JAL-2370 corrected applet mouse drag, refactored into ColumnSelection

[jalview.git] / src / jalview / datamodel / ColumnSelection.java

diff --git a/src/jalview/datamodel/ColumnSelection.java b/src/jalview/datamodel/ColumnSelection.java
index c467f4a..98a7fe2 100644 (file)
--- a/src/jalview/datamodel/ColumnSelection.java
+++ b/src/jalview/datamodel/ColumnSelection.java
@@ -1831,4 +1831,55 @@ public class ColumnSelection
     return changed;
   }
 
+  /**
+   * Adjusts column selections, and the given selection group, to match the
+   * range of a stretch (e.g. mouse drag) operation
+   * <p>
+   * Method refactored from ScalePanel.mouseDragged
+   * 
+   * @param res
+   *          current column position, adjusted for hidden columns
+   * @param sg
+   *          current selection group
+   * @param min
+   *          start position of the stretch group
+   * @param max
+   *          end position of the stretch group
+   */
+  public void stretchGroup(int res, SequenceGroup sg, int min, int max)
+  {
+    if (!contains(res))
+    {
+      addElement(res);
+    }
+
+    if (res > sg.getStartRes())
+    {
+      // expand selection group to the right
+      sg.setEndRes(res);
+    }
+    if (res < sg.getStartRes())
+    {
+      // expand selection group to the left
+      sg.setStartRes(res);
+    }
+
+    /*
+     * expand or shrink column selection to match the
+     * range of the drag operation
+     */
+    for (int col = min; col <= max; col++)
+    {
+      if (col < sg.getStartRes() || col > sg.getEndRes())
+      {
+        // shrinking drag - remove from selection
+        removeElement(col);
+      }
+      else
+      {
+        // expanding drag - add to selection
+        addElement(col);
+      }
+    }
+  }
 }