feat: support legend render

Author: 林舸

src/ui/legend/category.ts

@@ -1,5 +1,5 @@
 import { Component } from '../../core';
-import type { Group } from '../../shapes';
+import { HTML, type Group } from '../../shapes';
 import { BBox, select, Selection, splitStyle, subStyleProps } from '../../util';
 import type { TitleStyleProps } from './title';
 import { getBBox, Title } from './title';
@@ -9,6 +9,12 @@ import type { CategoryOptions, CategoryStyleProps } from './types';
 
 export type { CategoryOptions, CategoryStyleProps };
 
+class HtmlLegend extends HTML {
+  update(options: any) {
+    this.attr(options);
+  }
+}
+
 export class Category extends Component<CategoryStyleProps> {
   constructor(options: CategoryOptions) {
     super(options, CATEGORY_DEFAULT_OPTIONS);
@@ -35,6 +41,26 @@ export class Category extends Component<CategoryStyleProps> {
       .update(finalTitleStyle) as Selection<Title>;
   }
 
+  private renderCustom(container: Selection) {
+    const { data } = this.attributes;
+
+    const style = {
+      innerHTML: this.attributes.render(data),
+      pointerEvents: 'auto' as const,
+    };
+
+    container
+      .maybeAppendByClassName(
+        CLASS_NAMES.html,
+        () =>
+          new HtmlLegend({
+            className: CLASS_NAMES.html.name,
+            style,
+          })
+      )
+      .update(style) as Selection<Title>;
+  }
+
   private renderItems(container: Selection, bbox: DOMRect) {
     const { x, y, width, height } = bbox;
     const style = subStyleProps(this.attributes, 'title', true);
@@ -84,14 +110,18 @@ export class Category extends Component<CategoryStyleProps> {
   }
 
   render(attributes: Required<CategoryStyleProps>, container: Group) {
-    const { width, height, x = 0, y = 0 } = this.attributes;
+    const { width, height, x = 0, y = 0, render } = this.attributes;
     const ctn = select(container);
     container.style.transform = `translate(${x}, ${y})`;
 
-    this.renderTitle(ctn, width!, height!);
+    if (render as CategoryStyleProps['render']) {
+      this.renderCustom(ctn);
+    } else {
+      this.renderTitle(ctn, width!, height!);
 
-    this.renderItems(ctn, this.availableSpace);
+      this.renderItems(ctn, this.availableSpace);
 
-    this.adjustLayout();
+      this.adjustLayout();
+    }
   }
 }

src/ui/legend/category/items.ts

@@ -60,6 +60,7 @@ export type CategoryItemsStyleProps = GroupStyleProps &
     focus?: boolean;
     focusMarkerSize?: number;
     classNamePrefix?: string;
+    render?: (data: CategoryItemsDatum[]) => string | HTMLElement;
   };
 
 export type CategoryItemsOptions = ComponentOptions<CategoryItemsStyleProps>;

src/ui/legend/constant.ts

@@ -62,6 +62,7 @@ export const NAME_VALUE_RATIO = 0.5;
 export const CLASS_NAMES = classNames(
   {
     title: 'title',
+    html: 'html',
     titleGroup: 'title-group',
     items: 'items',
     itemsGroup: 'items-group',