searxng/searx/static/themes/__common__/js/image_layout.js
2021-10-01 18:06:55 +02:00

164 lines
5.3 KiB
JavaScript

/**
*
* Google Image Layout v0.0.1
* Description, by Anh Trinh.
* Heavily modified for searx
* https://ptgamr.github.io/2014-09-12-google-image-layout/
* https://ptgamr.github.io/google-image-layout/src/google-image-layout.js
*
* @license Free to use under the MIT License.
*
*/
(function (w, d) {
function ImageLayout(container_selector, results_selector, img_selector, margin, maxHeight) {
this.container_selector = container_selector;
this.results_selector = results_selector;
this.img_selector = img_selector;
this.margin = margin;
this.maxHeight = maxHeight;
this.isAlignDone = true;
}
/**
* Get the height that make all images fit the container
*
* width = w1 + w2 + w3 + ... = r1*h + r2*h + r3*h + ...
*
* @param {[type]} images the images to be calculated
* @param {[type]} width the container witdth
* @param {[type]} margin the margin between each image
*
* @return {[type]} the height
*/
ImageLayout.prototype._getHeigth = function (images, width) {
var i, img;
var r = 0;
for (i = 0; i < images.length; i++) {
img = images[i];
if ((img.naturalWidth > 0) && (img.naturalHeight > 0)) {
r += img.naturalWidth / img.naturalHeight;
} else {
// assume that not loaded images are square
r += 1;
}
}
return (width - images.length * this.margin) / r; //have to round down because Firefox will automatically roundup value with number of decimals > 3
};
ImageLayout.prototype._setSize = function (images, height) {
var i, img, imgWidth;
var imagesLength = images.length, resultNode;
for (i = 0; i < imagesLength; i++) {
img = images[i];
if ((img.naturalWidth > 0) && (img.naturalHeight > 0)) {
imgWidth = height * img.naturalWidth / img.naturalHeight;
} else {
// not loaded image : make it square as _getHeigth said it
imgWidth = height;
}
img.style.width = imgWidth + 'px';
img.style.height = height + 'px';
img.style.marginLeft = '3px';
img.style.marginTop = '3px';
img.style.marginRight = this.margin - 7 + 'px'; // -4 is the negative margin of the inline element
img.style.marginBottom = this.margin - 7 + 'px';
resultNode = img.parentNode.parentNode;
if (!resultNode.classList.contains('js')) {
resultNode.classList.add('js');
}
}
};
ImageLayout.prototype._alignImgs = function (imgGroup) {
var isSearching, slice, i, h;
var containerElement = d.querySelector(this.container_selector);
var containerCompStyles = window.getComputedStyle(containerElement);
var containerPaddingLeft = parseInt(containerCompStyles.getPropertyValue('padding-left'), 10);
var containerPaddingRight = parseInt(containerCompStyles.getPropertyValue('padding-right'), 10);
var containerWidth = containerElement.clientWidth - containerPaddingLeft - containerPaddingRight;
while (imgGroup.length > 0) {
isSearching = true;
for (i = 1; i <= imgGroup.length && isSearching; i++) {
slice = imgGroup.slice(0, i);
h = this._getHeigth(slice, containerWidth);
if (h < this.maxHeight) {
this._setSize(slice, h);
// continue with the remaining images
imgGroup = imgGroup.slice(i);
isSearching = false;
}
}
if (isSearching) {
this._setSize(slice, Math.min(this.maxHeight, h));
break;
}
}
};
ImageLayout.prototype.align = function () {
var i;
var results_selectorNode = d.querySelectorAll(this.results_selector);
var results_length = results_selectorNode.length;
var previous = null;
var current = null;
var imgGroup = [];
for (i = 0; i < results_length; i++) {
current = results_selectorNode[i];
if (current.previousElementSibling !== previous && imgGroup.length > 0) {
// the current image is not connected to previous one
// so the current image is the start of a new group of images.
// so call _alignImgs to align the current group
this._alignImgs(imgGroup);
// and start a new empty group of images
imgGroup = [];
}
// add the current image to the group (only the img tag)
imgGroup.push(current.querySelector(this.img_selector));
// update the previous variable
previous = current;
}
// align the remaining images
if (imgGroup.length > 0) {
this._alignImgs(imgGroup);
}
};
ImageLayout.prototype.watch = function () {
var i, img;
var obj = this;
var results_nodes = d.querySelectorAll(this.results_selector);
var results_length = results_nodes.length;
function throttleAlign() {
if (obj.isAlignDone) {
obj.isAlignDone = false;
setTimeout(function () {
obj.align();
obj.isAlignDone = true;
}, 100);
}
}
w.addEventListener('pageshow', throttleAlign);
w.addEventListener('load', throttleAlign);
w.addEventListener('resize', throttleAlign);
for (i = 0; i < results_length; i++) {
img = results_nodes[i].querySelector(this.img_selector);
if (img !== null && img !== undefined) {
img.addEventListener('load', throttleAlign);
img.addEventListener('error', throttleAlign);
}
}
};
w.searxng.ImageLayout = ImageLayout;
}(window, document));