Merge branch 'd1ngd0-ftr/boxes'

3 files changed, 186 insertions, 85 deletions

diff --git a/def.go b/def.go
index 605cdbc..ba96b2a 100644
--- a/def.go
+++ b/def.go
@@ -430,6 +430,7 @@ type Pdf interface {
 	SetLineWidth(width float64)
 	SetLink(link int, y float64, page int)
 	SetMargins(left, top, right float64)
+	SetPageBox(t string, pb PageBox)
 	SetProtection(actionFlag byte, userPassStr, ownerPassStr string)
 	SetRightMargin(margin float64)
 	SetSubject(subjectStr string, isUTF8 bool)
@@ -473,93 +474,100 @@ type Pdf interface {
 	Writef(h float64, fmtStr string, args ...interface{})
 }
 
+type PageBox struct {
+	SizeType
+	PointType
+}
+
 // Fpdf is the principal structure for creating a single PDF document
 type Fpdf struct {
-	page             int                       // current page number
-	n                int                       // current object number
-	offsets          []int                     // array of object offsets
-	templates        map[int64]Template        // templates used in this document
-	templateObjects  map[int64]int             // template object IDs within this document
-	buffer           fmtBuffer                 // buffer holding in-memory PDF
-	pages            []*bytes.Buffer           // slice[page] of page content; 1-based
-	state            int                       // current document state
-	compress         bool                      // compression flag
-	k                float64                   // scale factor (number of points in user unit)
-	defOrientation   string                    // default orientation
-	curOrientation   string                    // current orientation
-	stdPageSizes     map[string]SizeType       // standard page sizes
-	defPageSize      SizeType                  // default page size
-	curPageSize      SizeType                  // current page size
-	pageSizes        map[int]SizeType          // used for pages with non default sizes or orientations
-	unitStr          string                    // unit of measure for all rendered objects except fonts
-	wPt, hPt         float64                   // dimensions of current page in points
-	w, h             float64                   // dimensions of current page in user unit
-	lMargin          float64                   // left margin
-	tMargin          float64                   // top margin
-	rMargin          float64                   // right margin
-	bMargin          float64                   // page break margin
-	cMargin          float64                   // cell margin
-	x, y             float64                   // current position in user unit
-	lasth            float64                   // height of last printed cell
-	lineWidth        float64                   // line width in user unit
-	fontpath         string                    // path containing fonts
-	fontLoader       FontLoader                // used to load font files from arbitrary locations
-	coreFonts        map[string]bool           // array of core font names
-	fonts            map[string]fontDefType    // array of used fonts
-	fontFiles        map[string]fontFileType   // array of font files
-	diffs            []string                  // array of encoding differences
-	fontFamily       string                    // current font family
-	fontStyle        string                    // current font style
-	underline        bool                      // underlining flag
-	currentFont      fontDefType               // current font info
-	fontSizePt       float64                   // current font size in points
-	fontSize         float64                   // current font size in user unit
-	ws               float64                   // word spacing
-	images           map[string]*ImageInfoType // array of used images
-	aliasMap         map[string]string         // map of alias->replacement
-	pageLinks        [][]linkType              // pageLinks[page][link], both 1-based
-	links            []intLinkType             // array of internal links
-	outlines         []outlineType             // array of outlines
-	outlineRoot      int                       // root of outlines
-	autoPageBreak    bool                      // automatic page breaking
-	acceptPageBreak  func() bool               // returns true to accept page break
-	pageBreakTrigger float64                   // threshold used to trigger page breaks
-	inHeader         bool                      // flag set when processing header
-	headerFnc        func()                    // function provided by app and called to write header
-	headerHomeMode   bool                      // set position to home after headerFnc is called
-	inFooter         bool                      // flag set when processing footer
-	footerFnc        func()                    // function provided by app and called to write footer
-	footerFncLpi     func(bool)                // function provided by app and called to write footer with last page flag
-	zoomMode         string                    // zoom display mode
-	layoutMode       string                    // layout display mode
-	xmp              []byte                    // XMP metadata
-	title            string                    // title
-	subject          string                    // subject
-	author           string                    // author
-	keywords         string                    // keywords
-	creator          string                    // creator
-	creationDate     time.Time                 // override for dcoument CreationDate value
-	aliasNbPagesStr  string                    // alias for total number of pages
-	pdfVersion       string                    // PDF version number
-	fontDirStr       string                    // location of font definition files
-	capStyle         int                       // line cap style: butt 0, round 1, square 2
-	joinStyle        int                       // line segment join style: miter 0, round 1, bevel 2
-	dashArray        []float64                 // dash array
-	dashPhase        float64                   // dash phase
-	blendList        []blendModeType           // slice[idx] of alpha transparency modes, 1-based
-	blendMap         map[string]int            // map into blendList
-	blendMode        string                    // current blend mode
-	alpha            float64                   // current transpacency
-	gradientList     []gradientType            // slice[idx] of gradient records
-	clipNest         int                       // Number of active clipping contexts
-	transformNest    int                       // Number of active transformation contexts
-	err              error                     // Set if error occurs during life cycle of instance
-	protect          protectType               // document protection structure
-	layer            layerRecType              // manages optional layers in document
-	catalogSort      bool                      // sort resource catalogs in document
-	nJs              int                       // JavaScript object number
-	javascript       *string                   // JavaScript code to include in the PDF
-	colorFlag        bool                      // indicates whether fill and text colors are different
+	page             int                        // current page number
+	n                int                        // current object number
+	offsets          []int                      // array of object offsets
+	templates        map[int64]Template         // templates used in this document
+	templateObjects  map[int64]int              // template object IDs within this document
+	buffer           fmtBuffer                  // buffer holding in-memory PDF
+	pages            []*bytes.Buffer            // slice[page] of page content; 1-based
+	state            int                        // current document state
+	compress         bool                       // compression flag
+	k                float64                    // scale factor (number of points in user unit)
+	defOrientation   string                     // default orientation
+	curOrientation   string                     // current orientation
+	stdPageSizes     map[string]SizeType        // standard page sizes
+	defPageSize      SizeType                   // default page size
+	defPageBoxes     map[string]PageBox         // default page size
+	curPageSize      SizeType                   // current page size
+	pageSizes        map[int]SizeType           // used for pages with non default sizes or orientations
+	pageBoxes        map[int]map[string]PageBox // used to define the crop, trim, bleed and art boxes
+	unitStr          string                     // unit of measure for all rendered objects except fonts
+	wPt, hPt         float64                    // dimensions of current page in points
+	w, h             float64                    // dimensions of current page in user unit
+	lMargin          float64                    // left margin
+	tMargin          float64                    // top margin
+	rMargin          float64                    // right margin
+	bMargin          float64                    // page break margin
+	cMargin          float64                    // cell margin
+	x, y             float64                    // current position in user unit
+	lasth            float64                    // height of last printed cell
+	lineWidth        float64                    // line width in user unit
+	fontpath         string                     // path containing fonts
+	fontLoader       FontLoader                 // used to load font files from arbitrary locations
+	coreFonts        map[string]bool            // array of core font names
+	fonts            map[string]fontDefType     // array of used fonts
+	fontFiles        map[string]fontFileType    // array of font files
+	diffs            []string                   // array of encoding differences
+	fontFamily       string                     // current font family
+	fontStyle        string                     // current font style
+	underline        bool                       // underlining flag
+	currentFont      fontDefType                // current font info
+	fontSizePt       float64                    // current font size in points
+	fontSize         float64                    // current font size in user unit
+	ws               float64                    // word spacing
+	images           map[string]*ImageInfoType  // array of used images
+	aliasMap         map[string]string          // map of alias->replacement
+	pageLinks        [][]linkType               // pageLinks[page][link], both 1-based
+	links            []intLinkType              // array of internal links
+	outlines         []outlineType              // array of outlines
+	outlineRoot      int                        // root of outlines
+	autoPageBreak    bool                       // automatic page breaking
+	acceptPageBreak  func() bool                // returns true to accept page break
+	pageBreakTrigger float64                    // threshold used to trigger page breaks
+	inHeader         bool                       // flag set when processing header
+	headerFnc        func()                     // function provided by app and called to write header
+	headerHomeMode   bool                       // set position to home after headerFnc is called
+	inFooter         bool                       // flag set when processing footer
+	footerFnc        func()                     // function provided by app and called to write footer
+	footerFncLpi     func(bool)                 // function provided by app and called to write footer with last page flag
+	zoomMode         string                     // zoom display mode
+	layoutMode       string                     // layout display mode
+	xmp              []byte                     // XMP metadata
+	title            string                     // title
+	subject          string                     // subject
+	author           string                     // author
+	keywords         string                     // keywords
+	creator          string                     // creator
+	creationDate     time.Time                  // override for dcoument CreationDate value
+	aliasNbPagesStr  string                     // alias for total number of pages
+	pdfVersion       string                     // PDF version number
+	fontDirStr       string                     // location of font definition files
+	capStyle         int                        // line cap style: butt 0, round 1, square 2
+	joinStyle        int                        // line segment join style: miter 0, round 1, bevel 2
+	dashArray        []float64                  // dash array
+	dashPhase        float64                    // dash phase
+	blendList        []blendModeType            // slice[idx] of alpha transparency modes, 1-based
+	blendMap         map[string]int             // map into blendList
+	blendMode        string                     // current blend mode
+	alpha            float64                    // current transpacency
+	gradientList     []gradientType             // slice[idx] of gradient records
+	clipNest         int                        // Number of active clipping contexts
+	transformNest    int                        // Number of active transformation contexts
+	err              error                      // Set if error occurs during life cycle of instance
+	protect          protectType                // document protection structure
+	layer            layerRecType               // manages optional layers in document
+	catalogSort      bool                       // sort resource catalogs in document
+	nJs              int                        // JavaScript object number
+	javascript       *string                    // JavaScript code to include in the PDF
+	colorFlag        bool                       // indicates whether fill and text colors are different
 	color            struct {
 		// Composite values of colors
 		draw, fill, text colorType
diff --git a/fpdf.go b/fpdf.go
index 822d87f..43688dd 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -77,6 +77,8 @@ func fpdfNew(orientationStr, unitStr, sizeStr, fontDirStr string, size SizeType)
 	f.pages = make([]*bytes.Buffer, 0, 8)
 	f.pages = append(f.pages, bytes.NewBufferString("")) // pages[0] is unused (1-based)
 	f.pageSizes = make(map[int]SizeType)
+	f.pageBoxes = make(map[int]map[string]PageBox)
+	f.defPageBoxes = make(map[string]PageBox)
 	f.state = 0
 	f.fonts = make(map[string]fontDefType)
 	f.fontFiles = make(map[string]fontFileType)
@@ -335,6 +337,45 @@ func (f *Fpdf) SetCellMargin(margin float64) {
 	f.cMargin = margin
 }
 
+// SetPageBox sets the page box for the current page, and any following pages.
+// Allowable types are trim, trimbox, crop, cropbox, bleed, bleedbox, art and artbox
+// box types are case insensitive.
+func (f *Fpdf) SetPageBox(t string, pb PageBox) {
+	switch strings.ToLower(t) {
+	case "trim":
+		fallthrough
+	case "trimbox":
+		t = "TrimBox"
+	case "crop":
+		fallthrough
+	case "cropbox":
+		t = "CropBox"
+	case "bleed":
+		fallthrough
+	case "bleedbox":
+		t = "BleedBox"
+	case "art":
+		fallthrough
+	case "artbox":
+		t = "ArtBox"
+	default:
+		f.err = fmt.Errorf("%s is not a valid page box type", t)
+		return
+	}
+
+	pb.X = pb.X * f.k
+	pb.Y = pb.Y * f.k
+	pb.Wd = (pb.Wd * f.k) + pb.X
+	pb.Ht = (pb.Ht * f.k) + pb.Y
+
+	if f.page > 0 {
+		f.pageBoxes[f.page][t] = pb
+	}
+
+	// always override. page defaults are supplied in addPage function
+	f.defPageBoxes[t] = pb
+}
+
 // SetFontLocation sets the location in the file system of the font and font
 // definition files.
 func (f *Fpdf) SetFontLocation(fontDirStr string) {
@@ -2845,6 +2886,11 @@ func (f *Fpdf) beginpage(orientationStr string, size SizeType) {
 		return
 	}
 	f.page++
+	// add the default page boxes, if any exist, to the page
+	f.pageBoxes[f.page] = make(map[string]PageBox)
+	for box, pb := range f.defPageBoxes {
+		f.pageBoxes[f.page][box] = pb
+	}
 	f.pages = append(f.pages, bytes.NewBufferString(""))
 	f.pageLinks = append(f.pageLinks, make([]linkType, 0, 0))
 	f.state = 2
@@ -3185,6 +3231,9 @@ func (f *Fpdf) putpages() {
 		if ok {
 			f.outf("/MediaBox [0 0 %.2f %.2f]", pageSize.Wd, pageSize.Ht)
 		}
+		for t, pb := range f.pageBoxes[n] {
+			f.outf("/%s [%.2f %.2f %.2f %.2f]", t, pb.X, pb.Y, pb.Wd, pb.Ht)
+		}
 		f.out("/Resources 2 0 R")
 		// Links
 		if len(f.pageLinks[n]) > 0 {
diff --git a/fpdf_test.go b/fpdf_test.go
index 68a26ad..62bae17 100644
--- a/fpdf_test.go
+++ b/fpdf_test.go
@@ -2193,3 +2193,47 @@ func ExampleNewGrid() {
 	// Output:
 	// Successfully generated pdf/Fpdf_Grid.pdf
 }
+
+func pagebox(pdf *gofpdf.Fpdf, boxstr string, x, y, wd, ht float64) {
+	pdf.SetPageBox(boxstr, gofpdf.PageBox{gofpdf.SizeType{Wd: wd, Ht: ht}, gofpdf.PointType{X: x, Y: y}})
+}
+
+// This example demonstrates the use of a page box
+func ExamplePageBox() {
+	// pdfinfo (from http://www.xpdfreader.com) reports the following for this example:
+	// ~ pdfinfo -box pdf/Fpdf_PageBox.pdf
+	// Producer:       FPDF 1.7
+	// CreationDate:   Sat Jan  1 00:00:00 2000
+	// Tagged:         no
+	// Form:           none
+	// Pages:          1
+	// Encrypted:      no
+	// Page size:      493.23 x 739.85 pts (rotated 0 degrees)
+	// MediaBox:           0.00     0.00   595.28   841.89
+	// CropBox:           51.02    51.02   544.25   790.87
+	// BleedBox:          51.02    51.02   544.25   790.87
+	// TrimBox:           51.02    51.02   544.25   790.87
+	// ArtBox:            51.02    51.02   544.25   790.87
+	// File size:      1053 bytes
+	// Optimized:      no
+	// PDF version:    1.3
+	const (
+		wd        = 210
+		ht        = 297
+		fontsize  = 6
+		boxmargin = 3 * fontsize
+	)
+	pdf := gofpdf.New("P", "mm", "A4", "") // 210mm x 297mm
+	pagebox(pdf, "crop", boxmargin, boxmargin, wd-2*boxmargin, ht-2*boxmargin)
+	pdf.SetFont("Arial", "", pdf.UnitToPointConvert(fontsize))
+	pdf.AddPage()
+	pdf.MoveTo(fontsize, fontsize)
+	pdf.Write(fontsize, "This will be cropped from printed output")
+	pdf.MoveTo(boxmargin+fontsize, boxmargin+fontsize)
+	pdf.Write(fontsize, "This will be displayed in cropped output")
+	fileStr := example.Filename("Fpdf_PageBox")
+	err := pdf.OutputFileAndClose(fileStr)
+	example.Summary(err, fileStr)
+	// Output:
+	// Successfully generated pdf/Fpdf_PageBox.pdf
+}