+
+ boolean up = res < oldStartRes;
+ int widthsToScroll = Math.abs((res - oldStartRes) / width);
+ if (up)
+ {
+ widthsToScroll++;
+ }
+
+ int residuesToScroll = width * widthsToScroll;
+ int newStartRes = up ? oldStartRes - residuesToScroll : oldStartRes
+ + residuesToScroll;
+ if (newStartRes < 0)
+ {
+ newStartRes = 0;
+ }
+ return newStartRes;
+ }
+
+ /**
+ * Scroll so that (x,y) is visible. Fires a property change event.
+ *
+ * @param x
+ * x position in alignment (absolute position)
+ * @param y
+ * y position in alignment (absolute position)
+ */
+ public void scrollToVisible(int x, int y)
+ {
+ while (y < startSeq)
+ {
+ scrollUp(true);
+ }
+ while (y > endSeq)
+ {
+ scrollUp(false);
+ }
+
+ HiddenColumns hidden = al.getHiddenColumns();
+ while (x < hidden.visibleToAbsoluteColumn(startRes))
+ {
+ if (!scrollRight(false))
+ {
+ break;
+ }
+ }
+ while (x > hidden.visibleToAbsoluteColumn(endRes))
+ {
+ if (!scrollRight(true))
+ {
+ break;
+ }
+ }
+ }
+
+ /**
+ * Set the viewport location so that a position is visible
+ *
+ * @param x
+ * column to be visible: absolute position in alignment
+ * @param y
+ * row to be visible: absolute position in alignment
+ */
+ public boolean setViewportLocation(int x, int y)
+ {
+ boolean changedLocation = false;
+
+ // convert the x,y location to visible coordinates
+ int visX = al.getHiddenColumns().absoluteToVisibleColumn(x);
+ int visY = al.getHiddenSequences().findIndexWithoutHiddenSeqs(y);
+
+ // if (vis_x,vis_y) is already visible don't do anything
+ if (startRes > visX || visX > endRes
+ || startSeq > visY && visY > endSeq)
+ {
+ int[] old = new int[] { startRes, startSeq };
+ int[] newresseq;
+ if (wrappedMode)
+ {
+ int newstartres = calcWrappedStartResidue(visX);
+ setStartRes(newstartres);
+ newresseq = new int[] { startRes, startSeq };
+ }
+ else
+ {
+ // set the viewport x location to contain vis_x
+ int newstartres = visX;
+ int width = getViewportWidth();
+ if (newstartres + width - 1 > getVisibleAlignmentWidth() - 1)
+ {
+ newstartres = getVisibleAlignmentWidth() - width;
+ }
+ updateStartEndRes(newstartres, newstartres + width - 1);
+
+ // set the viewport y location to contain vis_y
+ int newstartseq = visY;
+ int height = getViewportHeight();
+ if (newstartseq + height - 1 > getVisibleAlignmentHeight() - 1)
+ {
+ newstartseq = getVisibleAlignmentHeight() - height;
+ }
+ updateStartEndSeq(newstartseq, newstartseq + height - 1);
+
+ newresseq = new int[] { startRes, startSeq };
+ }
+ changedLocation = true;
+ changeSupport.firePropertyChange(MOVE_VIEWPORT, old, newresseq);
+ }
+ return changedLocation;
+ }
+
+ /**
+ * Adjust sequence position for page up. Fires a property change event.
+ */
+ public void pageUp()
+ {
+ if (wrappedMode)
+ {
+ setStartRes(Math.max(0, getStartRes() - getViewportWidth()));
+ }
+ else
+ {
+ setViewportStartAndHeight(startSeq - (endSeq - startSeq),
+ getViewportHeight());
+ }
+ }
+
+ /**
+ * Adjust sequence position for page down. Fires a property change event.
+ */
+ public void pageDown()
+ {
+ if (wrappedMode)
+ {
+ /*
+ * if height is more than width (i.e. not all sequences fit on screen),
+ * increase page down to height
+ */
+ int newStart = getStartRes()
+ + Math.max(getViewportHeight(), getViewportWidth());
+
+ /*
+ * don't page down beyond end of alignment, or if not all
+ * sequences fit in the visible height
+ */
+ if (newStart < getVisibleAlignmentWidth())
+ {
+ setStartRes(newStart);
+ }
+ }
+ else
+ {
+ setViewportStartAndHeight(endSeq, getViewportHeight());
+ }