PDF rendering support

base/iox/imagex/wrapjs_js.go

@@ -130,6 +130,12 @@ func (im *JSRGBA) Update() {
 	im.JS.SetRGBA(im.RGBA)
 }
 
+// note: per https://github.com/whatwg/html/issues/4785 there is no way
+// to actually get the data back from the ImageBitmap :(
+
+// Underlying returns the underlying image data as a local image.RGBA.
+// Note that this may not be possible and a nil will be returned, because
+// there is no way to get the image data back from an ImageBitmap at this point.
 func (im *JSRGBA) Underlying() image.Image {
 	return im.RGBA
 }

base/iox/imagex/wrapjs_notjs.go

@@ -13,6 +13,12 @@ import (
 	"github.com/anthonynsimon/bild/transform"
 )
 
+// JSRGBA is a dummy version of this type so code does not have to be
+// conditionalized.
+type JSRGBA struct {
+	*image.RGBA
+}
+
 // WrapJS returns a JavaScript optimized wrapper around the given
 // [image.Image] on web, and just returns the image on other platforms.
 func WrapJS(src image.Image) image.Image {

colors/gradient/linear.go

@@ -14,11 +14,12 @@ import (
 	"cogentcore.org/core/math32"
 )
 
-// Linear represents a linear gradient. It implements the [image.Image] interface.
+// Linear represents a linear gradient along linear axis from Start to End.
+// It implements the [image.Image] interface.
 type Linear struct { //types:add -setters
 	Base
 
-	// the starting point of the gradient (x1 and y1 in SVG)
+	// the starting point of the gradient axis (x1 and y1 in SVG).
 	Start math32.Vector2
 
 	// the ending point of the gradient (x2 and y2 in SVG)
@@ -74,6 +75,12 @@ func (l *Linear) Update(opacity float32, box math32.Box2, objTransform math32.Ma
 	l.distanceLengthSquared = l.distance.LengthSquared()
 }
 
+// TransformedAxis returns the Start and End axis points as transformed
+// by the last Update call.
+func (l *Linear) TransformedAxis() (start, end math32.Vector2) {
+	return l.rStart, l.rEnd
+}
+
 // At returns the color of the linear gradient at the given point
 func (l *Linear) At(x, y int) color.Color {
 	switch len(l.Stops) {

colors/gradient/radial.go

@@ -96,6 +96,12 @@ func (r *Radial) Update(opacity float32, box math32.Box2, objTransform math32.Ma
 	r.rCenter, r.rFocal, r.rRadius = c, f, rs
 }
 
+// TransformedCoords returns the coordinate points as transformed
+// by the last Update call.
+func (r *Radial) TransformedCoords() (center, focal, radius math32.Vector2) {
+	return r.rCenter, r.rFocal, r.rRadius
+}
+
 const epsilonF = 1e-5
 
 // At returns the color of the radial gradient at the given point

colors/matcolor/scheme.go

@@ -117,14 +117,14 @@ func NewLightScheme(p *Palette) Scheme {
 		Custom:    map[string]Accent{},
 
 		SurfaceDim:    p.Neutral.AbsToneUniform(87),
-		Surface:       p.Neutral.AbsToneUniform(98),
-		SurfaceBright: p.Neutral.AbsToneUniform(98),
+		Surface:       p.Neutral.AbsToneUniform(99),
+		SurfaceBright: p.Neutral.AbsToneUniform(99),
 
 		SurfaceContainerLowest:  p.Neutral.AbsToneUniform(100),
-		SurfaceContainerLow:     p.Neutral.AbsToneUniform(96),
-		SurfaceContainer:        p.Neutral.AbsToneUniform(94),
-		SurfaceContainerHigh:    p.Neutral.AbsToneUniform(92),
-		SurfaceContainerHighest: p.Neutral.AbsToneUniform(90),
+		SurfaceContainerLow:     p.Neutral.AbsToneUniform(98),
+		SurfaceContainer:        p.Neutral.AbsToneUniform(96),
+		SurfaceContainerHigh:    p.Neutral.AbsToneUniform(94),
+		SurfaceContainerHighest: p.Neutral.AbsToneUniform(92),
 
 		SurfaceVariant:   p.NeutralVariant.AbsToneUniform(90),
 		OnSurface:        p.NeutralVariant.AbsToneUniform(10),
@@ -134,7 +134,7 @@ func NewLightScheme(p *Palette) Scheme {
 		InverseOnSurface: p.Neutral.AbsToneUniform(95),
 		InversePrimary:   p.Primary.AbsToneUniform(80),
 
-		Background:   p.Neutral.AbsToneUniform(98),
+		Background:   p.Neutral.AbsToneUniform(100),
 		OnBackground: p.Neutral.AbsToneUniform(10),
 
 		Outline:        p.NeutralVariant.AbsToneUniform(50),
@@ -182,7 +182,7 @@ func NewDarkScheme(p *Palette) Scheme {
 		InverseOnSurface: p.Neutral.AbsToneUniform(20),
 		InversePrimary:   p.Primary.AbsToneUniform(40),
 
-		Background:   p.Neutral.AbsToneUniform(6),
+		Background:   p.Neutral.AbsToneUniform(0),
 		OnBackground: p.Neutral.AbsToneUniform(90),
 
 		Outline:        p.NeutralVariant.AbsToneUniform(60),

content/bcontent/page.go

@@ -52,8 +52,16 @@ type Page struct {
 	// DateString is only used for parsing the date from the TOML front matter.
 	DateString string `toml:"Date" json:"-"`
 
-	// Authors are the optional authors of the page.
-	Authors []string
+	// Authors are the optional author(s) of the page.
+	Authors string
+
+	// Affiliations are optional institutional affiliations of the authors.
+	// This is only used for the PDF output.
+	Affiliations string
+
+	// Abstract is an optional abstract.
+	// This is only used for the PDF output.
+	Abstract string
 
 	// Draft indicates that the page is a draft and should not be visible on the web.
 	Draft bool

content/buttons.go

@@ -74,6 +74,12 @@ func (ct *Content) MakeToolbar(p *tree.Plan) {
 			ct.Scene.MenuSearchDialog("Search", "Search "+core.TheApp.Name())
 		})
 	})
+	tree.Add(p, func(w *core.Button) {
+		w.SetText("PDF").SetIcon(icons.PictureAsPdf).SetTooltip("PDF generates and opens / downloads the current page as a printable PDF file. See the Settings/Printer panel (Command+,) for settings.")
+		w.OnClick(func(e events.Event) {
+			ct.PagePDF("pdfs")
+		})
+	})
 }
 
 func (ct *Content) MenuSearch(items *[]core.ChooserItem) {

content/content.go

@@ -12,15 +12,14 @@ import (
 	"bytes"
 	"cmp"
 	"fmt"
-	"io"
 	"io/fs"
 	"net/http"
+	"os"
 	"path/filepath"
 	"slices"
 	"strconv"
 	"strings"
 
-	"github.com/gomarkdown/markdown/ast"
 	"golang.org/x/exp/maps"
 
 	"cogentcore.org/core/base/errors"
@@ -32,10 +31,10 @@ import (
 	"cogentcore.org/core/htmlcore"
 	"cogentcore.org/core/math32"
 	"cogentcore.org/core/styles"
-	"cogentcore.org/core/styles/abilities"
 	"cogentcore.org/core/styles/units"
 	"cogentcore.org/core/system"
 	"cogentcore.org/core/text/csl"
+	"cogentcore.org/core/text/paginate"
 	"cogentcore.org/core/tree"
 )
 
@@ -103,6 +102,10 @@ type Content struct {
 	// if any (in kebab-case).
 	currentHeading string
 
+	// inPDFRender indicates that it is rendering a PDF now, turning off
+	// elements that are not appropriate for that.
+	inPDFRender bool
+
 	// The previous and next page, if applicable. They must be stored on this struct
 	// to avoid stale local closure variables.
 	prevPage, nextPage *bcontent.Page
@@ -126,6 +129,7 @@ func (ct *Content) Init() {
 	ct.SetSplits(0.2, 0.8)
 
 	ct.Context = htmlcore.NewContext()
+	ct.Context.DelayedImageLoad = false // not useful for content
 	ct.Context.OpenURL = func(url string) {
 		ct.Open(url)
 	}
@@ -138,73 +142,9 @@ func (ct *Content) Init() {
 		errors.Log(ct.embedPage(ctx))
 		return true
 	}
-	ct.Context.AttributeHandlers["id"] = func(ctx *htmlcore.Context, w io.Writer, node ast.Node, entering bool, tag, value string) bool {
-		if ct.currentPage == nil {
-			return false
-		}
-		lbl := ct.currentPage.SpecialLabel(value)
-		ch := node.GetChildren()
-		if len(ch) == 2 { // image or table
-			if entering {
-				sty := htmlcore.MDGetAttr(node, "style")
-				if sty != "" {
-					if img, ok := ch[1].(*ast.Image); ok {
-						htmlcore.MDSetAttr(img, "style", sty)
-						delete(node.AsContainer().Attribute.Attrs, "style")
-					}
-				}
-				return false
-			}
-			cp := "\n<p><b>" + lbl + ":</b>"
-			if img, ok := ch[1].(*ast.Image); ok {
-				// fmt.Printf("Image: %s\n", string(img.Destination))
-				// fmt.Printf("Image: %#v\n", img)
-				nc := len(img.Children)
-				if nc > 0 {
-					if txt, ok := img.Children[0].(*ast.Text); ok {
-						// fmt.Printf("text: %s\n", string(txt.Literal)) // not formatted!
-						cp += " " + string(txt.Literal) // todo: not formatted!
-					}
-				}
-			} else {
-				title := htmlcore.MDGetAttr(node, "title")
-				if title != "" {
-					cp += " " + title
-				}
-			}
-			cp += "</p>\n"
-			w.Write([]byte(cp))
-		} else if entering {
-			cp := "\n<span id=\"" + value + "\"><b>" + lbl + ":</b>"
-			title := htmlcore.MDGetAttr(node, "title")
-			if title != "" {
-				cp += " " + title
-			}
-			cp += "</span>\n"
-			w.Write([]byte(cp))
-			// fmt.Println("id:", value, lbl)
-			// fmt.Printf("%#v\n", node)
-		}
-		return false
-	}
-	ct.Context.AddWidgetHandler(func(w core.Widget) {
-		switch x := w.(type) {
-		case *core.Text:
-			x.Styler(func(s *styles.Style) {
-				s.Max.X.Ch(120)
-			})
-		case *core.Image:
-			x.Styler(func(s *styles.Style) {
-				s.SetAbilities(true, abilities.Clickable, abilities.DoubleClickable)
-				s.Overflow.Set(styles.OverflowAuto)
-			})
-			x.OnDoubleClick(func(e events.Event) {
-				d := core.NewBody("Image")
-				core.NewImage(d).SetImage(x.Image)
-				d.RunWindowDialog(x)
-			})
-		}
-	})
+	ct.Context.ElementHandlers["pre"] = ct.htmlPreHandler
+	ct.Context.AttributeHandlers["id"] = ct.htmlIDAttributeHandler
+	ct.Context.AddWidgetHandler(ct.widgetHandler)
 
 	ct.Maker(func(p *tree.Plan) {
 		if ct.currentPage == nil {
@@ -224,19 +164,19 @@ func (ct *Content) Init() {
 				}
 			})
 			w.Maker(func(p *tree.Plan) {
-				if ct.currentPage.Title != "" {
+				if !ct.inPDFRender && ct.currentPage.Title != "" {
 					tree.Add(p, func(w *core.Text) {
 						w.SetType(core.TextDisplaySmall)
 						w.Updater(func() {
 							w.SetText(ct.currentPage.Title)
 						})
 					})
 				}
-				if len(ct.currentPage.Authors) > 0 {
+				if !ct.inPDFRender && len(ct.currentPage.Authors) > 0 {
 					tree.Add(p, func(w *core.Text) {
 						w.SetType(core.TextTitleLarge)
 						w.Updater(func() {
-							w.SetText("By " + strcase.FormatList(ct.currentPage.Authors...))
+							w.SetText("By " + ct.currentPage.Authors)
 						})
 					})
 				}
@@ -257,7 +197,9 @@ func (ct *Content) Init() {
 						errors.Log(ct.loadPage(w))
 					})
 				})
-				ct.makeBottomButtons(p)
+				if !ct.inPDFRender {
+					ct.makeBottomButtons(p)
+				}
 			})
 		})
 	})
@@ -372,6 +314,12 @@ func (ct *Content) addHistory(pg *bcontent.Page) {
 	ct.saveWebURL()
 }
 
+// reloadPage reloads the current page
+func (ct *Content) reloadPage() {
+	ct.renderedPage = nil
+	ct.Update()
+}
+
 // loadPage loads the current page content into the given frame if it is not already loaded.
 func (ct *Content) loadPage(w *core.Frame) error {
 	if ct.renderedPage == ct.currentPage {
@@ -529,3 +477,71 @@ func (ct *Content) setStageTitle() {
 		rw.SetStageTitle(name)
 	}
 }
+
+// PagePDF generates a PDF of the current page, to given file path
+// (directory). the page name is the file name.
+func (ct *Content) PagePDF(path string) error {
+	if ct.currentPage == nil {
+		return errors.Log(errors.New("Page empty"))
+	}
+	core.MessageSnackbar(ct, "Generating PDF...")
+
+	Settings.PDF.FontScale = (100.0 / core.AppearanceSettings.DocsFontSize)
+
+	ct.inPDFRender = true
+	ct.reloadPage()
+	ct.inPDFRender = false
+
+	refs := ct.PageRefs(ct.currentPage)
+
+	fname := ct.currentPage.Name + ".pdf"
+	if path != "" {
+		os.MkdirAll(path, 0777)
+		fname = filepath.Join(path, fname)
+	}
+	f, err := os.Create(fname)
+	if errors.Log(err) != nil {
+		return err
+	}
+	opts := Settings.PageSettings(ct, ct.currentPage)
+	if refs != nil {
+		paginate.PDF(f, opts.PDF, ct.rightFrame, refs)
+	} else {
+		paginate.PDF(f, opts.PDF, ct.rightFrame)
+	}
+	err = f.Close()
+
+	ct.reloadPage()
+
+	core.MessageSnackbar(ct, "PDF saved to: "+fname)
+	af := errors.Log1(filepath.Abs(fname))
+	core.TheApp.OpenURL("file://" + af)
+	return err
+}
+
+// PageRefs returns a core.Frame with the contents of the references cited
+// on the given page. if References is nil, or error, result will be nil.
+func (ct *Content) PageRefs(page *bcontent.Page) *core.Frame {
+	if ct.References == nil {
+		return nil
+	}
+	sty := csl.APA // todo: settings
+	var b bytes.Buffer
+	_, err := csl.GenerateMarkdown(&b, ct.Source, "## References", ct.References, sty, page.Filename)
+	if errors.Log(err) != nil {
+		return nil
+	}
+	// os.WriteFile("tmp-refs.md", b.Bytes(), 0666)
+
+	fr := core.NewFrame()
+	fr.Styler(func(s *styles.Style) {
+		s.Direction = styles.Column
+	})
+	err = htmlcore.ReadMD(ct.Context, fr, b.Bytes())
+	if errors.Log(err) != nil {
+		return nil
+	}
+	fr.StyleTree()
+	fr.SetScene(ct.Scene)
+	return fr
+}

content/examples/basic/basic.go

@@ -10,13 +10,16 @@ import (
 	"cogentcore.org/core/content"
 	"cogentcore.org/core/core"
 	"cogentcore.org/core/htmlcore"
+	_ "cogentcore.org/core/text/tex"
 	_ "cogentcore.org/core/yaegicore"
 )
 
 //go:embed content
 var econtent embed.FS
 
 func main() {
+	content.Settings.SiteTitle = "Cogent Content Example"
+	content.OfflineURL = "https://example.com"
 	b := core.NewBody("Cogent Content Example")
 	ct := content.NewContent(b).SetContent(econtent)
 	ct.Context.AddWikilinkHandler(htmlcore.GoDocWikilink("doc", "cogentcore.org/core"))