/**
* Provides a way to determine the next visually represented model location at which one might
* place a caret. Some views may not be visible, they might not be in the same order found in the
* model, or they just might not allow access to some of the locations in the model.
*
* <p>NOTE: You should only call this method if the passed-in <code>javax.swing.text.View</code>
* is an instance of {@link TokenOrientedView} and <code>javax.swing.text.TabExpander</code>;
* otherwise, a <code>ClassCastException</code> could be thrown.
*
* @param pos the position to convert >= 0
* @param a the allocated region in which to render
* @param direction the direction from the current position that can be thought of as the arrow
* keys typically found on a keyboard. This will be one of the following values:
* <ul>
* <li>SwingConstants.WEST
* <li>SwingConstants.EAST
* <li>SwingConstants.NORTH
* <li>SwingConstants.SOUTH
* </ul>
*
* @return the location within the model that best represents the next location visual position
* @exception BadLocationException
* @exception IllegalArgumentException if <code>direction</code> doesn't have one of the legal
* values above
*/
public static int getNextVisualPositionFrom(
int pos, Position.Bias b, Shape a, int direction, Position.Bias[] biasRet, View view)
throws BadLocationException {
biasRet[0] = Position.Bias.Forward;
// Do we want the "next position" above, below, to the left or right?
switch (direction) {
case NORTH:
case SOUTH:
if (pos == -1) {
pos = (direction == NORTH) ? Math.max(0, view.getEndOffset() - 1) : view.getStartOffset();
break;
}
RSyntaxTextArea target = (RSyntaxTextArea) view.getContainer();
Caret c = (target != null) ? target.getCaret() : null;
// YECK! Ideally, the x location from the magic caret
// position would be passed in.
Point mcp;
if (c != null) mcp = c.getMagicCaretPosition();
else mcp = null;
int x;
if (mcp == null) {
Rectangle loc = target.modelToView(pos);
x = (loc == null) ? 0 : loc.x;
} else {
x = mcp.x;
}
if (direction == NORTH) pos = getPositionAbove(target, pos, x, (TabExpander) view);
else pos = getPositionBelow(target, pos, x, (TabExpander) view);
break;
case WEST:
if (pos == -1) pos = Math.max(0, view.getEndOffset() - 1);
else pos = Math.max(0, pos - 1);
break;
case EAST:
if (pos == -1) pos = view.getStartOffset();
else pos = Math.min(pos + 1, view.getDocument().getLength());
break;
default:
throw new IllegalArgumentException("Bad direction: " + direction);
}
return pos;
}
