feat: cursor following page scrolling #229

docs/en/guide/option.md

@@ -53,6 +53,7 @@ interface IEditorOption {
   inactiveAlpha?: number // When the body content is out of focus, transparency. default: 0.6
   historyMaxRecordCount: number // History (undo redo) maximum number of records. default: 100
   printPixelRatio: number // Print the pixel ratio (larger values are clearer, but larger sizes). default: 3
+  maskMargin: IMargin // Masking margins above the editor（for example: menu bar, bottom toolbar）。default: [0, 0, 0, 0]
   wordBreak: WordBreak // Word and punctuation breaks: No punctuation in the first line of the BREAK_WORD &The word is not split, and the line is folded after BREAK_ALL full according to the width of the character. default: BREAK_WORD
   watermark?: IWatermark // Watermark{data:string; color?:string; opacity?:number; size?:number; font?:string;}
   control?: IControlOption // Control {placeholderColor?:string; bracketColor?:string; prefix?:string; postfix?:string;}

docs/guide/option.md

@@ -53,6 +53,7 @@ interface IEditorOption {
   inactiveAlpha?: number // 正文内容失焦时透明度。默认值：0.6
   historyMaxRecordCount: number // 历史（撤销重做）最大记录次数。默认：100次
   printPixelRatio: number // 打印像素比率（值越大越清晰，但尺寸越大）。默认：3
+  maskMargin: IMargin // 编辑器上的遮盖边距（如悬浮到编辑器上的菜单栏、底部工具栏）。默认：[0, 0, 0, 0]
   wordBreak: WordBreak // 单词与标点断行：BREAK_WORD首行不出现标点&单词不拆分、BREAK_ALL按字符宽度撑满后折行。默认：BREAK_WORD
   watermark?: IWatermark // 水印信息。{data:string; color?:string; opacity?:number; size?:number; font?:string;}
   control?: IControlOption // 控件信息。 {placeholderColor?:string; bracketColor?:string; prefix?:string; postfix?:string;}

src/editor/core/cursor/Cursor.ts

@@ -1,8 +1,11 @@
 import { CURSOR_AGENT_HEIGHT } from '../../dataset/constant/Cursor'
 import { EDITOR_PREFIX } from '../../dataset/constant/Editor'
+import { MoveDirection } from '../../dataset/enum/Observer'
 import { DeepRequired } from '../../interface/Common'
 import { ICursorOption } from '../../interface/Cursor'
 import { IEditorOption } from '../../interface/Editor'
+import { IElementPosition } from '../../interface/Element'
+import { findScrollContainer } from '../../utils'
 import { Draw } from '../draw/Draw'
 import { CanvasEvent } from '../event/CanvasEvent'
 import { Position } from '../position/Position'
@@ -15,6 +18,11 @@ export type IDrawCursorOption = ICursorOption & {
   hitLineStartIndex?: number
 }
 
+export interface IMoveCursorToVisibleOption {
+  direction: MoveDirection
+  cursorPosition: IElementPosition
+}
+
 export class Cursor {
   private readonly ANIMATION_CLASS = `${EDITOR_PREFIX}-cursor--animation`
 
@@ -153,4 +161,53 @@ export class Cursor {
     this.cursorDom.style.display = 'none'
     this._clearBlinkTimeout()
   }
+
+  public moveCursorToVisible(payload: IMoveCursorToVisibleOption) {
+    const { cursorPosition, direction } = payload
+    if (!cursorPosition || !direction) return
+    const {
+      pageNo,
+      coordinate: { leftTop, leftBottom }
+    } = cursorPosition
+    // 当前页面距离滚动容器顶部距离
+    const prePageY =
+      pageNo * (this.draw.getHeight() + this.draw.getPageGap()) +
+      this.container.getBoundingClientRect().top
+    // 向上移动时：以顶部距离为准，向下移动时：以底部位置为准
+    const isUp = direction === MoveDirection.UP
+    const x = leftBottom[0]
+    const y = isUp ? leftTop[1] + prePageY : leftBottom[1] + prePageY
+    // 查找滚动容器，如果是滚动容器是document，则限制范围为当前窗口
+    const scrollContainer = findScrollContainer(this.container)
+    const rect = {
+      left: 0,
+      right: 0,
+      top: 0,
+      bottom: 0
+    }
+    if (scrollContainer === document.documentElement) {
+      rect.right = window.innerWidth
+      rect.bottom = window.innerHeight
+    } else {
+      const { left, right, top, bottom } =
+        scrollContainer.getBoundingClientRect()
+      rect.left = left
+      rect.right = right
+      rect.top = top
+      rect.bottom = bottom
+    }
+    // 可视范围根据参数调整
+    const { maskMargin } = this.options
+    rect.top += maskMargin[0]
+    rect.bottom -= maskMargin[2]
+    // 不在可视范围时，移动滚动条到合适位置
+    if (
+      !(x >= rect.left && x <= rect.right && y >= rect.top && y <= rect.bottom)
+    ) {
+      const { scrollLeft, scrollTop } = scrollContainer
+      isUp
+        ? scrollContainer.scroll(scrollLeft, scrollTop - (rect.top - y))
+        : scrollContainer.scroll(scrollLeft, scrollTop + y - rect.bottom)
+    }
+  }
 }

src/editor/core/event/handlers/keydown.ts

@@ -2,6 +2,7 @@ import { EditorZone } from '../../..'
 import { ZERO } from '../../../dataset/constant/Common'
 import { ElementType } from '../../../dataset/enum/Element'
 import { KeyMap } from '../../../dataset/enum/KeyMap'
+import { MoveDirection } from '../../../dataset/enum/Observer'
 import { IElement, IElementPosition } from '../../../interface/Element'
 import { formatElementContext } from '../../../utils/element'
 import { isMod } from '../../../utils/hotkey'
@@ -196,7 +197,7 @@ export function keydown(evt: KeyboardEvent, host: CanvasEvent) {
   } else if (evt.key === KeyMap.Up || evt.key === KeyMap.Down) {
     if (isReadonly) return
     let anchorPosition: IElementPosition = cursorPosition
-    const isUp = evt.key === KeyMap.Up
+    // 扩大选区时，判断移动光标点
     if (evt.shiftKey) {
       if (startIndex === cursorPosition.index) {
         anchorPosition = positionList[endIndex]
@@ -213,14 +214,15 @@ export function keydown(evt: KeyboardEvent, host: CanvasEvent) {
         rightTop: [curRightX]
       }
     } = anchorPosition
-    // 向上时在首行、向下时再最尾则忽略
+    // 向上时在首行、向下时在尾行则忽略
+    const isUp = evt.key === KeyMap.Up
     if (
       (isUp && rowIndex === 0) ||
       (!isUp && rowIndex === draw.getRowCount() - 1)
     ) {
       return
     }
-    // 查找下一行信息
+    // 查找下一行位置列表
     const probablePosition: IElementPosition[] = []
     if (isUp) {
       let p = index - 1
@@ -269,10 +271,9 @@ export function keydown(evt: KeyboardEvent, host: CanvasEvent) {
       break
     }
     if (!nextIndex) return
-    const curIndex = nextIndex
     // shift则缩放选区
-    let anchorStartIndex = curIndex
+    let anchorStartIndex = nextIndex
-    let anchorEndIndex = curIndex
+    let anchorEndIndex = nextIndex
     if (evt.shiftKey) {
       if (startIndex !== endIndex) {
         if (startIndex === cursorPosition.index) {
@@ -300,6 +301,11 @@ export function keydown(evt: KeyboardEvent, host: CanvasEvent) {
       isSubmitHistory: false,
       isCompute: false
     })
+    // 将光标移动到可视范围内
+    draw.getCursor().moveCursorToVisible({
+      cursorPosition: positionList[isUp ? anchorStartIndex : anchorEndIndex],
+      direction: isUp ? MoveDirection.UP : MoveDirection.DOWN
+    })
   } else if (isMod(evt) && evt.key === KeyMap.Z) {
     if (isReadonly) return
     historyManager.undo()

src/editor/index.ts

@@ -148,6 +148,7 @@ export default class Editor {
       historyMaxRecordCount: 100,
       wordBreak: WordBreak.BREAK_WORD,
       printPixelRatio: 3,
+      maskMargin: [0, 0, 0, 0],
       ...options,
       header: headerOptions,
       footer: footerOptions,

src/editor/interface/Editor.ts

@@ -59,6 +59,7 @@ export interface IEditorOption {
   inactiveAlpha?: number
   historyMaxRecordCount?: number
   printPixelRatio?: number
+  maskMargin?: IMargin
   wordBreak?: WordBreak
   header?: IHeader
   footer?: IFooter

src/editor/utils/index.ts

@@ -219,3 +219,19 @@ export function convertStringToBase64(input: string) {
   const base64 = window.btoa(charArray.join(''))
   return base64
 }
+
+export function findScrollContainer(element: HTMLElement) {
+  let parent = element.parentElement
+  while (parent) {
+    const style = window.getComputedStyle(parent)
+    const overflowY = style.getPropertyValue('overflow-y')
+    if (
+      parent.scrollHeight > parent.clientHeight &&
+      (overflowY === 'auto' || overflowY === 'scroll')
+    ) {
+      return parent
+    }
+    parent = parent.parentElement
+  }
+  return document.documentElement
+}

src/mock.ts

@@ -430,5 +430,6 @@ export const options: IEditorOption = {
   },
   placeholder: {
     data: '请输入正文'
-  }
+  },
+  maskMargin: [60, 0, 30, 0] // 菜单栏高度60，底部工具栏30为遮盖层
 }