Better handle calendars without color

Signed-off-by: Raimund Schlüßler <raimund.schluessler@mailbox.org>

package-lock.json

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+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "chalk": {
@@ -21905,6 +22197,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "chalk": {
@@ -22020,6 +22323,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "chalk": {
@@ -22075,6 +22389,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "chalk": {
@@ -22144,6 +22469,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "chalk": {
@@ -22286,6 +22622,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "chalk": {
@@ -22454,6 +22801,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         }
       }
@@ -23829,6 +24187,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         }
       }
@@ -25138,6 +25507,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "fast-deep-equal": {
@@ -26327,6 +26707,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "chalk": {
@@ -26715,6 +27106,17 @@
           "dev": true,
           "requires": {
             "color-convert": "^1.9.0"
+          },
+          "dependencies": {
+            "color-convert": {
+              "version": "1.9.3",
+              "resolved": "https://registry.npmjs.org/color-convert/-/color-convert-1.9.3.tgz",
+              "integrity": "sha512-QfAUtd+vFdAtFQcC8CCyYt1fYWxSqAiK2cSD6zDB8N3cpsEBAvRxp9zOGg6G/SHHJYAT88/az/IuDGALsNVbGg==",
+              "dev": true,
+              "requires": {
+                "color-name": "1.1.3"
+              }
+            }
           }
         },
         "big.js": {

package.json

@@ -29,6 +29,7 @@
 		"@nextcloud/vue": "1.4.0",
 		"@vue/test-utils": "^1.0.0-beta.31",
 		"cdav-library": "github:nextcloud/cdav-library",
+		"color-convert": "^2.0.1",
 		"ical.js": "~1.3.0",
 		"jstimezonedetect": "",
 		"linkify-it": "~2.2.0",
@@ -37,6 +38,7 @@
 		"markdown-it-emoji": "~1.4.0",
 		"markdown-it-link-attributes": "~3.0.0",
 		"markdown-it-task-lists": "~2.1.1",
+		"md5": "^2.2.1",
 		"moment": "^2.24.0",
 		"p-limit": "^2.2.2",
 		"p-queue": "^6.3.0",

src/store/calendars.js

@@ -38,6 +38,7 @@ import pLimit from 'p-limit'
 import { isParentInList, searchSubTasks } from './storeHelper'
 import { findVTODObyState } from './cdav-requests'
 import router from '../router'
+import { detectColor, uidToHexColor } from '../utils/color.js'
 
 const calendarModel = {
 	id: '',
@@ -79,11 +80,19 @@ export function mapDavCollectionToCalendar(calendar, currentUserPrincipal) {
 	} else {
 		isSharedWithMe = (owner !== currentUserPrincipal.url)
 	}
+	const displayName = calendar.displayname || getCalendarUriFromUrl(calendar.url)
+	// calendar.color can be set to anything on the server,
+	// so make sure it's something that remotely looks like a color
+	let color = detectColor(calendar.color)
+	if (!color) {
+		// As fallback if we don't know what color that is supposed to be
+		color = uidToHexColor(displayName)
+	}
 	return {
 		// get last part of url
 		id: calendar.url.split('/').slice(-2, -1)[0],
-		displayName: calendar.displayname,
+		displayName,
-		color: calendar.color,
+		color,
 		enabled: calendar.enabled !== false,
 		owner,
 		readOnly: !calendar.isWriteable(),
@@ -118,6 +127,20 @@ export function mapDavShareeToSharee(sharee) {
 	}
 }
 
+/**
+ * Gets the calendar uri from the url
+ *
+ * @param {String} url The url to get calendar uri from
+ * @returns {string}
+ */
+function getCalendarUriFromUrl(url) {
+	if (url.endsWith('/')) {
+		url = url.substring(0, url.length - 1)
+	}
+
+	return url.substring(url.lastIndexOf('/') + 1)
+}
+
 const getters = {
 
 	/**

src/utils/color.js

@@ -0,0 +1,55 @@
+/**
+ * @copyright Copyright (c) 2019 Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+import convert from 'color-convert'
+import { uidToColor } from './uidToColor.js'
+
+/**
+ * Generates a hex color based on RGB string
+ *
+ * @param {String} uid The string to generate a color from
+ * @returns {string} The hex color
+ */
+export function uidToHexColor(uid) {
+	const color = uidToColor(uid)
+	return '#' + convert.rgb.hex(color.r, color.g, color.b)
+}
+
+/**
+ * Detects a color from a given string
+ *
+ * @param {String} color The color to get the real RGB hex string from
+ * @returns {string|boolean|*} String if color detected, boolean if not
+ */
+export function detectColor(color) {
+	if (/^(#)((?:[A-Fa-f0-9]{3}){1,2})$/.test(color)) { // #ff00ff and #f0f
+		return color
+	} else if (/^((?:[A-Fa-f0-9]{3}){1,2})$/.test(color)) { // ff00ff and f0f
+		return '#' + color
+	} else if (/^(#)((?:[A-Fa-f0-9]{8}))$/.test(color)) { // #ff00ffff and #f0ff
+		return color.substr(0, 7)
+	} else if (/^((?:[A-Fa-f0-9]{8}))$/.test(color)) { // ff00ffff and f0ff
+		return '#' + color.substr(0, 6)
+	}
+
+	return false
+
+}

src/utils/uidToColor.js

@@ -0,0 +1,117 @@
+/**
+ * @copyright Copyright (c) 2018 John Molakvoæ <skjnldsv@protonmail.com>
+ *
+ * @author John Molakvoæ <skjnldsv@protonmail.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+import md5 from 'md5'
+
+/**
+ * This is copied from nextcloud-vue for now, until it is exposed upstream.
+ */
+
+export const uidToColor = (uid) => {
+	// Normalize hash
+	let hash = uid.toLowerCase()
+
+	// Already a md5 hash?
+	if (hash.match(/^([0-9a-f]{4}-?){8}$/) === null) {
+		hash = md5(hash)
+	}
+
+	hash = hash.replace(/[^0-9a-f]/g, '')
+
+	const steps = 6
+	const finalPalette = GenColors(steps)
+
+	// Convert a string to an integer evenly
+	function hashToInt(hash, maximum) {
+		let finalInt = 0
+		const result = []
+
+		// Splitting evenly the string
+		for (let i = 0; i < hash.length; i++) {
+			// chars in md5 goes up to f, hex:16
+			result.push(parseInt(hash.charAt(i), 16) % 16)
+		}
+
+		// Adds up all results
+		for (const j in result) {
+			finalInt += result[j]
+		}
+
+		// chars in md5 goes up to f, hex:16
+		// make sure we're always using int in our operation
+		return parseInt(parseInt(finalInt, 10) % maximum, 10)
+	}
+	return finalPalette[hashToInt(hash, steps * 3)]
+}
+
+function Color(r, g, b) {
+	this.r = r
+	this.g = g
+	this.b = b
+}
+
+function stepCalc(steps, ends) {
+	const step = new Array(3)
+	step[0] = (ends[1].r - ends[0].r) / steps
+	step[1] = (ends[1].g - ends[0].g) / steps
+	step[2] = (ends[1].b - ends[0].b) / steps
+	return step
+}
+
+function mixPalette(steps, color1, color2) {
+	const palette = []
+	palette.push(color1)
+	const step = stepCalc(steps, [color1, color2])
+	for (let i = 1; i < steps; i++) {
+		const r = parseInt(color1.r + step[0] * i, 10)
+		const g = parseInt(color1.g + step[1] * i, 10)
+		const b = parseInt(color1.b + step[2] * i, 10)
+		palette.push(new Color(r, g, b))
+	}
+	return palette
+}
+
+/**
+ * Generate colors from the official nextcloud color
+ * You can provide how many colors you want (multiplied by 3)
+ * if step = 6
+ * 3 colors * 6 will result in 18 generated colors
+ *
+ * @param {number} [steps=6] Number of steps to go from a color to another
+ * @returns {Object[]}
+ */
+function GenColors(steps) {
+	if (!steps) {
+		steps = 6
+	}
+
+	const red = new Color(182, 70, 157)
+	const yellow = new Color(221, 203, 85)
+	const blue = new Color(0, 130, 201) // Nextcloud blue
+
+	const palette1 = mixPalette(steps, red, yellow)
+	const palette2 = mixPalette(steps, yellow, blue)
+	const palette3 = mixPalette(steps, blue, red)
+
+	return palette1.concat(palette2).concat(palette3)
+}
+
+export default uidToColor