all: group all image related method and functions into single file

This is to make it easy to see how it parsed and how it written to HTML,
make the code more searchable.

While at it, add test for block image.

1 files changed, 163 insertions, 0 deletions

diff --git a/element_image.go b/element_image.go
new file mode 100644
index 0000000..d98bb61
--- /dev/null
+++ b/element_image.go
@@ -0,0 +1,163 @@
+// SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package asciidoctor
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+
+	"git.sr.ht/~shulhan/pakakeh.go/lib/ascii"
+)
+
+// parseBlockImage parse the image block or line.
+// The line parameter must not contains the "image::" block or "image:"
+// macro prefix.
+func (el *element) parseBlockImage(doc *Document, line []byte) bool {
+	var attrBegin = bytes.IndexByte(line, '[')
+	if attrBegin < 0 {
+		return false
+	}
+	var attrEnd = bytes.IndexByte(line, ']')
+	if attrEnd < 0 {
+		return false
+	}
+
+	var link = bytes.TrimRight(line[:attrBegin], " \t")
+	link = applySubstitutions(doc, link)
+
+	if el.Attrs == nil {
+		el.Attrs = make(map[string]string)
+	}
+	el.Attrs[attrNameSrc] = string(link)
+
+	var listAttribute = bytes.Split(line[attrBegin+1:attrEnd], []byte(`,`))
+	if el.Attrs == nil {
+		el.Attrs = make(map[string]string)
+	}
+
+	var (
+		x        int
+		battr    []byte
+		hasWidth bool
+	)
+	for x, battr = range listAttribute {
+		if x == 0 {
+			var alt = bytes.TrimSpace(listAttribute[0])
+			if len(alt) == 0 {
+				var dot = bytes.IndexByte(link, '.')
+				if dot > 0 {
+					alt = link[:dot]
+				}
+			}
+			el.Attrs[attrNameAlt] = string(alt)
+			continue
+		}
+		if x == 1 {
+			if ascii.IsDigits(listAttribute[1]) {
+				el.Attrs[attrNameWidth] = string(listAttribute[1])
+				hasWidth = true
+				continue
+			}
+		}
+		if hasWidth && x == 2 {
+			if ascii.IsDigits(listAttribute[2]) {
+				el.Attrs[attrNameHeight] = string(listAttribute[2])
+			}
+		}
+
+		var attr = string(battr)
+		var kv = strings.SplitN(attr, `=`, 2)
+		if len(kv) != 2 {
+			continue
+		}
+		var key = strings.TrimSpace(kv[0])
+		var val = strings.Trim(kv[1], `"`)
+
+		switch key {
+		case attrNameFloat, attrNameAlign, attrNameRole:
+			if val == `center` {
+				val = `text-center`
+			}
+			el.addRole(val)
+
+		case attrNameLink:
+			val = string(applySubstitutions(doc, []byte(val)))
+			el.Attrs[key] = val
+
+		default:
+			el.Attrs[key] = val
+		}
+	}
+	return true
+}
+
+func parseInlineImage(doc *Document, content []byte) (el *element, n int) {
+	// If the next character is ':' (as in block "image::") mark it as
+	// invalid inline image, since this is block image that has been
+	// parsed but invalid (probably missing '[]').
+	if content[0] == ':' {
+		return nil, 0
+	}
+
+	_, n = indexByteUnescape(content, ']')
+	if n < 0 {
+		return nil, 0
+	}
+
+	var lineImage = content[:n+1]
+	el = &element{
+		elementAttribute: elementAttribute{
+			Attrs: make(map[string]string),
+		},
+		kind: elKindInlineImage,
+	}
+	if el.parseBlockImage(doc, lineImage) {
+		return el, n + 2
+	}
+	return nil, 0
+}
+
+func htmlWriteInlineImage(el *element, out io.Writer) {
+	var (
+		classes = strings.TrimSpace(`image ` + el.htmlClasses())
+
+		link     string
+		withLink bool
+	)
+
+	fmt.Fprintf(out, `<span class=%q>`, classes)
+	link, withLink = el.Attrs[attrNameLink]
+	if withLink {
+		fmt.Fprintf(out, `<a class=%q href=%q>`, attrValueImage, link)
+	}
+
+	var (
+		src = el.Attrs[attrNameSrc]
+		alt = el.Attrs[attrNameAlt]
+
+		width  string
+		height string
+		ok     bool
+	)
+
+	width, ok = el.Attrs[attrNameWidth]
+	if ok {
+		width = fmt.Sprintf(` width="%s"`, width)
+	}
+	height, ok = el.Attrs[attrNameHeight]
+	if ok {
+		height = fmt.Sprintf(` height="%s"`, height)
+	}
+
+	fmt.Fprintf(out, `<img src=%q alt=%q%s%s>`, src, alt, width, height)
+
+	if withLink {
+		fmt.Fprint(out, `</a>`)
+	}
+
+	fmt.Fprint(out, `</span>`)
+}