fronend/plugins/light-gallery/js/lg-zoom.js

/*! lightgallery - v1.2.21 - 2016-06-28
* http://sachinchoolur.github.io/lightGallery/
* Copyright (c) 2016 Sachin N; Licensed Apache 2.0 */
(function($, window, document, undefined) {

    'use strict';

    var defaults = {
        scale: 1,
        zoom: true,
        actualSize: true,
        enableZoomAfter: 300
    };

    var Zoom = function(element) {

        this.core = $(element).data('lightGallery');

        this.core.s = $.extend({}, defaults, this.core.s);

        if (this.core.s.zoom && this.core.doCss()) {
            this.init();

            // Store the zoomable timeout value just to clear it while closing
            this.zoomabletimeout = false;

            // Set the initial value center
            this.pageX = $(window).width() / 2;
            this.pageY = ($(window).height() / 2) + $(window).scrollTop();
        }

        return this;
    };

    Zoom.prototype.init = function() {

        var _this = this;
        var zoomIcons = '<span id="lg-zoom-in" class="lg-icon"></span><span id="lg-zoom-out" class="lg-icon"></span>';

        if (_this.core.s.actualSize) {
            zoomIcons += '<span id="lg-actual-size" class="lg-icon"></span>';
        }

        this.core.$outer.find('.lg-toolbar').append(zoomIcons);

        // Add zoomable class
        _this.core.$el.on('onSlideItemLoad.lg.tm.zoom', function(event, index, delay) {

            // delay will be 0 except first time
            var _speed = _this.core.s.enableZoomAfter + delay;

            // set _speed value 0 if gallery opened from direct url and if it is first slide
            if ($('body').hasClass('lg-from-hash') && delay) {

                // will execute only once
                _speed = 0;
            } else {

                // Remove lg-from-hash to enable starting animation.
                $('body').removeClass('lg-from-hash');
            }

            _this.zoomabletimeout = setTimeout(function() {
                _this.core.$slide.eq(index).addClass('lg-zoomable');
            }, _speed + 30);
        });

        var scale = 1;
        /**
         * @desc Image zoom
         * Translate the wrap and scale the image to get better user experience
         *
         * @param {String} scaleVal - Zoom decrement/increment value
         */
        var zoom = function(scaleVal) {

            var $image = _this.core.$outer.find('.lg-current .lg-image');
            var _x;
            var _y;

            // Find offset manually to avoid issue after zoom
            var offsetX = ($(window).width() - $image.width()) / 2;
            var offsetY = (($(window).height() - $image.height()) / 2) + $(window).scrollTop();

            _x = _this.pageX - offsetX;
            _y = _this.pageY - offsetY;

            var x = (scaleVal - 1) * (_x);
            var y = (scaleVal - 1) * (_y);

            $image.css('transform', 'scale3d(' + scaleVal + ', ' + scaleVal + ', 1)').attr('data-scale', scaleVal);

            $image.parent().css({
                left: -x + 'px',
                top: -y + 'px'
            }).attr('data-x', x).attr('data-y', y);
        };

        var callScale = function() {
            if (scale > 1) {
                _this.core.$outer.addClass('lg-zoomed');
            } else {
                _this.resetZoom();
            }

            if (scale < 1) {
                scale = 1;
            }

            zoom(scale);
        };

        var actualSize = function(event, $image, index, fromIcon) {
            var w = $image.width();
            var nw;
            if (_this.core.s.dynamic) {
                nw = _this.core.s.dynamicEl[index].width || $image[0].naturalWidth || w;
            } else {
                nw = _this.core.$items.eq(index).attr('data-width') || $image[0].naturalWidth || w;
            }

            var _scale;

            if (_this.core.$outer.hasClass('lg-zoomed')) {
                scale = 1;
            } else {
                if (nw > w) {
                    _scale = nw / w;
                    scale = _scale || 2;
                }
            }

            if (fromIcon) {
                _this.pageX = $(window).width() / 2;
                _this.pageY = ($(window).height() / 2) + $(window).scrollTop();
            } else {
                _this.pageX = event.pageX || event.originalEvent.targetTouches[0].pageX;
                _this.pageY = event.pageY || event.originalEvent.targetTouches[0].pageY;
            }

            callScale();
            setTimeout(function() {
                _this.core.$outer.removeClass('lg-grabbing').addClass('lg-grab');
            }, 10);
        };

        var tapped = false;

        // event triggered after appending slide content
        _this.core.$el.on('onAferAppendSlide.lg.tm.zoom', function(event, index) {

            // Get the current element
            var $image = _this.core.$slide.eq(index).find('.lg-image');

            $image.on('dblclick', function(event) {
                actualSize(event, $image, index);
            });

            $image.on('touchstart', function(event) {
                if (!tapped) {
                    tapped = setTimeout(function() {
                        tapped = null;
                    }, 300);
                } else {
                    clearTimeout(tapped);
                    tapped = null;
                    actualSize(event, $image, index);
                }

                event.preventDefault();
            });

        });

        // Update zoom on resize and orientationchange
        $(window).on('resize.lg.zoom scroll.lg.zoom orientationchange.lg.zoom', function() {
            _this.pageX = $(window).width() / 2;
            _this.pageY = ($(window).height() / 2) + $(window).scrollTop();
            zoom(scale);
        });

        $('#lg-zoom-out').on('click.lg', function() {
            if (_this.core.$outer.find('.lg-current .lg-image').length) {
                scale -= _this.core.s.scale;
                callScale();
            }
        });

        $('#lg-zoom-in').on('click.lg', function() {
            if (_this.core.$outer.find('.lg-current .lg-image').length) {
                scale += _this.core.s.scale;
                callScale();
            }
        });

        $('#lg-actual-size').on('click.lg', function(event) {
            actualSize(event, _this.core.$slide.eq(_this.core.index).find('.lg-image'), _this.core.index, true);
        });

        // Reset zoom on slide change
        _this.core.$el.on('onBeforeSlide.lg.tm', function() {
            scale = 1;
            _this.resetZoom();
        });

        // Drag option after zoom
        if (!_this.core.isTouch) {
            _this.zoomDrag();
        }

        if (_this.core.isTouch) {
            _this.zoomSwipe();
        }

    };

    // Reset zoom effect
    Zoom.prototype.resetZoom = function() {
        this.core.$outer.removeClass('lg-zoomed');
        this.core.$slide.find('.lg-img-wrap').removeAttr('style data-x data-y');
        this.core.$slide.find('.lg-image').removeAttr('style data-scale');

        // Reset pagx pagy values to center
        this.pageX = $(window).width() / 2;
        this.pageY = ($(window).height() / 2) + $(window).scrollTop();
    };

    Zoom.prototype.zoomSwipe = function() {
        var _this = this;
        var startCoords = {};
        var endCoords = {};
        var isMoved = false;

        // Allow x direction drag
        var allowX = false;

        // Allow Y direction drag
        var allowY = false;

        _this.core.$slide.on('touchstart.lg', function(e) {

            if (_this.core.$outer.hasClass('lg-zoomed')) {
                var $image = _this.core.$slide.eq(_this.core.index).find('.lg-object');

                allowY = $image.outerHeight() * $image.attr('data-scale') > _this.core.$outer.find('.lg').height();
                allowX = $image.outerWidth() * $image.attr('data-scale') > _this.core.$outer.find('.lg').width();
                if ((allowX || allowY)) {
                    e.preventDefault();
                    startCoords = {
                        x: e.originalEvent.targetTouches[0].pageX,
                        y: e.originalEvent.targetTouches[0].pageY
                    };
                }
            }

        });

        _this.core.$slide.on('touchmove.lg', function(e) {

            if (_this.core.$outer.hasClass('lg-zoomed')) {

                var _$el = _this.core.$slide.eq(_this.core.index).find('.lg-img-wrap');
                var distanceX;
                var distanceY;

                e.preventDefault();
                isMoved = true;

                endCoords = {
                    x: e.originalEvent.targetTouches[0].pageX,
                    y: e.originalEvent.targetTouches[0].pageY
                };

                // reset opacity and transition duration
                _this.core.$outer.addClass('lg-zoom-dragging');

                if (allowY) {
                    distanceY = (-Math.abs(_$el.attr('data-y'))) + (endCoords.y - startCoords.y);
                } else {
                    distanceY = -Math.abs(_$el.attr('data-y'));
                }

                if (allowX) {
                    distanceX = (-Math.abs(_$el.attr('data-x'))) + (endCoords.x - startCoords.x);
                } else {
                    distanceX = -Math.abs(_$el.attr('data-x'));
                }

                if ((Math.abs(endCoords.x - startCoords.x) > 15) || (Math.abs(endCoords.y - startCoords.y) > 15)) {
                    _$el.css({
                        left: distanceX + 'px',
                        top: distanceY + 'px'
                    });
                }

            }

        });

        _this.core.$slide.on('touchend.lg', function() {
            if (_this.core.$outer.hasClass('lg-zoomed')) {
                if (isMoved) {
                    isMoved = false;
                    _this.core.$outer.removeClass('lg-zoom-dragging');
                    _this.touchendZoom(startCoords, endCoords, allowX, allowY);

                }
            }
        });

    };

    Zoom.prototype.zoomDrag = function() {

        var _this = this;
        var startCoords = {};
        var endCoords = {};
        var isDraging = false;
        var isMoved = false;

        // Allow x direction drag
        var allowX = false;

        // Allow Y direction drag
        var allowY = false;

        _this.core.$slide.on('mousedown.lg.zoom', function(e) {

            // execute only on .lg-object
            var $image = _this.core.$slide.eq(_this.core.index).find('.lg-object');

            allowY = $image.outerHeight() * $image.attr('data-scale') > _this.core.$outer.find('.lg').height();
            allowX = $image.outerWidth() * $image.attr('data-scale') > _this.core.$outer.find('.lg').width();

            if (_this.core.$outer.hasClass('lg-zoomed')) {
                if ($(e.target).hasClass('lg-object') && (allowX || allowY)) {
                    e.preventDefault();
                    startCoords = {
                        x: e.pageX,
                        y: e.pageY
                    };

                    isDraging = true;

                    // ** Fix for webkit cursor issue https://code.google.com/p/chromium/issues/detail?id=26723
                    _this.core.$outer.scrollLeft += 1;
                    _this.core.$outer.scrollLeft -= 1;

                    _this.core.$outer.removeClass('lg-grab').addClass('lg-grabbing');
                }
            }
        });

        $(window).on('mousemove.lg.zoom', function(e) {
            if (isDraging) {
                var _$el = _this.core.$slide.eq(_this.core.index).find('.lg-img-wrap');
                var distanceX;
                var distanceY;

                isMoved = true;
                endCoords = {
                    x: e.pageX,
                    y: e.pageY
                };

                // reset opacity and transition duration
                _this.core.$outer.addClass('lg-zoom-dragging');

                if (allowY) {
                    distanceY = (-Math.abs(_$el.attr('data-y'))) + (endCoords.y - startCoords.y);
                } else {
                    distanceY = -Math.abs(_$el.attr('data-y'));
                }

                if (allowX) {
                    distanceX = (-Math.abs(_$el.attr('data-x'))) + (endCoords.x - startCoords.x);
                } else {
                    distanceX = -Math.abs(_$el.attr('data-x'));
                }

                _$el.css({
                    left: distanceX + 'px',
                    top: distanceY + 'px'
                });
            }
        });

        $(window).on('mouseup.lg.zoom', function(e) {

            if (isDraging) {
                isDraging = false;
                _this.core.$outer.removeClass('lg-zoom-dragging');

                // Fix for chrome mouse move on click
                if (isMoved && ((startCoords.x !== endCoords.x) || (startCoords.y !== endCoords.y))) {
                    endCoords = {
                        x: e.pageX,
                        y: e.pageY
                    };
                    _this.touchendZoom(startCoords, endCoords, allowX, allowY);

                }

                isMoved = false;
            }

            _this.core.$outer.removeClass('lg-grabbing').addClass('lg-grab');

        });
    };

    Zoom.prototype.touchendZoom = function(startCoords, endCoords, allowX, allowY) {

        var _this = this;
        var _$el = _this.core.$slide.eq(_this.core.index).find('.lg-img-wrap');
        var $image = _this.core.$slide.eq(_this.core.index).find('.lg-object');
        var distanceX = (-Math.abs(_$el.attr('data-x'))) + (endCoords.x - startCoords.x);
        var distanceY = (-Math.abs(_$el.attr('data-y'))) + (endCoords.y - startCoords.y);
        var minY = (_this.core.$outer.find('.lg').height() - $image.outerHeight()) / 2;
        var maxY = Math.abs(($image.outerHeight() * Math.abs($image.attr('data-scale'))) - _this.core.$outer.find('.lg').height() + minY);
        var minX = (_this.core.$outer.find('.lg').width() - $image.outerWidth()) / 2;
        var maxX = Math.abs(($image.outerWidth() * Math.abs($image.attr('data-scale'))) - _this.core.$outer.find('.lg').width() + minX);

        if ((Math.abs(endCoords.x - startCoords.x) > 15) || (Math.abs(endCoords.y - startCoords.y) > 15)) {
            if (allowY) {
                if (distanceY <= -maxY) {
                    distanceY = -maxY;
                } else if (distanceY >= -minY) {
                    distanceY = -minY;
                }
            }

            if (allowX) {
                if (distanceX <= -maxX) {
                    distanceX = -maxX;
                } else if (distanceX >= -minX) {
                    distanceX = -minX;
                }
            }

            if (allowY) {
                _$el.attr('data-y', Math.abs(distanceY));
            } else {
                distanceY = -Math.abs(_$el.attr('data-y'));
            }

            if (allowX) {
                _$el.attr('data-x', Math.abs(distanceX));
            } else {
                distanceX = -Math.abs(_$el.attr('data-x'));
            }

            _$el.css({
                left: distanceX + 'px',
                top: distanceY + 'px'
            });

        }
    };

    Zoom.prototype.destroy = function() {

        var _this = this;

        // Unbind all events added by lightGallery zoom plugin
        _this.core.$el.off('.lg.zoom');
        $(window).off('.lg.zoom');
        _this.core.$slide.off('.lg.zoom');
        _this.core.$el.off('.lg.tm.zoom');
        _this.resetZoom();
        clearTimeout(_this.zoomabletimeout);
        _this.zoomabletimeout = false;
    };

    $.fn.lightGallery.modules.zoom = Zoom;

})(jQuery, window, document);