Text generating operators in content creator. Some refactoring of annotator.

pdf/annotator/annotator.go

@@ -10,171 +10,8 @@ import (
 	pdf "github.com/unidoc/unidoc/pdf/model"
 )
 
-// The currently supported line ending styles are None, Arrow (ClosedArrow) and Butt.
-type LineEndingStyle int
 
-const (
-	LineEndingStyleNone  LineEndingStyle = 0
-	LineEndingStyleArrow LineEndingStyle = 1
-	LineEndingStyleButt  LineEndingStyle = 2
-)
 
-// Defines a line between point 1 (X1,Y1) and point 2 (X2,Y2).  The line ending styles can be none (regular line),
-// or arrows at either end.  The line also has a specified width, color and opacity.
-type LineAnnotationDef struct {
-	X1               float64
-	Y1               float64
-	X2               float64
-	Y2               float64
-	LineColor        *pdf.PdfColorDeviceRGB
-	Opacity          float64 // Alpha value (0-1).
-	LineWidth        float64
-	LineEndingStyle1 LineEndingStyle // Line ending style of point 1.
-	LineEndingStyle2 LineEndingStyle // Line ending style of point 2.
-}
 
-// Creates a line annotation object that can be added to page PDF annotations.
-func CreateLineAnnotation(lineDef LineAnnotationDef) (*pdf.PdfAnnotation, error) {
-	// Line annotation.
-	lineAnnotation := pdf.NewPdfAnnotationLine()
 
-	// Line endpoint locations.
-	lineAnnotation.L = pdfcore.MakeArrayFromFloats([]float64{lineDef.X1, lineDef.Y1, lineDef.X2, lineDef.Y2})
 
-	// Line endings.
-	le1 := pdfcore.MakeName("None")
-	if lineDef.LineEndingStyle1 == LineEndingStyleArrow {
-		le1 = pdfcore.MakeName("ClosedArrow")
-	}
-	le2 := pdfcore.MakeName("None")
-	if lineDef.LineEndingStyle2 == LineEndingStyleArrow {
-		le2 = pdfcore.MakeName("ClosedArrow")
-	}
-	lineAnnotation.LE = pdfcore.MakeArray(le1, le2)
-
-	// Opacity.
-	if lineDef.Opacity < 1.0 {
-		lineAnnotation.CA = pdfcore.MakeFloat(lineDef.Opacity)
-	}
-
-	r, g, b := lineDef.LineColor.R(), lineDef.LineColor.G(), lineDef.LineColor.B()
-	lineAnnotation.IC = pdfcore.MakeArrayFromFloats([]float64{r, g, b}) // fill color of line endings, rgb 0-1.
-	lineAnnotation.C = pdfcore.MakeArrayFromFloats([]float64{r, g, b})  // line color, rgb 0-1.
-	bs := pdf.NewBorderStyle()
-	bs.SetBorderWidth(lineDef.LineWidth) // Line width: 3 points.
-	lineAnnotation.BS = bs.ToPdfObject()
-
-	// Make the appearance stream (for uniform appearance).
-	apDict, bbox, err := makeLineAnnotationAppearanceStream(lineDef)
-	if err != nil {
-		return nil, err
-	}
-	lineAnnotation.AP = apDict
-
-	// The rect specifies the location and dimensions of the annotation.  Technically if the annotation could not
-	// be displayed if it goes outside these bounds, although rarely enforced.
-	lineAnnotation.Rect = pdfcore.MakeArrayFromFloats([]float64{bbox.Llx, bbox.Lly, bbox.Urx, bbox.Ury})
-
-	return lineAnnotation.PdfAnnotation, nil
-}
-
-// A rectangle defined with a specified Width and Height and a lower left corner at (X,Y).  The rectangle can
-// optionally have a border and a filling color.
-// The Width/Height includes the border (if any specified).
-type RectangleAnnotationDef 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).
-}
-
-// Creates a rectangle annotation object that can be added to page PDF annotations.
-func CreateRectangleAnnotation(rectDef RectangleAnnotationDef) (*pdf.PdfAnnotation, error) {
-	rectAnnotation := pdf.NewPdfAnnotationSquare()
-
-	if rectDef.BorderEnabled {
-		r, g, b := rectDef.BorderColor.R(), rectDef.BorderColor.G(), rectDef.BorderColor.B()
-		rectAnnotation.C = pdfcore.MakeArrayFromFloats([]float64{r, g, b})
-		bs := pdf.NewBorderStyle()
-		bs.SetBorderWidth(rectDef.BorderWidth)
-		rectAnnotation.BS = bs.ToPdfObject()
-	}
-
-	if rectDef.FillEnabled {
-		r, g, b := rectDef.FillColor.R(), rectDef.FillColor.G(), rectDef.FillColor.B()
-		rectAnnotation.IC = pdfcore.MakeArrayFromFloats([]float64{r, g, b})
-	} else {
-		rectAnnotation.IC = pdfcore.MakeArrayFromIntegers([]int{}) // No fill.
-	}
-
-	if rectDef.Opacity < 1.0 {
-		rectAnnotation.CA = pdfcore.MakeFloat(rectDef.Opacity)
-	}
-
-	// Make the appearance stream (for uniform appearance).
-	apDict, bbox, err := makeRectangleAnnotationAppearanceStream(rectDef)
-	if err != nil {
-		return nil, err
-	}
-
-	rectAnnotation.AP = apDict
-	rectAnnotation.Rect = pdfcore.MakeArrayFromFloats([]float64{bbox.Llx, bbox.Lly, bbox.Urx, bbox.Ury})
-
-	return rectAnnotation.PdfAnnotation, nil
-
-}
-
-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).
-}
-
-// 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
-
-}

pdf/annotator/circle.go

@@ -14,14 +14,53 @@ import (
 	pdf "github.com/unidoc/unidoc/pdf/model"
 )
 
-// Make the bezier path with the content creator.
+type CircleAnnotationDef struct {
-func drawBezierPathWithCreator(bpath draw.CubicBezierPath, creator *pdfcontent.ContentCreator) {
+	X             float64
-	for idx, c := range bpath.Curves {
+	Y             float64
-		if idx == 0 {
+	Width         float64
-			creator.Add_m(c.P0.X, c.P0.Y)
+	Height        float64
-		}
+	FillEnabled   bool // Show fill?
-		creator.Add_c(c.P1.X, c.P1.Y, c.P2.X, c.P2.Y, c.P3.X, c.P3.Y)
+	FillColor     *pdf.PdfColorDeviceRGB
+	BorderEnabled bool // Show border?
+	BorderWidth   float64
+	BorderColor   *pdf.PdfColorDeviceRGB
+	Opacity       float64 // Alpha value (0-1).
+}
+
+// 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) {

pdf/annotator/line.go

@@ -15,15 +15,72 @@ import (
 	pdf "github.com/unidoc/unidoc/pdf/model"
 )
 
-// Make the path with the content creator.
+// The currently supported line ending styles are None, Arrow (ClosedArrow) and Butt.
-func drawPathWithCreator(path draw.Path, creator *pdfcontent.ContentCreator) {
+type LineEndingStyle int
-	for idx, p := range path.Points {
+
-		if idx == 0 {
+const (
-			creator.Add_m(p.X, p.Y)
+	LineEndingStyleNone  LineEndingStyle = 0
-		} else {
+	LineEndingStyleArrow LineEndingStyle = 1
-			creator.Add_l(p.X, p.Y)
+	LineEndingStyleButt  LineEndingStyle = 2
-		}
+)
+
+// Defines a line between point 1 (X1,Y1) and point 2 (X2,Y2).  The line ending styles can be none (regular line),
+// or arrows at either end.  The line also has a specified width, color and opacity.
+type LineAnnotationDef struct {
+	X1               float64
+	Y1               float64
+	X2               float64
+	Y2               float64
+	LineColor        *pdf.PdfColorDeviceRGB
+	Opacity          float64 // Alpha value (0-1).
+	LineWidth        float64
+	LineEndingStyle1 LineEndingStyle // Line ending style of point 1.
+	LineEndingStyle2 LineEndingStyle // Line ending style of point 2.
+}
+
+// Creates a line annotation object that can be added to page PDF annotations.
+func CreateLineAnnotation(lineDef LineAnnotationDef) (*pdf.PdfAnnotation, error) {
+	// Line annotation.
+	lineAnnotation := pdf.NewPdfAnnotationLine()
+
+	// Line endpoint locations.
+	lineAnnotation.L = pdfcore.MakeArrayFromFloats([]float64{lineDef.X1, lineDef.Y1, lineDef.X2, lineDef.Y2})
+
+	// Line endings.
+	le1 := pdfcore.MakeName("None")
+	if lineDef.LineEndingStyle1 == LineEndingStyleArrow {
+		le1 = pdfcore.MakeName("ClosedArrow")
 	}
+	le2 := pdfcore.MakeName("None")
+	if lineDef.LineEndingStyle2 == LineEndingStyleArrow {
+		le2 = pdfcore.MakeName("ClosedArrow")
+	}
+	lineAnnotation.LE = pdfcore.MakeArray(le1, le2)
+
+	// Opacity.
+	if lineDef.Opacity < 1.0 {
+		lineAnnotation.CA = pdfcore.MakeFloat(lineDef.Opacity)
+	}
+
+	r, g, b := lineDef.LineColor.R(), lineDef.LineColor.G(), lineDef.LineColor.B()
+	lineAnnotation.IC = pdfcore.MakeArrayFromFloats([]float64{r, g, b}) // fill color of line endings, rgb 0-1.
+	lineAnnotation.C = pdfcore.MakeArrayFromFloats([]float64{r, g, b})  // line color, rgb 0-1.
+	bs := pdf.NewBorderStyle()
+	bs.SetBorderWidth(lineDef.LineWidth) // Line width: 3 points.
+	lineAnnotation.BS = bs.ToPdfObject()
+
+	// Make the appearance stream (for uniform appearance).
+	apDict, bbox, err := makeLineAnnotationAppearanceStream(lineDef)
+	if err != nil {
+		return nil, err
+	}
+	lineAnnotation.AP = apDict
+
+	// The rect specifies the location and dimensions of the annotation.  Technically if the annotation could not
+	// be displayed if it goes outside these bounds, although rarely enforced.
+	lineAnnotation.Rect = pdfcore.MakeArrayFromFloats([]float64{bbox.Llx, bbox.Lly, bbox.Urx, bbox.Ury})
+
+	return lineAnnotation.PdfAnnotation, nil
 }
 
 func makeLineAnnotationAppearanceStream(lineDef LineAnnotationDef) (*pdfcore.PdfObjectDictionary, *pdf.PdfRectangle, error) {

pdf/annotator/rectangle.go

@@ -14,6 +14,58 @@ import (
 	pdf "github.com/unidoc/unidoc/pdf/model"
 )
 
+// A rectangle defined with a specified Width and Height and a lower left corner at (X,Y).  The rectangle can
+// optionally have a border and a filling color.
+// The Width/Height includes the border (if any specified).
+type RectangleAnnotationDef 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).
+}
+
+// Creates a rectangle annotation object that can be added to page PDF annotations.
+func CreateRectangleAnnotation(rectDef RectangleAnnotationDef) (*pdf.PdfAnnotation, error) {
+	rectAnnotation := pdf.NewPdfAnnotationSquare()
+
+	if rectDef.BorderEnabled {
+		r, g, b := rectDef.BorderColor.R(), rectDef.BorderColor.G(), rectDef.BorderColor.B()
+		rectAnnotation.C = pdfcore.MakeArrayFromFloats([]float64{r, g, b})
+		bs := pdf.NewBorderStyle()
+		bs.SetBorderWidth(rectDef.BorderWidth)
+		rectAnnotation.BS = bs.ToPdfObject()
+	}
+
+	if rectDef.FillEnabled {
+		r, g, b := rectDef.FillColor.R(), rectDef.FillColor.G(), rectDef.FillColor.B()
+		rectAnnotation.IC = pdfcore.MakeArrayFromFloats([]float64{r, g, b})
+	} else {
+		rectAnnotation.IC = pdfcore.MakeArrayFromIntegers([]int{}) // No fill.
+	}
+
+	if rectDef.Opacity < 1.0 {
+		rectAnnotation.CA = pdfcore.MakeFloat(rectDef.Opacity)
+	}
+
+	// Make the appearance stream (for uniform appearance).
+	apDict, bbox, err := makeRectangleAnnotationAppearanceStream(rectDef)
+	if err != nil {
+		return nil, err
+	}
+
+	rectAnnotation.AP = apDict
+	rectAnnotation.Rect = pdfcore.MakeArrayFromFloats([]float64{bbox.Llx, bbox.Lly, bbox.Urx, bbox.Ury})
+
+	return rectAnnotation.PdfAnnotation, nil
+
+}
+
 func makeRectangleAnnotationAppearanceStream(rectDef RectangleAnnotationDef) (*pdfcore.PdfObjectDictionary, *pdf.PdfRectangle, error) {
 	form := pdf.NewXObjectForm()
 	form.Resources = pdf.NewPdfPageResources()

pdf/annotator/utils.go

@@ -0,0 +1,27 @@
+package annotator
+
+import (
+	pdfcontent "github.com/unidoc/unidoc/pdf/contentstream"
+	"github.com/unidoc/unidoc/pdf/contentstream/draw"
+)
+
+// Make the path with the content creator.
+func drawPathWithCreator(path draw.Path, creator *pdfcontent.ContentCreator) {
+	for idx, p := range path.Points {
+		if idx == 0 {
+			creator.Add_m(p.X, p.Y)
+		} else {
+			creator.Add_l(p.X, p.Y)
+		}
+	}
+}
+
+// Make the bezier path with the content creator.
+func drawBezierPathWithCreator(bpath draw.CubicBezierPath, creator *pdfcontent.ContentCreator) {
+	for idx, c := range bpath.Curves {
+		if idx == 0 {
+			creator.Add_m(c.P0.X, c.P0.Y)
+		}
+		creator.Add_c(c.P1.X, c.P1.Y, c.P2.X, c.P2.Y, c.P3.X, c.P3.Y)
+	}
+}

pdf/contentstream/creator.go

@@ -414,7 +414,6 @@ func (this *ContentCreator) Add_k(c, m, y, k float64) *ContentCreator {
 
 /* Shading operators. */
 
-// sh: Paint the shape and color described by a shading dictionary.
 func (this *ContentCreator) Add_sh(name PdfObjectName) *ContentCreator {
 	op := ContentStreamOperation{}
 	op.Operand = "sh"
@@ -422,3 +421,163 @@ func (this *ContentCreator) Add_sh(name PdfObjectName) *ContentCreator {
 	this.operands = append(this.operands, &op)
 	return this
 }
+
+/* Text related operators */
+
+/* Text state operators */
+
+// BT: Begin text.
+func (this *ContentCreator) Add_BT() *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "BT"
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// ET: End text.
+func (this *ContentCreator) Add_ET() *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "ET"
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// Tc: Set character spacing.
+func (this *ContentCreator) Add_Tc(charSpace float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tc"
+	op.Params = makeParamsFromFloats([]float64{charSpace})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// Tw: Set word spacing.
+func (this *ContentCreator) Add_Tw(wordSpace float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tw"
+	op.Params = makeParamsFromFloats([]float64{wordSpace})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// Tz: Set horizontal scaling.
+func (this *ContentCreator) Add_Tz(scale float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tz"
+	op.Params = makeParamsFromFloats([]float64{scale})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// TL: Set leading.
+func (this *ContentCreator) Add_Tl(leading float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tl"
+	op.Params = makeParamsFromFloats([]float64{leading})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// Tf: Set font and font size.
+func (this *ContentCreator) Add_Tf(fontName PdfObjectName, fontSize float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tf"
+	op.Params = makeParamsFromNames([]PdfObjectName{fontName})
+	op.Params = append(op.Params, makeParamsFromFloats([]float64{fontSize})...)
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// Tr: Set text rendering mode.
+func (this *ContentCreator) Add_Tr(render int64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tr"
+	op.Params = makeParamsFromInts([]int64{render})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// Ts: Set text rise.
+func (this *ContentCreator) Add_Ts(rise float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Ts"
+	op.Params = makeParamsFromFloats([]float64{rise})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+/* Text positioning operators. */
+
+// Td: Move to start of next line with offset (tx, ty).
+func (this *ContentCreator) Add_Td(tx, ty float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Td"
+	op.Params = makeParamsFromFloats([]float64{tx, ty})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// TD: Move to start of next line with offset (tx, ty).
+func (this *ContentCreator) Add_TD(tx, ty float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "TD"
+	op.Params = makeParamsFromFloats([]float64{tx, ty})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// Tm: Set the text line matrix.
+func (this *ContentCreator) Add_Tm(a, b, c, d, e, f float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tm"
+	op.Params = makeParamsFromFloats([]float64{a, b, c, d, e, f})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// T*: Move to the start of next line.
+func (this *ContentCreator) Add_Tstar() *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "T*"
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+/* Text showing operators */
+
+// Tj: Show a text string.
+func (this *ContentCreator) Add_Tj(textstr PdfObjectString) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "Tj"
+	op.Params = makeParamsFromStrings([]PdfObjectString{textstr})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// ': Move to next line and show a string.
+func (this *ContentCreator) Add_quote(textstr PdfObjectString) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "'"
+	op.Params = makeParamsFromStrings([]PdfObjectString{textstr})
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// '': Move to next line and show a string, using aw and ac as word and character spacing respectively.
+func (this *ContentCreator) Add_quotes(textstr PdfObjectString, aw, ac float64) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "''"
+	op.Params = makeParamsFromFloats([]float64{aw, ac})
+	op.Params = append(op.Params, makeParamsFromStrings([]PdfObjectString{textstr})...)
+	this.operands = append(this.operands, &op)
+	return this
+}
+
+// TJ. Show one or more text string.  Array of numbers (displacement) and strings.
+func (this *ContentCreator) Add_TJ(vals ...PdfObject) *ContentCreator {
+	op := ContentStreamOperation{}
+	op.Operand = "TJ"
+	op.Params = vals
+	this.operands = append(this.operands, &op)
+	return this
+}

pdf/contentstream/utils.go

@@ -23,6 +23,14 @@ func makeParamsFromNames(vals []PdfObjectName) []PdfObject {
 	return params
 }
 
+func makeParamsFromStrings(vals []PdfObjectString) []PdfObject {
+	params := []PdfObject{}
+	for _, val := range vals {
+		params = append(params, MakeString(string(val)))
+	}
+	return params
+}
+
 func makeParamsFromInts(vals []int64) []PdfObject {
 	params := []PdfObject{}
 	for _, val := range vals {

pdf/model/page.go

@@ -554,6 +554,26 @@ func (this *PdfPage) HasImageResource(name PdfObjectName) bool {
 	} else {
 		return false
 	}
+
+}
+
+// Check if has font resource by name.
+func (this *PdfPage) HasFontByName(name PdfObjectName) bool {
+	resources, err := this.GetResources()
+	if err != nil {
+		return false
+	}
+
+	fontDict, has := resources.Font.(*PdfObjectDictionary)
+	if !has {
+		return false
+	}
+
+	if _, has := (*fontDict)[name]; has {
+		return true
+	} else {
+		return false
+	}
 }
 
 // Add a graphics state to the XObject resources.

pdf/model/resources.go

@@ -15,8 +15,7 @@ import (
 // Page resources model.
 // Implements PdfModel.
 type PdfPageResources struct {
-	ExtGState PdfObject
+	ExtGState  PdfObject
-	//ColorSpace PdfObject
 	ColorSpace *PdfPageResourcesColorspaces
 	Pattern    PdfObject
 	Shading    PdfObject