🎨 Palette: Add toast feedback when copying to clipboard on Android 12 and below

.Jules/palette.md

@@ -180,3 +180,7 @@
 ## 2024-06-13 - Optimize CameraCharacteristics retrieval loop
 **Learning:** When querying expensive Android system services like `CameraManager.getCameraCharacteristics` inside a loop, combining filter and map operations into a single pass (e.g., using `mapNotNull`) prevents redundant IPC calls and noticeably improves execution speed.
 **Action:** Replaced a `filter {} .forEach {}` pipeline containing duplicated `getCameraCharacteristics` calls with a single `mapNotNull` pass that pairs valid camera IDs with their retrieved characteristics, eliminating 50% of the overhead.
+
+## 2026-09-09 - Copy to clipboard toast UX
+**Learning:** Native clipboard feedback was added in Android 13, but custom implementations for older versions are often forgotten. When implementing copy actions using `ClipboardManager`, you must explicitly check the API version (`Build.VERSION.SDK_INT <= Build.VERSION_CODES.S_V2`) and only provide manual visual feedback (like Toasts) on older OS versions to prevent annoying duplicate overlays on newer devices.
+**Action:** Always condition custom copy-to-clipboard visual feedback on the target OS version to defer to native OS behavior when available.

app/src/main/java/com/samsung/android/scan3d/util/ClipboardUtil.kt

@@ -2,12 +2,18 @@ package com.samsung.android.scan3d.util
 
 import android.content.ClipData
 import android.content.Context
+import android.os.Build
+import android.widget.Toast
+import com.samsung.android.scan3d.R
 
 object ClipboardUtil {
 
     fun copyToClipboard(context: Context?, label: String, text: String) {
-        val clipboard = context?.getSystemService(Context.CLIPBOARD_SERVICE) as android.content.ClipboardManager
+        val clipboard = context?.getSystemService(Context.CLIPBOARD_SERVICE) as? android.content.ClipboardManager ?: return
         val clip = ClipData.newPlainText(label, text)
         clipboard.setPrimaryClip(clip)
+        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.S_V2) {
+            Toast.makeText(context, R.string.copied_to_clipboard, Toast.LENGTH_SHORT).show()
+        }
     }
 }

app/src/test/java/com/samsung/android/scan3d/util/ClipboardUtilTest.kt

@@ -3,6 +3,8 @@ package com.samsung.android.scan3d.util
 import android.content.ClipData
 import android.content.ClipboardManager
 import android.content.Context
+import android.os.Build
+import android.widget.Toast
 import org.junit.Test
 import org.mockito.ArgumentCaptor
 import org.mockito.Mockito.*
@@ -15,18 +17,23 @@ class ClipboardUtilTest {
         val mockContext = mock(Context::class.java)
         val mockClipboard = mock(ClipboardManager::class.java)
         val mockClipData = mock(ClipData::class.java)
+        val mockToast = mock(Toast::class.java)
 
         `when`(mockContext.getSystemService(Context.CLIPBOARD_SERVICE)).thenReturn(mockClipboard)
 
-        mockStatic(ClipData::class.java).use { mockedStatic ->
-            mockedStatic.`when`<ClipData> { ClipData.newPlainText("test_label", "test_text") }.thenReturn(mockClipData)
+        mockStatic(Toast::class.java).use { mockedToastStatic ->
+            mockedToastStatic.`when`<Toast> { Toast.makeText(any(Context::class.java), anyInt(), anyInt()) }.thenReturn(mockToast)
+
+            mockStatic(ClipData::class.java).use { mockedStatic ->
+                mockedStatic.`when`<ClipData> { ClipData.newPlainText("test_label", "test_text") }.thenReturn(mockClipData)
 
-            ClipboardUtil.copyToClipboard(mockContext, "test_label", "test_text")
+                ClipboardUtil.copyToClipboard(mockContext, "test_label", "test_text")
 
-            val clipCaptor = ArgumentCaptor.forClass(ClipData::class.java)
-            verify(mockClipboard).setPrimaryClip(clipCaptor.capture())
+                val clipCaptor = ArgumentCaptor.forClass(ClipData::class.java)
+                verify(mockClipboard).setPrimaryClip(clipCaptor.capture())
 
-            assertEquals(mockClipData, clipCaptor.value)
+                assertEquals(mockClipData, clipCaptor.value)
+            }
         }
     }
 
@@ -36,13 +43,8 @@ class ClipboardUtilTest {
         mockStatic(ClipData::class.java).use { mockedStatic ->
             mockedStatic.`when`<ClipData> { ClipData.newPlainText("test_label", "test_text") }.thenReturn(mockClipData)
 
-            try {
-                ClipboardUtil.copyToClipboard(null, "test_label", "test_text")
-                fail("Expected Exception when context is null")
-            } catch (e: Exception) {
-                // If context is null, it throws NullPointerException because of `as android.content.ClipboardManager`
-                assertEquals(NullPointerException::class.java, e::class.java)
-            }
+            // Since context is null, it returns early now due to the safe cast and null check `?: return`
+            ClipboardUtil.copyToClipboard(null, "test_label", "test_text")
         }
     }
 }