Files
ofdgo/ofdgo_pdf_action.go
T
2026-10-19 10:10:27 +08:00

414 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"
"errors"
"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 {
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()
}
// 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.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{
ctx: p.ctx, reader: p.reader, editor: editor, renderer: p.renderer,
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 := editor.resourceReader()
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
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 {
if p.warning == nil || ctx.Err() != nil || errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) || errors.Is(err, errPDFMediaRead) {
return err
}
p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("PDF outline %q actions not transferred to OFD: %v", item.Title, err)})
actions = nil
}
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 err != nil {
if ctx.Err() != nil {
return ctx.Err()
}
if p.warning == nil || errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) || errors.Is(err, errPDFMediaRead) {
return err
}
p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("PDF outlines not transferred to OFD: %v", err)})
return nil
}
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) {
object, err := p.reader.Resolve(item.Action)
if err != nil {
return nil, err
}
dest, err := p.reader.Resolve(item.Destination)
if err != nil {
return nil, err
}
if dest != nil {
if object != nil {
return nil, fmt.Errorf("PDF outline has both destination and action")
}
object = pdfgo.Dictionary{"S": pdfgo.Name("GoTo"), "D": dest}
}
currentPage := -1
var actions []Action
err = p.reader.WalkActions(ctx, object, func(info pdfgo.ActionInfo) error {
converted, err := p.linkActions(pdfgo.Annotation{Dictionary: pdfgo.Dictionary{"A": info.Dictionary}}, p.warning == nil, &currentPage)
if err != nil {
if errors.Is(err, errPDFMediaRead) {
return err
}
var unsupported *pdfgo.UnsupportedError
if p.warning != nil && (errors.As(err, &unsupported) || errors.Is(err, pdfgo.ErrInvalidDestination) || errors.Is(err, pdfgo.ErrInvalidAction)) {
p.warning(pdfgo.Diagnostic{Message: fmt.Sprintf("PDF outline action not transferred to OFD: %v", err)})
currentPage = -1
return nil
}
return err
}
if converted != nil {
actions = append(actions, converted...)
} else {
currentPage = -1
}
return nil
})
return actions, err
}