From bef980d8536bd7da240abcbf357e3ed3b064b523 Mon Sep 17 00:00:00 2001
From: kiramt <k.mourao@dundee.ac.uk>
Date: Tue, 27 Jun 2017 09:36:37 +0100
Subject: [PATCH] JAL-2600 Add in IdCanvas and checks for 0 size images

---
 src/jalview/gui/AnnotationPanel.java |   21 +++++++++-------
 src/jalview/gui/IdCanvas.java        |   46 ++++++++++++++++++++++------------
 src/jalview/gui/SeqCanvas.java       |   33 +++++++++++++-----------
 3 files changed, 60 insertions(+), 40 deletions(-)

diff --git a/src/jalview/gui/AnnotationPanel.java b/src/jalview/gui/AnnotationPanel.java
index e98b79e..3dee5a8 100755
--- a/src/jalview/gui/AnnotationPanel.java
+++ b/src/jalview/gui/AnnotationPanel.java
@@ -993,17 +993,20 @@ public class AnnotationPanel extends JPanel implements AwtRenderPanelI,
       imgWidth = (av.getRanges().getEndRes() - av.getRanges().getStartRes()
               + 1) * av.getCharWidth();
 
-      BufferedImage newimage = new BufferedImage(imgWidth,
-              ap.getAnnotationPanel().getHeight(),
-              BufferedImage.TYPE_INT_ARGB);
+      if (imgWidth > 0)
+      {
+        BufferedImage newimage = new BufferedImage(imgWidth,
+                ap.getAnnotationPanel().getHeight(),
+                BufferedImage.TYPE_INT_ARGB);
 
-      gg = (Graphics2D) newimage.getGraphics();
-      gg.setFont(av.getFont());
-      gg.drawImage(image, null, 0, 0);
-      image = newimage;
+        gg = (Graphics2D) newimage.getGraphics();
+        gg.setFont(av.getFont());
+        gg.drawImage(image, null, 0, 0);
+        image = newimage;
 
-      transX = (er - horizontal - sr) * av.getCharWidth();
-      sr = er - horizontal - sr;
+        transX = (er - horizontal - sr) * av.getCharWidth();
+        sr = er - horizontal - sr;
+      }
     }
     else
     {
diff --git a/src/jalview/gui/IdCanvas.java b/src/jalview/gui/IdCanvas.java
index 5ce36cb..cfbc403 100755
--- a/src/jalview/gui/IdCanvas.java
+++ b/src/jalview/gui/IdCanvas.java
@@ -153,7 +153,7 @@ public class IdCanvas extends JPanel implements ViewportListenerI
    * @param vertical
    *          DOCUMENT ME!
    */
-  public void fastPaint(int vertical)
+  public void fastPaint(int vertical, boolean isresize)
   {
     if (gg == null)
     {
@@ -171,26 +171,37 @@ public class IdCanvas extends JPanel implements ViewportListenerI
     int es = ranges.getEndSeq();
     int transY = 0;
 
-    if (vertical > 0) // scroll down
+    if (isresize)
     {
-      ss = es - vertical;
-
-      if (ss < ranges.getStartSeq())
-      { // ie scrolling too fast, more than a page at a time
-        ss = ranges.getStartSeq();
-      }
-      else
+      if (vertical != 0)
       {
         transY = imgHeight - ((vertical + 1) * av.getCharHeight());
+        ss = es - vertical - ss;
       }
     }
-    else if (vertical < 0) // scroll up
+    else
     {
-      es = ss - vertical;
+      if (vertical > 0) // scroll down
+      {
+        ss = es - vertical;
 
-      if (es > ranges.getEndSeq())
+        if (ss < ranges.getStartSeq())
+        { // ie scrolling too fast, more than a page at a time
+          ss = ranges.getStartSeq();
+        }
+        else
+        {
+          transY = imgHeight - ((vertical + 1) * av.getCharHeight());
+        }
+      }
+      else if (vertical < 0) // scroll up
       {
-        es = ranges.getEndSeq();
+        es = ss - vertical;
+
+        if (es > ranges.getEndSeq())
+        {
+          es = ranges.getEndSeq();
+        }
       }
     }
 
@@ -524,10 +535,13 @@ public class IdCanvas extends JPanel implements ViewportListenerI
   public void propertyChange(PropertyChangeEvent evt)
   {
     // Respond to viewport range changes (e.g. alignment panel was scrolled)
-    if (evt.getPropertyName().equals("startseq")
-            || evt.getPropertyName().equals("endseq"))
+    if (evt.getPropertyName().equals("startseq"))
+    {
+      fastPaint((int) evt.getNewValue() - (int) evt.getOldValue(), false);
+    }
+    else if (evt.getPropertyName().equals("endseq"))
     {
-      fastPaint((int) evt.getNewValue() - (int) evt.getOldValue());
+      fastPaint((int) evt.getNewValue() - (int) evt.getOldValue(), true);
     }
   }
 }
diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index fdad32b..f1b473c 100755
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -303,23 +303,26 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
       imgWidth -= (imgWidth % charWidth);
       imgHeight -= (imgHeight % charHeight);
 
-      BufferedImage newimg = new BufferedImage(imgWidth, imgHeight,
-              BufferedImage.TYPE_INT_ARGB);
+      if ((imgWidth > 0) && (imgHeight > 0))
+      {
+        BufferedImage newimg = new BufferedImage(imgWidth, imgHeight,
+                BufferedImage.TYPE_INT_ARGB);
 
-      gg = (Graphics2D) newimg.getGraphics();
-      gg.setFont(av.getFont());
-      gg.drawImage(img, null, 0, 0);
-      img = newimg;
+        gg = (Graphics2D) newimg.getGraphics();
+        gg.setFont(av.getFont());
+        gg.drawImage(img, null, 0, 0);
+        img = newimg;
 
-      if (horizontal != 0)
-      {
-        transX = (er - horizontal - sr) * charWidth;
-        sr = er - horizontal - sr;
-      }
-      else if (vertical != 0)
-      {
-        transY = imgHeight - ((vertical + 1) * charHeight);
-        ss = es - vertical - ss;
+        if (horizontal != 0)
+        {
+          transX = (er - horizontal - sr) * charWidth;
+          sr = er - horizontal - sr;
+        }
+        else if (vertical != 0)
+        {
+          transY = imgHeight - ((vertical + 1) * charHeight);
+          ss = es - vertical - ss;
+        }
       }
     }
     else
-- 
1.7.10.2