+ /**
+ * 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 void drawCursor(Graphics g, int startRes, int endRes,
+ int startSeq,
+ int endSeq)
+ {
+ // convert the cursorY into a position on the visible alignment
+ int cursor_ypos = cursorY;
+
+ // don't do work unless we have to
+ if (cursor_ypos >= startSeq && cursor_ypos <= endSeq)
+ {
+ int yoffset = 0;
+ int xoffset = 0;
+ int startx = startRes;
+ int endx = endRes;
+
+ // convert the cursorX into a position on the visible alignment
+ int cursor_xpos = av.getAlignment().getHiddenColumns()
+ .absoluteToVisibleColumn(cursorX);
+
+ if (av.getAlignment().getHiddenColumns().isVisible(cursorX))
+ {
+
+ 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 < cursor_xpos))
+ {
+ // 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 (cursor_xpos >= startx && cursor_xpos <= endx)
+ {
+ // get the character the cursor is drawn at
+ SequenceI seq = av.getAlignment().getSequenceAt(cursorY);
+ char s = seq.getCharAt(cursorX);
+
+ seqRdr.drawCursor(g, s,
+ xoffset + (cursor_xpos - startx) * av.getCharWidth(),
+ yoffset + (cursor_ypos - startSeq) * av.getCharHeight());
+ }
+ }
+ }
+ }
+
+