javax.swing.text.View#NORTH源码实例Demo

@Override
public int getNextVisualPositionFromChecked(int offset, Bias bias, Shape alloc, int direction, Bias[] biasRet) {
    int startOffset = getStartOffset();
    int endOffset = startOffset + getLength();
    int retOffset = -1;
    switch (direction) {
        case EAST:
            biasRet[0] = Bias.Forward;
            if (offset == -1) {
                retOffset = getStartOffset();
            } else {
                retOffset = offset + 1;
                if (retOffset >= endOffset) {
                    retOffset = endOffset;
                    biasRet[0] = Bias.Backward;
                }
            }
            break;

        case WEST:
            biasRet[0] = Bias.Forward;
            if (offset == -1) {
                retOffset = endOffset - 1;
            } else {
                retOffset = offset - 1;
                if (retOffset < startOffset) {
                    retOffset = -1;
                }
            }
            break;

        case View.NORTH:
        case View.SOUTH:
            break; // Return -1
        default:
            throw new IllegalArgumentException("Bad direction: " + direction);
    }
    return retOffset;
}
 

@Override
public int getNextVisualPositionFromChecked(int offset, Bias bias, Shape alloc, int direction, Bias[] biasRet) {
    int retOffset;
    biasRet[0] = Bias.Forward; // BaseCaret ignores bias
    int viewStartOffset = getStartOffset();
    switch (direction) {
        case View.EAST:
            if (offset == -1) {
                retOffset = viewStartOffset;
            } else {
                retOffset = -1;
            }
            break;

        case View.WEST:
            if (offset == -1) {
                retOffset = viewStartOffset;
            } else if (offset == viewStartOffset) { // Regular offset
                retOffset = -1;
            } else {
                retOffset = viewStartOffset;
            }
            break;

        case View.NORTH:
        case View.SOUTH:
            retOffset = -1;
            break;
        default:
            throw new IllegalArgumentException("Bad direction: " + direction);
    }
    return retOffset;
}