From e65df2c2289b3b05c94ace285ae64a7cbc4999a8 Mon Sep 17 00:00:00 2001
From: Jim Procter <jprocter@issues.jalview.org>
Date: Tue, 2 May 2017 17:56:13 +0100
Subject: [PATCH] JAL-1632 compare size of input against minimums for
 calculation and enable/disable buttons

---
 resources/lang/Messages.properties      |    1 +
 src/jalview/gui/CalculationChooser.java |   72 +++++++++++++++++++++++++++++--
 2 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/resources/lang/Messages.properties b/resources/lang/Messages.properties
index f65102c..5ac4269 100644
--- a/resources/lang/Messages.properties
+++ b/resources/lang/Messages.properties
@@ -385,6 +385,7 @@ label.invalid_selection = Invalid Selection
 label.principal_component_analysis_must_take_least_four_input_sequences = Principal component analysis must take\nat least 4 input sequences.
 label.sequence_selection_insufficient = Sequence selection insufficient
 label.you_need_more_two_sequences_selected_build_tree = You need to have more than two sequences selected to build a tree!
+label.you_need_more_than_n_sequences = You need to have more than {0} sequences
 label.not_enough_sequences = Not enough sequences
 label.selected_region_to_tree_may_only_contain_residues_or_gaps =  The selected region to create a tree may\nonly contain residues or gaps.\nTry using the Pad function in the edit menu,\nor one of the multiple sequence alignment web services.
 label.sequences_selection_not_aligned = Sequences in selection are not aligned
diff --git a/src/jalview/gui/CalculationChooser.java b/src/jalview/gui/CalculationChooser.java
index 7f245b1..694b096 100644
--- a/src/jalview/gui/CalculationChooser.java
+++ b/src/jalview/gui/CalculationChooser.java
@@ -163,15 +163,18 @@ public class CalculationChooser extends JPanel
     calcTypes.add(pca);
     calcTypes.add(neighbourJoining);
     calcTypes.add(averageDistance);
+    
+    ActionListener calcChanged = new ActionListener()
     {
       @Override
-      public void itemStateChanged(ItemEvent e)
+      public void actionPerformed(ActionEvent e)
       {
-        neighbourJoining.setEnabled(tree.isSelected());
-        averageDistance.setEnabled(tree.isSelected());
+        validateCalcTypes();
       }
     };
-
+    pca.addActionListener(calcChanged);
+    neighbourJoining.addActionListener(calcChanged);
+    averageDistance.addActionListener(calcChanged);
     /*
      * score models drop-down - with added tooltips!
      */
@@ -264,6 +267,67 @@ public class CalculationChooser extends JPanel
   }
 
   /**
+   * enable calculations applicable for the current alignment or selection.
+   */
+  protected void validateCalcTypes()
+  {
+    int size = af.getViewport().getAlignment().getHeight();
+    if (af.getViewport().getSelectionGroup() != null)
+    {
+      size = af.getViewport().getSelectionGroup().getSize();
+    }
+    if (!(checkEnabled(pca, size, 4)
+            | checkEnabled(neighbourJoining, size, 3) | checkEnabled(
+              averageDistance, size, 3)))
+    {
+      ok.setToolTipText(null);
+      ok.setEnabled(true);
+    }
+    else
+    {
+      ok.setEnabled(false);
+    }
+  }
+
+  /**
+   * Check the input and disable a calculation's radio button if necessary. A
+   * tooltip is shown for disabled calculations.
+   * 
+   * @param calc
+   *          - radio button for the calculation being validated
+   * @param size
+   *          - size of input to calculation
+   * @param minsize
+   *          - minimum size for calculation
+   * @return true if size < minsize *and* calc.isSelected
+   */
+  private boolean checkEnabled(JRadioButton calc, int size, int minsize)
+  {
+    String ttip = MessageManager.formatMessage(
+            "label.you_need_more_than_n_sequences", minsize);
+
+    calc.setEnabled(size >= minsize);
+    if (!calc.isEnabled())
+    {
+      calc.setToolTipText(ttip);
+    }
+    else
+    {
+      calc.setToolTipText(null);
+    }
+    if (calc.isSelected())
+    {
+      modelNames.setEnabled(calc.isEnabled());
+      if (!calc.isEnabled())
+      {
+        ok.setEnabled(false);
+        ok.setToolTipText(ttip);
+        return true;
+      }
+    }
+    return false;
+  }
+  /**
    * A rather elaborate helper method (blame Swing, not me) that builds a
    * drop-down list of score models (by name) with descriptions as tooltips.
    * There is also a tooltip shown for the currently selected item when hovering
-- 
1.7.10.2