feat(a11y): add textures to fill options (#1138)

Allow optional textured fill as `TexturedStylesBase` for area and bar series fill via `AreaStyle.texture` and `RectStyles.texture` props.

Co-authored-by: Debajyoti Halder <rondebajyoti@gmail.com>

.eslintignore

@@ -16,3 +16,6 @@ license_header.js
 # Compiled source
 src/utils/d3-delaunay/*
 **/dist
+
+# auto generated directories
+integration/tmp

.eslintrc.js

@@ -403,6 +403,7 @@ module.exports = {
       files: ['stories/**/*.ts?(x)', 'docs/**/*.ts?(x)'],
       rules: {
         '@typescript-eslint/no-unsafe-call': 0,
+        '@typescript-eslint/no-unnecessary-type-assertion': 0,
       },
     },
     {

api/charts.api.md

@@ -120,6 +120,7 @@ export interface AreaSeriesStyle {
 export interface AreaStyle {
     fill?: Color | ColorVariant;
     opacity: number;
+    texture?: TexturedStyles;
     visible: boolean;
 }
 
@@ -1585,6 +1586,7 @@ export interface RectBorderStyle {
 export interface RectStyle {
     fill?: Color | ColorVariant;
     opacity: number;
+    texture?: TexturedStyles;
     widthPixel?: Pixels;
     widthRatio?: Ratio;
 }
@@ -1962,6 +1964,50 @@ export interface TextStyle {
     padding: number | SimplePadding;
 }
 
+// @public (undocumented)
+export interface TexturedPathStyles extends TexturedStylesBase {
+    path: string | Path2D;
+}
+
+// @public (undocumented)
+export interface TexturedShapeStyles extends TexturedStylesBase {
+    shape: TextureShape;
+}
+
+// @public
+export type TexturedStyles = TexturedPathStyles | TexturedShapeStyles;
+
+// @public (undocumented)
+export interface TexturedStylesBase {
+    dash?: number[];
+    fill?: Color | ColorVariant;
+    offset?: Partial<Point> & {
+        global?: boolean;
+    };
+    opacity?: number;
+    rotation?: number;
+    shapeRotation?: number;
+    size?: number;
+    // Warning: (ae-forgotten-export) The symbol "Point" needs to be exported by the entry point index.d.ts
+    spacing?: Partial<Point> | number;
+    stroke?: Color | ColorVariant;
+    strokeWidth?: number;
+}
+
+// @public (undocumented)
+export const TextureShape: Readonly<{
+    Line: "line";
+    Circle: "circle";
+    Square: "square";
+    Diamond: "diamond";
+    Plus: "plus";
+    X: "x";
+    Triangle: "triangle";
+}>;
+
+// @public (undocumented)
+export type TextureShape = $Values<typeof TextureShape>;
+
 // @public (undocumented)
 export interface Theme {
     // (undocumented)

integration/tests/stylings_stories.test.ts

@@ -0,0 +1,52 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { SeriesType } from '../../src';
+import { common } from '../page_objects';
+
+describe('Stylings stories', () => {
+  describe('Texture', () => {
+    describe.each([SeriesType.Bar, SeriesType.Area])('%s', (seriesType) => {
+      it(`should use custom path`, async () => {
+        await common.expectChartAtUrlToMatchScreenshot(
+          `http://localhost:9001/?path=/story/stylings--with-texture&knob-Use custom path_Texture=true&knob-Custom path_Texture=M -7.75 -2.5 l 5.9 0 l 1.85 -6.1 l 1.85 6.1 l 5.9 0 l -4.8 3.8 l 1.85 6.1 l -4.8 -3.8 l -4.8 3.8 l 1.85 -6.1 l -4.8 -3.8 z&knob-Use stroke color_Texture=true&knob-Stoke color_Texture=&knob-Stroke width_Texture=1&knob-Use fill color_Texture=true&knob-Fill color_Texture=&knob-Rotation (degrees)_Pattern=45&knob-Opacity_Texture=1&knob-Shape rotation (degrees)_Texture=0&knob-Shape size - custom path_Texture=20&knob-Shape spacing - x_Pattern=10&knob-Shape spacing - y_Pattern=0&knob-Pattern offset - x_Pattern=0&knob-Pattern offset - y_Pattern=0&knob-Apply offset along global coordinate axes_Pattern=true&knob-Series opacity_Series=1&knob-Show series fill_Series=&knob-Series color_Series=rgba(0,0,0,1)&knob-Series type_Series=${seriesType}`,
+        );
+      });
+
+      it(`should render texture with lines as shape`, async () => {
+        await common.expectChartAtUrlToMatchScreenshot(
+          `http://localhost:9001/?path=/story/stylings--with-texture&knob-Use custom path_Texture=&knob-Shape_Texture=line&knob-Use stroke color_Texture=true&knob-Stoke color_Texture=rgba(0,0,0,1)&knob-Stroke width_Texture=1&knob-Stroke dash_Texture[0]=10&knob-Stroke dash_Texture[1]= 5&knob-Use fill color_Texture=&knob-Fill color_Texture=rgba(30,165,147,0.28)&knob-Rotation (degrees)_Pattern=-45&knob-Opacity_Texture=1&knob-Shape rotation (degrees)_Texture=0&knob-Shape size_Texture=20&knob-Shape spacing - x_Pattern=0&knob-Shape spacing - y_Pattern=0&knob-Pattern offset - x_Pattern=0&knob-Pattern offset - y_Pattern=0&knob-Apply offset along global coordinate axes_Pattern=true&knob-Series opacity_Series=1&knob-Show series fill_Series=&knob-Series color_Series=rgba(0,0,0,1)&knob-Series type_Series=${seriesType}`,
+        );
+      });
+
+      it(`should allow any random texture customization`, async () => {
+        await common.expectChartAtUrlToMatchScreenshot(
+          `http://localhost:9001/?path=/story/stylings--texture-multiple-series&knob-Total series=4&knob-Show legend=&knob-Show series fill=&knob-Chart color=rgba(0,0,0,1)&knob-Shape_Randomized parameters=true&knob-Rotation_Randomized parameters=true&knob-Shape rotation_Randomized parameters=true&knob-Size_Randomized parameters=true&knob-X spacing_Randomized parameters=true&knob-Y spacing_Randomized parameters=true&knob-X offset_Randomized parameters=true&knob-Y offset_Randomized parameters=true&knob-Series type=${seriesType}&knob-Shape_Default parameters=circle&knob-Stroke width_Default parameters=1&knob-Rotation (degrees)_Default parameters=45&knob-Shape rotation (degrees)_Default parameters=0&knob-Shape size_Default parameters=20&knob-Opacity_Default parameters=1&knob-Shape spacing - x_Default parameters=10&knob-Shape spacing - y_Default parameters=10&knob-Pattern offset - x_Default parameters=0&knob-Pattern offset - y_Default parameters=0`,
+        );
+      });
+
+      it(`should use hover opacity for texture`, async () => {
+        await common.expectChartWithMouseAtUrlToMatchScreenshot(
+          `http://localhost:9001/?path=/story/stylings--texture-multiple-series&knob-Total series=4&knob-Show legend=true&knob-Show series fill=&knob-Chart color=rgba(0,0,0,1)&knob-Shape_Randomized parameters=true&knob-Rotation_Randomized parameters=&knob-Shape rotation_Randomized parameters=&knob-Size_Randomized parameters=true&knob-X spacing_Randomized parameters=&knob-Y spacing_Randomized parameters=&knob-X offset_Randomized parameters=&knob-Y offset_Randomized parameters=&knob-Series type=${seriesType}&knob-Shape_Default parameters=circle&knob-Stroke width_Default parameters=1&knob-Rotation (degrees)_Default parameters=45&knob-Shape rotation (degrees)_Default parameters=0&knob-Shape size_Default parameters=20&knob-Opacity_Default parameters=1&knob-Shape spacing - x_Default parameters=10&knob-Shape spacing - y_Default parameters=10&knob-Pattern offset - x_Default parameters=0&knob-Pattern offset - y_Default parameters=0`,
+          { top: 45, right: 40 },
+        );
+      });
+    });
+  });
+});

package.json

@@ -171,6 +171,7 @@
     "html-webpack-plugin": "^4.5.2",
     "husky": "^4.3.6",
     "jest": "^26.6.3",
+    "jest-canvas-mock": "^2.3.1",
     "jest-extended": "^0.11.5",
     "jest-image-snapshot": "^4.3.0",
     "jest-matcher-utils": "^26.6.2",

src/chart_types/xy_chart/renderer/canvas/areas.ts

@@ -41,7 +41,7 @@ interface AreaGeometriesProps {
 }
 
 /** @internal */
-export function renderAreas(ctx: CanvasRenderingContext2D, props: AreaGeometriesProps) {
+export function renderAreas(ctx: CanvasRenderingContext2D, imgCanvas: HTMLCanvasElement, props: AreaGeometriesProps) {
   const { sharedStyle, highlightedLegendItem, areas, rotation, clippings, renderingArea } = props;
 
   withContext(ctx, (ctx) => {
@@ -54,7 +54,7 @@ export function renderAreas(ctx: CanvasRenderingContext2D, props: AreaGeometries
           rotation,
           renderingArea,
           (ctx) => {
-            renderArea(ctx, area, sharedStyle, clippings, highlightedLegendItem);
+            renderArea(ctx, imgCanvas, area, sharedStyle, clippings, highlightedLegendItem);
           },
           { area: clippings, shouldClip: true },
         );
@@ -96,15 +96,17 @@ export function renderAreas(ctx: CanvasRenderingContext2D, props: AreaGeometries
 
 function renderArea(
   ctx: CanvasRenderingContext2D,
+  imgCanvas: HTMLCanvasElement,
   glyph: AreaGeometry,
   sharedStyle: SharedGeometryStateStyle,
   clippings: Rect,
   highlightedLegendItem?: LegendItem,
 ) {
   const { area, color, transform, seriesIdentifier, seriesAreaStyle, clippedRanges, hideClippedRanges } = glyph;
   const geometryStateStyle = getGeometryStateStyle(seriesIdentifier, sharedStyle, highlightedLegendItem);
-  const fill = buildAreaStyles(color, seriesAreaStyle, geometryStateStyle);
-  renderAreaPath(ctx, transform, area, fill, clippedRanges, clippings, hideClippedRanges);
+  const styles = buildAreaStyles(ctx, imgCanvas, color, seriesAreaStyle, geometryStateStyle);
+
+  renderAreaPath(ctx, transform, area, styles, clippedRanges, clippings, hideClippedRanges);
 }
 
 function renderAreaLines(
@@ -116,7 +118,7 @@ function renderAreaLines(
 ) {
   const { lines, color, seriesIdentifier, transform, seriesAreaLineStyle, clippedRanges, hideClippedRanges } = glyph;
   const geometryStateStyle = getGeometryStateStyle(seriesIdentifier, sharedStyle, highlightedLegendItem);
-  const stroke = buildLineStyles(color, seriesAreaLineStyle, geometryStateStyle);
+  const styles = buildLineStyles(color, seriesAreaLineStyle, geometryStateStyle);
 
-  renderLinePaths(ctx, transform, lines, stroke, clippedRanges, clippings, hideClippedRanges);
+  renderLinePaths(ctx, transform, lines, styles, clippedRanges, clippings, hideClippedRanges);
 }

src/chart_types/xy_chart/renderer/canvas/bars.ts

@@ -32,6 +32,7 @@ import { withPanelTransform } from './utils/panel_transform';
 /** @internal */
 export function renderBars(
   ctx: CanvasRenderingContext2D,
+  imgCanvas: HTMLCanvasElement,
   barGeometries: Array<PerPanel<BarGeometry[]>>,
   sharedStyle: SharedGeometryStateStyle,
   clippings: Rect,
@@ -40,13 +41,22 @@ export function renderBars(
   rotation?: Rotation,
 ) {
   withContext(ctx, (ctx) => {
-    const barRenderer = renderPerPanelBars(ctx, clippings, sharedStyle, renderingArea, highlightedLegendItem, rotation);
+    const barRenderer = renderPerPanelBars(
+      ctx,
+      imgCanvas,
+      clippings,
+      sharedStyle,
+      renderingArea,
+      highlightedLegendItem,
+      rotation,
+    );
     barGeometries.forEach(barRenderer);
   });
 }
 
 function renderPerPanelBars(
   ctx: CanvasRenderingContext2D,
+  imgCanvas: HTMLCanvasElement,
   clippings: Rect,
   sharedStyle: SharedGeometryStateStyle,
   renderingArea: Dimensions,
@@ -66,7 +76,14 @@ function renderPerPanelBars(
         bars.forEach((barGeometry) => {
           const { x, y, width, height, color, seriesStyle, seriesIdentifier } = barGeometry;
           const geometryStateStyle = getGeometryStateStyle(seriesIdentifier, sharedStyle, highlightedLegendItem);
-          const { fill, stroke } = buildBarStyles(color, seriesStyle.rect, seriesStyle.rectBorder, geometryStateStyle);
+          const { fill, stroke } = buildBarStyles(
+            ctx,
+            imgCanvas,
+            color,
+            seriesStyle.rect,
+            seriesStyle.rectBorder,
+            geometryStateStyle,
+          );
           const rect = { x, y, width, height };
           withContext(ctx, (ctx) => {
             renderRect(ctx, rect, fill, stroke);

src/chart_types/xy_chart/renderer/canvas/primitives/path.ts

@@ -20,6 +20,7 @@
 import { RGBtoString } from '../../../../../common/color_library_wrappers';
 import { Rect, Stroke, Fill } from '../../../../../geoms/types';
 import { withContext, withClipRanges } from '../../../../../renderers/canvas';
+import { getRadians } from '../../../../../utils/common';
 import { ClippedRanges } from '../../../../../utils/geometry';
 import { Point } from '../../../../../utils/point';
 import { renderMultiLine } from './line';
@@ -93,6 +94,23 @@ export function renderAreaPath(
 function renderPathFill(ctx: CanvasRenderingContext2D, path: string, fill: Fill) {
   const path2d = new Path2D(path);
   ctx.fillStyle = RGBtoString(fill.color);
-  ctx.beginPath();
   ctx.fill(path2d);
+
+  if (fill.texture) {
+    ctx.clip(path2d);
+
+    const rotation = getRadians(fill.texture.rotation ?? 0);
+    const { offset } = fill.texture;
+
+    if (offset && offset.global) ctx.translate(offset?.x ?? 0, offset?.y ?? 0);
+    if (rotation) ctx.rotate(rotation);
+    if (offset && !offset.global) ctx.translate(offset?.x ?? 0, offset?.y ?? 0);
+
+    ctx.fillStyle = fill.texture.pattern;
+
+    // Use oversized rect to fill rotation/offset beyond path
+    const rotationRectFillSize = ctx.canvas.clientWidth * ctx.canvas.clientHeight;
+    ctx.translate(-rotationRectFillSize / 2, -rotationRectFillSize / 2);
+    ctx.fillRect(0, 0, rotationRectFillSize, rotationRectFillSize);
+  }
 }

src/chart_types/xy_chart/renderer/canvas/primitives/rect.ts

@@ -19,6 +19,8 @@
 
 import { RGBtoString } from '../../../../../common/color_library_wrappers';
 import { Rect, Fill, Stroke } from '../../../../../geoms/types';
+import { withContext } from '../../../../../renderers/canvas';
+import { getRadians } from '../../../../../utils/common';
 
 /** @internal */
 export function renderRect(
@@ -38,9 +40,32 @@ export function renderRect(
     const y = rect.y + borderOffset;
     const width = rect.width - borderOffset * 2;
     const height = rect.height - borderOffset * 2;
+
     drawRect(ctx, { x, y, width, height });
     ctx.fillStyle = RGBtoString(fill.color);
     ctx.fill();
+
+    if (fill.texture) {
+      const { texture } = fill;
+      withContext(ctx, (ctx) => {
+        drawRect(ctx, { x, y, width, height });
+        ctx.clip();
+
+        const rotation = getRadians(texture.rotation ?? 0);
+        const { offset } = texture;
+
+        if (offset && offset.global) ctx.translate(offset?.x ?? 0, offset?.y ?? 0);
+        if (rotation) ctx.rotate(rotation);
+        if (offset && !offset.global) ctx.translate(offset?.x ?? 0, offset?.y ?? 0);
+
+        ctx.fillStyle = texture.pattern;
+
+        // Use oversized rect to fill rotation/offset beyond path
+        const rotationRectFillSize = ctx.canvas.clientWidth * ctx.canvas.clientHeight;
+        ctx.translate(-rotationRectFillSize / 2, -rotationRectFillSize / 2);
+        ctx.fillRect(0, 0, rotationRectFillSize, rotationRectFillSize);
+      });
+    }
   }
 
   if (stroke && stroke.width > 0.001) {
@@ -74,39 +99,3 @@ function drawRect(ctx: CanvasRenderingContext2D, rect: Rect) {
   ctx.lineTo(x, y + height);
   ctx.lineTo(x, y);
 }
-
-/** @internal */
-export function renderMultiRect(ctx: CanvasRenderingContext2D, rects: Rect[], fill?: Fill, stroke?: Stroke) {
-  if (!fill && !stroke && rects.length > 0) {
-    return;
-  }
-
-  const rectsLength = rects.length;
-  ctx.beginPath();
-  for (let i = 0; i < rectsLength; i++) {
-    const { width, height, x, y } = rects[i];
-    ctx.moveTo(x, y);
-    ctx.lineTo(x + width, y);
-    ctx.lineTo(x + width, y + height);
-    ctx.lineTo(x, y + height);
-    ctx.lineTo(x, y);
-  }
-
-  if (fill) {
-    ctx.fillStyle = RGBtoString(fill.color);
-    ctx.fill();
-  }
-  if (stroke && stroke.width > 0.001) {
-    // Canvas2d stroke ignores an exact zero line width
-    ctx.strokeStyle = RGBtoString(stroke.color);
-    ctx.lineWidth = stroke.width;
-    ctx.stroke();
-
-    if (stroke.dash) {
-      ctx.setLineDash(stroke.dash);
-    } else {
-      // Setting linecap with dash causes solid line
-      ctx.lineCap = 'square';
-    }
-  }
-}

src/chart_types/xy_chart/renderer/canvas/primitives/shapes.ts

@@ -19,6 +19,7 @@
 
 import { Circle, Fill, Stroke } from '../../../../../geoms/types';
 import { withContext } from '../../../../../renderers/canvas';
+import { getRadians } from '../../../../../utils/common';
 import { PointShape } from '../../../../../utils/themes/theme';
 import { ShapeRendererFn } from '../../shapes_paths';
 import { fillAndStroke } from './utils';
@@ -38,7 +39,7 @@ export function renderShape(
     const [pathFn, rotation] = ShapeRendererFn[shape];
     const { x, y, radius } = coordinates;
     ctx.translate(x, y);
-    ctx.rotate((rotation * Math.PI) / 180);
+    ctx.rotate(getRadians(rotation));
     ctx.beginPath();
 
     const path = new Path2D(pathFn(radius));