValueChanged(AdjustmentEvent evt)
   {
+    // update annotation label display
     ap.alabels.setScrollOffset(-evt.getValue());
   }
 
-- 
1.7.10.2