private void viewChanged() {
if (pageInfo == null) return;
int w = canvas.getCoordinateSpaceWidth(), h = canvas.getCoordinateSpaceHeight();
int pw = (int) (pageInfo.width * zoom), ph = (int) (pageInfo.height * zoom);
if (pw < w) {
centerX = pw / 2;
} else {
centerX = Math.max(centerX, w / 2 - pageMargin);
centerX = Math.min(centerX, pw - w / 2 + pageMargin);
}
if (ph < h) {
centerY = ph / 2;
} else {
centerY = Math.max(centerY, h / 2 - pageMargin);
centerY = Math.min(centerY, ph - h / 2 + pageMargin);
}
double pw2 = pw + 2 * pageMargin, ph2 = ph + 2 * pageMargin;
app.getHorizontalScrollbar().setThumb((centerX + pageMargin) / pw2, w / pw2);
app.getVerticalScrollbar().setThumb((centerY + pageMargin) / ph2, h / ph2);
if (app.getTextLayer() != null)
app.getTextLayer().setViewPosition(page, w / 2 - centerX, h / 2 - centerY, zoom);
}
