feat(编辑能力): 完善保存另存与后台编辑

internal/webui/webui.go

@@ -419,6 +419,7 @@ type outputContext struct {
 type businessEngine struct {
 	currentSession *Session
 	currentEditor  *ofdgo.Editor
+	saveSnapshot   *ofdgo.Editor
 	pendingImport  *ofdgo.Reader
 	copiedObjects  *editorClipboard
 	copiedStyle    *ofdgo.GraphicObject
@@ -7162,6 +7163,54 @@ func (e *businessEngine) saveSigned(args []platformValue) (any, error) {
 	return successResult(map[string]any{"mime": "application/ofd", "label": "OFD"}), nil
 }
 
+// prepareSave 创建独立保存快照，后续写出不占用当前编辑文档
+// 入参: args 取消检查回调
+// 返回: any 快照修订, error 准备错误
+func (e *businessEngine) prepareSave(args []platformValue) (any, error) {
+	e.saveSnapshot = nil
+	editor := e.currentEditor
+	if editor == nil {
+		if e.currentSession == nil {
+			return nil, fmt.Errorf("ofd document is not opened")
+		}
+		var err error
+		editor, err = e.currentSession.Reader.Editor()
+		if err != nil {
+			return nil, err
+		}
+	}
+	ctx := e.operationContext()
+	if len(args) > 0 {
+		ctx = e.newOutputContext(args[0])
+	}
+	snapshot, err := editor.Snapshot(ctx)
+	if err != nil {
+		return nil, err
+	}
+	e.saveSnapshot = snapshot
+	return successResult(map[string]any{"revision": editor.Revision()}), nil
+}
+
+// savePrepared 写出并释放已准备的快照，不修改当前编辑状态
+// 入参: args 写出回调、进度回调及输出配置
+// 返回: any 保存结果, error 保存错误
+func (e *businessEngine) savePrepared(args []platformValue) (any, error) {
+	snapshot := e.saveSnapshot
+	e.saveSnapshot = nil
+	if snapshot == nil {
+		return nil, fmt.Errorf("save snapshot is not prepared")
+	}
+	return e.saveEditor(snapshot, args)
+}
+
+// discardSave 释放尚未写出的保存快照
+// 入参: args 空参数
+// 返回: any 操作结果, error 错误信息
+func (e *businessEngine) discardSave(args []platformValue) (any, error) {
+	e.saveSnapshot = nil
+	return successResult(nil), nil
+}
+
 // saveDocument 分块写出当前编辑文档或指定页面
 // 入参: args 数据写出回调、可选准备进度回调和可选页面索引
 // 返回: any 保存结果, error 错误信息
@@ -7403,6 +7452,9 @@ func (e *businessEngine) businessCommands() map[string]func([]platformValue) (an
 		"ofdgoUndo":                   func([]platformValue) (any, error) { return e.restoreEditor(false) },
 		"ofdgoRedo":                   func([]platformValue) (any, error) { return e.restoreEditor(true) },
 		"ofdgoSaveDocument":           e.saveDocument,
+		"ofdgoPrepareSave":            e.prepareSave,
+		"ofdgoSaveSnapshot":           e.savePrepared,
+		"ofdgoDiscardSave":            e.discardSave,
 		"ofdgoSetEncryption":          e.setEncryption,
 		"ofdgoSaveSigned":             e.saveSigned,
 		"ofdgoPreviewSignatureSeal":   e.previewSignatureSeal,

internal/webui/webui_native.go

@@ -82,6 +82,7 @@ type NativeEngine struct {
 	CleanupOutput func(context.Context, NativeOutputTarget) error
 	gate          chan struct{}
 	once          sync.Once
+	saves         sync.WaitGroup
 	closed        bool
 }
 
@@ -149,13 +150,33 @@ func (e *NativeEngine) Call(ctx context.Context, name string, args []any, emit f
 	case <-ctx.Done():
 		return nativeFailure(ctx.Err())
 	}
-	defer func() { <-e.gate }()
+	locked := true
+	defer func() {
+		if locked {
+			<-e.gate
+		}
+	}()
 	if err := ctx.Err(); err != nil {
 		return nativeFailure(err)
 	}
 	if e.closed {
 		return nativeFailure(fmt.Errorf("native engine is closed"))
 	}
+	if name == "ofdgoSaveSnapshot" {
+		snapshot := e.saveSnapshot
+		e.saveSnapshot = nil
+		if snapshot == nil {
+			return nativeFailure(fmt.Errorf("save snapshot is not prepared"))
+		}
+		output := &NativeEngine{OpenWriter: e.OpenWriter}
+		output.currentEditor = snapshot
+		e.saves.Add(1)
+		defer e.saves.Done()
+		<-e.gate
+		locked = false
+		defer output.Close()
+		return output.Call(ctx, "ofdgoSaveDocument", args, emit)
+	}
 	e.ctx = ctx
 	if e.currentSession != nil {
 		e.currentSession.Renderer.OutputContext = ctx
@@ -219,6 +240,8 @@ func (e *NativeEngine) Close() error {
 	e.gate <- struct{}{}
 	defer func() { <-e.gate }()
 	e.closed = true
+	e.saveSnapshot = nil
+	e.saves.Wait()
 	var err error
 	if e.currentSession != nil {
 		err = e.currentSession.Close()
@@ -728,7 +751,7 @@ func (c *nativeCall) prepare(name string, args []any) ([]any, error) {
 		args = append(args, c.fileCallback(files))
 	}
 	switch name {
-	case "ofdgoResources":
+	case "ofdgoResources", "ofdgoPrepareSave":
 		return append(args, checkpoint), nil
 	case "ofdgoImportPages", "ofdgoImportDocuments", "ofdgoImportImages":
 		return append(args, c.progress("import", "", true)), nil

internal/webui/webui_wasm.go

@@ -56,6 +56,8 @@ func RunWASM() {
 		"ofdgoImportPages":      true,
 		"ofdgoImportDocuments":  true,
 		"ofdgoSaveDocument":     true,
+		"ofdgoPrepareSave":      true,
+		"ofdgoSaveSnapshot":     true,
 		"ofdgoSetEncryption":    true,
 		"ofdgoSaveSigned":       true,
 	}