gopdf/template_impl.go

304 lines
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Go
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2021-03-02 13:27:45 +01:00
package gofpdf
import (
"bytes"
"crypto/sha1"
"encoding/gob"
"errors"
"fmt"
)
/*
* Copyright (c) 2015 Kurt Jung (Gmail: kurt.w.jung),
* Marcus Downing, Jan Slabon (Setasign)
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
// newTpl creates a template, copying graphics settings from a template if one is given
func newTpl(corner PointType, size SizeType, orientationStr, unitStr, fontDirStr string, fn func(*Tpl), copyFrom *Fpdf) Template {
sizeStr := ""
fpdf := fpdfNew(orientationStr, unitStr, sizeStr, fontDirStr, size)
tpl := Tpl{*fpdf}
if copyFrom != nil {
tpl.loadParamsFromFpdf(copyFrom)
}
tpl.Fpdf.AddPage()
fn(&tpl)
bytes := make([][]byte, len(tpl.Fpdf.pages))
// skip the first page as it will always be empty
for x := 1; x < len(bytes); x++ {
bytes[x] = tpl.Fpdf.pages[x].Bytes()
}
templates := make([]Template, 0, len(tpl.Fpdf.templates))
for _, key := range templateKeyList(tpl.Fpdf.templates, true) {
templates = append(templates, tpl.Fpdf.templates[key])
}
images := tpl.Fpdf.images
template := FpdfTpl{corner, size, bytes, images, templates, tpl.Fpdf.page}
return &template
}
// FpdfTpl is a concrete implementation of the Template interface.
type FpdfTpl struct {
corner PointType
size SizeType
bytes [][]byte
images map[string]*ImageInfoType
templates []Template
page int
}
// ID returns the global template identifier
func (t *FpdfTpl) ID() string {
return fmt.Sprintf("%x", sha1.Sum(t.Bytes()))
}
// Size gives the bounding dimensions of this template
func (t *FpdfTpl) Size() (corner PointType, size SizeType) {
return t.corner, t.size
}
// Bytes returns the actual template data, not including resources
func (t *FpdfTpl) Bytes() []byte {
return t.bytes[t.page]
}
// FromPage creates a new template from a specific Page
func (t *FpdfTpl) FromPage(page int) (Template, error) {
// pages start at 1
if page == 0 {
return nil, errors.New("Pages start at 1 No template will have a page 0")
}
if page > t.NumPages() {
return nil, fmt.Errorf("The template does not have a page %d", page)
}
// if it is already pointing to the correct page
// there is no need to create a new template
if t.page == page {
return t, nil
}
t2 := *t
t2.page = page
return &t2, nil
}
// FromPages creates a template slice with all the pages within a template.
func (t *FpdfTpl) FromPages() []Template {
p := make([]Template, t.NumPages())
for x := 1; x <= t.NumPages(); x++ {
// the only error is when accessing a
// non existing template... that can't happen
// here
p[x-1], _ = t.FromPage(x)
}
return p
}
// Images returns a list of the images used in this template
func (t *FpdfTpl) Images() map[string]*ImageInfoType {
return t.images
}
// Templates returns a list of templates used in this template
func (t *FpdfTpl) Templates() []Template {
return t.templates
}
// NumPages returns the number of available pages within the template. Look at FromPage and FromPages on access to that content.
func (t *FpdfTpl) NumPages() int {
// the first page is empty to
// make the pages begin at one
return len(t.bytes) - 1
}
// Serialize turns a template into a byte string for later deserialization
func (t *FpdfTpl) Serialize() ([]byte, error) {
b := new(bytes.Buffer)
enc := gob.NewEncoder(b)
err := enc.Encode(t)
return b.Bytes(), err
}
// DeserializeTemplate creaties a template from a previously serialized
// template
func DeserializeTemplate(b []byte) (Template, error) {
tpl := new(FpdfTpl)
dec := gob.NewDecoder(bytes.NewBuffer(b))
err := dec.Decode(tpl)
return tpl, err
}
// childrenImages returns the next layer of children images, it doesn't dig into
// children of children. Applies template namespace to keys to ensure
// no collisions. See UseTemplateScaled
func (t *FpdfTpl) childrenImages() map[string]*ImageInfoType {
childrenImgs := make(map[string]*ImageInfoType)
for x := 0; x < len(t.templates); x++ {
imgs := t.templates[x].Images()
for key, val := range imgs {
name := sprintf("t%s-%s", t.templates[x].ID(), key)
childrenImgs[name] = val
}
}
return childrenImgs
}
// childrensTemplates returns the next layer of children templates, it doesn't dig into
// children of children.
func (t *FpdfTpl) childrensTemplates() []Template {
childrenTmpls := make([]Template, 0)
for x := 0; x < len(t.templates); x++ {
tmpls := t.templates[x].Templates()
childrenTmpls = append(childrenTmpls, tmpls...)
}
return childrenTmpls
}
// GobEncode encodes the receiving template into a byte buffer. Use GobDecode
// to decode the byte buffer back to a template.
func (t *FpdfTpl) GobEncode() ([]byte, error) {
w := new(bytes.Buffer)
encoder := gob.NewEncoder(w)
childrensTemplates := t.childrensTemplates()
firstClassTemplates := make([]Template, 0)
found_continue:
for x := 0; x < len(t.templates); x++ {
for y := 0; y < len(childrensTemplates); y++ {
if childrensTemplates[y].ID() == t.templates[x].ID() {
continue found_continue
}
}
firstClassTemplates = append(firstClassTemplates, t.templates[x])
}
err := encoder.Encode(firstClassTemplates)
childrenImgs := t.childrenImages()
firstClassImgs := make(map[string]*ImageInfoType)
for key, img := range t.images {
if _, ok := childrenImgs[key]; !ok {
firstClassImgs[key] = img
}
}
if err == nil {
err = encoder.Encode(firstClassImgs)
}
if err == nil {
err = encoder.Encode(t.corner)
}
if err == nil {
err = encoder.Encode(t.size)
}
if err == nil {
err = encoder.Encode(t.bytes)
}
if err == nil {
err = encoder.Encode(t.page)
}
return w.Bytes(), err
}
// GobDecode decodes the specified byte buffer into the receiving template.
func (t *FpdfTpl) GobDecode(buf []byte) error {
r := bytes.NewBuffer(buf)
decoder := gob.NewDecoder(r)
firstClassTemplates := make([]*FpdfTpl, 0)
err := decoder.Decode(&firstClassTemplates)
t.templates = make([]Template, len(firstClassTemplates))
for x := 0; x < len(t.templates); x++ {
t.templates[x] = Template(firstClassTemplates[x])
}
firstClassImages := t.childrenImages()
t.templates = append(t.childrensTemplates(), t.templates...)
t.images = make(map[string]*ImageInfoType)
if err == nil {
err = decoder.Decode(&t.images)
}
for k, v := range firstClassImages {
t.images[k] = v
}
if err == nil {
err = decoder.Decode(&t.corner)
}
if err == nil {
err = decoder.Decode(&t.size)
}
if err == nil {
err = decoder.Decode(&t.bytes)
}
if err == nil {
err = decoder.Decode(&t.page)
}
return err
}
// Tpl is an Fpdf used for writing a template. It has most of the facilities of
// an Fpdf, but cannot add more pages. Tpl is used directly only during the
// limited time a template is writable.
type Tpl struct {
Fpdf
}
func (t *Tpl) loadParamsFromFpdf(f *Fpdf) {
t.Fpdf.compress = false
t.Fpdf.k = f.k
t.Fpdf.x = f.x
t.Fpdf.y = f.y
t.Fpdf.lineWidth = f.lineWidth
t.Fpdf.capStyle = f.capStyle
t.Fpdf.joinStyle = f.joinStyle
t.Fpdf.color.draw = f.color.draw
t.Fpdf.color.fill = f.color.fill
t.Fpdf.color.text = f.color.text
t.Fpdf.fonts = f.fonts
t.Fpdf.currentFont = f.currentFont
t.Fpdf.fontFamily = f.fontFamily
t.Fpdf.fontSize = f.fontSize
t.Fpdf.fontSizePt = f.fontSizePt
t.Fpdf.fontStyle = f.fontStyle
t.Fpdf.ws = f.ws
for key, value := range f.images {
t.Fpdf.images[key] = value
}
}