feat(编辑能力): 优化编辑响应与资源复用

assets/webui/ofdgo.js

@@ -4828,6 +4828,9 @@ async function changeDocument(name, item, ...args) {
 		openSeq = advanceDocumentSequence();
 		if (changingFont) {
 			await refreshFontBinding(doc, openSeq);
+		} else if (restoring && !doc.changes?.all && doc.changes?.pages?.length === 1 && doc.changes.pages[0] === state.pageIndex && (restoredIndex < 0 || restoredIndex === state.pageIndex)) {
+			if (location) canvasEditor.pendingSelection = {index:state.pageIndex, ids:location.ids};
+			await refreshEditorPage(doc, state.pageIndex, openSeq, clearSelection);
 		} else if (item || name === "ofdgoPasteObjects" || inserting || editingAnnotation) {
 			await refreshEditorPage(doc, item ? item.index : args[0], openSeq, clearSelection);
 		} else {
@@ -4960,7 +4963,7 @@ async function refreshFontBinding(doc, openSeq) {
 
 async function refreshEditorPage(doc, index, openSeq, clearSelection = false) {
 	state.doc = doc;
-	resetSearch();
+	const search = refreshSearchPages([index], openSeq);
 	state.documentSelection = null;
 	pageView.resetPageLoading();
 	try {
@@ -4997,6 +5000,7 @@ async function refreshEditorPage(doc, index, openSeq, clearSelection = false) {
 			renderMeta(true);
 			updateControls();
 			loadDocumentDetails(openSeq);
+			await search;
 			for (const shell of el.svgHost.children) pageView.observeFlowPage(shell);
 			for (const button of el.pageList.children) pageView.observeThumbnail(button, Number(button.dataset.pageIndex), openSeq);
 		}
@@ -10771,6 +10775,39 @@ function resetSearch(clearInput = true) {
 	clearSearchHighlights();
 }
 
+async function refreshSearchPages(pages, openSeq) {
+	const tab = documentTab(), target = tab.state, query = target.searchQuery;
+	if (!query || target.searchRunning) { resetSearch(false); return; }
+	const seq = ++target.searchSeq;
+	target.searchRunning = true;
+	const selected = target.searchMatches[target.searchIndex];
+	try {
+		const matches = target.searchMatches.filter(match => !pages.includes(match.page));
+		for (const page of pages) {
+			const result = await callTabWASM(tab, "ofdgoSearchPage", page, query);
+			if (tab.closed || target.openSeq !== openSeq || target.searchSeq !== seq) return;
+			for (const match of result || []) matches.push({...match, page});
+		}
+		matches.sort((a,b) => a.page - b.page);
+		target.searchMatches = matches;
+		target.searchIndex = selected ? matches.indexOf(selected) : -1;
+		if (isForegroundDocument(tab)) {
+			el.searchResults.replaceChildren();
+			clearSearchHighlights();
+			el.searchStatus.textContent = matches.length ? "搜索完成" : "暂无结果";
+			renderSearchResults();
+			if (target.searchIndex >= 0) renderSearchHighlights(matches[target.searchIndex].page);
+		}
+	} catch (err) {
+		if (target.openSeq === openSeq && target.searchSeq === seq) {
+			target.searchQuery = "";
+			if (isForegroundDocument(tab)) { resetSearch(false); showError(err, false); }
+		}
+	} finally {
+		if (target.searchSeq === seq) target.searchRunning = false;
+	}
+}
+
 async function searchDocument() {
 	if (!state.doc || document.body.hasAttribute("data-busy")) {
 		return;

internal/webui/webui.go

@@ -365,11 +365,12 @@ type editorClipboard struct {
 // editorInfo 编辑文档信息与操作状态
 type editorInfo struct {
 	DocumentInfo
-	Revision         uint64   `json:"revision"`
+	Revision         uint64              `json:"revision"`
-	CanUndo          bool     `json:"canUndo"`
+	CanUndo          bool                `json:"canUndo"`
-	CanRedo          bool     `json:"canRedo"`
+	CanRedo          bool                `json:"canRedo"`
-	PageCapabilities []uint   `json:"pageCapabilities"`
+	PageCapabilities []uint              `json:"pageCapabilities"`
-	EditWarnings     []string `json:"editWarnings,omitempty"`
+	EditWarnings     []string            `json:"editWarnings,omitempty"`
+	Changes          ofdgo.EditorChanges `json:"changes"`
 }
 
 // editorPageInfo 页面操作结果与目标页面
@@ -3203,7 +3204,7 @@ func (e *businessEngine) encodeResult(result apiResult) string {
 // editorSummary 获取当前编辑文档状态
 // 返回: editorInfo 文档信息
 func (e *businessEngine) editorSummary() editorInfo {
-	info := editorInfo{DocumentInfo: e.currentSession.Summary(), Revision: e.currentEditor.Revision(), CanUndo: e.currentEditor.CanUndo(), CanRedo: e.currentEditor.CanRedo()}
+	info := editorInfo{DocumentInfo: e.currentSession.Summary(), Revision: e.currentEditor.Revision(), CanUndo: e.currentEditor.CanUndo(), CanRedo: e.currentEditor.CanRedo(), Changes: e.currentEditor.Changes()}
 	if !e.currentSession.doc.Permissions.Edit {
 		info.EditWarnings = append(info.EditWarnings, "原文件声明不允许编辑")
 	}
@@ -6741,6 +6742,25 @@ func (e *businessEngine) previewEditor(editor *ofdgo.Editor, annotations bool) (
 			session.Renderer.SetFontFS(session.fontFS)
 			editor.SetFontFS(session.fontFS)
 		}
+		changes := editor.Changes()
+		if editor == e.currentEditor && !changes.All && len(session.boxCache) == len(e.currentSession.boxCache) {
+			changed := changes.Pages
+			for index, page := range e.currentSession.pageCache {
+				if !slices.Contains(changed, index) {
+					session.pageCache[index] = page
+				}
+			}
+			for _, index := range e.currentSession.textOrder {
+				if !slices.Contains(changed, index) {
+					session.cachePageText(index, e.currentSession.textCache[index])
+				}
+			}
+			for index, box := range e.currentSession.boxCache {
+				if !slices.Contains(changed, index) {
+					session.boxCache[index] = box
+				}
+			}
+		}
 		if editor == e.currentEditor {
 			session.input, e.currentSession.input = e.currentSession.input, nil
 		}

ofdgo_compression.go

@@ -70,6 +70,7 @@ type outputOptimization struct {
 	protected bool
 	completed int
 	deflater  *flate.Writer
+	resources *editorResourceSelection
 }
 
 // outputCompressionBuffer 限制候选ZIP编码，不能缩小时终止本次压缩

ofdgo_editor.go

@@ -46,38 +46,41 @@ const editorPathValidationLimit = 1024
 // 阶段可重复，准备完成不代表保存成功
 // 回调不可重入修改编辑器，可返回context.Canceled等调用方停止原因
 type Editor struct {
-	OnWriteProgress  func(stage string, completed, total int) error
+	OnWriteProgress    func(stage string, completed, total int) error
-	Info             DocInfo
+	Info               DocInfo
-	pages            []PageContent
+	pages              []PageContent
-	resources        []editorResource
+	resources          []editorResource
-	runtimeResources *Resources
+	runtimeResources   *Resources
-	fonts            map[string]*FontResource
+	fonts              map[string]*FontResource
-	fontRegistration editorFontRegistration
+	fontRegistration   editorFontRegistration
-	fontDirs         []string
+	fontDirs           []string
-	fontFS           []fs.FS
+	fontFS             []fs.FS
-	fontRenderer     *Renderer
+	fontRenderer       *Renderer
-	fontSourcesCache *fontSourceCache
+	fontSourcesCache   *fontSourceCache
-	fontMetrics      map[string]FontMetrics
+	fontMetrics        map[string]FontMetrics
-	backends         RenderBackends
+	backends           RenderBackends
-	images           map[string]image.Point
+	images             map[string]image.Point
-	resourceID       map[editorResourceKey]string
+	resourceID         map[editorResourceKey]string
-	maxID            int
+	maxID              int
-	history          []editorChange
+	history            []editorChange
-	historyIndex     int
+	historyIndex       int
-	historyLimit     int
+	historyLimit       int
-	revision         uint64
+	revision           uint64
-	serial           uint64
+	serial             uint64
-	source           *editorSource
+	source             *editorSource
-	origins          map[string]*editorObjectOrigin
+	origins            map[string]*editorObjectOrigin
-	removedPages     map[string]bool
+	removedPages       map[string]bool
-	structureRemaps  map[string][]map[string]string
+	structureRemaps    map[string][]map[string]string
-	outlines         []byte
+	outlines           []byte
-	encryption       *encryptionState
+	encryption         *encryptionState
-	output           *outputOptimization
+	output             *outputOptimization
-	saveTarget       Output
+	saveTarget         Output
-	snapshotArchive  *editorSnapshotArchive
+	snapshotArchive    *editorSnapshotArchive
-	validatedPaths   *renderCache[string, bool]
+	validatedPaths     *renderCache[string, bool]
-	richIndex        *richTextIndex
+	changes            EditorChanges
+	transactionChanges *EditorChanges
+	objectIndex        *editorObjectIndex
+	richIndex          *richTextIndex
 }
 
 // editorResource 文档内嵌资源
@@ -892,13 +895,8 @@ func (e *Editor) findObject(page int, id string) (*Layer, int, error) {
 	if err != nil {
 		return nil, 0, err
 	}
-	for i := range content.Content.Layer {
+	if position, ok := e.objectPositions(content)[id]; ok {
-		layer := &content.Content.Layer[i]
+		return &content.Content.Layer[position.layer], position.index, nil
-		for index, object := range layer.Objects {
-			if editorObjectID(object) == id && id != "" {
-				return layer, index, nil
-			}
-		}
 	}
 	return nil, 0, fmt.Errorf("object %q not found on page %d", id, page)
 }

ofdgo_editor_batch.go

@@ -30,6 +30,36 @@ type editorObjectPosition struct {
 	index int
 }
 
+// editorObjectIndex 复用最近页面的只读对象位置，图层容器替换后重新建立
+type editorObjectIndex struct {
+	layers    []Layer
+	positions map[string]editorObjectPosition
+}
+
+// objectPositions 获取页面的对象位置索引，重复编号保留第一个匹配
+// 入参: page 内部只读页面
+// 返回: map[string]editorObjectPosition 只读索引
+func (e *Editor) objectPositions(page *PageContent) map[string]editorObjectPosition {
+	layers := page.Content.Layer
+	if len(layers) == 0 {
+		return nil
+	}
+	if cached := e.objectIndex; cached != nil && len(cached.layers) == len(layers) && &cached.layers[0] == &layers[0] {
+		return cached.positions
+	}
+	positions := make(map[string]editorObjectPosition)
+	for i, layer := range layers {
+		for j, object := range layer.Objects {
+			id := editorObjectID(object)
+			if _, exists := positions[id]; id != "" && !exists {
+				positions[id] = editorObjectPosition{i, j}
+			}
+		}
+	}
+	e.objectIndex = &editorObjectIndex{layers: layers, positions: positions}
+	return positions
+}
+
 // ObjectPosition 对象在图层或页块直接成员中的位置，Index从0开始，Count不含嵌套页块的对象
 type ObjectPosition struct {
 	Layer     string
@@ -709,7 +739,7 @@ func (e *Editor) replaceLayers(page int, layers []Layer) {
 func (e *Editor) replacePreparedLayers(page int, after []Layer) {
 	if e.historyLimit == 0 {
 		e.pages[page].Content.Layer = after
-		e.recordChange()
+		e.recordChange(page)
 		return
 	}
 	before := copyEditorPage(e.pages[page])
@@ -738,7 +768,7 @@ func (e *Editor) replacePreparedLayers(page int, after []Layer) {
 		e.pages[page].Content.Layer = copyEditorPage(PageContent{Content: Content{Layer: layers}}).Content.Layer
 	}
 	apply(e, after)
-	if change := e.recordChange(); change != nil {
+	if change := e.recordChange(page); change != nil {
 		change.undo = func(e *Editor) { apply(e, before.Content.Layer) }
 		change.redo = func(e *Editor) { apply(e, after) }
 	}
@@ -835,6 +865,15 @@ func (e *Editor) updateObjectOrigins(page int, objects []GraphicObject, preserve
 		return nil
 	}
 	apply := func(e *Editor, objects []GraphicObject, origins map[string]*editorObjectOrigin) {
+		layers := slices.Clone(e.pages[page].Content.Layer)
+		cloned := make(map[int]bool)
+		for _, index := range indexes {
+			if !cloned[index.layer] {
+				layers[index.layer].Objects = slices.Clone(layers[index.layer].Objects)
+				cloned[index.layer] = true
+			}
+		}
+		e.pages[page].Content.Layer = layers
 		for i, index := range indexes {
 			e.pages[page].Content.Layer[index.layer].Objects[index.index] = objects[i]
 		}
@@ -843,7 +882,7 @@ func (e *Editor) updateObjectOrigins(page int, objects []GraphicObject, preserve
 		}
 	}
 	apply(e, after, afterOrigins)
-	if change := e.recordChange(); change != nil {
+	if change := e.recordChange(page); change != nil {
 		change.undo = func(e *Editor) { apply(e, before, beforeOrigins) }
 		change.redo = func(e *Editor) { apply(e, after, afterOrigins) }
 	}
@@ -891,30 +930,19 @@ func (e *Editor) selectedObjects(page int, ids []string) ([]GraphicObject, []edi
 	if len(ids) == 0 {
 		return objects, indexes, nil
 	}
-	selected := make(map[string]int, len(ids))
+	positions := e.objectPositions(content)
+	selected := make(map[string]bool, len(ids))
 	for i, id := range ids {
-		if _, exists := selected[id]; exists {
+		if selected[id] {
 			return nil, nil, fmt.Errorf("duplicate object %q", id)
 		}
-		selected[id] = i
+		selected[id] = true
-	}
+		position, ok := positions[id]
-	for i, layer := range content.Content.Layer {
+		if !ok {
-		for j, object := range layer.Objects {
-			id := editorObjectID(object)
-			if index, ok := selected[id]; ok && id != "" {
-				objects[index] = object
-				indexes[index] = editorObjectPosition{i, j}
-				delete(selected, id)
-				if len(selected) == 0 {
-					return objects, indexes, nil
-				}
-			}
-		}
-	}
-	for _, id := range ids {
-		if _, missing := selected[id]; missing {
 			return nil, nil, fmt.Errorf("object %q not found on page %d", id, page)
 		}
+		indexes[i] = position
+		objects[i] = content.Content.Layer[position.layer].Objects[position.index]
 	}
 	return objects, indexes, nil
 }

ofdgo_editor_copy.go

@@ -19,6 +19,7 @@ import (
 	"encoding/xml"
 	"fmt"
 	"reflect"
+	"slices"
 	"strconv"
 	"sync"
 )
@@ -241,6 +242,22 @@ func (e *Editor) copiedLayerStyle(object GraphicObject) string {
 // 入参: value 原值
 // 返回: T 独立副本
 func cloneEditorData[T any](value T) T {
+	switch source := any(value).(type) {
+	case GraphicObject:
+		return any(copyEditorGraphicObject(source)).(T)
+	case TextObject:
+		return any(copyEditorTextObject(source)).(T)
+	case PathObject:
+		return any(copyEditorPathObject(source)).(T)
+	case ImageObject:
+		return any(copyEditorImageObject(source)).(T)
+	case CompositeGraphicUnit:
+		return any(copyEditorCompositeGraphicUnit(source)).(T)
+	case PageContent:
+		return any(copyEditorPageContent(source)).(T)
+	case Layer:
+		return any(copyEditorLayer(source)).(T)
+	}
 	source := reflect.ValueOf(value)
 	if !source.IsValid() {
 		return value
@@ -336,3 +353,174 @@ func editorCloneFields(kind reflect.Type) []int {
 	actual, _ := editorClonePlans.LoadOrStore(kind, fields)
 	return actual.([]int)
 }
+
+// copyEditorGraphicObject 复制GraphicObject的可变字段，保留内部只读状态
+// 入参: value 原值
+// 返回: GraphicObject 独立副本
+func copyEditorGraphicObject(value GraphicObject) GraphicObject {
+	value.TextObject = copyEditorTextObject(value.TextObject)
+	value.PathObject = copyEditorPathObject(value.PathObject)
+	value.ImageObject = copyEditorImageObject(value.ImageObject)
+	value.CompositeGraphicUnit = copyEditorCompositeGraphicUnit(value.CompositeGraphicUnit)
+	return value
+}
+
+// copyEditorTextObject 复制TextObject的可变字段，保留内部只读状态
+// 入参: value 原值
+// 返回: TextObject 独立副本
+func copyEditorTextObject(value TextObject) TextObject {
+	if value.DashOffset != nil {
+		copied := *value.DashOffset
+		value.DashOffset = &copied
+	}
+	if value.Alpha != nil {
+		copied := *value.Alpha
+		value.Alpha = &copied
+	}
+	if value.Visible != nil {
+		copied := *value.Visible
+		value.Visible = &copied
+	}
+	if value.Fill != nil {
+		copied := *value.Fill
+		value.Fill = &copied
+	}
+	if value.Stroke != nil {
+		copied := *value.Stroke
+		value.Stroke = &copied
+	}
+	value.StrokeColor = cloneEditorData(value.StrokeColor)
+	value.FillColor = cloneEditorData(value.FillColor)
+	value.CGTransform = slices.Clone(value.CGTransform)
+	value.TextCode = slices.Clone(value.TextCode)
+	value.Clips = cloneEditorData(value.Clips)
+	value.Actions = cloneEditorData(value.Actions)
+	return value
+}
+
+// copyEditorPathObject 复制PathObject的可变字段，保留内部只读状态
+// 入参: value 原值
+// 返回: PathObject 独立副本
+func copyEditorPathObject(value PathObject) PathObject {
+	if value.DashOffset != nil {
+		copied := *value.DashOffset
+		value.DashOffset = &copied
+	}
+	if value.Alpha != nil {
+		copied := *value.Alpha
+		value.Alpha = &copied
+	}
+	if value.Visible != nil {
+		copied := *value.Visible
+		value.Visible = &copied
+	}
+	if value.Stroke != nil {
+		copied := *value.Stroke
+		value.Stroke = &copied
+	}
+	if value.Fill != nil {
+		copied := *value.Fill
+		value.Fill = &copied
+	}
+	value.StrokeColor = cloneEditorData(value.StrokeColor)
+	value.FillColor = cloneEditorData(value.FillColor)
+	value.Clips = cloneEditorData(value.Clips)
+	value.Actions = cloneEditorData(value.Actions)
+	return value
+}
+
+// copyEditorImageObject 复制ImageObject的可变字段，保留内部只读状态
+// 入参: value 原值
+// 返回: ImageObject 独立副本
+func copyEditorImageObject(value ImageObject) ImageObject {
+	if value.Alpha != nil {
+		copied := *value.Alpha
+		value.Alpha = &copied
+	}
+	if value.Visible != nil {
+		copied := *value.Visible
+		value.Visible = &copied
+	}
+	value.Border = cloneEditorData(value.Border)
+	value.Clips = cloneEditorData(value.Clips)
+	value.Actions = cloneEditorData(value.Actions)
+	return value
+}
+
+// copyEditorCompositeGraphicUnit 复制CompositeGraphicUnit的可变字段，保留内部只读状态
+// 入参: value 原值
+// 返回: CompositeGraphicUnit 独立副本
+func copyEditorCompositeGraphicUnit(value CompositeGraphicUnit) CompositeGraphicUnit {
+	if value.Alpha != nil {
+		copied := *value.Alpha
+		value.Alpha = &copied
+	}
+	if value.Visible != nil {
+		copied := *value.Visible
+		value.Visible = &copied
+	}
+	value.Objects = slices.Clone(value.Objects)
+	for i := range value.Objects {
+		value.Objects[i] = copyEditorGraphicObject(value.Objects[i])
+	}
+	value.TextObject = slices.Clone(value.TextObject)
+	for i := range value.TextObject {
+		value.TextObject[i] = copyEditorTextObject(value.TextObject[i])
+	}
+	value.PathObject = slices.Clone(value.PathObject)
+	for i := range value.PathObject {
+		value.PathObject[i] = copyEditorPathObject(value.PathObject[i])
+	}
+	value.ImageObject = slices.Clone(value.ImageObject)
+	for i := range value.ImageObject {
+		value.ImageObject[i] = copyEditorImageObject(value.ImageObject[i])
+	}
+	value.CompositeGraphicUnit = slices.Clone(value.CompositeGraphicUnit)
+	for i := range value.CompositeGraphicUnit {
+		value.CompositeGraphicUnit[i] = copyEditorCompositeGraphicUnit(value.CompositeGraphicUnit[i])
+	}
+	value.Clips = cloneEditorData(value.Clips)
+	value.Actions = cloneEditorData(value.Actions)
+	return value
+}
+
+// copyEditorPageContent 复制PageContent的可变字段，保留内部只读状态
+// 入参: value 原值
+// 返回: PageContent 独立副本
+func copyEditorPageContent(value PageContent) PageContent {
+	value.Template = slices.Clone(value.Template)
+	value.PageRes = slices.Clone(value.PageRes)
+	value.Content.Layer = slices.Clone(value.Content.Layer)
+	for i := range value.Content.Layer {
+		value.Content.Layer[i] = copyEditorLayer(value.Content.Layer[i])
+	}
+	value.Actions = cloneEditorData(value.Actions)
+	return value
+}
+
+// copyEditorLayer 复制Layer的可变字段，保留内部只读状态
+// 入参: value 原值
+// 返回: Layer 独立副本
+func copyEditorLayer(value Layer) Layer {
+	value.Objects = slices.Clone(value.Objects)
+	for i := range value.Objects {
+		value.Objects[i] = copyEditorGraphicObject(value.Objects[i])
+	}
+	value.TextObject = slices.Clone(value.TextObject)
+	for i := range value.TextObject {
+		value.TextObject[i] = copyEditorTextObject(value.TextObject[i])
+	}
+	value.PathObject = slices.Clone(value.PathObject)
+	for i := range value.PathObject {
+		value.PathObject[i] = copyEditorPathObject(value.PathObject[i])
+	}
+	value.ImageObject = slices.Clone(value.ImageObject)
+	for i := range value.ImageObject {
+		value.ImageObject[i] = copyEditorImageObject(value.ImageObject[i])
+	}
+	value.CompositeGraphicUnit = slices.Clone(value.CompositeGraphicUnit)
+	for i := range value.CompositeGraphicUnit {
+		value.CompositeGraphicUnit[i] = copyEditorCompositeGraphicUnit(value.CompositeGraphicUnit[i])
+	}
+	return value
+}

ofdgo_editor_font.go

@@ -34,8 +34,9 @@ type editorFontUsage struct {
 	unsafe bool
 }
 
-// editorFontSubset 保存单个新增字体最近一次裁剪结果，不保留历史字形集合
+// editorFontSubset 保存单个新增字体及其快照最近一次裁剪结果，不保留历史字形集合
 type editorFontSubset struct {
+	source [32]byte
 	glyphs []uint16
 	data   []byte
 	mapped bool
@@ -317,13 +318,13 @@ func (e *Editor) subsetSnapshotFonts(ctx context.Context, progress editorProgres
 	if e.source == nil || e.backends.FontResources == nil {
 		return nil, ctx.Err()
 	}
-	candidates := make(map[string]bool)
+	candidates := make(map[string]int)
-	for _, resource := range e.resources {
+	for i, resource := range e.resources {
 		if err := ctx.Err(); err != nil {
 			return nil, err
 		}
 		if resource.font != nil && resource.font.FontFile != "" && e.source.reader.fileNames[resource.name] {
-			candidates[resource.name] = true
+			candidates[resource.name] = i
 		}
 	}
 	if len(candidates) == 0 {
@@ -399,15 +400,24 @@ func (e *Editor) subsetSnapshotFonts(ctx context.Context, progress editorProgres
 		if font.unsafe {
 			continue
 		}
-		subset, err := e.backends.FontResources.SubsetFont(data, slices.Sorted(maps.Keys(glyphs)), preserve)
+		ids := slices.Sorted(maps.Keys(glyphs))
-		if err != nil {
+		checksum := sha256.Sum256(data)
-			return nil, err
+		resource := &e.resources[candidates[name]]
+		if resource.subset == nil || resource.subset.source != checksum || resource.subset.mapped != preserve || !slices.Equal(resource.subset.glyphs, ids) {
+			subset, err := e.backends.FontResources.SubsetFont(data, ids, preserve)
+			if err != nil {
+				return nil, err
+			}
+			if err := ctx.Err(); err != nil {
+				return nil, err
+			}
+			if len(subset) >= len(data) {
+				subset = nil
+			}
+			resource.subset = &editorFontSubset{source: checksum, glyphs: ids, data: subset, mapped: preserve}
 		}
-		if err := ctx.Err(); err != nil {
+		if len(resource.subset.data) != 0 {
-			return nil, err
+			result[name] = resource.subset.data
-		}
-		if len(subset) != 0 && len(subset) < len(data) {
-			result[name] = subset
 		}
 	}
 	return result, progress.report("fonts", len(candidates), len(candidates))
@@ -593,7 +603,7 @@ func (e *Editor) subsetNewFonts(progress editorProgress) (map[string][]byte, err
 			return nil, err
 		}
 		resource := &e.resources[i]
-		if resource.font == nil {
+		if resource.font == nil || e.source != nil && e.source.reader.fileNames[resource.name] {
 			continue
 		}
 		usage := used[resource.font.ID]

ofdgo_editor_group.go

@@ -253,7 +253,7 @@ func (e *Editor) replaceGroup(page int, indexes []editorObjectPosition, objects
 		}
 	}
 	apply(e, after, origins)
-	if change := e.recordChange(); change != nil {
+	if change := e.recordChange(page); change != nil {
 		change.undo = func(e *Editor) { apply(e, before, previous) }
 		change.redo = func(e *Editor) { apply(e, after, origins) }
 	}

ofdgo_editor_history.go

@@ -21,10 +21,43 @@ import (
 
 // editorChange 页面或对象操作及其修订标识
 type editorChange struct {
-	undo   func(*Editor)
+	undo    func(*Editor)
-	redo   func(*Editor)
+	redo    func(*Editor)
-	before uint64
+	before  uint64
-	after  uint64
+	after   uint64
+	changes EditorChanges
+}
+
+// EditorChanges 描述最近一次修改或历史回放的刷新范围
+// All表示文档结构或共享资源变化；否则Pages为受影响的零基页码
+// 返回值只覆盖最近一次操作，调用方应在每次操作后读取
+type EditorChanges struct {
+	All   bool  `json:"all"`
+	Pages []int `json:"pages,omitempty"`
+}
+
+// Changes 获取最近一次有效修改的独立刷新范围
+// 返回: EditorChanges 变化范围；未发生修改时为空
+func (e *Editor) Changes() EditorChanges {
+	return EditorChanges{All: e.changes.All, Pages: slices.Clone(e.changes.Pages)}
+}
+
+// merge 合并同一事务中的变化范围
+// 入参: change 待合并的变化
+func (c *EditorChanges) merge(change EditorChanges) {
+	if c.All {
+		return
+	}
+	if change.All {
+		c.All = true
+		c.Pages = nil
+		return
+	}
+	for _, page := range change.Pages {
+		if !slices.Contains(c.Pages, page) {
+			c.Pages = append(c.Pages, page)
+		}
+	}
 }
 
 // Transaction 将多项修改作为一次原子操作提交，失败时保留原文档及历史
@@ -37,6 +70,8 @@ func (e *Editor) Transaction(edit func(*Editor) error) error {
 	before.Info = cloneEditorData(e.Info)
 	next := e.transactionSnapshot()
 	next.history, next.historyIndex, next.historyLimit = nil, 0, 0
+	pending := &EditorChanges{}
+	next.transactionChanges = pending
 	*e = next
 	committed := false
 	defer func() {
@@ -48,6 +83,11 @@ func (e *Editor) Transaction(edit func(*Editor) error) error {
 		return err
 	}
 	changed := e.revision != before.revision
+	changes := *pending
+	if e.transactionChanges != pending {
+		changes = EditorChanges{All: true}
+	}
+	e.transactionChanges = before.transactionChanges
 	e.history, e.historyIndex, e.historyLimit = before.history, before.historyIndex, before.historyLimit
 	if !sameBackend(e.backends.FontResources, before.backends.FontResources) {
 		e.clearFontResourceCache()
@@ -62,7 +102,7 @@ func (e *Editor) Transaction(edit func(*Editor) error) error {
 	}
 	if changed {
 		e.serial, e.revision = before.serial, before.revision
-		e.recordTransaction(before)
+		e.recordTransaction(before, changes)
 	}
 	committed = true
 	return nil
@@ -108,6 +148,7 @@ func (e *Editor) Undo() bool {
 	e.historyIndex--
 	change := e.history[e.historyIndex]
 	change.undo(e)
+	e.changes, e.objectIndex = change.changes, nil
 	e.revision = change.before
 	return true
 }
@@ -120,6 +161,7 @@ func (e *Editor) Redo() bool {
 	}
 	change := e.history[e.historyIndex]
 	change.redo(e)
+	e.changes, e.objectIndex = change.changes, nil
 	e.historyIndex++
 	e.revision = change.after
 	return true
@@ -132,15 +174,12 @@ func (e *Editor) Revision() uint64 {
 	return e.revision
 }
 
-// transactionSnapshot 复制可变容器，保留只读XML、图元及二进制资源的共享
+// transactionSnapshot 复制顶层容器，共享按替换方式更新的页面图层、图元和二进制资源
 // 返回: Editor 独立事务状态
 func (e *Editor) transactionSnapshot() Editor {
 	next := *e
 	next.Info = cloneEditorData(e.Info)
-	next.pages = make([]PageContent, len(e.pages))
+	next.pages = slices.Clone(e.pages)
-	for i, page := range e.pages {
-		next.pages[i] = copyEditorPage(page)
-	}
 	next.resources = slices.Clone(e.resources)
 	next.fonts, next.images, next.resourceID = maps.Clone(e.fonts), maps.Clone(e.images), maps.Clone(e.resourceID)
 	next.origins = maps.Clone(e.origins)
@@ -213,9 +252,13 @@ func (e *Editor) retainDocumentResources(source *Editor) {
 }
 
 // recordTransaction 记录事务快照，在各自资源视图中保留后续注册的资源
-// 入参: before 修改前的文档状态
+// 入参: before 修改前的文档状态, changes 可选的事务变化范围
-func (e *Editor) recordTransaction(before Editor) {
+func (e *Editor) recordTransaction(before Editor, changes ...EditorChanges) {
-	if change := e.recordChange(); change != nil {
+	scope := EditorChanges{All: true}
+	if len(changes) != 0 {
+		scope = changes[0]
+	}
+	if change := e.recordChangeScope(scope); change != nil {
 		after := e.transactionSnapshot()
 		before.history, after.history = nil, nil
 		change.undo = func(e *Editor) {
@@ -230,10 +273,23 @@ func (e *Editor) recordTransaction(before Editor) {
 }
 
 // recordChange 分配修订标识并为已完成的有效修改预留记录
+// 入参: pages 受影响页码，省略表示全局变化
 // 返回: *editorChange 记录，未启用历史时为nil
-func (e *Editor) recordChange() *editorChange {
+func (e *Editor) recordChange(pages ...int) *editorChange {
+	return e.recordChangeScope(EditorChanges{All: len(pages) == 0, Pages: slices.Clone(pages)})
+}
+
+// recordChangeScope 分配修订并记录变更范围，事务中同步合并
+// 入参: scope 变更范围
+// 返回: *editorChange 可补充回放操作的记录
+func (e *Editor) recordChangeScope(scope EditorChanges) *editorChange {
+	e.objectIndex = nil
+	e.changes = scope
+	if e.transactionChanges != nil {
+		e.transactionChanges.merge(scope)
+	}
 	e.serial++
-	change := editorChange{before: e.revision, after: e.serial}
+	change := editorChange{before: e.revision, after: e.serial, changes: scope}
 	e.revision = e.serial
 	if e.historyLimit == 0 {
 		return nil

ofdgo_writer.go

@@ -791,6 +791,14 @@ func (e *Editor) writePartsWithPages(ctx context.Context, write func(string, []b
 	return nil
 }
 
+// editorResourceSelection 保存单次输出中同一编辑快照的资源筛选结果
+type editorResourceSelection struct {
+	owner         *Editor
+	fonts, images []editorResource
+	spaces        []ColorSpace
+	files         map[string]bool
+}
+
 // usedResources 沿图层、对象及资源依赖筛选新增资源和共享文件，不修改资源池
 // 入参: ctx 取消上下文
 // 返回: []editorResource 新增字体, []editorResource 新增图片, []ColorSpace 新增颜色空间, map[string]bool 独立资源文件集合, error 取消错误
@@ -798,6 +806,10 @@ func (e *Editor) usedResources(ctx context.Context) (fonts, images []editorResou
 	if err := ctx.Err(); err != nil {
 		return nil, nil, nil, nil, err
 	}
+	if e.output != nil && e.output.resources != nil && e.output.resources.owner == e {
+		cached := e.output.resources
+		return slices.Clone(cached.fonts), slices.Clone(cached.images), slices.Clone(cached.spaces), maps.Clone(cached.files), nil
+	}
 	used := make(map[string]bool)
 	promoted := make(map[string]bool)
 	files := make(map[string]bool)
@@ -945,6 +957,9 @@ func (e *Editor) usedResources(ctx context.Context) (fonts, images []editorResou
 	if err := ctx.Err(); err != nil {
 		return nil, nil, nil, nil, err
 	}
+	if e.output != nil {
+		e.output.resources = &editorResourceSelection{owner: e, fonts: slices.Clone(fonts), images: slices.Clone(images), spaces: slices.Clone(spaces), files: maps.Clone(files)}
+	}
 	return fonts, images, spaces, files, nil
 }