SimpMusic Icons

Icons live in composeApp/src/commonMain/kotlin/com/maxrave/simpmusic/ui/icon/, one file per icon, each declaring val SimpIcons.<Name>: ImageVector.

Two things are deliberately absent and must not come back:

• the material-icons-core / material-icons-extended dependency (Icons.Rounded.*)
• XML icon drawables in composeResources/drawable used through painterResource(...)

Adding an icon

Google's font service generates the Compose file directly — no conversion tool needed:

curl -sfL --compressed \
  "https://fonts.gstatic.com/render/v1/Material+Symbols+Rounded/24dp/<symbol_name>.kt?var=opsz,wght,FILL,GRAD,ROND@24,400,1,0,50" \
  -o <PascalName>.kt

Keep these axes identical for every icon, or the set stops looking like one set: Rounded, opsz 24, wght 400, GRAD 0, ROND 50, FILL=1.

Use FILL=0 only for the "off" half of a state pair — FavoriteBorder, AddCircleOutline, DownloadForOfflineOutlined. At FILL=1 the off state renders identically to the on state and the distinction is lost.

Then edit the downloaded file:

1. package com.example.test → package com.maxrave.simpmusic.ui.icon
2. public val <symbol_name>: ImageVector → val SimpIcons.<PascalName>: ImageVector
3. Rename the backing field _<symbol_name> → _<PascalName>, and name = "<symbol_name>" → "<PascalName>"
4. If the glyph must flip in RTL, add autoMirror = true, inside ImageVector.Builder(...) (currently: ArrowForwardIos, QueueMusic, Sort, TrendingUp, VolumeOff, VolumeUp)

Using an icon

import com.maxrave.simpmusic.ui.icon.PlayArrow   // per-icon import, required
import com.maxrave.simpmusic.ui.icon.SimpIcons

Icon(SimpIcons.PlayArrow, contentDescription = null)

The project's own icon buttons take an ImageVector: RippleIconButton(imageVector = …), LiquidGlassIconButton(imageVector = …), ActionButton(icon = …).

Traps

Every icon needs its own import. val SimpIcons.X is an extension property; importing the SimpIcons object alone leaves it unresolved. This is the same mechanism that lets R8 strip unused icons, so never "simplify" the set into a map or a when — that would ship all of them.

ImageVector is not a Painter. Icon and Image have overloads for both, so those look fine. These do not, and need rememberVectorPainter(SimpIcons.X):

• AsyncImage(placeholder = …, error = …)
• anything drawn inside a DrawScope (with(painter) { draw(...) })
• custom composables whose parameter is typed Painter

Do not text-replace blindly. A regex swap of Res.drawable.X → SimpIcons.X produced 40 compile errors in one pass: it also hit Painter parameters, and it landed inside multi-line painterResource(\n Res.drawable.X,\n) calls, leaving the syntactically valid but wrong painterResource(SimpIcons.X).

Do not replace an icon whose colour carries meaning. These stay as resources:

If a state needs that colour with a shared symbol, pass it explicitly — e.g. ActionButton's iconColor = Color(0xFF00A0CB) for the downloaded state.

Verify the symbol name exists before assuming a mapping, against google/material-design-icons → variablefont/MaterialSymbolsRounded[FILL,GRAD,opsz,wght].codepoints. Legacy names such as favorite_border, add_circle_outline and thumb_up_alt do still exist; person_add_alt_1 does not (use person_add).

The response is gzipped even when the request asks for identity — curl --compressed, or decompress by magic bytes (\x1f\x8b) when fetching from a script.