JAL-2811 Add layer for cursor in SeqCanvas

diff --git a/src/jalview/gui/SeqCanvas.java b/src/jalview/gui/SeqCanvas.java
index 2a9c704..bd2862a 100755 (executable)
--- a/src/jalview/gui/SeqCanvas.java
+++ b/src/jalview/gui/SeqCanvas.java
@@ -364,11 +364,14 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
             ranges.getStartRes(), ranges.getEndRes(),
             ranges.getStartSeq(), ranges.getEndSeq());
 
+    BufferedImage cursorImage = drawCursor(ranges.getStartRes(),
+            ranges.getEndRes(), ranges.getStartSeq(), ranges.getEndSeq());
+
     if ((img != null) && (fastPaint
             || (getVisibleRect().width != g.getClipBounds().width)
             || (getVisibleRect().height != g.getClipBounds().height)))
     {
-      BufferedImage lcimg = buildLocalImage(selectImage);
+      BufferedImage lcimg = buildLocalImage(selectImage, cursorImage);
       g.drawImage(lcimg, 0, 0, this);
       fastPaint = false;
     }
@@ -408,7 +411,7 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
       }
 
       // lcimg is a local *copy* of img which we'll draw selectImage on top of
-      BufferedImage lcimg = buildLocalImage(selectImage);
+      BufferedImage lcimg = buildLocalImage(selectImage, cursorImage);
       g.drawImage(lcimg, 0, 0, this);
     }
   }
@@ -493,7 +496,8 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
    * Make a local image by combining the cached image img
    * with any selection
    */
-  private BufferedImage buildLocalImage(BufferedImage selectImage)
+  private BufferedImage buildLocalImage(BufferedImage selectImage,
+          BufferedImage cursorImage)
   {
     // clone the cached image
     BufferedImage lcimg = new BufferedImage(img.getWidth(), img.getHeight(),
@@ -508,6 +512,12 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
               AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
       g2d.drawImage(selectImage, 0, 0, this);
     }
+    // overlay cursor on lcimg
+    if (cursorImage != null)
+    {
+      g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
+      g2d.drawImage(cursorImage, 0, 0, this);
+    }
     g2d.dispose();
 
     return lcimg;
@@ -1142,12 +1152,12 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
         }
       }
 
-      if (av.cursorMode && cursorY == i && cursorX >= startRes
+      /*      if (av.cursorMode && cursorY == i && cursorX >= startRes
               && cursorX <= endRes)
       {
         seqRdr.drawCursor(nextSeq, cursorX, (cursorX - startRes) * charWidth,
                 offset + ((i - startSeq) * charHeight));
-      }
+      }*/
     }
 
     if (av.getSelectionGroup() != null
@@ -1245,6 +1255,60 @@ public class SeqCanvas extends JComponent implements ViewportListenerI
     return selectionImage;
   }
 
+  /**
+   * Draw the cursor as a separate image and overlay
+   * 
+   * @param startRes
+   *          start residue of area to draw cursor in
+   * @param endRes
+   *          end residue of area to draw cursor in
+   * @param startSeq
+   *          start sequence of area to draw cursor in
+   * @param endSeq
+   *          end sequence of are to draw cursor in
+   * @return a transparent image of the same size as the sequence canvas, with
+   *         the cursor drawn on it, if any
+   */
+  private BufferedImage drawCursor(int startRes, int endRes, int startSeq,
+          int endSeq)
+  {
+    // define our cursor image
+    BufferedImage cursorImage = null;
+
+    if (av.cursorMode && cursorY >= startSeq && cursorY <= endSeq
+            && cursorX >= startRes && cursorX <= endRes)
+    {
+      // get a new image of the correct size
+      cursorImage = setupImage();
+      Graphics2D g = (Graphics2D) cursorImage.getGraphics();
+
+      // get the character the cursor is drawn at
+      SequenceI seq = av.getAlignment().getSequenceAt(cursorY);
+      char s = seq.getCharAt(cursorX);
+
+      int offset = 0;
+      if (av.getWrapAlignment())
+      {
+        // work out the correct offset for the cursor
+        offset = wrappedSpaceAboveAlignment;
+        int currentWidth = 0;
+        while ((currentWidth < wrappedVisibleWidths)
+                && (currentWidth < cursorX))
+        {
+          offset += wrappedRepeatHeightPx;
+          currentWidth++;
+        }
+      }
+
+      seqRdr.drawCursor(g, s,
+              (cursorX - startRes) * av.getCharWidth(),
+              offset + ((cursorY - startSeq) * av.getCharHeight()));
+      g.dispose();
+    }
+
+    return cursorImage;
+  }
+
   /*
    * Set up graphics for selection group
    */

diff --git a/src/jalview/gui/SequenceRenderer.java b/src/jalview/gui/SequenceRenderer.java
index 0a1e8ef..81b394b 100755 (executable)
--- a/src/jalview/gui/SequenceRenderer.java
+++ b/src/jalview/gui/SequenceRenderer.java
@@ -481,21 +481,30 @@ public class SequenceRenderer implements jalview.api.SequenceRenderer
     }
   }
 
-  public void drawCursor(SequenceI seq, int res, int x1, int y1)
+  /**
+   * Draw a sequence canvas cursor
+   * 
+   * @param g
+   *          graphics context to draw on
+   * @param s
+   *          character to draw at cursor
+   * @param x1
+   *          x position of cursor in graphics context
+   * @param y1
+   *          y position of cursor in graphics context
+   */
+  public void drawCursor(Graphics g, char s, int x1, int y1)
   {
     int pady = av.getCharHeight() / 5;
     int charOffset = 0;
-    graphics.setColor(Color.black);
-    graphics.fillRect(x1, y1, av.getCharWidth(), av.getCharHeight());
+    g.setColor(Color.black);
+    g.fillRect(x1, y1, av.getCharWidth(), av.getCharHeight());
 
     if (av.isValidCharWidth())
     {
-      graphics.setColor(Color.white);
-
-      char s = seq.getCharAt(res);
-
+      g.setColor(Color.white);
       charOffset = (av.getCharWidth() - fm.charWidth(s)) / 2;
-      graphics.drawString(String.valueOf(s), charOffset + x1,
+      g.drawString(String.valueOf(s), charOffset + x1,
               (y1 + av.getCharHeight()) - pady);
     }