webui/js/wordcloud.js

/*
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
 this work for additional information regarding copyright ownership.
 The ASF licenses this file to You under the Apache License, Version 2.0
 (the "License"); you may not use this file except in compliance with
 the License.  You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
*/

const SVG_NAMESPACE = "http://www.w3.org/2000/svg"


function fastIntersect(x,y,nx,ny) {
    if (x.getAttribute("id") == y.getAttribute("id")) { // can't collide with itself
        return false
    }
    let spacing = 2 // number of pixels to keep elements apart
    nx = nx ? nx : 0
    ny = ny ? ny : 0
    let a = x.getBoundingClientRect()
    let b = y.getBoundingClientRect()
    return !(b.left-spacing > (a.right+nx)
        || b.right+spacing < (a.left+nx)
        || b.top-spacing > (a.bottom+ny)
        || b.bottom+spacing < (a.top+ny));
}

function makeWord(word, size, daterange) {
    let textBox = document.createElementNS(SVG_NAMESPACE, "text");
    textBox.setAttribute("font-size", size + "px")
    textBox.setAttribute("x", "0")
    textBox.setAttribute("y", "40")
    textBox.setAttribute("class", "cloudword")
    textBox.setAttribute("onclick", "search(\"" + word + "\", '" + daterange + "')")
    textBox.textContent = word
    return textBox
}

async function wordCloud(hash, width, height, obj, daterange) {
    let total = 0
    let boxes = []
    let space = width * height
    for (let i in hash) {
        total += Math.sqrt(hash[i])
    }
    let hashSorted = []
    for (let word in hash) hashSorted.push(word)
    hashSorted = hashSorted.sort(function(a,b) { return hash[a] > hash[b] })
    let svg = document.createElementNS(SVG_NAMESPACE, "svg");
    document.body.appendChild(svg)
    svg.setAttribute("width",  width)
    svg.setAttribute("height",  height)
    svg.setAttribute("class", "wordcloud")
    for (let word of hashSorted) {
        let size = 0;
        let expected_area = ( Math.sqrt(hash[word]) / total ) * (space*0.9)
        
        let textBox = document.createElementNS(SVG_NAMESPACE, "text");
        textBox.textContent = word
        textBox.setAttribute("font-size", "100px")
        svg.appendChild(textBox)
        
        let w = textBox.getBoundingClientRect();
        
        for (let s = 100; s > 0; s-=5) {
                        
            let area = w.width * w.height * ( (s/100)*(s/100) );
            if (area <= expected_area ) {
                size = s;
                svg.removeChild(textBox)
                break
            }
        }

        let popped = false

        // Try with random placement

        textBox = makeWord(word, size, daterange)
        textBox.setAttribute("id", "svg_wc_" + word)
        svg.appendChild(textBox)
        if (!popped) {
            textBox.setAttribute("x", 0)
            textBox.setAttribute("y", 0)
            for (let ss = size; ss > 5; ss *= 0.9) {
               // alert(ss)
                if (popped) {
                    break
                }
                textBox.setAttribute("font-size", ss + "px")
                
                w = textBox.getBoundingClientRect()
                for (let l = 0; l < 80; l++) {
                    let nx = 4 + (Math.random() * (width-8-w.width))
                    let ny = 4 + w.height + ((l/80) * (height-8-w.height))
                    let it = false
                    for (let box of boxes) {
                        if (fastIntersect(textBox, box, nx, ny)) {
                            it = true
                            break
                        }
                    }
                    if (it == false) {
                        popped = true
                        textBox.setAttribute("x", nx)
                        textBox.setAttribute("y", ny)
                        break
                    } 
                }
            }
        }
        
        
        
        if (popped) {
            let color = 'hsl('+ Math.random()*360 +', 40%, 50%)';
            textBox.setAttribute("fill", color)
            boxes.push(textBox)
        } else {
            //alert("Could not add " + word)
            svg.removeChild(textBox)
        }
        
    }
    
    // Try to size up texts a bit
    for (let textBox of boxes) {
        let osize = parseFloat(textBox.getAttribute('font-size'))
        let psize = osize
        for (let n = 1; n < 1.4; n+=0.2) {
            let nsize = osize * n
            textBox.setAttribute("font-size", nsize + "px")
            let w = textBox.getBoundingClientRect()
            let good = true
            for (let box of boxes) {
                if (fastIntersect(textBox, box)) {
                    good = false
                    break
                }
            }
            if (!good || w.right > width-4 || w.top < 4) {
                textBox.setAttribute("font-size", psize + "px")
                break
            }
            psize = nsize
        }
    }
    document.body.removeChild(svg)
    obj.inject(svg);
}