From a19aa5efc2e64c17927336f422adde1837c27042 Mon Sep 17 00:00:00 2001
From: Ben Soares <b.soares@dundee.ac.uk>
Date: Fri, 4 Aug 2023 16:28:09 +0100
Subject: [PATCH] JAL-244 Adjust wrapped alignment widths to always maintain a
 visible wrapped sequence width (and also avoid zero
 divisions)

---
 src/jalview/gui/AlignmentPanel.java  |   20 +++++++++++++++++---
 src/jalview/gui/IdwidthAdjuster.java |   12 ++++++++++++
 src/jalview/gui/SeqCanvas.java       |   14 ++++++++++++++
 3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/src/jalview/gui/AlignmentPanel.java b/src/jalview/gui/AlignmentPanel.java
index 98639be..63455cb 100644
--- a/src/jalview/gui/AlignmentPanel.java
+++ b/src/jalview/gui/AlignmentPanel.java
@@ -886,10 +886,24 @@ public class AlignmentPanel extends GAlignmentPanel implements
   public void paintComponent(Graphics g)
   {
     invalidate(); // needed so that the id width adjuster works correctly
-
     Dimension d = getIdPanel().getIdCanvas().getPreferredSize();
-    idPanelHolder.setPreferredSize(d);
-    hscrollFillerPanel.setPreferredSize(new Dimension(d.width, 12));
+    int idWidth = d.width;
+
+    // check wrapped alignment as at least 1 residue width
+    if (av.getWrapAlignment())
+    {
+      SeqCanvas sc = this.getSeqPanel().seqCanvas;
+      if (sc != null && sc.getWidth() < sc.getMinimumWrappedCanvasWidth())
+      {
+        // need to make some adjustments
+        idWidth -= (sc.getMinimumWrappedCanvasWidth() - sc.getWidth());
+        av.setIdWidth(idWidth);
+        validateAnnotationDimensions(false);
+      }
+    }
+
+    idPanelHolder.setPreferredSize(new Dimension(idWidth, d.height));
+    hscrollFillerPanel.setPreferredSize(new Dimension(idWidth, 12));
 
     validate(); // needed so that the id width adjuster works correctly
 
diff --git a/src/jalview/gui/IdwidthAdjuster.java b/src/jalview/gui/IdwidthAdjuster.java
index 6de3c97..8a6c7eb 100755
--- a/src/jalview/gui/IdwidthAdjuster.java
+++ b/src/jalview/gui/IdwidthAdjuster.java
@@ -136,6 +136,18 @@ public class IdwidthAdjuster extends JPanel
       return;
     }
 
+    /*
+     * don't allow residue width to be < 1 in wrapped format
+     */
+    if (viewport.getWrapAlignment())
+    {
+      SeqCanvas sc = ap.getSeqPanel().seqCanvas;
+      if (sc != null && sc.getWrappedCanvasWidth(sc.getWidth() - dif) < 1)
+      {
+        return;
+      }
+    }
+
     oldX = evt.getX();
 
     /*
diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index d15cdcf..19d7c21 100755
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -550,6 +550,20 @@ public class SeqCanvas extends JPanel implements ViewportListenerI
     return (canvasWidth - labelWidthEast - labelWidthWest) / charWidth;
   }
 
+  public int getMinimumWrappedCanvasWidth()
+  {
+    int charWidth = av.getCharWidth();
+    FontMetrics fm = getFontMetrics(av.getFont());
+    int labelWidth = 0;
+    if (av.getScaleRightWrapped() || av.getScaleLeftWrapped())
+    {
+      labelWidth = getLabelWidth(fm);
+    }
+    labelWidthEast = av.getScaleRightWrapped() ? labelWidth : 0;
+    labelWidthWest = av.getScaleLeftWrapped() ? labelWidth : 0;
+    return labelWidthEast + labelWidthWest + charWidth;
+  }
+
   /**
    * Returns a pixel width sufficient to show the largest sequence coordinate
    * (end position) in the alignment, calculated as the FontMetrics width of
-- 
1.7.10.2