feat: add background image option

docs/en/guide/option.md

@@ -27,7 +27,6 @@ interface IEditorOption {
   height?: number // Paper height. default: 1123
   scale?: number // scaling. default: 1
   pageGap?: number // Paper spacing. default: 20
-  backgroundColor?: string // Paper background color. default: #FFFFFF
   underlineColor?: string // Underline color. default: #000000
   strikeoutColor?: string // Strikeout color. default: #FF0000
   rangeColor?: string // Range color. default: #AECBFA
@@ -68,6 +67,7 @@ interface IEditorOption {
   group?: IGroup // Group option. {opacity?:number; backgroundColor?:string; activeOpacity?:number; activeBackgroundColor?:string; disabled?:boolean}
   pageBreak?: IPageBreak // PageBreak option。{font?:string; fontSize?:number; lineDash?:number[];}
   zone?: IZoneOption // Zone option。{tipDisabled?:boolean;}
+  background?: IBackgroundOption // Background option. {color?:string; image?:string; size?:BackgroundSize; repeat?:BackgroundRepeat;}。default: {color: '#FFFFFF'}
 }
 ```
 

docs/guide/option.md

@@ -27,7 +27,6 @@ interface IEditorOption {
   height?: number // 纸张高度。默认：1123
   scale?: number // 缩放比例。默认：1
   pageGap?: number // 纸张间隔。默认：20
-  backgroundColor?: string // 纸张背景色。默认：#FFFFFF
   underlineColor?: string // 下划线颜色。默认：#000000
   strikeoutColor?: string // 删除线颜色。默认：#FF0000
   rangeColor?: string // 选区颜色。默认：#AECBFA
@@ -68,6 +67,7 @@ interface IEditorOption {
   group?: IGroup // 成组配置。{opacity?:number; backgroundColor?:string; activeOpacity?:number; activeBackgroundColor?:string; disabled?:boolean}
   pageBreak?: IPageBreak // 分页符配置。{font?:string; fontSize?:number; lineDash?:number[];}
   zone?: IZoneOption // 编辑器区域配置。{tipDisabled?:boolean;}
+  background?: IBackgroundOption // 背景配置。{color?:string; image?:string; size?:BackgroundSize; repeat?:BackgroundRepeat;}。默认：{color: '#FFFFFF'}
 }
 ```
 

src/editor/core/draw/frame/Background.ts

@@ -1,3 +1,7 @@
+import {
+  BackgroundRepeat,
+  BackgroundSize
+} from '../../../dataset/enum/Background'
 import { DeepRequired } from '../../../interface/Common'
 import { IEditorOption } from '../../../interface/Editor'
 import { Draw } from '../Draw'
@@ -5,19 +9,104 @@ import { Draw } from '../Draw'
 export class Background {
   private draw: Draw
   private options: DeepRequired<IEditorOption>
+  private imageCache: Map<string, HTMLImageElement>
 
   constructor(draw: Draw) {
     this.draw = draw
     this.options = draw.getOptions()
+    this.imageCache = new Map()
   }
 
-  public render(ctx: CanvasRenderingContext2D, pageNo: number) {
-    const { backgroundColor } = this.options
-    const width = this.draw.getCanvasWidth(pageNo)
-    const height = this.draw.getCanvasHeight(pageNo)
+  private _renderBackgroundColor(
+    ctx: CanvasRenderingContext2D,
+    color: string,
+    width: number,
+    height: number
+  ) {
     ctx.save()
-    ctx.fillStyle = backgroundColor
+    ctx.fillStyle = color
     ctx.fillRect(0, 0, width, height)
     ctx.restore()
   }
+
+  private _drawImage(
+    ctx: CanvasRenderingContext2D,
+    imageElement: HTMLImageElement,
+    width: number,
+    height: number
+  ) {
+    const { background, scale } = this.options
+    // contain
+    if (background.size === BackgroundSize.CONTAIN) {
+      const imageWidth = imageElement.width * scale
+      const imageHeight = imageElement.height * scale
+      if (
+        !background.repeat ||
+        background.repeat === BackgroundRepeat.NO_REPEAT
+      ) {
+        ctx.drawImage(imageElement, 0, 0, imageWidth, imageHeight)
+      } else {
+        let startX = 0
+        let startY = 0
+        const repeatXCount =
+          background.repeat === BackgroundRepeat.REPEAT ||
+          background.repeat === BackgroundRepeat.REPEAT_X
+            ? Math.ceil((width * scale) / imageWidth)
+            : 1
+        const repeatYCount =
+          background.repeat === BackgroundRepeat.REPEAT ||
+          background.repeat === BackgroundRepeat.REPEAT_Y
+            ? Math.ceil((height * scale) / imageHeight)
+            : 1
+        for (let x = 0; x < repeatXCount; x++) {
+          for (let y = 0; y < repeatYCount; y++) {
+            ctx.drawImage(imageElement, startX, startY, imageWidth, imageHeight)
+            startY += imageHeight
+          }
+          startY = 0
+          startX += imageWidth
+        }
+      }
+    } else {
+      // cover
+      ctx.drawImage(imageElement, 0, 0, width * scale, height * scale)
+    }
+  }
+
+  private _renderBackgroundImage(
+    ctx: CanvasRenderingContext2D,
+    width: number,
+    height: number
+  ) {
+    const { background } = this.options
+    const imageElementCache = this.imageCache.get(background.image)
+    if (imageElementCache) {
+      this._drawImage(ctx, imageElementCache, width, height)
+    } else {
+      const img = new Image()
+      img.setAttribute('crossOrigin', 'Anonymous')
+      img.src = background.image
+      img.onload = () => {
+        this.imageCache.set(background.image, img)
+        this._drawImage(ctx, img, width, height)
+        // 避免层级上浮，触发编辑器二次渲染
+        this.draw.render({
+          isCompute: false,
+          isSubmitHistory: false
+        })
+      }
+    }
+  }
+
+  public render(ctx: CanvasRenderingContext2D, pageNo: number) {
+    const { background } = this.options
+    if (background.image) {
+      const { width, height } = this.options
+      this._renderBackgroundImage(ctx, width, height)
+    } else {
+      const width = this.draw.getCanvasWidth(pageNo)
+      const height = this.draw.getCanvasHeight(pageNo)
+      this._renderBackgroundColor(ctx, background.color, width, height)
+    }
+  }
 }

src/editor/dataset/constant/Background.ts

@@ -0,0 +1,9 @@
+import { IBackgroundOption } from '../../interface/Background'
+import { BackgroundRepeat, BackgroundSize } from '../enum/Background'
+
+export const defaultBackground: Readonly<Required<IBackgroundOption>> = {
+  color: '#FFFFFF',
+  image: '',
+  size: BackgroundSize.COVER,
+  repeat: BackgroundRepeat.NO_REPEAT
+}

src/editor/dataset/enum/Background.ts

@@ -0,0 +1,11 @@
+export enum BackgroundSize {
+  CONTAIN = 'contain',
+  COVER = 'cover'
+}
+
+export enum BackgroundRepeat {
+  REPEAT = 'repeat',
+  NO_REPEAT = 'no-repeat',
+  REPEAT_X = 'repeat-x',
+  REPEAT_Y = 'repeat-y'
+}

src/editor/index.ts

@@ -75,6 +75,9 @@ import { IRange } from './interface/Range'
 import { deepClone, splitText } from './utils'
 import { IZoneOption } from './interface/Zone'
 import { defaultZoneOption } from './dataset/constant/Zone'
+import { IBackgroundOption } from './interface/Background'
+import { defaultBackground } from './dataset/constant/Background'
+import { BackgroundRepeat, BackgroundSize } from './dataset/enum/Background'
 
 export default class Editor {
   public command: Command
@@ -138,6 +141,10 @@ export default class Editor {
       ...defaultZoneOption,
       ...options.zone
     }
+    const backgroundOptions: Required<IBackgroundOption> = {
+      ...defaultBackground,
+      ...options.background
+    }
 
     const editorOptions: DeepRequired<IEditorOption> = {
       mode: EditorMode.EDIT,
@@ -153,7 +160,6 @@ export default class Editor {
       height: 1123,
       scale: 1,
       pageGap: 20,
-      backgroundColor: '#FFFFFF',
       underlineColor: '#000000',
       strikeoutColor: '#FF0000',
       rangeAlpha: 0.6,
@@ -194,7 +200,8 @@ export default class Editor {
       placeholder: placeholderOptions,
       group: groupOptions,
       pageBreak: pageBreakOptions,
-      zone: zoneOptions
+      zone: zoneOptions,
+      background: backgroundOptions
     }
     // 数据处理
     data = deepClone(data)
@@ -292,7 +299,9 @@ export {
   ListType,
   ListStyle,
   WordBreak,
-  ControlIndentation
+  ControlIndentation,
+  BackgroundRepeat,
+  BackgroundSize
 }
 
 // 对外类型

src/editor/interface/Background.ts

@@ -0,0 +1,8 @@
+import { BackgroundRepeat, BackgroundSize } from '../dataset/enum/Background'
+
+export interface IBackgroundOption {
+  color?: string
+  image?: string
+  size?: BackgroundSize
+  repeat?: BackgroundRepeat
+}

src/editor/interface/Editor.ts

@@ -5,6 +5,7 @@ import {
   PaperDirection,
   WordBreak
 } from '../dataset/enum/Editor'
+import { IBackgroundOption } from './Background'
 import { ICheckboxOption } from './Checkbox'
 import { IPadding } from './Common'
 import { IControlOption } from './Control'
@@ -40,7 +41,6 @@ export interface IEditorOption {
   height?: number
   scale?: number
   pageGap?: number
-  backgroundColor?: string
   underlineColor?: string
   strikeoutColor?: string
   rangeColor?: string
@@ -81,6 +81,7 @@ export interface IEditorOption {
   group?: IGroup
   pageBreak?: IPageBreak
   zone?: IZoneOption
+  background?: IBackgroundOption
 }
 
 export interface IEditorResult {