[fenix] For https://github.com/mozilla-mobile/fenix/issues/26115 - Change homescreen Show all button color according to wallpaper

app/src/main/java/org/mozilla/fenix/compose/home/HomeSectionHeader.kt

@@ -4,14 +4,15 @@
 
 package org.mozilla.fenix.compose.home
 
-import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.wrapContentHeight
 import androidx.compose.foundation.text.ClickableText
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
@@ -20,10 +21,14 @@ import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import mozilla.components.lib.state.ext.observeAsComposableState
 import org.mozilla.fenix.R
+import org.mozilla.fenix.components.components
 import org.mozilla.fenix.compose.SectionHeader
+import org.mozilla.fenix.compose.inComposePreview
 import org.mozilla.fenix.theme.FirefoxTheme
 import org.mozilla.fenix.theme.Theme
+import org.mozilla.fenix.wallpapers.Wallpaper
 
 /**
  * Homepage header.
@@ -37,6 +42,47 @@ fun HomeSectionHeader(
     headerText: String,
     description: String,
     onShowAllClick: () -> Unit
+) {
+    if (inComposePreview) {
+        HomeSectionHeaderContent(
+            headerText = headerText,
+            description = description,
+            onShowAllClick = onShowAllClick
+        )
+    } else {
+        val wallpaperState = components.appStore
+            .observeAsComposableState { state -> state.wallpaperState }.value
+
+        val isWallpaperDefault =
+            (wallpaperState?.currentWallpaper ?: Wallpaper.Default) == Wallpaper.Default
+
+        HomeSectionHeaderContent(
+            headerText = headerText,
+            description = description,
+            showAllTextColor = if (isWallpaperDefault) {
+                FirefoxTheme.colors.textAccent
+            } else {
+                FirefoxTheme.colors.textPrimary
+            },
+            onShowAllClick = onShowAllClick,
+        )
+    }
+}
+
+/**
+ * Homepage header content.
+ *
+ * @param headerText The header string.
+ * @param description The description for click action
+ * @param showAllTextColor [Color] for the "Show all" button.
+ * @param onShowAllClick Invoked when "Show all" button is clicked.
+ */
+@Composable
+private fun HomeSectionHeaderContent(
+    headerText: String,
+    description: String,
+    showAllTextColor: Color = FirefoxTheme.colors.textAccent,
+    onShowAllClick: () -> Unit,
 ) {
     Row(
         modifier = Modifier.fillMaxWidth(),
@@ -55,7 +101,7 @@ fun HomeSectionHeader(
                     contentDescription = description
                 },
             style = TextStyle(
-                color = FirefoxTheme.colors.textAccent,
+                color = showAllTextColor,
                 fontSize = 14.sp
             ),
             onClick = { onShowAllClick() }