mirror of
https://github.com/unidoc/unipdf.git
synced 2025-04-26 13:48:55 +08:00
133 lines
3.9 KiB
Go
133 lines
3.9 KiB
Go
/*
|
|
* This file is subject to the terms and conditions defined in
|
|
* file 'LICENSE.md', which is part of this source code package.
|
|
*/
|
|
|
|
package annotator
|
|
|
|
import (
|
|
"github.com/unidoc/unipdf/v3/common"
|
|
|
|
"github.com/unidoc/unipdf/v3/contentstream/draw"
|
|
pdfcore "github.com/unidoc/unipdf/v3/core"
|
|
pdf "github.com/unidoc/unipdf/v3/model"
|
|
)
|
|
|
|
type CircleAnnotationDef struct {
|
|
X float64
|
|
Y float64
|
|
Width float64
|
|
Height float64
|
|
FillEnabled bool // Show fill?
|
|
FillColor *pdf.PdfColorDeviceRGB
|
|
BorderEnabled bool // Show border?
|
|
BorderWidth float64
|
|
BorderColor *pdf.PdfColorDeviceRGB
|
|
Opacity float64 // Alpha value (0-1).
|
|
}
|
|
|
|
// CreateCircleAnnotation creates a circle/ellipse annotation object with appearance stream that can be added to
|
|
// page PDF annotations.
|
|
func CreateCircleAnnotation(circDef CircleAnnotationDef) (*pdf.PdfAnnotation, error) {
|
|
circAnnotation := pdf.NewPdfAnnotationCircle()
|
|
|
|
if circDef.BorderEnabled {
|
|
r, g, b := circDef.BorderColor.R(), circDef.BorderColor.G(), circDef.BorderColor.B()
|
|
circAnnotation.C = pdfcore.MakeArrayFromFloats([]float64{r, g, b})
|
|
bs := pdf.NewBorderStyle()
|
|
bs.SetBorderWidth(circDef.BorderWidth)
|
|
circAnnotation.BS = bs.ToPdfObject()
|
|
}
|
|
|
|
if circDef.FillEnabled {
|
|
r, g, b := circDef.FillColor.R(), circDef.FillColor.G(), circDef.FillColor.B()
|
|
circAnnotation.IC = pdfcore.MakeArrayFromFloats([]float64{r, g, b})
|
|
} else {
|
|
circAnnotation.IC = pdfcore.MakeArrayFromIntegers([]int{}) // No fill.
|
|
}
|
|
|
|
if circDef.Opacity < 1.0 {
|
|
circAnnotation.CA = pdfcore.MakeFloat(circDef.Opacity)
|
|
}
|
|
|
|
// Make the appearance stream (for uniform appearance).
|
|
apDict, bbox, err := makeCircleAnnotationAppearanceStream(circDef)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
circAnnotation.AP = apDict
|
|
circAnnotation.Rect = pdfcore.MakeArrayFromFloats([]float64{bbox.Llx, bbox.Lly, bbox.Urx, bbox.Ury})
|
|
|
|
return circAnnotation.PdfAnnotation, nil
|
|
|
|
}
|
|
|
|
func makeCircleAnnotationAppearanceStream(circDef CircleAnnotationDef) (*pdfcore.PdfObjectDictionary, *pdf.PdfRectangle, error) {
|
|
form := pdf.NewXObjectForm()
|
|
form.Resources = pdf.NewPdfPageResources()
|
|
|
|
gsName := ""
|
|
if circDef.Opacity < 1.0 {
|
|
// Create graphics state with right opacity.
|
|
gsState := pdfcore.MakeDict()
|
|
gsState.Set("ca", pdfcore.MakeFloat(circDef.Opacity))
|
|
gsState.Set("CA", pdfcore.MakeFloat(circDef.Opacity))
|
|
err := form.Resources.AddExtGState("gs1", gsState)
|
|
if err != nil {
|
|
common.Log.Debug("Unable to add extgstate gs1")
|
|
return nil, nil, err
|
|
}
|
|
|
|
gsName = "gs1"
|
|
}
|
|
|
|
content, localBbox, globalBbox, err := drawPdfCircle(circDef, gsName)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
err = form.SetContentStream(content, nil)
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
|
|
// Local bounding box for the XObject Form.
|
|
form.BBox = localBbox.ToPdfObject()
|
|
|
|
apDict := pdfcore.MakeDict()
|
|
apDict.Set("N", form.ToPdfObject())
|
|
|
|
return apDict, globalBbox, nil
|
|
}
|
|
|
|
func drawPdfCircle(circDef CircleAnnotationDef, gsName string) ([]byte, *pdf.PdfRectangle, *pdf.PdfRectangle, error) {
|
|
// The annotation is drawn locally in a relative coordinate system with 0,0 as the origin rather than an offset.
|
|
circle := draw.Circle{
|
|
X: circDef.X,
|
|
Y: circDef.Y,
|
|
Width: circDef.Width,
|
|
Height: circDef.Height,
|
|
FillEnabled: circDef.FillEnabled,
|
|
FillColor: circDef.FillColor,
|
|
BorderEnabled: circDef.BorderEnabled,
|
|
BorderWidth: circDef.BorderWidth,
|
|
BorderColor: circDef.BorderColor,
|
|
Opacity: circDef.Opacity,
|
|
}
|
|
|
|
content, localBbox, err := circle.Draw(gsName)
|
|
if err != nil {
|
|
return nil, nil, nil, err
|
|
}
|
|
|
|
// Bounding box - global page coordinate system (with offset).
|
|
globalBbox := &pdf.PdfRectangle{}
|
|
globalBbox.Llx = circDef.X + localBbox.Llx
|
|
globalBbox.Lly = circDef.Y + localBbox.Lly
|
|
globalBbox.Urx = circDef.X + localBbox.Urx
|
|
globalBbox.Ury = circDef.Y + localBbox.Ury
|
|
|
|
return content, localBbox, globalBbox, nil
|
|
}
|