X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fdatamodel%2FStartRegionIterator.java;fp=src%2Fjalview%2Fdatamodel%2FStartRegionIterator.java;h=bd036e41e397ddb2c7c147bdf55ecc310c9a5ef4;hb=aad3640b07f836362df7ea025fa09127a0a06145;hp=0000000000000000000000000000000000000000;hpb=783c351b9a8aed11ea41c9db193e8ae3be20b017;p=jalview.git

diff --git a/src/jalview/datamodel/StartRegionIterator.java b/src/jalview/datamodel/StartRegionIterator.java
new file mode 100644
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+++ b/src/jalview/datamodel/StartRegionIterator.java
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+package jalview.datamodel;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * An iterator which iterates over visible start positions of hidden column
+ * regions in a range.
+ */
+public class StartRegionIterator implements Iterator<Integer>
+{
+  // start position to iterate from
+  private int start;
+
+  // end position to iterate to
+  private int end;
+
+  // current index in hiddenColumns
+  private int currentPosition = 0;
+
+  // local copy or reference to hiddenColumns
+  private List<Integer> positions = null;
+
+  /**
+   * Construct an iterator over hiddenColums bounded at [lowerBound,upperBound]
+   * 
+   * @param lowerBound
+   *          lower bound to iterate from
+   * @param upperBound
+   *          upper bound to iterate to
+   * @param useCopyCols
+   *          whether to make a local copy of hiddenColumns for iteration (set
+   *          to true if calling from outwith the HiddenColumns class)
+   */
+  StartRegionIterator(int lowerBound, int upperBound,
+          List<int[]> hiddenColumns)
+  {
+    this(null, lowerBound, upperBound, hiddenColumns);
+  }
+
+  /**
+   * Construct an iterator over hiddenColums bounded at [lowerBound,upperBound]
+   * 
+   * @param pos
+   *          a hidden cursor position to start from - may be null
+   * @param lowerBound
+   *          lower bound to iterate from - will be ignored if pos != null
+   * @param upperBound
+   *          upper bound to iterate to
+   * @param hiddenColumns
+   *          the hidden columns collection to use
+   */
+  StartRegionIterator(HiddenCursorPosition pos, int lowerBound,
+          int upperBound, List<int[]> hiddenColumns)
+  {
+    start = lowerBound;
+    end = upperBound;
+
+    if (hiddenColumns != null)
+    {
+      positions = new ArrayList<>(hiddenColumns.size());
+
+      // navigate to start, keeping count of hidden columns
+      int i = 0;
+      int hiddenSoFar = 0;
+      
+      if (pos != null)
+      {
+        // use the cursor position provided
+        i = pos.getRegionIndex();
+        hiddenSoFar = pos.getHiddenSoFar();
+      }
+      else
+      {
+        // navigate to start
+        while ((i < hiddenColumns.size())
+                && (hiddenColumns.get(i)[0] < start + hiddenSoFar))
+        {
+          int[] region = hiddenColumns.get(i);
+          hiddenSoFar += region[1] - region[0] + 1;
+          i++;
+        }
+      }
+
+      // iterate from start to end, adding start positions of each
+      // hidden region. Positions are visible columns count, not absolute
+      while (i < hiddenColumns.size()
+              && (hiddenColumns.get(i)[0] <= end + hiddenSoFar))
+      {
+        int[] region = hiddenColumns.get(i);
+        positions.add(region[0] - hiddenSoFar);
+        hiddenSoFar += region[1] - region[0] + 1;
+        i++;
+      }
+    }
+    else
+    {
+      positions = new ArrayList<>();
+    }
+
+  }
+
+  @Override
+  public boolean hasNext()
+  {
+    return (currentPosition < positions.size());
+  }
+
+  /**
+   * Get next hidden region start position
+   * 
+   * @return the start position in *visible* coordinates
+   */
+  @Override
+  public Integer next()
+  {
+    int result = positions.get(currentPosition);
+    currentPosition++;
+    return result;
+  }
+}
+