MOBILE-4653 color: Validate colors and handle alpha

src/core/singletons/colors.ts

@@ -42,11 +42,25 @@ export enum CoreIonicColorNames {
  */
 export class CoreColors {
 
+    protected static readonly BLACK_TRANSPARENT_COLORS =
+        ['rgba(0, 0, 0, 0)', 'transparent', '#00000000', '#0000', 'hsl(0, 0%, 0%, 0)'];
+
     // Avoid creating singleton instances.
     private constructor() {
         // Nothing to do.
     }
 
+    /**
+     * Check if a color is valid.
+     * Accepted formats are rgb, rgba, hsl, hsla, hex and named colors.
+     *
+     * @param color Color in any format.
+     * @returns Whether color is valid.
+     */
+    static isValid(color: string): boolean {
+        return CoreColors.getColorRGBA(color).length >= 3;
+    }
+
     /**
      * Returns better contrast color.
      *
@@ -58,23 +72,30 @@ export class CoreColors {
     }
 
     /**
-     * Returns the same color % darker.
+     * Returns the same color % darker. Returned color is always hex, unless the color isn't valid.
      *
      * @param color Color to get darker.
      * @returns Darker Hex RGB color.
      */
     static darker(color: string, percent: number = 48): string {
         const inversePercent = 1 - (percent / 100);
-        const components = CoreColors.hexToRGB(color);
-        components.red = Math.floor(components.red * inversePercent);
-        components.green = Math.floor(components.green * inversePercent);
-        components.blue = Math.floor(components.blue * inversePercent);
 
-        return CoreColors.RGBToHex(components);
+        const rgba = CoreColors.getColorRGBA(color);
+        if (rgba.length < 3) {
+            return color; // Color not valid, return original value.
+        }
+
+        const red = Math.floor(rgba[0] * inversePercent);
+        const green = Math.floor(rgba[1] * inversePercent);
+        const blue = Math.floor(rgba[2] * inversePercent);
+
+        return rgba[3] !== undefined ?
+            CoreColors.getColorHex(`rgba(${red}, ${green}, ${blue}, ${rgba[3]})`) :
+            CoreColors.getColorHex(`rgb(${red}, ${green}, ${blue})`);
     }
 
     /**
-     * Returns the same color % lighter.
+     * Returns the same color % lighter. Returned color is always hex, unless the color isn't valid.
      *
      * @param color Color to get lighter.
      * @returns Lighter Hex RGB color.
@@ -83,12 +104,18 @@ export class CoreColors {
         percent = percent / 100;
         const inversePercent = 1 - percent;
 
-        const components = CoreColors.hexToRGB(color);
+        const rgba = CoreColors.getColorRGBA(color);
-        components.red = Math.floor(255 * percent + components.red * inversePercent);
+        if (rgba.length < 3) {
-        components.green = Math.floor(255 * percent + components.green * inversePercent);
+            return color; // Color not valid, return original value.
-        components.blue = Math.floor(255 * percent + components.blue * inversePercent);
+        }
 
-        return CoreColors.RGBToHex(components);
+        const red = Math.floor(255 * percent + rgba[0] * inversePercent);
+        const green = Math.floor(255 * percent + rgba[1] * inversePercent);
+        const blue = Math.floor(255 * percent + rgba[2] * inversePercent);
+
+        return rgba[3] !== undefined ?
+            CoreColors.getColorHex(`rgba(${red}, ${green}, ${blue}, ${rgba[3]})`) :
+            CoreColors.getColorHex(`rgb(${red}, ${green}, ${blue})`);
     }
 
     /**
@@ -99,19 +126,24 @@ export class CoreColors {
      */
     static getColorHex(color: string): string {
         const rgba = CoreColors.getColorRGBA(color);
-        if (rgba.length === 0) {
+        if (rgba.length < 3) {
             return '';
         }
 
-        const hex = [0,1,2].map(
+        let hex = [0,1,2].map(
             (idx) => CoreColors.componentToHex(rgba[idx]),
         ).join('');
 
+        if (rgba.length > 3) {
+            hex += CoreColors.componentToHex(Math.round(rgba[3] * 255));
+        }
+
         return '#' + hex;
     }
 
     /**
      * Returns RGBA color from any color format.
+     * Only works with RGB, RGBA, HSL, HSLA, hex and named colors.
      *
      * @param color Color in any format.
      * @returns Red, green, blue and alpha.
@@ -119,15 +151,28 @@ export class CoreColors {
     static getColorRGBA(color: string): number[] {
         if (!color.match(/rgba?\(.*\)/)) {
             // Convert the color to RGB format.
+            // Use backgroundColor instead of color because it detects invalid colors like rgb(0, 80) or #0F.
+            const originalColor = color;
             const d = document.createElement('span');
-            d.style.color = color;
+            d.style.backgroundColor = color;
             document.body.appendChild(d);
 
-            color = getComputedStyle(d).color;
+            color = getComputedStyle(d).backgroundColor;
             document.body.removeChild(d);
+
+            // Check that the color is valid. Some invalid colors return rgba(0, 0, 0, 0).
+            if (
+                !color.match(/rgba?\(.*\)/) ||
+                (color === 'rgba(0, 0, 0, 0)' && !CoreColors.BLACK_TRANSPARENT_COLORS.includes(originalColor))
+            ) {
+                return [];
+            }
         }
 
-        const matches = color.match(/\d+[^.]|\d*\.\d*/g) || [];
+        const matches = color.match(/\d+(\.\d+)?|\.\d+/g) || [];
+        if (matches.length < 3) {
+            return [];
+        }
 
         return matches.map((a, index) => index < 3 ? parseInt(a, 10) : parseFloat(a));
     }
@@ -139,9 +184,12 @@ export class CoreColors {
      * @returns Luma number based on SMPTE C, Rec. 709 weightings.
      */
     protected static luma(color: string): number {
-        const rgb = CoreColors.hexToRGB(color);
+        const rgba = CoreColors.getColorRGBA(color);
+        if (rgba.length < 3) {
+            return 0; // Color not valid.
+        }
 
-        return (rgb.red * 0.2126) + (rgb.green * 0.7152) + (rgb.blue * 0.0722);
+        return (rgba[0] * 0.2126) + (rgba[1] * 0.7152) + (rgba[2] * 0.0722);
     }
 
     /**
@@ -149,39 +197,19 @@ export class CoreColors {
      *
      * @param color Hexadec RGB Color.
      * @returns RGB color components.
+     * @deprecated since 5.0. Use getColorRGBA instead.
      */
     static hexToRGB(color: string): ColorComponents {
-        if (color.charAt(0) == '#') {
+        const rgba = CoreColors.getColorRGBA(color);
-            color = color.substring(1);
-        }
-
-        if (color.length === 3) {
-            color = color.charAt(0) + color.charAt(0) + color.charAt(1) + color.charAt(1) + color.charAt(2) + color.charAt(2);
-        } else if (color.length !== 6) {
-            throw('Invalid hex color: ' + color);
-        }
 
         return {
-            red: parseInt(color.substring(0, 2), 16),
+            red: rgba[0] ?? 0,
-            green: parseInt(color.substring(2, 4), 16),
+            green: rgba[1] ?? 0,
-            blue: parseInt(color.substring(4, 6), 16),
+            blue: rgba[2] ?? 0,
         };
 
     }
 
-    /**
-     * Converts RGB components to Hex string.
-     *
-     * @param color Color components.
-     * @returns RGB color in string.
-     */
-    protected static RGBToHex(color: ColorComponents): string {
-        return '#' + CoreColors.componentToHex(color.red) +
-            CoreColors.componentToHex(color.green) +
-            CoreColors.componentToHex(color.blue);
-
-    }
-
     /**
      * Converts a color component from decimal to hexadec.
      *

src/core/singletons/tests/colors.test.ts

@@ -16,6 +16,25 @@ import { CoreColors } from '@singletons/colors';
 
 describe('CoreColors singleton', () => {
 
+    it('checks if a color is valid', () => {
+        expect(CoreColors.isValid('')).toBe(false);
+        expect(CoreColors.isValid('#000000')).toBe(true);
+        expect(CoreColors.isValid('#00000000')).toBe(true);
+        expect(CoreColors.isValid('#000')).toBe(true);
+        expect(CoreColors.isValid('#0000')).toBe(true);
+        expect(CoreColors.isValid('#00')).toBe(false);
+        expect(CoreColors.isValid('#00000')).toBe(false);
+        expect(CoreColors.isValid('rgb(0,0,0)')).toBe(true);
+        expect(CoreColors.isValid('rgba(0,0,0,0)')).toBe(true);
+        expect(CoreColors.isValid('rgb(0,0)')).toBe(false);
+        expect(CoreColors.isValid('hsl(0, 100%, 0%)')).toBe(true);
+        expect(CoreColors.isValid('hsla(0, 100%, 0%, 0)')).toBe(true);
+        expect(CoreColors.isValid('hsl(0, 100%)')).toBe(false);
+
+        // @todo There are problems when testing color names (e.g. violet).
+        // They work fine in real browsers but not in unit tests.
+    });
+
     it('determines if white contrast is better', () => {
         expect(CoreColors.isWhiteContrastingBetter('#000000')).toBe(true);
         expect(CoreColors.isWhiteContrastingBetter('#999999')).toBe(true);
@@ -26,6 +45,12 @@ describe('CoreColors singleton', () => {
         expect(CoreColors.isWhiteContrastingBetter('#0000ff')).toBe(true);
         expect(CoreColors.isWhiteContrastingBetter('#ff00ff')).toBe(true);
         expect(CoreColors.isWhiteContrastingBetter('#ffff00')).toBe(false);
+        expect(CoreColors.isWhiteContrastingBetter('rgb(0, 0, 0)')).toBe(true);
+        expect(CoreColors.isWhiteContrastingBetter('rgb(153, 153, 153)')).toBe(true);
+        expect(CoreColors.isWhiteContrastingBetter('rgb(255, 255, 255)')).toBe(false);
+        expect(CoreColors.isWhiteContrastingBetter('hsl(0, 100%, 0%)')).toBe(true);
+        expect(CoreColors.isWhiteContrastingBetter('hsl(0, 0%, 60%)')).toBe(true);
+        expect(CoreColors.isWhiteContrastingBetter('hsl(0, 0%, 100%)')).toBe(false);
     });
 
     it('makes color darker', () => {
@@ -33,6 +58,13 @@ describe('CoreColors singleton', () => {
         expect(CoreColors.darker('#ffffff', 20)).toEqual('#cccccc');
         expect(CoreColors.darker('#ffffff', 80)).toEqual('#323232');
         expect(CoreColors.darker('#aabbcc', 40)).toEqual('#66707a');
+        expect(CoreColors.darker('rgb(255, 255, 255)', 50)).toEqual('#7f7f7f');
+        expect(CoreColors.darker('rgba(255, 255, 255, 0.5)', 50)).toEqual('#7f7f7f80');
+        expect(CoreColors.darker('hsl(0, 0%, 100%)', 50)).toEqual('#7f7f7f');
+        expect(CoreColors.darker('hsla(0, 0%, 100%, 0.8)', 50)).toEqual('#7f7f7fcc');
+
+        // Invalid colors return original value.
+        expect(CoreColors.darker('#fffff', 50)).toEqual('#fffff');
     });
 
     it('makes color lighter', () => {
@@ -40,12 +72,22 @@ describe('CoreColors singleton', () => {
         expect(CoreColors.lighter('#000000', 20)).toEqual('#333333');
         expect(CoreColors.lighter('#000000', 80)).toEqual('#cccccc');
         expect(CoreColors.lighter('#223344', 40)).toEqual('#7a848e');
+        expect(CoreColors.lighter('rgb(0, 0, 0)', 50)).toEqual('#7f7f7f');
+        expect(CoreColors.lighter('rgba(0, 0, 0, 0.5)', 50)).toEqual('#7f7f7f80');
+        expect(CoreColors.lighter('hsl(0, 100%, 0%)', 50)).toEqual('#7f7f7f');
+        expect(CoreColors.lighter('hsla(0, 100%, 0%, 0.4)', 50)).toEqual('#7f7f7f66');
+
+        // Invalid colors return original value.
+        expect(CoreColors.darker('#00000', 50)).toEqual('#00000');
     });
 
     it('gets color hex value', () => {
         expect(CoreColors.getColorHex('#123456')).toEqual('#123456');
+        expect(CoreColors.getColorHex('#12345680')).toEqual('#12345680');
         expect(CoreColors.getColorHex('rgb(255, 100, 70)')).toEqual('#ff6446');
-        expect(CoreColors.getColorHex('rgba(255, 100, 70, 0.5)')).toEqual('#ff6446');
+        expect(CoreColors.getColorHex('rgba(255, 100, 70, 0.5)')).toEqual('#ff644680');
+        expect(CoreColors.getColorHex('hsl(0, 0%, 60%)')).toEqual('#999999');
+        expect(CoreColors.getColorHex('hsla(0, 0%, 60%, 0.8)')).toEqual('#999999cc');
 
         // @todo There are problems when testing color names (e.g. violet) or hsf colors.
         // They work fine in real browsers but not in unit tests.
@@ -53,31 +95,16 @@ describe('CoreColors singleton', () => {
 
     it('gets color RGBA value', () => {
         expect(CoreColors.getColorRGBA('#123456')).toEqual([18, 52, 86]);
+        expect(CoreColors.getColorRGBA('#123456cc')).toEqual([18, 52, 86, 0.8]);
         expect(CoreColors.getColorRGBA('rgb(255, 100, 70)')).toEqual([255, 100, 70]);
         expect(CoreColors.getColorRGBA('rgba(255, 100, 70, 0.5)')).toEqual([255, 100, 70, 0.5]);
+        expect(CoreColors.getColorRGBA('hsl(0, 0%, 60%)')).toEqual([153, 153, 153]);
+        expect(CoreColors.getColorRGBA('hsl(0, 0%, 60%, 0.3)')).toEqual([153, 153, 153, 0.3]);
 
         // @todo There are problems when testing color names (e.g. violet) or hsf colors.
         // They work fine in real browsers but not in unit tests.
     });
 
-    it('converts hex to rgb', () => {
-        expect(CoreColors.hexToRGB('#000000')).toEqual({
-            red: 0,
-            green: 0,
-            blue: 0,
-        });
-        expect(CoreColors.hexToRGB('#ffffff')).toEqual({
-            red: 255,
-            green: 255,
-            blue: 255,
-        });
-        expect(CoreColors.hexToRGB('#aabbcc')).toEqual({
-            red: 170,
-            green: 187,
-            blue: 204,
-        });
-    });
-
     it('gets toolbar background color', () => {
         document.body.style.setProperty('--core-header-toolbar-background', '#aabbcc');
         expect(CoreColors.getToolbarBackgroundColor()).toEqual('#aabbcc');

upgrade.txt

@@ -6,6 +6,7 @@ For more information about upgrading, read the official documentation: https://m
 
  - The logout process has been refactored, now it uses a logout page to trigger Angular guards. CoreSites.logout now uses this process, and CoreSites.logoutForRedirect is deprecated and shouldn't be used anymore.
  - The parameters of treatDownloadedFile of plugin file handlers have changed. Now the third parameter is an object with all the optional parameters.
+ - Some CoreColors functions have been refactored to handle alpha and to validate colors.
 
 === 4.5.0 ===