calibre-web/cps/static/js/kthoom.js

/*
 * kthoom.js
 *
 * Licensed under the MIT License
 *
 * Copyright(c) 2011 Google Inc.
 * Copyright(c) 2011 antimatter15
*/

/* Reference Documentation:

  * Web Workers: http://www.whatwg.org/specs/web-workers/current-work/
  * Web Workers in Mozilla: https://developer.mozilla.org/En/Using_web_workers
  * File API (FileReader): http://www.w3.org/TR/FileAPI/
  * Typed Arrays: http://www.khronos.org/registry/typedarray/specs/latest/#6

*/
/* global bitjs */

if (window.opera) {
    window.console.log = function(str) {
        opera.postError(str);
    };
}

var kthoom;

// gets the element with the given id
function getElem(id) {
    if (document.documentElement.querySelector) {
        // querySelector lookup
        return document.body.querySelector("#" + id);
    }
    // getElementById lookup
    return document.getElementById(id);
}

if (window.kthoom === undefined) {
    kthoom = {};
}

// key codes
kthoom.Key = {
    ESCAPE: 27,
    LEFT: 37,
    UP: 38,
    RIGHT: 39,
    DOWN: 40, 
    A: 65, B: 66, C: 67, D: 68, E: 69, F: 70, G: 71, H: 72, I: 73, J: 74, K: 75, L: 76, M: 77, 
    N: 78, O: 79, P: 80, Q: 81, R: 82, S: 83, T: 84, U: 85, V: 86, W: 87, X: 88, Y: 89, Z: 90,
    QUESTION_MARK: 191,
    LEFT_SQUARE_BRACKET: 219,
    RIGHT_SQUARE_BRACKET: 221
};

// The rotation orientation of the comic.
kthoom.rotateTimes = 0;

// global variables
var unarchiver = null;
var currentImage = 0;
var imageFiles = [];
var imageFilenames = [];
var totalImages = 0;
var lastCompletion = 0;

var hflip = false, vflip = false, fitMode = kthoom.Key.B;
var canKeyNext = true, canKeyPrev = true;

kthoom.saveSettings = function() {
    localStorage.kthoomSettings = JSON.stringify({
        rotateTimes: kthoom.rotateTimes,
        hflip: hflip,
        vflip: vflip,
        fitMode: fitMode
    });
};

kthoom.loadSettings = function() {
    try {
        if (localStorage.kthoomSettings.length < 10){
            return;
        }
        var s = JSON.parse(localStorage.kthoomSettings);
        kthoom.rotateTimes = s.rotateTimes;
        hflip = s.hflip;
        vflip = s.vflip;
        fitMode = s.fitMode;
    } catch (err) {
        alert("Error load settings");
    }
};

var createURLFromArray = function(array, mimeType) {
    var offset = array.byteOffset, len = array.byteLength;
    var url;
    var blob;

    if (mimeType === 'image/xml+svg') {
        const xmlStr = new TextDecoder('utf-8').decode(array);
        return 'data:image/svg+xml;UTF-8,' + encodeURIComponent(xmlStr);
  }

    // TODO: Move all this browser support testing to a common place
    //     and do it just once.

    // Blob constructor, see http://dev.w3.org/2006/webapi/FileAPI/#dfn-Blob.
    if (typeof Blob === "function") {
        blob = new Blob([array], {type: mimeType});
    } else {
        throw "Browser support for Blobs is missing.";
    }

    if (blob.slice) {
        blob = blob.slice(offset, offset + len, mimeType);
    } else {
        throw "Browser support for Blobs is missing.";
    }

    if ((typeof URL !== "function" && typeof URL !== "object") ||
      typeof URL.createObjectURL !== "function") {
        throw "Browser support for Object URLs is missing";
    }

    return URL.createObjectURL(blob);
};


// Stores an image filename and its data: URI.
// TODO: investigate if we really need to store as base64 (leave off ;base64 and just
//       non-safe URL characters are encoded as %xx ?)
//       This would save 25% on memory since base64-encoded strings are 4/3 the size of the binary
kthoom.ImageFile = function(file) {
    this.filename = file.filename;
    var fileExtension = file.filename.split(".").pop().toLowerCase();
    var mimeType = fileExtension === "png" ? "image/png" :
        (fileExtension === "jpg" || fileExtension === "jpeg") ? "image/jpeg" :
            fileExtension === "gif" ? "image/gif" : fileExtension == 'svg' ? 'image/xml+svg' : undefined;
    this.dataURI = createURLFromArray(file.fileData, mimeType);
    this.data = file;
};


kthoom.initProgressMeter = function() {
    var svgns = "http://www.w3.org/2000/svg";
    var pdiv = $("#progress")[0]; 
    var svg = document.createElementNS(svgns, "svg");
    svg.style.width = "100%";
    svg.style.height = "100%";

    var defs = document.createElementNS(svgns, "defs");

    var patt = document.createElementNS(svgns, "pattern");
    patt.id = "progress_pattern";
    patt.setAttribute("width", "30");
    patt.setAttribute("height", "20");
    patt.setAttribute("patternUnits", "userSpaceOnUse");

    var rect = document.createElementNS(svgns, "rect");
    rect.setAttribute("width", "100%");
    rect.setAttribute("height", "100%");
    rect.setAttribute("fill", "#cc2929");

    var poly = document.createElementNS(svgns, "polygon");
    poly.setAttribute("fill", "yellow");
    poly.setAttribute("points", "15,0 30,0 15,20 0,20");

    patt.appendChild(rect);
    patt.appendChild(poly);
    defs.appendChild(patt);

    svg.appendChild(defs);

    var g = document.createElementNS(svgns, "g");

    var outline = document.createElementNS(svgns, "rect");
    outline.setAttribute("y", "1");
    outline.setAttribute("width", "100%");
    outline.setAttribute("height", "15");
    outline.setAttribute("fill", "#777");
    outline.setAttribute("stroke", "white");
    outline.setAttribute("rx", "5");
    outline.setAttribute("ry", "5");
    g.appendChild(outline);

    var title = document.createElementNS(svgns, "text");
    title.id = "progress_title";
    title.appendChild(document.createTextNode("0%"));
    title.setAttribute("y", "13");
    title.setAttribute("x", "99.5%");
    title.setAttribute("fill", "white");
    title.setAttribute("font-size", "12px");
    title.setAttribute("text-anchor", "end");
    g.appendChild(title);

    var meter = document.createElementNS(svgns, "rect");
    meter.id = "meter";
    meter.setAttribute("width", "0%");
    meter.setAttribute("height", "17");
    meter.setAttribute("fill", "url(#progress_pattern)");
    meter.setAttribute("rx", "5");
    meter.setAttribute("ry", "5");

    var meter2 = document.createElementNS(svgns, "rect");
    meter2.id = "meter2";
    meter2.setAttribute("width", "0%");
    meter2.setAttribute("height", "17");
    meter2.setAttribute("opacity", "0.8");
    meter2.setAttribute("fill", "#007fff");
    meter2.setAttribute("rx", "5");
    meter2.setAttribute("ry", "5");

    g.appendChild(meter);
    g.appendChild(meter2);

    var page = document.createElementNS(svgns, "text");
    page.id = "page";
    page.appendChild(document.createTextNode("0/0"));
    page.setAttribute("y", "13");
    page.setAttribute("x", "0.5%");
    page.setAttribute("fill", "white");
    page.setAttribute("font-size", "12px");
    g.appendChild(page);
  
  
    svg.appendChild(g);
    pdiv.appendChild(svg);
    var l;
    svg.onclick = function(e) {
        for (var x = pdiv, l = 0; x !== document.documentElement; x = x.parentNode) l += x.offsetLeft;
        var page = Math.max(1, Math.ceil(((e.clientX - l) / pdiv.offsetWidth) * totalImages)) - 1;
        currentImage = page;
        updatePage();
    };
}

kthoom.setProgressMeter = function(pct, optLabel) {
    pct = (pct * 100);
    var part = 1 / totalImages;
    var remain = ((pct - lastCompletion) / 100) / part;
    var fract = Math.min(1, remain);
    var smartpct = ((imageFiles.length / totalImages) + (fract * part)) * 100;
    if (totalImages === 0) smartpct = pct;
  
    // + Math.min((pct - lastCompletion), 100/totalImages * 0.9 + (pct - lastCompletion - 100/totalImages)/2, 100/totalImages);
    var oldval = parseFloat(getElem("meter").getAttribute("width"));
    if (isNaN(oldval)) oldval = 0;
    var weight = 0.5;
    smartpct = ((weight * smartpct) + ((1 - weight) * oldval));
    if (pct === 100) smartpct = 100;

    if (!isNaN(smartpct)) {
        getElem("meter").setAttribute("width", smartpct + "%");
    }
    var title = getElem("progress_title");
    while (title.firstChild) title.removeChild(title.firstChild);

    var labelText = pct.toFixed(2) + "% " + imageFiles.length + "/" + totalImages + "";
    if (optLabel) {
        labelText = optLabel + " " + labelText;
    }
    title.appendChild(document.createTextNode(labelText));

    getElem("meter2").setAttribute("width",
        100 * (totalImages === 0 ? 0 : ((currentImage + 1) / totalImages)) + "%");

    var titlePage = getElem("page");
    while (titlePage.firstChild) titlePage.removeChild(titlePage.firstChild);
    titlePage.appendChild(document.createTextNode( (currentImage + 1) + "/" + totalImages ));

    if (pct > 0) {
        //getElem('nav').className = '';
        getElem("progress").className = "";
    }
}

function loadFromArrayBuffer(ab) {
    var start = (new Date).getTime();
    var h = new Uint8Array(ab, 0, 10);
    var pathToBitJS = "../../static/js/";
    if (h[0] === 0x52 && h[1] === 0x61 && h[2] === 0x72 && h[3] === 0x21) { //Rar!
        unarchiver = new bitjs.archive.Unrarrer(ab, pathToBitJS);
    } else if (h[0] === 80 && h[1] === 75) { //PK (Zip)
        unarchiver = new bitjs.archive.Unzipper(ab, pathToBitJS);
    } else { // Try with tar
        unarchiver = new bitjs.archive.Untarrer(ab, pathToBitJS);
    }
    // Listen for UnarchiveEvents.
    if (unarchiver) {
        unarchiver.addEventListener(bitjs.archive.UnarchiveEvent.Type.PROGRESS,
            function(e) {
                var percentage = e.currentBytesUnarchived / e.totalUncompressedBytesInArchive;
                totalImages = e.totalFilesInArchive;
                kthoom.setProgressMeter(percentage, "Unzipping");
                // display nav
                lastCompletion = percentage * 100;
            });
        unarchiver.addEventListener(bitjs.archive.UnarchiveEvent.Type.EXTRACT,
            function(e) {
            // convert DecompressedFile into a bunch of ImageFiles
                if (e.unarchivedFile) {
                    var f = e.unarchivedFile;
                    // add any new pages based on the filename
                    if (imageFilenames.indexOf(f.filename) === -1) {
                        imageFilenames.push(f.filename);
                        imageFiles.push(new kthoom.ImageFile(f));
                    }
                }
                // display first page if we haven't yet
                if (imageFiles.length === currentImage + 1) {
                    updatePage();
                }
            });
        unarchiver.addEventListener(bitjs.archive.UnarchiveEvent.Type.FINISH,
            function() {
                var diff = ((new Date).getTime() - start) / 1000;
                console.log("Unarchiving done in " + diff + "s");
            });
        unarchiver.start();
    } else {
        alert("Some error");
    }
}


function updatePage() {
    var title = getElem("page");
    while (title.firstChild) title.removeChild(title.firstChild);
    title.appendChild(document.createTextNode( (currentImage + 1 ) + "/" + totalImages ));

    getElem("meter2").setAttribute("width",
        100 * (totalImages === 0 ? 0 : ((currentImage + 1 ) / totalImages)) + "%");
    if (imageFiles[currentImage]) {
        setImage(imageFiles[currentImage].dataURI);
    } else {
        setImage("loading");
    }
}

function setImage(url) {
    var canvas = $("#mainImage")[0];
    var x = $("#mainImage")[0].getContext("2d");
    $("#mainText").hide();
    if (url === "loading") {
        updateScale(true);
        canvas.width = innerWidth - 100;
        canvas.height = 200;
        x.fillStyle = "red";
        x.font = "50px sans-serif";
        x.strokeStyle = "black";
        x.fillText("Loading Page #" + (currentImage + 1), 100, 100);
    } else {
        if ($("body").css("scrollHeight") / innerHeight > 1) {
            $("body").css("overflowY", "scroll");
        }

        var img = new Image();
        img.onerror = function() {
            canvas.width = innerWidth - 100;
            canvas.height = 300;
            updateScale(true);
            x.fillStyle = "orange";
            x.font = "50px sans-serif";
            x.strokeStyle = "black";
            x.fillText("Page #" + (currentImage + 1) + " (" +
              imageFiles[currentImage].filename + ")", 100, 100);
            x.fillStyle = "red";
            x.fillText("Is corrupt or not an image", 100, 200);

            var xhr = new XMLHttpRequest();
            if (/(html|htm)$/.test(imageFiles[currentImage].filename)) {
                xhr.open("GET", url, true);
                xhr.onload = function() {
                    //document.getElementById('mainText').style.display = '';
                    $("#mainText").css("display", "");
                    $("#mainText").innerHTML("<iframe style=\"width:100%;height:700px;border:0\" src=\"data:text/html," + escape(xhr.responseText) + "\"></iframe>");
                }
                xhr.send(null);
            } else if (!/(jpg|jpeg|png|gif)$/.test(imageFiles[currentImage].filename) && imageFiles[currentImage].data.uncompressedSize < 10 * 1024) {
                xhr.open("GET", url, true);
                xhr.onload = function() {
                    $("#mainText").css("display", "");
                    $("#mainText").innerText(xhr.responseText);
                };
                xhr.send(null);
            }
        };
        img.onload = function() {
            var h = img.height,
                w = img.width,
                sw = w,
                sh = h;
            kthoom.rotateTimes =  (4 + kthoom.rotateTimes) % 4;
            x.save();
            if (kthoom.rotateTimes % 2 === 1) {
                sh = w;
                sw = h;
            }
            canvas.height = sh;
            canvas.width = sw;
            x.translate(sw / 2, sh / 2);
            x.rotate(Math.PI / 2 * kthoom.rotateTimes);
            x.translate(-w / 2, -h / 2);
            if (vflip) {
                x.scale(1, -1);
                x.translate(0, -h);
            }
            if (hflip) {
                x.scale(-1, 1);
                x.translate(-w, 0);
            }
            canvas.style.display = "none";
            scrollTo(0, 0);
            x.drawImage(img, 0, 0);

            updateScale();

            canvas.style.display = "";
            $("body").css("overflowY", "");
            x.restore();
        };
        img.src = url;
    }
}

function showPrevPage() {
    currentImage--;
    if (currentImage < 0) {
        // Freeze on the current page.
        currentImage++;
    } else {
        updatePage();
    }
}

function showNextPage() {
    currentImage++;
    if (currentImage >= Math.max(totalImages, imageFiles.length)) {
        // Freeze on the current page.
        currentImage--;
    } else {
        updatePage();
    }
}

function updateScale(clear) {
    var mainImageStyle = getElem("mainImage").style;
    mainImageStyle.width = "";
    mainImageStyle.height = "";
    mainImageStyle.maxWidth = "";
    mainImageStyle.maxHeight = "";
    var maxheight = innerHeight - 15;
    if (!/main/.test(getElem("titlebar").className)) {
        maxheight -= 25;
    }
    if (clear || fitMode === kthoom.Key.N) {
    } else if (fitMode === kthoom.Key.B) {
        mainImageStyle.maxWidth = "100%";
        mainImageStyle.maxHeight = maxheight + "px";
    } else if (fitMode === kthoom.Key.H) {
        mainImageStyle.height = maxheight + "px";
    } else if (fitMode === kthoom.Key.W) {
        mainImageStyle.width = "100%";
    }
    kthoom.saveSettings();
}

function keyHandler(evt) {
    var code = evt.keyCode;

    if ($("#progress").css("display") === "none"){
        return;
    }
    canKeyNext = (($("body").css("offsetWidth") + $("body").css("scrollLeft")) / $("body").css("scrollWidth")) >= 1;
    canKeyPrev = (scrollX <= 0);

    if (evt.ctrlKey || evt.shiftKey || evt.metaKey) return;
    switch (code) {
        case kthoom.Key.LEFT:
            if (canKeyPrev) showPrevPage();
            break;
        case kthoom.Key.RIGHT:
            if (canKeyNext) showNextPage();
            break;
        case kthoom.Key.L:
            kthoom.rotateTimes--;
            if (kthoom.rotateTimes < 0) {
                kthoom.rotateTimes = 3;
            }
            updatePage();
            break;
        case kthoom.Key.R:
            kthoom.rotateTimes++;
            if (kthoom.rotateTimes > 3) {
                kthoom.rotateTimes = 0;
            }
            updatePage();
            break;
        case kthoom.Key.F:
            if (!hflip && !vflip) {
                hflip = true;
            } else if (hflip === true) {
                vflip = true;
                hflip = false;
            } else if (vflip === true) {
                vflip = false;
            }
            updatePage();
            break;
        case kthoom.Key.W:
            fitMode = kthoom.Key.W;
            updateScale();
            break;
        case kthoom.Key.H:
            fitMode = kthoom.Key.H;
            updateScale();
            break;
        case kthoom.Key.B:
            fitMode = kthoom.Key.B;
            updateScale();
            break;
        case kthoom.Key.N:
            fitMode = kthoom.Key.N;
            updateScale();
            break;
        default:
            //console.log('KeyCode = ' + code);
            break;
    }
}

function init(filename) {
    if (!window.FileReader) {
        alert("Sorry, kthoom will not work with your browser because it does not support the File API.  Please try kthoom with Chrome 12+ or Firefox 7+");
    } else {
        var request = new XMLHttpRequest();
        request.open("GET", filename);
        request.responseType = "arraybuffer";
        request.setRequestHeader("X-Test", "test1");
        request.setRequestHeader("X-Test", "test2");
        request.addEventListener("load", function(event) {
            if (request.status >= 200 && request.status < 300) {
                loadFromArrayBuffer(request.response);
            } else {
                console.warn(request.statusText, request.responseText);
            }
        });
        request.send();
        kthoom.initProgressMeter();
        document.body.className += /AppleWebKit/.test(navigator.userAgent) ? " webkit" : "";
        updateScale(true);
        kthoom.loadSettings();
        $(document).keydown(keyHandler);

        $(window).resize(function() {
            var f = (screen.width - innerWidth < 4 && screen.height - innerHeight < 4);
            getElem("titlebar").className = f ? "main" : "";
            updateScale();
        });

        $("#mainImage").click(function(evt) {
            // Firefox does not support offsetX/Y so we have to manually calculate
            // where the user clicked in the image.
            var mainContentWidth = $("#mainContent").width();
            var mainContentHeight = $("#mainContent").height();
            var comicWidth = evt.target.clientWidth;
            var comicHeight = evt.target.clientHeight;
            var offsetX = (mainContentWidth - comicWidth) / 2;
            var offsetY = (mainContentHeight - comicHeight) / 2;
            var clickX = !!evt.offsetX ? evt.offsetX : (evt.clientX - offsetX);
            var clickY = !!evt.offsetY ? evt.offsetY : (evt.clientY - offsetY);

            // Determine if the user clicked/tapped the left side or the
            // right side of the page.
            var clickedPrev = false;
            switch (kthoom.rotateTimes) {
            case 0:
              clickedPrev = clickX < (comicWidth / 2);
              break;
            case 1:
              clickedPrev = clickY < (comicHeight / 2);
              break;
            case 2:
              clickedPrev = clickX > (comicWidth / 2);
              break;
            case 3:
              clickedPrev = clickY > (comicHeight / 2);
              break;
            }
            if (clickedPrev) {
                showPrevPage();
            } else {
                showNextPage();
            }
        });
    }
}