SlideShow._getBackgroundColour - Code Metrics - Inspection of "Initial support for auto-luminance" - nextcloud/gallery - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#179)

by Olivier

created 2017-03-12 17:49 UTC

SlideShow._getBackgroundColour A

↳ Parent: Project

Complexity

Conditions	3
Paths	2

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
cc	3
c	1
b	0
f	0
nc	2
nop	1
dl	0
loc	7
rs	9.4285

/* global Gallery, Thumbnails, DOMPurify */
(function ($, OC, OCA, t) {
	"use strict";
	/**
	 * Slideshow featuring zooming
	 *
	 * @constructor
	 */
	var SlideShow = function () {
	};

	SlideShow.prototype = {
		slideshowTemplate: null,
		container: null,
		zoomablePreviewContainer: null,
		controls: null,
		imageCache: {},
		/** {Image} */
		currentImage: null,
		errorLoadingImage: false,
		onStop: null,
		zoomablePreview: null,
		active: false,
		backgroundToggle: false,
		// We need 6 hexas for comparison reasons
		darkBackgroundColour: '#000000',
		lightBackgroundColour: '#ffffff',

		/**
		 * Initialises the slideshow
		 *
		 * @param {boolean} autoPlay
		 * @param {number} interval
		 * @param {Array} features
		 */
		init: function (autoPlay, interval, features) {
			if (features.indexOf('background_colour_toggle') > -1) {
				this.backgroundToggle = true;
			}

			return $.when(this._getSlideshowTemplate()).then(function ($tmpl) {
				// Move the slideshow outside the content so we can hide the content
				$('body').append($tmpl);
				this.container = $('#slideshow');
				this.zoomablePreviewContainer = this.container.find('.bigshotContainer');
				this.zoomablePreview = new SlideShow.ZoomablePreview(this.container);
				this.controls =
					new SlideShow.Controls(
						this,
						this.container,
						this.zoomablePreview,
						interval,
						features);
				this.controls.init();

				this._initControlsAutoFader();

				// Only modern browsers can manipulate history
				if (history && history.pushState) {

					// Stop the slideshow when backing out.
					$(window).bind('popstate.slideshow', function () {
						if (this.active === true) {
							this.active = false;
							this.controls.stop();
						}
					}.bind(this));
				}
			}.bind(this)).fail(function () {
				OC.Notification.show(t('core', 'Error loading slideshow template'));
			});
		},

		/**
		 * Refreshes the slideshow's data
		 *
		 * @param {{name:string, url: string, path: string, fallBack: string}[]} images
		 * @param {boolean} autoPlay
		 */
		setImages: function (images, autoPlay) {
			this._hideImage();
			this.images = images;
			this.controls.update(images, autoPlay);
		},

		/**
		 * Launches the slideshow
		 *
		 * @param {number} index
		 *
		 * @returns {*}
		 */
		show: function (index) {
			this.hideErrorNotification();
			this.active = true;
			this.container.show();
			this.container.css('background-position', 'center');
			this._hideImage();
			this.container.find('.icon-loading-dark').show();
			var currentImageId = index;
			return this.loadImage(this.images[index]).then(function (img) {
				this.container.css('background-position', '-10000px 0');

				// check if we moved along while we were loading
				if (currentImageId === index) {
					var image = this.images[index];
					var transparent = this._isTransparent(image.mimeType);
					this.controls.showActionButtons(transparent, Gallery.token, image.permissions);
					this.errorLoadingImage = false;
					this.currentImage = img;
					img.setAttribute('alt', image.name);
					$(img).css('position', 'absolute');
					$(img).css('background-color', image.backgroundColour);
					if (transparent && this.backgroundToggle === true) {
						var $border = 30 / window.devicePixelRatio;
						$(img).css('outline', $border + 'px solid ' + image.backgroundColour);
					}

					this.zoomablePreview.startBigshot(img, this.currentImage, image.mimeType);

					this._setUrl(image.path);
					this.controls.show(currentImageId);
					this.container.find('.icon-loading-dark').hide();
				}
			}.bind(this), function () {
				// Don't do anything if the user has moved along while we were loading as it would
				// mess up the index
				if (currentImageId === index) {
					this.errorLoadingImage = true;
					this.showErrorNotification(null);
					this._setUrl(this.images[index].path);
					this.images.splice(index, 1);
					this.controls.updateControls(this.images, this.errorLoadingImage);
				}
			}.bind(this));
		},

		/**
		 * Loads the image to show in the slideshow and preloads the next one
		 *
		 * @param {Object} preview
		 *
		 * @returns {*}
		 */
		loadImage: function (preview) {
			var url = preview.url;
			var mimeType = preview.mimeType;

			if (!this.imageCache[url]) {
				this.imageCache[url] = new $.Deferred();
				var image = new Image();


				image.onload = function () {
					preview.backgroundColour = this._getBackgroundColour(image);
					if (this.imageCache[url]) {
						this.imageCache[url].resolve(image);
					}
				}.bind(this);
				image.onerror = function () {
					if (this.imageCache[url]) {
						this.imageCache[url].reject(url);
					}
				}.bind(this);
				if (mimeType === 'image/svg+xml') {
					image.src = this._getSVG(url);
				} else {
					image.src = url;
				}
			}
			return this.imageCache[url];
		},

		/**
		 * Shows a new image in the slideshow and preloads the next in the list
		 *
		 * @param {number} current
		 * @param {Object} next
		 */
		next: function (current, next) {
			this.show(current).then(function () {
				// Preloads the next image in the list
				this.loadImage(next);
			}.bind(this));
		},

		/**
		 * Determines which colour to use for the background
		 *
		 * @param {*} image
		 *
		 * @returns {string}
		 * @private
		 */
		_getBackgroundColour: function (image) {
			var backgroundColour = this.darkBackgroundColour;
			if (this._isTransparent(image.mimeType) && this._isMainlyDark(image)) {
				backgroundColour = this.lightBackgroundColour;
			}
			return backgroundColour;
		},

		/**
		 * Calculates the luminance of an image to determine if an image is mainly dark
		 *
		 * @param {*} image
		 *
		 * @returns {boolean}
		 * @private
		 */
		_isMainlyDark: function (image) {
			var isMainlyDark = true;
			var numberOfSamples = 1000; // Seems to be the sweet spot
			// The name has to be 'canvas'
			var lumiCanvas = document.createElement('canvas');

			var imgArea = image.width * image.height;
			var canArea = numberOfSamples;
			var factor = Math.sqrt(canArea / imgArea);

			var scaledWidth = factor * image.width;
			var scaledHeight = factor * image.height;
			lumiCanvas.width = scaledWidth;
			lumiCanvas.height = scaledHeight;
			var lumiCtx = lumiCanvas.getContext('2d');
			lumiCtx.drawImage(image, 0, 0, scaledWidth, scaledHeight);
			var imgData = lumiCtx.getImageData(0, 0, lumiCanvas.width, lumiCanvas.height);
			var pix = imgData.data; // pix.length will be approximately 4*numberOfSamples (for RGBA)
			var pixelArraySize = pix.length;
			var totalLuminance = 0;
			var sampleNumber = 1;
			var averageLuminance;
			var totalAlpha = 0;
			var alphaLevel;
			var red = 0;
			var green = 0;
			var blue = 0;
			var alpha = 0;
			var lum = 0;
			var alphaThreshold = 0.1;

			var sampleCounter = 0;
			var itemsPerPixel = 4; // red, green, blue, alpha
			var sampleSize = Math.floor(pixelArraySize / (itemsPerPixel * numberOfSamples));
			if (sampleSize <= 0) {
				sampleSize = 1;
			}
			// i += 4 because 4 colours for every pixel
			for (var i = 0, n = pixelArraySize; i < n; i += itemsPerPixel * sampleSize) {
				sampleCounter++;
				alpha = pix[i + 3] / 255;
				totalAlpha += alpha;
				if (Math.ceil(alpha * 100) / 100 > alphaThreshold) {
					red = pix[i];
					green = pix[i + 1];
					blue = pix[i + 2];
					// Luminance formula from
					// http://stackoverflow.com/questions/596216/formula-to-determine-brightness-of-rgb-color
					lum = (red + red + green + green + green + blue) / 6;
					//lum = (red * 0.299 + green * 0.587 + blue * 0.114 );
					totalLuminance += lum * alpha;
					sampleNumber++;
				}
			}

			// Deletes the canvas
			lumiCanvas = null;


			// Calculate the optimum background colour for this image
			averageLuminance = Math.ceil((totalLuminance / sampleNumber) * 100) / 100;
			alphaLevel = Math.ceil((totalAlpha / numberOfSamples) * 100);
			if (averageLuminance < 50 && alphaLevel < 90) {
				isMainlyDark = false;
			}

			return isMainlyDark;
		},

		/**
		 * Stops the slideshow
		 */
		stop: function () {
			this.active = false;
			this.images = null;
			this._hideImage();
			if (this.onStop) {
				this.onStop();
			}
		},

		/**
		 * Sends the current image as a download
		 *
		 * @param {string} downloadUrl
		 *
		 * @returns {boolean}
		 */
		getImageDownload: function (downloadUrl) {
			OC.redirect(downloadUrl);
			return false;
		},

		/**
		 * Changes the colour of the background of the image
		 */
		toggleBackground: function () {
			var toHex = function (x) {
				return ("0" + parseInt(x).toString(16)).slice(-2);
			};
			var container = this.zoomablePreviewContainer.children('img');
			var rgb = container.css('background-color').match(/\d+/g);
			var hex = "#" + toHex(rgb[0]) + toHex(rgb[1]) + toHex(rgb[2]);
			var $border = 30 / window.devicePixelRatio;
			var newBackgroundColor;

			// Grey #363636
			if (hex === this.darkBackgroundColour) {
				newBackgroundColor = this.lightBackgroundColour;
			} else {
				newBackgroundColor = this.darkBackgroundColour;
			}

			container.css('background-color', newBackgroundColor);
			if (this.backgroundToggle === true) {
				container.css('outline', $border + 'px solid ' + newBackgroundColor);
			}

		},

		/**
		 * Shows an error notification
		 *
		 * @param {string} message
		 */
		showErrorNotification: function (message) {
			if ($.isEmptyObject(message)) {
				message = t('gallery',
					'<strong>Error!</strong> Could not generate a preview of this file.<br>' +
					'Please go to the next slide while we remove this image from the slideshow');
			}
			this.container.find('.notification').html(message);
			this.container.find('.notification').show();
			this.controls.hideButton('.changeBackground');
		},

		/**
		 * Hides the error notification
		 */
		hideErrorNotification: function () {
			this.container.find('.notification').hide();
			this.container.find('.notification').html('');
		},

		/**
		 * Removes a specific button from the interface
		 *
		 * @param button
		 */
		removeButton: function (button) {
			this.controls.removeButton(button);
		},

		/**
		 * Deletes an image from the slideshow
		 *
		 * @param {object} image
		 * @param {number} currentIndex
		 */
		deleteImage: function (image, currentIndex) {
			// These are Gallery specific commands to be replaced
			// which should sit somewhere else
			if (!window.galleryFileAction) {
				delete Gallery.imageMap[image.path];
				delete Thumbnails.map[image.file];
				Gallery.albumMap[Gallery.currentAlbum].images.splice(currentIndex, 1);
				Gallery.view.init(Gallery.currentAlbum);
			}
		},

		/**
		 * Automatically fades the controls after 3 seconds
		 *
		 * @private
		 */
		_initControlsAutoFader: function () {
			var inactiveCallback = function () {
				this.container.addClass('inactive');
			}.bind(this);
			var inactiveTimeout = setTimeout(inactiveCallback, 3000);

			this.container.on('mousemove touchstart', function () {
				this.container.removeClass('inactive');
				clearTimeout(inactiveTimeout);
				inactiveTimeout = setTimeout(inactiveCallback, 3000);
			}.bind(this));
		},

		/**
		 * Simplest way to detect if image is transparent.
		 *
		 * That's very inaccurate since it doesn't include images which support transparency
		 *
		 * @param mimeType
		 * @returns {boolean}
		 * @private
		 */
		_isTransparent: function (mimeType) {
			return !(mimeType === 'image/jpeg'
				|| mimeType === 'image/x-dcraw'
				|| mimeType === 'application/font-sfnt'
				|| mimeType === 'application/x-font'
			);
		},

		/**
		 * Changes the browser Url, based on the current image
		 *
		 * @param {string} path
		 * @private
		 */
		_setUrl: function (path) {
			if (history && history.replaceState) {

				history.replaceState('', '', '#' + encodeURI(path));
			}
		},

		/**
		 * Hides the current image (before loading the next)
		 *
		 * @private
		 */
		_hideImage: function () {
			this.zoomablePreviewContainer.empty();
			this.controls.hideActionButtons();
		},

		/**
		 * Retrieves an SVG
		 *
		 * An SVG can't be simply attached to a src attribute like a bitmap image
		 *
		 * @param {string} source
		 *
		 * @returns {*}
		 * @private
		 */
		_getSVG: function (source) {
			var svgPreview = null;
			// DOMPurify only works with IE10+ and we load SVGs in the IMG tag
			if (window.btoa &&
				document.implementation.hasFeature("http://www.w3.org/TR/SVG11/feature#Image",
					"1.1")) {
				var xmlHttp = new XMLHttpRequest();

				xmlHttp.open("GET", source, false);
				xmlHttp.send(null);
				if (xmlHttp.status === 200) {
					var pureSvg = DOMPurify.sanitize(xmlHttp.responseText, {ADD_TAGS: ['filter']});
					// Remove XML comment garbage left in the purified data
					var badTag = pureSvg.indexOf(']&gt;');
					var fixedPureSvg = pureSvg.substring(badTag < 0 ? 0 : 5, pureSvg.length);
					svgPreview = "data:image/svg+xml;base64," + window.btoa(fixedPureSvg);
				}
			}

			return svgPreview;
		},

		/**
		 * Retrieves the slideshow's template
		 *
		 * @returns {*}
		 * @private
		 */
		_getSlideshowTemplate: function () {
			var defer = $.Deferred();
			if (!this.$slideshowTemplate) {
				var self = this;
				var url = OC.generateUrl('apps/gallery/slideshow', null);
				$.get(url, function (tmpl) {
					var template = $(tmpl);
					var tmplButton;
					var buttonsArray = [
						{
							el: '.next',
							trans: t('gallery', 'Next')
						},
						{
							el: '.play',
							trans: t('gallery', 'Play')
						},
						{
							el: '.pause',
							trans: t('gallery', 'Pause')
						},
						{
							el: '.previous',
							trans: t('gallery', 'Previous')
						},
						{
							el: '.exit',
							trans: t('gallery', 'Close')
						},
						{
							el: '.downloadImage',
							trans: t('gallery', 'Download'),
							toolTip: true
						},
						{
							el: '.changeBackground',
							trans: t('gallery', 'Toggle background'),
							toolTip: true
						},
						{
							el: '.deleteImage',
							trans: t('gallery', 'Delete'),
							toolTip: true
						}
					];
					for (var i = 0; i < buttonsArray.length; i++) {
						var button = buttonsArray[i];

						tmplButton = template.find(button.el);
						tmplButton.val(button.trans);
						if (button.toolTip) {
							tmplButton.attr("title", button.trans);
						}
					}
					self.$slideshowTemplate = template;
					defer.resolve(self.$slideshowTemplate);
				})
					.fail(function () {
						defer.reject();
					});
			} else {
				defer.resolve(this.$slideshowTemplate);
			}
			return defer.promise();
		}
	};

	window.SlideShow = SlideShow;
})(jQuery, OC, OCA, t);


1			/* global Gallery, Thumbnails, DOMPurify */
2			(function ($, OC, OCA, t) {
3			"use strict";
4			/**
5			* Slideshow featuring zooming
6			*
7			* @constructor
8			*/
9			var SlideShow = function () {
10			};
11
12			SlideShow.prototype = {
13			slideshowTemplate: null,
14			container: null,
15			zoomablePreviewContainer: null,
16			controls: null,
17			imageCache: {},
18			/** {Image} */
19			currentImage: null,
20			errorLoadingImage: false,
21			onStop: null,
22			zoomablePreview: null,
23			active: false,
24			backgroundToggle: false,
25			// We need 6 hexas for comparison reasons
26			darkBackgroundColour: '#000000',
27			lightBackgroundColour: '#ffffff',
28
29			/**
30			* Initialises the slideshow
31			*
32			* @param {boolean} autoPlay
33			* @param {number} interval
34			* @param {Array} features
35			*/
36			init: function (autoPlay, interval, features) {
37			if (features.indexOf('background_colour_toggle') > -1) {
38			this.backgroundToggle = true;
39			}
40
41			return $.when(this._getSlideshowTemplate()).then(function ($tmpl) {
42			// Move the slideshow outside the content so we can hide the content
43			$('body').append($tmpl);
44			this.container = $('#slideshow');
45			this.zoomablePreviewContainer = this.container.find('.bigshotContainer');
46			this.zoomablePreview = new SlideShow.ZoomablePreview(this.container);
47			this.controls =
48			new SlideShow.Controls(
49			this,
50			this.container,
51			this.zoomablePreview,
52			interval,
53			features);
54			this.controls.init();
55
56			this._initControlsAutoFader();
57
58			// Only modern browsers can manipulate history
59			if (history && history.pushState) {
			0 ignored issues – show Best Practice introduced 2016-09-04 17:37 UTC by Report Bug Copy Issue Report If you intend to check if the variable `history` is declared in the current environment, consider using `typeof history === "undefined"` instead. This is safe if the variable is not actually declared. Loading history...
60			// Stop the slideshow when backing out.
61			$(window).bind('popstate.slideshow', function () {
62			if (this.active === true) {
63			this.active = false;
64			this.controls.stop();
65			}
66			}.bind(this));
67			}
68			}.bind(this)).fail(function () {
69			OC.Notification.show(t('core', 'Error loading slideshow template'));
70			});
71			},
72
73			/**
74			* Refreshes the slideshow's data
75			*
76			* @param {{name:string, url: string, path: string, fallBack: string}[]} images
77			* @param {boolean} autoPlay
78			*/
79			setImages: function (images, autoPlay) {
80			this._hideImage();
81			this.images = images;
82			this.controls.update(images, autoPlay);
83			},
84
85			/**
86			* Launches the slideshow
87			*
88			* @param {number} index
89			*
90			* @returns {*}
91			*/
92			show: function (index) {
93			this.hideErrorNotification();
94			this.active = true;
95			this.container.show();
96			this.container.css('background-position', 'center');
97			this._hideImage();
98			this.container.find('.icon-loading-dark').show();
99			var currentImageId = index;
100			return this.loadImage(this.images[index]).then(function (img) {
101			this.container.css('background-position', '-10000px 0');
102
103			// check if we moved along while we were loading
104			if (currentImageId === index) {
105			var image = this.images[index];
106			var transparent = this._isTransparent(image.mimeType);
107			this.controls.showActionButtons(transparent, Gallery.token, image.permissions);
108			this.errorLoadingImage = false;
109			this.currentImage = img;
110			img.setAttribute('alt', image.name);
111			$(img).css('position', 'absolute');
112			$(img).css('background-color', image.backgroundColour);
113			if (transparent && this.backgroundToggle === true) {
114			var $border = 30 / window.devicePixelRatio;
115			$(img).css('outline', $border + 'px solid ' + image.backgroundColour);
116			}
117
118			this.zoomablePreview.startBigshot(img, this.currentImage, image.mimeType);
119
120			this._setUrl(image.path);
121			this.controls.show(currentImageId);
122			this.container.find('.icon-loading-dark').hide();
123			}
124			}.bind(this), function () {
125			// Don't do anything if the user has moved along while we were loading as it would
126			// mess up the index
127			if (currentImageId === index) {
128			this.errorLoadingImage = true;
129			this.showErrorNotification(null);
130			this._setUrl(this.images[index].path);
131			this.images.splice(index, 1);
132			this.controls.updateControls(this.images, this.errorLoadingImage);
133			}
134			}.bind(this));
135			},
136
137			/**
138			* Loads the image to show in the slideshow and preloads the next one
139			*
140			* @param {Object} preview
141			*
142			* @returns {*}
143			*/
144			loadImage: function (preview) {
145			var url = preview.url;
146			var mimeType = preview.mimeType;
147
148			if (!this.imageCache[url]) {
149			this.imageCache[url] = new $.Deferred();
150			var image = new Image();
			0 ignored issues – show Bug introduced 2016-09-04 17:37 UTC by Report Bug Copy Issue Report The variable `Image` seems to be never declared. If this is a global, consider adding a `/** global: Image */` comment. This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed. To learn more about declaring variables in Javascript, see the MDN. Loading history...
151
152			image.onload = function () {
153			preview.backgroundColour = this._getBackgroundColour(image);
154			if (this.imageCache[url]) {
155			this.imageCache[url].resolve(image);
156			}
157			}.bind(this);
158			image.onerror = function () {
159			if (this.imageCache[url]) {
160			this.imageCache[url].reject(url);
161			}
162			}.bind(this);
163			if (mimeType === 'image/svg+xml') {
164			image.src = this._getSVG(url);
165			} else {
166			image.src = url;
167			}
168			}
169			return this.imageCache[url];
170			},
171
172			/**
173			* Shows a new image in the slideshow and preloads the next in the list
174			*
175			* @param {number} current
176			* @param {Object} next
177			*/
178			next: function (current, next) {
179			this.show(current).then(function () {
180			// Preloads the next image in the list
181			this.loadImage(next);
182			}.bind(this));
183			},
184
185			/**
186			* Determines which colour to use for the background
187			*
188			* @param {*} image
189			*
190			* @returns {string}
191			* @private
192			*/
193			_getBackgroundColour: function (image) {
194			var backgroundColour = this.darkBackgroundColour;
195			if (this._isTransparent(image.mimeType) && this._isMainlyDark(image)) {
196			backgroundColour = this.lightBackgroundColour;
197			}
198			return backgroundColour;
199			},
200
201			/**
202			* Calculates the luminance of an image to determine if an image is mainly dark
203			*
204			* @param {*} image
205			*
206			* @returns {boolean}
207			* @private
208			*/
209			_isMainlyDark: function (image) {
210			var isMainlyDark = true;
211			var numberOfSamples = 1000; // Seems to be the sweet spot
212			// The name has to be 'canvas'
213			var lumiCanvas = document.createElement('canvas');
214
215			var imgArea = image.width * image.height;
216			var canArea = numberOfSamples;
217			var factor = Math.sqrt(canArea / imgArea);
218
219			var scaledWidth = factor * image.width;
220			var scaledHeight = factor * image.height;
221			lumiCanvas.width = scaledWidth;
222			lumiCanvas.height = scaledHeight;
223			var lumiCtx = lumiCanvas.getContext('2d');
224			lumiCtx.drawImage(image, 0, 0, scaledWidth, scaledHeight);
225			var imgData = lumiCtx.getImageData(0, 0, lumiCanvas.width, lumiCanvas.height);
226			var pix = imgData.data; // pix.length will be approximately 4*numberOfSamples (for RGBA)
227			var pixelArraySize = pix.length;
228			var totalLuminance = 0;
229			var sampleNumber = 1;
230			var averageLuminance;
231			var totalAlpha = 0;
232			var alphaLevel;
233			var red = 0;
234			var green = 0;
235			var blue = 0;
236			var alpha = 0;
237			var lum = 0;
238			var alphaThreshold = 0.1;
239
240			var sampleCounter = 0;
241			var itemsPerPixel = 4; // red, green, blue, alpha
242			var sampleSize = Math.floor(pixelArraySize / (itemsPerPixel * numberOfSamples));
243			if (sampleSize <= 0) {
244			sampleSize = 1;
245			}
246			// i += 4 because 4 colours for every pixel
247			for (var i = 0, n = pixelArraySize; i < n; i += itemsPerPixel * sampleSize) {
248			sampleCounter++;
249			alpha = pix[i + 3] / 255;
250			totalAlpha += alpha;
251			if (Math.ceil(alpha * 100) / 100 > alphaThreshold) {
252			red = pix[i];
253			green = pix[i + 1];
254			blue = pix[i + 2];
255			// Luminance formula from
256			// http://stackoverflow.com/questions/596216/formula-to-determine-brightness-of-rgb-color
257			lum = (red + red + green + green + green + blue) / 6;
258			//lum = (red * 0.299 + green * 0.587 + blue * 0.114 );
259			totalLuminance += lum * alpha;
260			sampleNumber++;
261			}
262			}
263
264			// Deletes the canvas
265			lumiCanvas = null;
			0 ignored issues – show Unused Code introduced 2016-11-24 00:07 UTC by Report Bug Copy Issue Report The assignment to `lumiCanvas` seems to be never used. If you intend to free memory here, this is not necessary since the variable leaves the scope anyway. Loading history...
266
267			// Calculate the optimum background colour for this image
268			averageLuminance = Math.ceil((totalLuminance / sampleNumber) * 100) / 100;
269			alphaLevel = Math.ceil((totalAlpha / numberOfSamples) * 100);
270			if (averageLuminance < 50 && alphaLevel < 90) {
271			isMainlyDark = false;
272			}
273
274			return isMainlyDark;
275			},
276
277			/**
278			* Stops the slideshow
279			*/
280			stop: function () {
281			this.active = false;
282			this.images = null;
283			this._hideImage();
284			if (this.onStop) {
285			this.onStop();
286			}
287			},
288
289			/**
290			* Sends the current image as a download
291			*
292			* @param {string} downloadUrl
293			*
294			* @returns {boolean}
295			*/
296			getImageDownload: function (downloadUrl) {
297			OC.redirect(downloadUrl);
298			return false;
299			},
300
301			/**
302			* Changes the colour of the background of the image
303			*/
304			toggleBackground: function () {
305			var toHex = function (x) {
306			return ("0" + parseInt(x).toString(16)).slice(-2);
307			};
308			var container = this.zoomablePreviewContainer.children('img');
309			var rgb = container.css('background-color').match(/\d+/g);
310			var hex = "#" + toHex(rgb[0]) + toHex(rgb[1]) + toHex(rgb[2]);
311			var $border = 30 / window.devicePixelRatio;
312			var newBackgroundColor;
313
314			// Grey #363636
315			if (hex === this.darkBackgroundColour) {
316			newBackgroundColor = this.lightBackgroundColour;
317			} else {
318			newBackgroundColor = this.darkBackgroundColour;
319			}
320
321			container.css('background-color', newBackgroundColor);
322			if (this.backgroundToggle === true) {
323			container.css('outline', $border + 'px solid ' + newBackgroundColor);
324			}
325
326			},
327
328			/**
329			* Shows an error notification
330			*
331			* @param {string} message
332			*/
333			showErrorNotification: function (message) {
334			if ($.isEmptyObject(message)) {
335			message = t('gallery',
336			'<strong>Error!</strong> Could not generate a preview of this file.<br>' +
337			'Please go to the next slide while we remove this image from the slideshow');
338			}
339			this.container.find('.notification').html(message);
340			this.container.find('.notification').show();
341			this.controls.hideButton('.changeBackground');
342			},
343
344			/**
345			* Hides the error notification
346			*/
347			hideErrorNotification: function () {
348			this.container.find('.notification').hide();
349			this.container.find('.notification').html('');
350			},
351
352			/**
353			* Removes a specific button from the interface
354			*
355			* @param button
356			*/
357			removeButton: function (button) {
358			this.controls.removeButton(button);
359			},
360
361			/**
362			* Deletes an image from the slideshow
363			*
364			* @param {object} image
365			* @param {number} currentIndex
366			*/
367			deleteImage: function (image, currentIndex) {
368			// These are Gallery specific commands to be replaced
369			// which should sit somewhere else
370			if (!window.galleryFileAction) {
371			delete Gallery.imageMap[image.path];
372			delete Thumbnails.map[image.file];
373			Gallery.albumMap[Gallery.currentAlbum].images.splice(currentIndex, 1);
374			Gallery.view.init(Gallery.currentAlbum);
375			}
376			},
377
378			/**
379			* Automatically fades the controls after 3 seconds
380			*
381			* @private
382			*/
383			_initControlsAutoFader: function () {
384			var inactiveCallback = function () {
385			this.container.addClass('inactive');
386			}.bind(this);
387			var inactiveTimeout = setTimeout(inactiveCallback, 3000);
388
389			this.container.on('mousemove touchstart', function () {
390			this.container.removeClass('inactive');
391			clearTimeout(inactiveTimeout);
392			inactiveTimeout = setTimeout(inactiveCallback, 3000);
393			}.bind(this));
394			},
395
396			/**
397			* Simplest way to detect if image is transparent.
398			*
399			* That's very inaccurate since it doesn't include images which support transparency
400			*
401			* @param mimeType
402			* @returns {boolean}
403			* @private
404			*/
405			_isTransparent: function (mimeType) {
406			return !(mimeType === 'image/jpeg'
407			\|\| mimeType === 'image/x-dcraw'
408			\|\| mimeType === 'application/font-sfnt'
409			\|\| mimeType === 'application/x-font'
410			);
411			},
412
413			/**
414			* Changes the browser Url, based on the current image
415			*
416			* @param {string} path
417			* @private
418			*/
419			_setUrl: function (path) {
420			if (history && history.replaceState) {
			0 ignored issues – show Best Practice introduced 2016-09-04 17:37 UTC by Report Bug Copy Issue Report If you intend to check if the variable `history` is declared in the current environment, consider using `typeof history === "undefined"` instead. This is safe if the variable is not actually declared. Loading history...
421			history.replaceState('', '', '#' + encodeURI(path));
422			}
423			},
424
425			/**
426			* Hides the current image (before loading the next)
427			*
428			* @private
429			*/
430			_hideImage: function () {
431			this.zoomablePreviewContainer.empty();
432			this.controls.hideActionButtons();
433			},
434
435			/**
436			* Retrieves an SVG
437			*
438			* An SVG can't be simply attached to a src attribute like a bitmap image
439			*
440			* @param {string} source
441			*
442			* @returns {*}
443			* @private
444			*/
445			_getSVG: function (source) {
446			var svgPreview = null;
447			// DOMPurify only works with IE10+ and we load SVGs in the IMG tag
448			if (window.btoa &&
449			document.implementation.hasFeature("http://www.w3.org/TR/SVG11/feature#Image",
450			"1.1")) {
451			var xmlHttp = new XMLHttpRequest();
			0 ignored issues – show Bug introduced 2016-09-04 17:37 UTC by Report Bug Copy Issue Report The variable `XMLHttpRequest` seems to be never declared. If this is a global, consider adding a `/** global: XMLHttpRequest */` comment. This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed. To learn more about declaring variables in Javascript, see the MDN. Loading history...
452			xmlHttp.open("GET", source, false);
453			xmlHttp.send(null);
454			if (xmlHttp.status === 200) {
455			var pureSvg = DOMPurify.sanitize(xmlHttp.responseText, {ADD_TAGS: ['filter']});
456			// Remove XML comment garbage left in the purified data
457			var badTag = pureSvg.indexOf(']>');
458			var fixedPureSvg = pureSvg.substring(badTag < 0 ? 0 : 5, pureSvg.length);
459			svgPreview = "data:image/svg+xml;base64," + window.btoa(fixedPureSvg);
460			}
461			}
462
463			return svgPreview;
464			},
465
466			/**
467			* Retrieves the slideshow's template
468			*
469			* @returns {*}
470			* @private
471			*/
472			_getSlideshowTemplate: function () {
473			var defer = $.Deferred();
474			if (!this.$slideshowTemplate) {
475			var self = this;
476			var url = OC.generateUrl('apps/gallery/slideshow', null);
477			$.get(url, function (tmpl) {
478			var template = $(tmpl);
479			var tmplButton;
480			var buttonsArray = [
481			{
482			el: '.next',
483			trans: t('gallery', 'Next')
484			},
485			{
486			el: '.play',
487			trans: t('gallery', 'Play')
488			},
489			{
490			el: '.pause',
491			trans: t('gallery', 'Pause')
492			},
493			{
494			el: '.previous',
495			trans: t('gallery', 'Previous')
496			},
497			{
498			el: '.exit',
499			trans: t('gallery', 'Close')
500			},
501			{
502			el: '.downloadImage',
503			trans: t('gallery', 'Download'),
504			toolTip: true
505			},
506			{
507			el: '.changeBackground',
508			trans: t('gallery', 'Toggle background'),
509			toolTip: true
510			},
511			{
512			el: '.deleteImage',
513			trans: t('gallery', 'Delete'),
514			toolTip: true
515			}
516			];
517			for (var i = 0; i < buttonsArray.length; i++) {
518			var button = buttonsArray[i];
519
520			tmplButton = template.find(button.el);
521			tmplButton.val(button.trans);
522			if (button.toolTip) {
523			tmplButton.attr("title", button.trans);
524			}
525			}
526			self.$slideshowTemplate = template;
527			defer.resolve(self.$slideshowTemplate);
528			})
529			.fail(function () {
530			defer.reject();
531			});
532			} else {
533			defer.resolve(this.$slideshowTemplate);
534			}
535			return defer.promise();
536			}
537			};
538
539			window.SlideShow = SlideShow;
540			})(jQuery, OC, OCA, t);
541

nextcloud / gallery

Pull Request — master (#179)

SlideShow._getBackgroundColour A

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