Files
ofdgo/ofdgo_pdf_action.go
2026-10-21 13:03:03 +08:00

442 lines
14 KiB
Go

// 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 (
"bytes"
"context"
"encoding/xml"
"fmt"
"math"
"strconv"
codecpdf "github.com/xiaoqidun/ofdgo/internal/codec/pdf"
"github.com/xiaoqidun/pdfgo"
)
// pdfDestinationFontBackend 禁止内容度量忽略实际绘制所需的缺失字体
type pdfDestinationFontBackend struct {
FontBackend
}
// 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 {
raw, err := p.pdfCatalogObject("OpenAction")
if err != nil {
return err
}
opened, err := p.reader.ReadOpenAction(ctx)
if err != nil {
if err := p.recoverPDFObject(ctx, "OpenAction", raw, err); err != nil {
return 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, raw)
if err != nil {
return err
}
if err := p.editor.SetDocumentActions(actions); err != nil {
return err
}
triggers, err := p.reader.ReadDocumentTriggers(ctx)
if err != nil {
object, readErr := p.pdfCatalogObject("AA")
if readErr != nil {
return readErr
}
return p.recoverPDFObject(ctx, "Document.AA", object, err)
}
for _, trigger := range triggers {
if _, err := p.reader.ReadJavaScriptAction(ctx, trigger.Action); err != nil {
if err := p.recoverPDFObject(ctx, "Document.AA."+string(trigger.Event), trigger.Action, err); err != nil {
return err
}
continue
}
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 p.recoverPDFObject(ctx, "Page.AA", page.Dictionary["AA"], 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, original 可选原始来源
// 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, original ...pdfgo.Object) ([]Action, error) {
raw := object
if len(original) != 0 {
raw = original[0]
}
retained, warned := false, false
warning := p.warning
if warning != nil {
p.warning = func(diagnostic pdfgo.Diagnostic) {
warned = true
warning(diagnostic)
}
defer func() { p.warning = warning }()
}
retain := func(cause error) error {
if cause != nil && (p.warning == nil || !pdfAuxiliaryError(cause)) {
return cause
}
if retained {
if cause != nil {
p.warning(pdfgo.Diagnostic{Message: "PDF Action." + event + " retained as metadata: " + cause.Error()})
}
return ctx.Err()
}
var err error
if cause != nil {
err = p.recoverPDFObject(ctx, "Action."+event, raw, cause)
} else if p.warning != nil {
err = p.preservePDFObject(ctx, "Action."+event, raw)
}
retained = err == nil
return err
}
var actions []Action
var conversionErr error
err := p.reader.WalkActions(ctx, object, func(info pdfgo.ActionInfo) error {
annotation := source
annotation.Dictionary = pdfgo.Dictionary{"A": info.Dictionary}
warned = false
warnings := len(p.report.Warnings)
converted, err := p.convertLinkActions(annotation, p.warning == nil, currentPage)
if err != nil {
conversionErr = retain(err)
*currentPage = -1
return conversionErr
}
if p.warning != nil && (converted == nil || warned || len(p.report.Warnings) != warnings) {
if err := retain(nil); err != nil {
conversionErr = err
return err
}
}
for _, action := range converted {
action.Event = event
actions = append(actions, action)
}
return nil
})
if conversionErr != nil {
return nil, conversionErr
}
if err != nil {
if err := retain(err); err != nil {
return nil, err
}
*currentPage = -1
}
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 p.recoverPDFObject(ctx, owner+".AA."+string(trigger.Event), trigger.Action, err)
}
feature := owner + " trigger " + string(trigger.Event)
return p.recoverPDFObject(ctx, owner+".AA."+string(trigger.Event), trigger.Action, &pdfgo.UnsupportedError{Feature: feature})
}
// 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, p.recoverPDFObject(ctx, "Annotation.AA", annotation.Dictionary["AA"], 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:
if err := p.unmappedTrigger(ctx, "annotation", trigger); err != nil {
return nil, err
}
continue
}
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()
}
// ResolveFont 沿用字体匹配,只在实际绘制缺少字体数据时中止度量
// 入参: renderer 度量渲染器, id 字体标识, exact 是否禁止无关回退
// 返回: ResolvedFont 字体资源, error 解析或缺失错误
func (b pdfDestinationFontBackend) ResolveFont(renderer *Renderer, id string, exact bool) (ResolvedFont, error) {
font, err := b.FontBackend.ResolveFont(renderer, id, exact)
if err == nil && len(font.Data) == 0 {
err = fmt.Errorf("PDF destination font %q unavailable", id)
}
return font, err
}
// destinationBounds 度量目标页内容并缓存页面内范围,不包含注解或像素取整
// 入参: page PDF目标页
// 返回: Box OFD内容范围, error 度量错误
func (p *pdfImporter) destinationBounds(page *pdfgo.Page) (Box, error) {
if err := p.ctx.Err(); err != nil {
return Box{}, err
}
if box, ok := p.destinationBoxes[page.Reference]; ok {
return box, nil
}
if index, ok := p.pageIndexes[page.Reference]; ok {
previous := p.page
p.page = index
defer func() { p.page = previous }()
}
matrix, width, height := codecpdf.PageMatrix(page)
editor := NewEditor()
editor.SetResources(p.resources)
editor.SetRenderBackends(p.editor.Backends())
editor.SetFontDirs(p.editor.fontDirs...)
editor.SetFontFS(p.editor.fontFS...)
editor.fontSourcesCache = p.renderer.fontSourcesCache
editor.validatedPaths = p.editor.pathValidationCache()
if _, err := editor.AddPage(width, height); err != nil {
return Box{}, err
}
local := pdfImporter{
resources: p.resources,
ctx: p.ctx, reader: p.reader, editor: editor, renderer: p.renderer,
warning: p.warning,
matrix: matrix, pageBox: page.CropBox, pageWidth: width, pageHeight: height,
rasterDPI: p.rasterDPI, fontIDs: make(map[*pdfgo.Font]string),
resolveFile: p.resolveFile, resolveReference: p.resolveReference,
references: &codecpdf.ReferenceCache{},
halftones: p.halftones, halftoneWarnings: make(map[*pdfgo.Halftone]bool),
}
defer local.references.Close()
if err := local.compositePage(nil, func(visitor pdfgo.Visitor) error {
return p.reader.WalkPage(p.ctx, page, visitor)
}); err != nil {
return Box{}, fmt.Errorf("PDF destination content: %w", err)
}
if err := local.commitObjects(); err != nil {
return Box{}, err
}
reader, err := local.temporaryReader()
if err != nil {
return Box{}, err
}
defer reader.Close()
renderer := p.renderer.childRenderer(reader)
renderer.TransparentBackground = true
renderer.RenderAnnotations = false
if renderer.backends.Fonts != nil {
renderer.backends.Fonts = pdfDestinationFontBackend{renderer.backends.Fonts}
}
scene, err := renderer.CompilePageContext(p.ctx, &editor.pages[0])
if err != nil {
return Box{}, err
}
if scene == nil {
return Box{}, fmt.Errorf("PDF destination content scene unavailable")
}
geometry, err := renderer.Geometry()
if err != nil {
return Box{}, err
}
box, err := scene.BoundsContext(p.ctx, geometry)
if err != nil {
return Box{}, err
}
left, top := math.Max(0, box.X), math.Max(0, box.Y)
right, bottom := math.Min(width, box.X+box.W), math.Min(height, box.Y+box.H)
box = Box{X: left, Y: top, W: right - left, H: bottom - top}
if !finite(left) || !finite(top) || !finite(right) || !finite(bottom) || box.W <= 0 || box.H <= 0 {
return Box{}, fmt.Errorf("PDF destination content bounds empty or invalid")
}
if err := p.ctx.Err(); err != nil {
return Box{}, err
}
if p.destinationBoxes == nil {
p.destinationBoxes = make(map[pdfgo.Reference]Box)
}
p.destinationBoxes[page.Reference] = box
return box, nil
}
// outlines 按先序批量转换目录,保留层级、展开状态和动作顺序
// 入参: ctx 取消上下文
// 返回: error 严格模式转换错误或取消错误
func (p *pdfImporter) outlines(ctx context.Context) error {
count := 0
var conversionErr error
data, err := encodeOFDXMLContext(ctx, func(x *ofdXML) {
x.root("Outlines", nil)
depth := 0
err := p.reader.WalkOutlines(ctx, func(level int, item pdfgo.OutlineItem) error {
actions, err := p.outlineActions(ctx, item)
if err != nil {
conversionErr = err
return err
}
for depth > level {
x.end("OutlineElem")
depth--
}
attrs := ofdAttrs{{Name: xml.Name{Local: "Title"}, Value: item.Title}}
attrs.add("Expanded", strconv.FormatBool(item.Expanded))
x.start("OutlineElem", attrs)
x.actions(actions)
depth++
count++
return x.err
})
if err != nil {
x.err = err
return
}
for depth > 0 {
x.end("OutlineElem")
depth--
}
x.end("Outlines")
})
if conversionErr != nil {
return conversionErr
}
if err != nil {
if ctx.Err() != nil {
return ctx.Err()
}
if p.warning == nil || !pdfAuxiliaryError(err) {
return err
}
object, readErr := p.pdfCatalogObject("Outlines")
if readErr != nil {
return readErr
}
return p.recoverPDFObject(ctx, "Outlines", object, err)
}
if count > 0 {
p.editor.outlines = bytes.TrimPrefix(data, []byte(xml.Header))
}
return nil
}
// outlineActions 转换目录目标及动作链,不为无目标节点补充跳转
// 入参: ctx 取消上下文, item PDF目录节点
// 返回: []Action OFD动作序列, error 动作或取消错误
func (p *pdfImporter) outlineActions(ctx context.Context, item pdfgo.OutlineItem) ([]Action, error) {
raw := item.Action
object, err := p.reader.Resolve(item.Action)
if err != nil {
return nil, p.recoverPDFObject(ctx, "Outline.A", item.Action, err)
}
dest, err := p.reader.Resolve(item.Destination)
if err != nil {
return nil, p.recoverPDFObject(ctx, "Outline.Dest", item.Destination, err)
}
if dest != nil {
if object != nil {
return nil, p.recoverPDFObject(ctx, "Outline", pdfgo.Dictionary{"A": item.Action, "Dest": item.Destination}, fmt.Errorf("PDF outline has both destination and action"))
}
object = pdfgo.Dictionary{"S": pdfgo.Name("GoTo"), "D": dest}
raw = item.Destination
}
currentPage := -1
return p.eventActions(ctx, object, "CLICK", pdfgo.Annotation{}, &currentPage, raw)
}