public SinglePageLayout(Djvu_html5 app) {
this.app = app;
this.tileCache = app.getTileCache();
this.pageCache = app.getPageCache();
pageCache.addFullDecodeListener(this);
tileCache.addTileCacheListener(this);
this.canvas = app.getCanvas();
this.background = app.getBackground();
this.pageMargin = app.getPageMargin();
new PanController();
boolean pageParam = false;
try {
page = Integer.parseInt(Window.Location.getParameter("p")) - 1;
pageParam = true;
} catch (Exception e) {
page = 0;
}
locationUpdateEnabled = pageParam || app.getLocationUpdateEnabled();
pageCache.fetchPage(page);
}
public void redraw() {
Context2d graphics2d = canvas.getContext2d();
int w = canvas.getCoordinateSpaceWidth(), h = canvas.getCoordinateSpaceHeight();
graphics2d.setFillStyle(background);
graphics2d.fillRect(0, 0, w, h);
if (pageInfo == null) return;
int subsample = toSubsample(zoom);
double scale = zoom / toZoom(subsample);
graphics2d.save();
int startX = w / 2 - centerX, startY = h / 2 - centerY;
graphics2d.translate(startX, startY);
graphics2d.scale(scale, scale);
graphics2d.translate(-startX, -startY);
graphics2d.scale(1, -1); // DjVu images have y-axis inverted
int tileSize = tileCache.tileSize;
int pw = (int) (pageInfo.width * zoom), ph = (int) (pageInfo.height * zoom);
range.xmin = (int) (Math.max(0, centerX - w * 0.5) / tileSize / scale);
range.xmax = (int) Math.ceil(Math.min(pw, centerX + w * 0.5) / tileSize / scale);
range.ymin = (int) (Math.max(0, centerY - h * 0.5) / tileSize / scale);
range.ymax = (int) Math.ceil(Math.min(ph, centerY + h * 0.5) / tileSize / scale);
imagesArray = tileCache.getTileImages(page, subsample, range, imagesArray);
for (int y = range.ymin; y <= range.ymax; y++)
for (int x = range.xmin; x <= range.xmax; x++) {
CanvasElement canvasElement = imagesArray[y - range.ymin][x - range.xmin];
graphics2d.drawImage(
canvasElement,
startX + x * tileSize,
-startY - y * tileSize - canvasElement.getHeight());
}
graphics2d.restore();
// missing tile graphics may exceed the page boundary
graphics2d.fillRect(startX + pw, 0, w, h);
graphics2d.fillRect(0, startY + ph, w, h);
}