M4.90: Save for Web (Legacy) previews and saves optimised GIF, JPEG, PNG-8 and PNG-24 images, slices and HTML

File > Export > Save for Web (Legacy) (Ctrl/Cmd+Alt+Shift+S) opens a dialog with Original,
Optimized, 2-Up and 4-Up views showing each file's size and download time, and settings for
colour reduction, colours, dither, transparency and matte, interlacing, web snap, lossy GIF,
JPEG quality, the colour table (lock, map to transparent, web shift, sort), image size and
anti-aliasing, Clip to Artboard, sRGB, metadata, slices (all or selected), HTML output and
presets. Preview in Browser opens the HTML page.

Engine: document.exportForWeb, document.exportForWeb.preview (its byte count is the size of
the file Save writes), webExport.settings and webExport.presets.list/save/delete. Saved presets
and the remembered settings are stored in Prefs. Render: quantize_locked, and encode::web for
web snap, colour table edits, lossy GIF and GIF/JPEG comments. PNG files get an sRGB chunk.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/cmd/fileio/imagemap.rs

@@ -125,8 +125,8 @@ fn polygon(path: &kurbo::BezPath, tolerance: f64) -> Option<Vec<kurbo::Point>> {
     (pts.len() >= 3).then_some(pts)
 }
 
-/// Escape text for an HTML attribute.
-fn attr(s: &str) -> String {
+/// Escape text for an HTML attribute (or element text).
+pub(crate) fn attr(s: &str) -> String {
     s.chars().filter(|c| !c.is_control()).fold(String::with_capacity(s.len()), |mut o, c| {
         match c {
             '&' => o.push_str("&amp;"),

crates/engine/src/cmd/fileio/mod.rs

@@ -25,7 +25,7 @@ pub mod dxfimport;
 mod encode;
 pub mod eps;
 mod export;
-mod imagemap;
+pub(crate) mod imagemap;
 mod load;
 mod metafile;
 mod native;

crates/engine/src/cmd/mod.rs

@@ -64,6 +64,7 @@ pub(crate) mod typecmd;
 mod typemenu;
 pub(crate) mod views;
 pub mod wand;
+pub mod webexport;
 mod xform;
 
 use serde::Serialize;
@@ -233,6 +234,7 @@ pub fn command_specs() -> &'static [CommandSpec] {
         v.extend(print::specs());
         v.extend(recovery::specs());
         v.extend(fileio::dxfimport::specs());
+        v.extend(webexport::specs());
         v
     })
 }

crates/engine/src/cmd/slices.rs

@@ -209,7 +209,7 @@ fn selected(s: &Session) -> Result<Vec<NodeId>> {
     Ok(selected_slices(&st.doc, &st.selection))
 }
 
-fn selected_slices(d: &Document, sel: &vectorcraft_doc::Selection) -> Vec<NodeId> {
+pub(crate) fn selected_slices(d: &Document, sel: &vectorcraft_doc::Selection) -> Vec<NodeId> {
     let objects = sel.objects.iter().filter(|id| d.node(**id).is_some_and(|n| n.slice.is_some()));
     dedup(sel.slices.iter().chain(objects).copied().collect())
 }