Fix WindowSizeClass breakpoint compat

app/src/minApi21/java/io/nekohasekai/sfa/compat/WindowSizeClassCompat.kt

@@ -0,0 +1,17 @@
+package io.nekohasekai.sfa.compat
+
+import androidx.window.core.layout.WindowSizeClass
+import androidx.window.core.layout.WindowWidthSizeClass
+
+object WindowSizeClassCompat {
+    const val WIDTH_DP_MEDIUM_LOWER_BOUND = 600
+    const val WIDTH_DP_EXPANDED_LOWER_BOUND = 840
+}
+
+fun WindowSizeClass.isWidthAtLeastBreakpointCompat(breakpointDp: Int): Boolean = when {
+    breakpointDp <= WindowSizeClassCompat.WIDTH_DP_MEDIUM_LOWER_BOUND ->
+        windowWidthSizeClass != WindowWidthSizeClass.COMPACT
+    breakpointDp <= WindowSizeClassCompat.WIDTH_DP_EXPANDED_LOWER_BOUND ->
+        windowWidthSizeClass == WindowWidthSizeClass.EXPANDED
+    else -> windowWidthSizeClass == WindowWidthSizeClass.EXPANDED
+}