package pl.djvuhtml5.client;
import static pl.djvuhtml5.client.TileRenderer.toZoom;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.function.Consumer;
import com.google.gwt.canvas.client.Canvas;
import com.google.gwt.canvas.dom.client.Context2d;
import com.google.gwt.canvas.dom.client.ImageData;
import com.google.gwt.dom.client.CanvasElement;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.ImageElement;
import com.google.gwt.typedarrays.shared.Uint8Array;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.lizardtech.djvu.DjVuInfo;
import com.lizardtech.djvu.GMap;
import com.lizardtech.djvu.GRect;
import com.lizardtech.djvu.text.DjVuText;
import pl.djvuhtml5.client.TileRenderer.TileInfo;
public class DataStore {
private List<DjVuInfo> pageInfos;
private List<DjVuText> pageTexts;
private Map<TileInfo, CanvasElement> tiles = new HashMap<>();
private final CanvasElement missingTileImage;
private final List<Consumer<Integer>> pageCountListeners = new ArrayList<>();
private final List<Consumer<Integer>> textListeners = new ArrayList<>();
private final List<Consumer<Integer>> infoListeners = new ArrayList<>();
private final List<Consumer<Integer>> tileListeners = new ArrayList<>();
private final GRect tempRect = new GRect();
private final TileInfo tempTI = new TileInfo();
private final int tileSize;
private CanvasElement bufferCanvas;
private ImageData bufferImageData;
public DataStore() {
missingTileImage = prepareMissingTileImage();
this.tileSize = DjvuContext.getTileSize();
bufferCanvas = createImage(tileSize, tileSize);
}
private CanvasElement prepareMissingTileImage() {
int tileSize = DjvuContext.getTileSize();
CanvasElement canvas = createImage(tileSize, tileSize);
Context2d context2d = canvas.getContext2d();
context2d.setFillStyle("white");
context2d.fillRect(0, 0, canvas.getWidth(), canvas.getHeight());
Image image = new Image();
final ImageElement imageElement = image.getElement().cast();
imageElement.getStyle().setProperty("visibility", "hidden");
Event.setEventListener(imageElement, event -> {
if (Event.ONLOAD == event.getTypeInt()) {
missingTileImage.getContext2d().drawImage(imageElement, 0, 0);
RootPanel.get().getElement().removeChild(imageElement);
}
});
RootPanel.get().getElement().appendChild(imageElement);
image.setUrl(getBlankImageUrl());
return canvas;
}
private String getBlankImageUrl() {
Element element = new Label().getElement().cast();
element.addClassName("blankImage");
RootPanel.get().getElement().appendChild(element);
try {
String url = Djvu_html5.getComputedStyleProperty(element, "background-image");
url = url.replaceAll("^url\\(['\"]?(.*)['\"]\\)$", "$1");
return url;
} finally {
RootPanel.get().getElement().removeChild(element);
}
}
public void addPageCountListener(Consumer<Integer> listener) {
pageCountListeners.add(listener);
}
public void addTextListener(Consumer<Integer> listener) {
textListeners.add(listener);
}
public void addInfoListener(Consumer<Integer> listener) {
infoListeners.add(listener);
}
public void addTileListener(Consumer<Integer> listener) {
tileListeners.add(listener);
}
public int getPageCount() {
return pageInfos != null ? pageInfos.size() : 1;
}
public void setPageCount(int pageCount) {
pageInfos = Arrays.asList(new DjVuInfo[pageCount]);
pageTexts = Arrays.asList(new DjVuText[pageCount]);
for (Consumer<Integer> l : pageCountListeners)
l.accept(pageCount);
}
public DjVuInfo getPageInfo(int pageNum) {
return pageInfos != null ? pageInfos.get(pageNum) : null;
}
public void setPageInfo(int pageNum, DjVuInfo info) {
pageInfos.set(pageNum, info);
for (Consumer<Integer> l : infoListeners)
l.accept(pageNum);
}
public DjVuText getText(int pageNum) {
return pageTexts != null ? pageTexts.get(pageNum) : null;
}
public void setText(int pageNum, DjVuText text) {
pageTexts.set(pageNum, text);
for (Consumer<Integer> l : textListeners)
l.accept(pageNum);
}
public CanvasElement[][] getTileImages(int pageNum, int subsample, GRect range, CanvasElement[][] reuse) {
CanvasElement[][] result = reuse;
int w = range.width() + 1, h = range.height() + 1;
if (reuse == null || reuse.length != h || reuse[0].length != w) {
result = new CanvasElement[h][w];
}
tempTI.page = pageNum;
tempTI.subsample = subsample;
for (int y = range.ymin; y <= range.ymax; y++)
for (int x = range.xmin; x <= range.xmax; x++)
result[y - range.ymin][x - range.xmin] = getTileImage(tempTI.setXY(x, y));
return result;
}
public void releaseTileImages(List<TileInfo> tiles) {
for (TileInfo tile : tiles)
this.tiles.remove(tile);
}
private CanvasElement getTileImage(TileInfo tileInfo) {
CanvasElement tileImage = tiles.get(tileInfo);
if (tileImage != null)
return tileImage;
DjVuInfo pageInfo = getPageInfo(tileInfo.page);
int tileSize = DjvuContext.getTileSize();
// fill with rescaled other tiles
ArrayList<TileInfo> fetched = new ArrayList<>();
tileInfo.getPageRect(tempRect, tileSize, pageInfo);
GRect tempRect2 = new GRect();
for (Entry<TileInfo, CanvasElement> entry : tiles.entrySet()) {
TileInfo ti = entry.getKey();
if (ti.page == tileInfo.page) {
ti.getPageRect(tempRect2, tileSize, pageInfo);
if (tempRect2.intersect(tempRect2, tempRect))
fetched.add(ti);
}
}
if (fetched.isEmpty())
return missingTileImage;
Collections.sort(fetched, (ti1, ti2) -> ti2.subsample - ti1.subsample);
tileInfo.getScreenRect(tempRect, tileSize, pageInfo);
tileImage = createImage(tempRect.width(), tempRect.height());
tiles.put(new TileInfo(tileInfo), tileImage);
Context2d context = tileImage.getContext2d();
tileInfo.getScreenRect(tempRect, tileSize, pageInfo);
double zoom = toZoom(tileInfo.subsample);
for (TileInfo ti : fetched) {
context.save();
double scale = zoom / toZoom(ti.subsample);
ti.getScreenRect(tempRect2, tileSize, pageInfo);
context.translate(-tempRect.xmin, -tempRect.ymin);
context.scale(scale, scale);
context.translate(tempRect2.xmin, tempRect2.ymin);
context.drawImage(tiles.get(ti), 0, 0);
context.restore();
}
return tileImage;
}
public void setTile(TileInfo tileInfo, GMap bufferGMap) {
if (bufferImageData == null || bufferImageData.getWidth() != bufferGMap.getDataWidth()
|| bufferImageData.getHeight() != bufferGMap.getDataHeight()) {
bufferImageData = bufferCanvas.getContext2d()
.createImageData(bufferGMap.getDataWidth(), bufferGMap.getDataHeight());
}
Uint8Array imageArray = bufferImageData.getData().cast();
imageArray.set(bufferGMap.getImageData());
bufferCanvas.getContext2d().putImageData(bufferImageData, -bufferGMap.getBorder(), 0);
CanvasElement tile = tiles.get(tileInfo);
if (tile == null) {
tile = createImage(bufferGMap.getDataWidth() - bufferGMap.getBorder(), bufferGMap.getDataHeight());
tiles.put(new TileInfo(tileInfo), tile);
}
Context2d c = tile.getContext2d();
c.setFillStyle("white");
c.fillRect(0, 0, tileSize, tileSize);
c.drawImage(bufferCanvas, 0, 0);
for (Consumer<Integer> listener : tileListeners)
listener.accept(tileInfo.page);
}
public static CanvasElement createImage(int width, int height) {
Canvas canvas = Canvas.createIfSupported();
canvas.setWidth(width + "px");
canvas.setCoordinateSpaceWidth(width);
canvas.setHeight(height + "px");
canvas.setCoordinateSpaceHeight(height);
return canvas.getCanvasElement();
}
}
