vis.js is a dynamic, browser-based visualization library
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// DOM utility methods
/**
* this prepares the JSON container for allocating SVG elements
* @param {Object} JSONcontainer
* @private
*/
exports.prepareElements = function(JSONcontainer) {
// cleanup the redundant svgElements;
for (var elementType in JSONcontainer) {
if (JSONcontainer.hasOwnProperty(elementType)) {
JSONcontainer[elementType].redundant = JSONcontainer[elementType].used;
JSONcontainer[elementType].used = [];
}
}
};
/**
* this cleans up all the unused SVG elements. By asking for the parentNode, we only need to supply the JSON container from
* which to remove the redundant elements.
*
* @param {Object} JSONcontainer
* @private
*/
exports.cleanupElements = function(JSONcontainer) {
// cleanup the redundant svgElements;
for (var elementType in JSONcontainer) {
if (JSONcontainer.hasOwnProperty(elementType)) {
if (JSONcontainer[elementType].redundant) {
for (var i = 0; i < JSONcontainer[elementType].redundant.length; i++) {
JSONcontainer[elementType].redundant[i].parentNode.removeChild(JSONcontainer[elementType].redundant[i]);
}
JSONcontainer[elementType].redundant = [];
}
}
}
};
/**
* Ensures that all elements are removed first up so they can be recreated cleanly
* @param {Object} JSONcontainer
*/
exports.resetElements = function(JSONcontainer) {
exports.prepareElements(JSONcontainer);
exports.cleanupElements(JSONcontainer);
exports.prepareElements(JSONcontainer);
};
/**
* Allocate or generate an SVG element if needed. Store a reference to it in the JSON container and draw it in the svgContainer
* the JSON container and the SVG container have to be supplied so other svg containers (like the legend) can use this.
*
* @param {string} elementType
* @param {Object} JSONcontainer
* @param {Object} svgContainer
* @returns {Element}
* @private
*/
exports.getSVGElement = function (elementType, JSONcontainer, svgContainer) {
var element;
// allocate SVG element, if it doesnt yet exist, create one.
if (JSONcontainer.hasOwnProperty(elementType)) { // this element has been created before
// check if there is an redundant element
if (JSONcontainer[elementType].redundant.length > 0) {
element = JSONcontainer[elementType].redundant[0];
JSONcontainer[elementType].redundant.shift();
}
else {
// create a new element and add it to the SVG
element = document.createElementNS('http://www.w3.org/2000/svg', elementType);
svgContainer.appendChild(element);
}
}
else {
// create a new element and add it to the SVG, also create a new object in the svgElements to keep track of it.
element = document.createElementNS('http://www.w3.org/2000/svg', elementType);
JSONcontainer[elementType] = {used: [], redundant: []};
svgContainer.appendChild(element);
}
JSONcontainer[elementType].used.push(element);
return element;
};
/**
* Allocate or generate an SVG element if needed. Store a reference to it in the JSON container and draw it in the svgContainer
* the JSON container and the SVG container have to be supplied so other svg containers (like the legend) can use this.
*
* @param {string} elementType
* @param {Object} JSONcontainer
* @param {Element} DOMContainer
* @param {Element} insertBefore
* @returns {*}
*/
exports.getDOMElement = function (elementType, JSONcontainer, DOMContainer, insertBefore) {
var element;
// allocate DOM element, if it doesnt yet exist, create one.
if (JSONcontainer.hasOwnProperty(elementType)) { // this element has been created before
// check if there is an redundant element
if (JSONcontainer[elementType].redundant.length > 0) {
element = JSONcontainer[elementType].redundant[0];
JSONcontainer[elementType].redundant.shift();
}
else {
// create a new element and add it to the SVG
element = document.createElement(elementType);
if (insertBefore !== undefined) {
DOMContainer.insertBefore(element, insertBefore);
}
else {
DOMContainer.appendChild(element);
}
}
}
else {
// create a new element and add it to the SVG, also create a new object in the svgElements to keep track of it.
element = document.createElement(elementType);
JSONcontainer[elementType] = {used: [], redundant: []};
if (insertBefore !== undefined) {
DOMContainer.insertBefore(element, insertBefore);
}
else {
DOMContainer.appendChild(element);
}
}
JSONcontainer[elementType].used.push(element);
return element;
};
/**
* Draw a point object. This is a separate function because it can also be called by the legend.
* The reason the JSONcontainer and the target SVG svgContainer have to be supplied is so the legend can use these functions
* as well.
*
* @param {number} x
* @param {number} y
* @param {Object} groupTemplate: A template containing the necessary information to draw the datapoint e.g., {style: 'circle', size: 5, className: 'className' }
* @param {Object} JSONcontainer
* @param {Object} svgContainer
* @param {Object} labelObj
* @returns {vis.PointItem}
*/
exports.drawPoint = function(x, y, groupTemplate, JSONcontainer, svgContainer, labelObj) {
var point;
if (groupTemplate.style == 'circle') {
point = exports.getSVGElement('circle', JSONcontainer, svgContainer);
point.setAttributeNS(null, "cx", x);
point.setAttributeNS(null, "cy", y);
point.setAttributeNS(null, "r", 0.5 * groupTemplate.size);
}
else {
point = exports.getSVGElement('rect', JSONcontainer, svgContainer);
point.setAttributeNS(null, "x", x - 0.5 * groupTemplate.size);
point.setAttributeNS(null, "y", y - 0.5 * groupTemplate.size);
point.setAttributeNS(null, "width", groupTemplate.size);
point.setAttributeNS(null, "height", groupTemplate.size);
}
if (groupTemplate.styles !== undefined) {
point.setAttributeNS(null, "style", groupTemplate.styles);
}
point.setAttributeNS(null, "class", groupTemplate.className + " vis-point");
//handle label
if (labelObj) {
var label = exports.getSVGElement('text', JSONcontainer, svgContainer);
if (labelObj.xOffset) {
x = x + labelObj.xOffset;
}
if (labelObj.yOffset) {
y = y + labelObj.yOffset;
}
if (labelObj.content) {
label.textContent = labelObj.content;
}
if (labelObj.className) {
label.setAttributeNS(null, "class", labelObj.className + " vis-label");
}
label.setAttributeNS(null, "x", x);
label.setAttributeNS(null, "y", y);
}
return point;
};
/**
* draw a bar SVG element centered on the X coordinate
*
* @param {number} x
* @param {number} y
* @param {number} width
* @param {number} height
* @param {string} className
* @param {Object} JSONcontainer
* @param {Object} svgContainer
* @param {string} style
*/
exports.drawBar = function (x, y, width, height, className, JSONcontainer, svgContainer, style) {
if (height != 0) {
if (height < 0) {
height *= -1;
y -= height;
}
var rect = exports.getSVGElement('rect',JSONcontainer, svgContainer);
rect.setAttributeNS(null, "x", x - 0.5 * width);
rect.setAttributeNS(null, "y", y);
rect.setAttributeNS(null, "width", width);
rect.setAttributeNS(null, "height", height);
rect.setAttributeNS(null, "class", className);
if (style) {
rect.setAttributeNS(null, "style", style);
}
}
};