X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Frenderer%2Fseqfeatures%2FFeatureColourFinder.java;h=57366b9abe13424f23f4dd838c923981291ac5f9;hb=eb190489441b102c7dce1ee0121df7efd3e74b1a;hp=ba63834366cfa39255085207382126a677769af0;hpb=136c0793b90b72b928c4d77dc109dd5c644e00d3;p=jalview.git

diff --git a/src/jalview/renderer/seqfeatures/FeatureColourFinder.java b/src/jalview/renderer/seqfeatures/FeatureColourFinder.java
index ba63834..57366b9 100644
--- a/src/jalview/renderer/seqfeatures/FeatureColourFinder.java
+++ b/src/jalview/renderer/seqfeatures/FeatureColourFinder.java
@@ -1,8 +1,29 @@
+/*
+ * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
+ * Copyright (C) $$Year-Rel$$ The Jalview Authors
+ * 
+ * This file is part of Jalview.
+ * 
+ * Jalview is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License 
+ * as published by the Free Software Foundation, either version 3
+ * of the License, or (at your option) any later version.
+ *  
+ * Jalview 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with Jalview.  If not, see <http://www.gnu.org/licenses/>.
+ * The Jalview Authors are detailed in the 'AUTHORS' file.
+ */
 package jalview.renderer.seqfeatures;
 
 import jalview.api.FeatureRenderer;
 import jalview.api.FeaturesDisplayedI;
 import jalview.datamodel.SequenceI;
+import jalview.util.Platform;
 import jalview.viewmodel.seqfeatures.FeatureRendererModel;
 
 import java.awt.Color;
@@ -28,6 +49,8 @@ public class FeatureColourFinder
    */
   private BufferedImage offscreenImage;
 
+  private Graphics goff;
+
   /**
    * Constructor
    * 
@@ -37,6 +60,7 @@ public class FeatureColourFinder
   {
     featureRenderer = fr;
     offscreenImage = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
+    goff = offscreenImage.getGraphics();
   }
 
   /**
@@ -74,11 +98,17 @@ public class FeatureColourFinder
      */
     if (featureRenderer.getTransparency() != 1f)
     {
-      g = offscreenImage.getGraphics();
-      if (defaultColour != null)
+      g = goff;
+      Color c = (defaultColour == null ? Color.white : defaultColour);
+      if (Platform.isJS())
       {
-        offscreenImage.setRGB(0, 0, defaultColour.getRGB());
+        // Clear the HTML5 canvas color.
+        // otherwise we get a smearing.
+        // For whatever reason, this is necessary BH 2019.10.01.
+        g.setColor(c);
+        g.fillRect(0, 0, 1, 1);
       }
+      offscreenImage.setRGB(0, 0, c.getRGB());
     }
 
     Color c = featureRenderer.findFeatureColour(seq, column + 1, g);
@@ -89,8 +119,17 @@ public class FeatureColourFinder
 
     if (g != null)
     {
+      if (Platform.isJS())
+      {
+        /*
+         * for JavaScript the pixel itself
+         * is a resource that needs to be recreated in getRGB(0,0)
+         */
+        offscreenImage.flush();
+      }
       c = new Color(offscreenImage.getRGB(0, 0));
     }
+
     return c;
   }
 
@@ -100,7 +139,7 @@ public class FeatureColourFinder
    * 
    * @return
    */
-  boolean noFeaturesDisplayed()
+  public boolean noFeaturesDisplayed()
   {
     if (featureRenderer == null
             || !featureRenderer.getViewport().isShowSequenceFeatures())