+ /**
+ * 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;
+
+ // don't do work unless we have to
+ if (av.cursorMode && cursorY >= startSeq && cursorY <= endSeq)
+ {
+ int yoffset = 0;
+ int xoffset = 0;
+ int startx = startRes;
+ int endx = endRes;
+ if (av.getWrapAlignment())
+ {
+ // work out the correct offsets for the cursor
+ int charHeight = av.getCharHeight();
+ int charWidth = av.getCharWidth();
+ int canvasWidth = getWidth();
+ int canvasHeight = getHeight();
+
+ // height gap above each panel
+ int hgap = charHeight;
+ if (av.getScaleAboveWrapped())
+ {
+ hgap += charHeight;
+ }
+
+ int cWidth = (canvasWidth - labelWidthEast - labelWidthWest)
+ / charWidth;
+ int cHeight = av.getAlignment().getHeight() * charHeight;
+
+ endx = startx + cWidth - 1;
+ int ypos = hgap; // vertical offset
+
+ // iterate down the wrapped panels
+ while ((ypos <= canvasHeight) && (endx < cursorX))
+ {
+ // update vertical offset
+ ypos += cHeight + getAnnotationHeight() + hgap;
+
+ // update horizontal offset
+ startx += cWidth;
+ endx = startx + cWidth - 1;
+ }
+ yoffset = ypos;
+ xoffset = labelWidthWest;
+ }
+
+ // now check if cursor is within range for x values
+ if (cursorX >= startx && cursorX <= endx)
+ {
+ // 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);
+
+ seqRdr.drawCursor(g, s,
+ xoffset + (cursorX - startx) * av.getCharWidth(),
+ yoffset + (cursorY - startSeq) * av.getCharHeight());
+ g.dispose();
+ }
+ }
+
+ return cursorImage;
+ }
+
+