feat(文件归并): 归并PDF适配与解析逻辑

ofdgo_pdf_action.go

@@ -0,0 +1,209 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// documentOpenActions 转换文档初始目标与打开动作，不执行脚本或打开资源
+// 入参: ctx 取消上下文
+// 返回: error 动作、编码或取消错误
+func (p *pdfImporter) documentOpenActions(ctx context.Context) error {
+	opened, err := p.reader.ReadOpenAction(ctx)
+	if err != nil {
+		if p.warning == nil || !errors.Is(err, pdfgo.ErrInvalidDestination) {
+			return err
+		}
+		p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("invalid PDF initial destination ignored: %v", err)})
+	}
+	var object pdfgo.Object
+	if opened.Action != nil {
+		object = opened.Action
+	}
+	if dest := opened.Destination; dest != nil {
+		array := append(pdfgo.Array{dest.Page, dest.Mode}, dest.Parameters...)
+		object = pdfgo.Dictionary{"S": pdfgo.Name("GoTo"), "D": array}
+	}
+	currentPage := 0
+	actions, err := p.eventActions(ctx, object, "DO", pdfgo.Annotation{}, &currentPage)
+	if err != nil {
+		return err
+	}
+	if err := p.editor.SetDocumentActions(actions); err != nil {
+		return err
+	}
+	triggers, err := p.reader.ReadDocumentTriggers(ctx)
+	if err != nil {
+		return err
+	}
+	for _, trigger := range triggers {
+		if _, err := p.reader.ReadJavaScriptAction(ctx, trigger.Action); err != nil {
+			return err
+		}
+		if err := p.unmappedTrigger(ctx, "document", trigger); err != nil {
+			return err
+		}
+	}
+	return ctx.Err()
+}
+
+// pageOpenActions 将页面打开动作放在注解打开动作之前，关闭事件不改为打开事件
+// 入参: ctx 取消上下文, page PDF页面
+// 返回: error 事件、动作或取消错误
+func (p *pdfImporter) pageOpenActions(ctx context.Context, page *pdfgo.Page) error {
+	p.pageActionPage = p.page
+	triggers, err := p.reader.ReadPageTriggers(ctx, page)
+	if err != nil {
+		return err
+	}
+	for _, trigger := range triggers {
+		if trigger.Event != "O" {
+			if err := p.unmappedTrigger(ctx, "page", trigger); err != nil {
+				return err
+			}
+			continue
+		}
+		actions, err := p.eventActions(ctx, trigger.Action, "PO", pdfgo.Annotation{}, &p.pageActionPage)
+		if err != nil {
+			return err
+		}
+		if err := p.editor.SetPageActions(p.page, actions); err != nil {
+			return err
+		}
+	}
+	return ctx.Err()
+}
+
+// eventActions 按原顺序转换动作链，保留事件类型与链内跳转页状态
+// 入参: ctx 取消上下文, object 动作对象, event OFD事件, source 触发注解，零值表示非图元动作, currentPage 当前页面
+// 返回: []Action 转换动作, error 动作或取消错误
+func (p *pdfImporter) eventActions(ctx context.Context, object pdfgo.Object, event string, source pdfgo.Annotation, currentPage *int) ([]Action, error) {
+	var actions []Action
+	err := p.reader.WalkActions(ctx, object, func(info pdfgo.ActionInfo) error {
+		annotation := source
+		annotation.Dictionary = pdfgo.Dictionary{"A": info.Dictionary}
+		converted, err := p.linkActions(annotation, p.warning == nil, currentPage)
+		if err != nil {
+			if errors.Is(err, errPDFMediaRead) {
+				return err
+			}
+			var unsupported *pdfgo.UnsupportedError
+			if event != "CLICK" && p.warning != nil && errors.Is(err, pdfgo.ErrInvalidAction) {
+				p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("invalid PDF %s action ignored: %v", event, err)})
+				return nil
+			}
+			if event != "CLICK" && p.warning != nil && errors.Is(err, pdfgo.ErrInvalidDestination) {
+				p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("invalid PDF %s destination ignored: %v", event, err)})
+				return nil
+			}
+			if event != "CLICK" && p.warning != nil && errors.As(err, &unsupported) {
+				p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("PDF %s action not transferred to OFD: %s", event, unsupported.Feature)})
+				return nil
+			}
+			return err
+		}
+		for _, action := range converted {
+			action.Event = event
+			actions = append(actions, action)
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return actions, ctx.Err()
+}
+
+// unmappedTrigger 校验无法映射的事件链，按导入策略报告而不改变触发条件
+// 入参: ctx 取消上下文, owner 事件归属, trigger PDF事件
+// 返回: error 动作链、取消或严格模式错误
+func (p *pdfImporter) unmappedTrigger(ctx context.Context, owner string, trigger pdfgo.ActionTrigger) error {
+	if err := p.reader.WalkActions(ctx, trigger.Action, func(pdfgo.ActionInfo) error { return nil }); err != nil {
+		return err
+	}
+	feature := owner + " trigger " + string(trigger.Event)
+	if p.warning == nil {
+		return &pdfgo.UnsupportedError{Feature: feature}
+	}
+	p.warning(pdfgo.Diagnostic{Message: "PDF " + feature + " not transferred to OFD"})
+	return nil
+}
+
+// annotationTriggerActions 按事件转换注解动作，页面打开动作独立于注解外观
+// 入参: ctx 取消上下文, annotation PDF注解, event OFD事件
+// 返回: []Action 动作序列, error 事件、动作或取消错误
+func (p *pdfImporter) annotationTriggerActions(ctx context.Context, annotation pdfgo.Annotation, event string) ([]Action, error) {
+	if annotation.Subtype == "Widget" && event == "CLICK" {
+		return nil, ctx.Err()
+	}
+	triggers, err := p.reader.ReadAnnotationTriggers(ctx, annotation)
+	if err != nil {
+		return nil, err
+	}
+	if len(triggers) == 0 {
+		return nil, ctx.Err()
+	}
+	flags, err := p.reader.ReadAnnotationFlags(annotation)
+	if err != nil {
+		return nil, err
+	}
+	var converted []Action
+	for _, trigger := range triggers {
+		if trigger.Event == "PC" || trigger.Event == "PV" || trigger.Event == "PI" {
+			if event == "PO" {
+				if err := p.unmappedTrigger(ctx, "annotation", trigger); err != nil {
+					return nil, err
+				}
+			}
+			continue
+		}
+		if (trigger.Event == "PO") != (event == "PO") {
+			continue
+		}
+		if flags&64 != 0 && (trigger.Event == "E" || trigger.Event == "X" || trigger.Event == "D" || trigger.Event == "U") {
+			continue
+		}
+		switch trigger.Event {
+		case "U", "PO":
+		default:
+			return nil, &pdfgo.UnsupportedError{Feature: "annotation trigger " + string(trigger.Event)}
+		}
+		currentPage := p.page
+		if event == "PO" {
+			currentPage = p.pageActionPage
+		}
+		var source pdfgo.Annotation
+		if event == "CLICK" {
+			source = annotation
+		}
+		actions, err := p.eventActions(ctx, trigger.Action, event, source, &currentPage)
+		if err != nil {
+			return nil, err
+		}
+		converted = append(converted, actions...)
+		if event == "PO" {
+			p.pageActionPage = currentPage
+		}
+	}
+	if event == "PO" && len(converted) != 0 && (p.page < 0 || p.page >= len(p.editor.pages)) {
+		return nil, fmt.Errorf("invalid annotation trigger page")
+	}
+	return converted, ctx.Err()
+}