Make links a static accent and default avatars a flat tint

Links now use the flat accent colour and default avatars the same
semi-transparent warm tint as dates and delivery ticks, instead of
sampling the sunrise gradient by on-screen position.

The sampling machinery did real work on every frame: link colour
recomposed as items scrolled, and each default avatar rendered
through an offscreen compositing layer to mask the gradient onto the
icon. Both are gone — links are a plain span colour, avatars set
their icon tint directly. Bubbles keep the position-sampled gradient
(they can't be flat-tinted: the wallpaper pattern would show through
and hurt text legibility). Non-SIMPLEX themes are unaffected.

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/ui/theme/SimplexBrushes.kt

@@ -6,13 +6,9 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.composed
 import androidx.compose.ui.draw.drawBehind
-import androidx.compose.ui.draw.drawWithContent
 import androidx.compose.ui.geometry.Offset
-import androidx.compose.ui.graphics.BlendMode
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.CompositingStrategy
-import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.layout.onSizeChanged
 import androidx.compose.ui.layout.positionInWindow
@@ -31,12 +27,6 @@ import kotlin.math.sin
 private const val SIMPLEX_TILT_DEG = 20f
 
 // Per-wallpaper gradient stops live in PresetWallpaper._simplexStops (ChatWallpaper.kt).
-// Only LINK_STOPS is global — aligned with primary accent, not wallpaper-dependent.
-private val LINK_STOPS = listOf(
-  0.55f to oklch(0.7993f, 0.1442f, 220.36f),  // hue aligned with primary (cyan) — sRGB #00D3F9
-  0.80f to oklch(0.8600f, 0.1000f, 220.36f),  // lighter, same hue
-)
-
 val LocalSimplexLinkColor = compositionLocalOf<Color?> { null }
 
 class ChatViewportInfo(
@@ -74,23 +64,6 @@ private fun axisEndpoints(winW: Float, winH: Float): Pair<Offset, Offset> {
   return start to end
 }
 
-private fun sampleStops(stops: List<Pair<Float, Color>>, t: Float): Color {
-  if (t <= stops.first().first) return stops.first().second
-  if (t >= stops.last().first) return stops.last().second
-  for (i in 0 until stops.size - 1) {
-    val a = stops[i]; val b = stops[i + 1]
-    if (t in a.first..b.first) {
-      val f = (t - a.first) / (b.first - a.first)
-      return Color(
-        red = a.second.red + f * (b.second.red - a.second.red),
-        green = a.second.green + f * (b.second.green - a.second.green),
-        blue = a.second.blue + f * (b.second.blue - a.second.blue),
-      )
-    }
-  }
-  return stops.last().second
-}
-
 enum class SimplexBubbleSlot { Sent, SentQuote, Received, ReceivedQuote }
 
 /** SimplexStops for a wallpaper, or null when it has none. */
@@ -169,37 +142,9 @@ fun Modifier.chatBubbleBackground(
   )
 }
 
-// Tint a single-colour icon (e.g. default ProfileImage placeholder) with the
-// SIMPLEX axis brush. Drawn as an overlay using BlendMode.SrcAtop so the brush
-// is masked by the icon's existing alpha — the icon's shape is preserved and
-// only its colour is replaced by the gradient.
-fun Modifier.simplexAvatarBrushOverlay(slot: SimplexBubbleSlot): Modifier = composed {
-  if (!isSimplexActive()) return@composed this
-  val viewport = LocalChatViewportInfo.current ?: return@composed this
-  val avatarPos = remember { mutableStateOf(Offset.Zero) }
-  val stops = stopsFor(slot) ?: return@composed this
-  this
-    .onGloballyPositioned { avatarPos.value = it.positionInWindow() }
-    .graphicsLayer { compositingStrategy = CompositingStrategy.Offscreen }
-    .drawWithContent {
-      drawContent()
-      val sz = viewport.sizePx.value
-      if (sz.width == 0 || sz.height == 0) return@drawWithContent
-      val (axisStartLocal, axisEndLocal) = axisEndpoints(sz.width.toFloat(), sz.height.toFloat())
-      val viewportOrigin = viewport.originInWindow.value
-      val offset = viewportOrigin - avatarPos.value
-      val brush = Brush.linearGradient(
-        colorStops = stops,
-        start = axisStartLocal + offset,
-        end = axisEndLocal + offset,
-      )
-      drawRect(brush, blendMode = BlendMode.SrcAtop)
-    }
-}
-
-// Static tinted-transparency for small text on the SIMPLEX gradient. A semi-transparent
-// warm colour blends with the gradient at every height, so text stays uniformly legible
-// without sampling the axis by screen position (bubbles and avatars still sample it).
+// Static tinted-transparency for small text and default avatars on the SIMPLEX gradient. A
+// semi-transparent warm colour blends with the gradient at every height, so it stays uniformly
+// legible without sampling the axis by screen position (only bubbles still sample it).
 // Composition-scoped: honours the per-chat override / wallpaper preview, and its fallback is
 // the composition secondary, so non-SIMPLEX chats keep their own (override-aware) colour.
 @Composable
@@ -213,28 +158,3 @@ fun simplexAuthorTint(): Color {
   if (!isSimplexActive()) return MaterialTheme.colors.onBackground
   return activeSimplexStops()?.authorTint ?: MaterialTheme.colors.onBackground
 }
-
-// Link colour still samples the axis — accent cyan aligned across the whole screen.
-@Composable
-fun simplexLinkColor(): Pair<Color, Modifier> = simplexAxisSampledColor(LINK_STOPS, MaterialTheme.colors.primary)
-
-@Composable
-private fun simplexAxisSampledColor(stops: List<Pair<Float, Color>>?, fallback: Color): Pair<Color, Modifier> {
-  val isSimplex = isSimplexActive()
-  val viewport = LocalChatViewportInfo.current
-  if (!isSimplex || viewport == null || stops == null) return fallback to Modifier
-  val color = remember(stops) { mutableStateOf(stops.first().second) }
-  val mod = Modifier.onGloballyPositioned { coords ->
-    val sz = viewport.sizePx.value
-    if (sz.width == 0 || sz.height == 0) return@onGloballyPositioned
-    val pos = coords.positionInWindow() - viewport.originInWindow.value
-    val cx = pos.x + coords.size.width / 2f
-    val cy = pos.y + coords.size.height / 2f
-    val (axisStart, axisEnd) = axisEndpoints(sz.width.toFloat(), sz.height.toFloat())
-    val span = (axisEnd - axisStart)
-    val spanLen2 = span.x * span.x + span.y * span.y
-    val t = ((cx - axisStart.x) * span.x + (cy - axisStart.y) * span.y) / spanLen2
-    color.value = sampleStops(stops, t.coerceIn(0f, 1f))
-  }
-  return color.value to mod
-}

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/ChatView.kt

@@ -2064,10 +2064,8 @@ fun BoxScope.ChatItemsList(
                       }
                       Row(Modifier.graphicsLayer { translationX = selectionOffset.toPx() }) {
                         val member = cItem.chatDir.groupMember
-                        val memberAvatarOverlay = if (CurrentColors.value.base == DefaultTheme.SIMPLEX && member.image == null)
-                          Modifier.simplexAvatarBrushOverlay(SimplexBubbleSlot.ReceivedQuote) else Modifier
-                        Box(Modifier.clickable { showMemberInfo(chatInfo.groupInfo, member) }.then(memberAvatarOverlay)) {
-                          MemberImage(member)
+                        Box(Modifier.clickable { showMemberInfo(chatInfo.groupInfo, member) }) {
+                          MemberImage(member, color = if (CurrentColors.value.base == DefaultTheme.SIMPLEX && member.image == null) simplexSecondaryTint() else MaterialTheme.colors.secondaryVariant)
                         }
                         Box(modifier = Modifier.padding(top = 2.dp, start = 4.dp).chatItemOffset(cItem, itemSeparation.largeGap, revealed = revealed.value)) {
                           ChatItemViewShortHand(cItem, itemSeparation, range, false, dismissState.offset.value)
@@ -2299,9 +2297,7 @@ fun BoxScope.ChatItemsList(
           .padding(top = DEFAULT_PADDING_HALF)
           .let { if (CurrentColors.value.base == DefaultTheme.SIMPLEX) it else it.background(MaterialTheme.appColors.receivedMessage) }
       ) {
-        Box(if (CurrentColors.value.base == DefaultTheme.SIMPLEX && chatInfo.image == null) Modifier.simplexAvatarBrushOverlay(SimplexBubbleSlot.ReceivedQuote) else Modifier) {
-          ChatInfoImage(chatInfo, size = alertProfileImageSize, iconColor = MaterialTheme.colors.secondaryVariant.mixWith(MaterialTheme.colors.onBackground, 0.97f))
-        }
+        ChatInfoImage(chatInfo, size = alertProfileImageSize, iconColor = if (CurrentColors.value.base == DefaultTheme.SIMPLEX && chatInfo.image == null) simplexSecondaryTint() else MaterialTheme.colors.secondaryVariant.mixWith(MaterialTheme.colors.onBackground, 0.97f))
         val bannerBadge = chatInfo.nameBadge
         val uriHandler = LocalUriHandler.current
         Text(
@@ -2820,8 +2816,8 @@ private suspend fun preloadItemsAfter(
 val MEMBER_IMAGE_SIZE: Dp = 37.dp
 
 @Composable
-fun MemberImage(member: GroupMember) {
-  MemberProfileImage(MEMBER_IMAGE_SIZE * fontSizeSqrtMultiplier, member, backgroundColor = MaterialTheme.colors.background)
+fun MemberImage(member: GroupMember, color: Color = MaterialTheme.colors.secondaryVariant) {
+  MemberProfileImage(MEMBER_IMAGE_SIZE * fontSizeSqrtMultiplier, member, color = color, backgroundColor = MaterialTheme.colors.background)
 }
 
 @Composable

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CIFileView.kt

@@ -55,16 +55,12 @@ fun CIFileView(
     ) {
       val isDefaultTint = color == (if (isInDarkTheme()) FileDark else FileLight)
       val isSimplex = CurrentColors.value.base == DefaultTheme.SIMPLEX
-      val outerOverlay = if (isSimplex && isDefaultTint)
-        Modifier.simplexAvatarBrushOverlay(SimplexBubbleSlot.ReceivedQuote) else Modifier
-      Box(outerOverlay.fillMaxSize()) {
-        Icon(
-          painterResource(MR.images.ic_draft_filled),
-          stringResource(MR.strings.icon_descr_file),
-          Modifier.fillMaxSize(),
-          tint = color
-        )
-      }
+      Icon(
+        painterResource(MR.images.ic_draft_filled),
+        stringResource(MR.strings.icon_descr_file),
+        Modifier.fillMaxSize(),
+        tint = if (isSimplex && isDefaultTint) simplexSecondaryTint() else color
+      )
       if (innerIcon != null) {
         Icon(
           innerIcon,

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/CIGroupInvitationView.kt

@@ -53,15 +53,11 @@ fun CIGroupInvitationView(
       if (action && !inProgress.value) if (chatIncognito) Indigo else MaterialTheme.colors.primary
       else if (isInDarkTheme()) FileDark else FileLight
     val isSimplex = CurrentColors.value.base == DefaultTheme.SIMPLEX
-    val avatarOverlayMod = if (isSimplex && groupInvitation.groupProfile.image == null)
-      Modifier.simplexAvatarBrushOverlay(SimplexBubbleSlot.ReceivedQuote) else Modifier
 
     Row(
       Modifier.defaultMinSize(minWidth = 220.dp)
     ) {
-      Box(avatarOverlayMod) {
-        ProfileImage(size = 54.dp, image = groupInvitation.groupProfile.image, icon = MR.images.ic_supervised_user_circle_filled, color = iconColor)
-      }
+      ProfileImage(size = 54.dp, image = groupInvitation.groupProfile.image, icon = MR.images.ic_supervised_user_circle_filled, color = if (isSimplex && groupInvitation.groupProfile.image == null) simplexSecondaryTint() else iconColor)
       Spacer(Modifier.width(8.dp))
       Column(
         Modifier.defaultMinSize(minHeight = 54.dp),

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/FramedItemView.kt

@@ -207,13 +207,11 @@ fun FramedItemView(
   val transparentBackground = (ci.content.msgContent is MsgContent.MCImage || ci.content.msgContent is MsgContent.MCVideo) &&
       !ci.meta.isLive && ci.content.text.isEmpty() && ci.quotedItem == null && ci.meta.itemForwarded == null
 
-  val (linkColor, linkModifier) = simplexLinkColor()
   Box(Modifier
     .clipChatItem(ci, tailVisible, revealed = true)
-    .chatBubbleBackground(sent = sent, isQuote = false, transparent = transparentBackground)
-    .then(linkModifier)) {
+    .chatBubbleBackground(sent = sent, isQuote = false, transparent = transparentBackground)) {
     var metaColor: Color? = null
-    CompositionLocalProvider(LocalSimplexLinkColor provides linkColor) {
+    CompositionLocalProvider(LocalSimplexLinkColor provides MaterialTheme.colors.primary) {
     Box(contentAlignment = Alignment.BottomEnd) {
       val chatItemTail = remember { appPreferences.chatItemTail.state }
       val style = shapeStyle(ci, chatItemTail.value, tailVisible, true)