void Text::scroll_to(DimensionName dimension, Coord position) {
// let the user scroll to the right (or down) past the current size.
/*
if (position > (upper(dimension) - cur_length(dimension))) {
position = upper(dimension) - cur_length(dimension);
}
*/
// if (position < lower(dimension)) {
// position = lower(dimension);
// }
if (dimension == Dimension_X) {
if (position < lower(dimension)) {
position = lower(dimension);
}
} else {
if (position > (upper(dimension) - cur_length(dimension))) {
position = upper(dimension) - cur_length(dimension);
}
}
if (position == cur_lower(dimension)) {
return;
}
cur_lower(dimension, position);
notify(dimension);
damage();
}
void Text::scroll_backward(DimensionName dimension) {
FontBoundingBox fbb;
font_->font_bbox(fbb);
if (dimension == Dimension_X) {
scroll_to(dimension, cur_lower(Dimension_X) - width(' '));
} else {
scroll_to(dimension, cur_lower(Dimension_Y) -
(fbb.ascent() + fbb.descent()));
}
}
void Scrollable::scroll_to(DimensionName d, Coord lower) {
Coord p = lower;
Coord prevdx = dx_;
Coord prevdy = dy_;
constrain(d, p);
if (p != cur_lower(d)) {
if (d == Dimension_X) dx_ = p;
else dy_ = p;
redraw();
for (int i=0; i<page_->count(); i++) {
Coord x, y;
page_->location(i, x, y);
page_->move(i, x+prevdx-dx_, y+prevdy-dy_);
}
notify(d);
redraw();
};
}
Coord Adjustable::cur_length(DimensionName d) const {
return cur_upper(d) - cur_lower(d);
}
void Adjustable::page_backward(DimensionName d) {
scroll_to(d, cur_lower(d) - large_scroll(d));
}
void Adjustable::scroll_backward(DimensionName d) {
scroll_to(d, cur_lower(d) - small_scroll(d));
}
void Text::page_backward(DimensionName dimension) {
scroll_to(dimension, cur_lower(dimension) - cur_length(dimension));
}
Coord Text::cur_length(DimensionName dimension) const {
return cur_upper(dimension) - cur_lower(dimension);
}
