change (room avatar) : introduce RoomAvatar and AvatarCluster to replace CompositeAvatar

libraries/designsystem/src/main/kotlin/io/element/android/libraries/designsystem/components/avatar/AvatarCluster.kt

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2024 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.designsystem.components.avatar
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.layout.size
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import io.element.android.libraries.designsystem.preview.ElementThemedPreview
+import io.element.android.libraries.designsystem.preview.PreviewGroup
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.collections.immutable.toPersistentList
+import java.util.Collections
+import kotlin.math.PI
+import kotlin.math.cos
+import kotlin.math.sin
+
+private const val MAX_AVATAR_COUNT = 4
+
+@Composable
+fun AvatarCluster(
+    avatars: ImmutableList<AvatarData>,
+    modifier: Modifier = Modifier,
+    hideAvatarImages: Boolean = false,
+    contentDescription: String? = null,
+) {
+    val limitedAvatars = avatars.take(MAX_AVATAR_COUNT)
+    val numberOfAvatars = limitedAvatars.size
+    if (numberOfAvatars == 4) {
+        // Swap 2 and 3 so that the 4th avatar is at the bottom right
+        Collections.swap(limitedAvatars, 2, 3)
+    }
+    when (numberOfAvatars) {
+        0 -> {
+            error("Unsupported number of avatars: 0")
+        }
+        1 -> {
+            Avatar(
+                avatarData = limitedAvatars[0],
+                modifier = modifier,
+                contentDescription = contentDescription,
+                hideImage = hideAvatarImages
+            )
+        }
+        else -> {
+            val size = limitedAvatars.first().size
+            val angle = 2 * Math.PI / numberOfAvatars
+            val offsetRadius = when (numberOfAvatars) {
+                2 -> size.dp.value / 4.2
+                3 -> size.dp.value / 4.0
+                4 -> size.dp.value / 3.1
+                else -> error("Unsupported number of heroes: $numberOfAvatars")
+            }
+            val heroAvatarSize = when (numberOfAvatars) {
+                2 -> size.dp / 2.2f
+                3 -> size.dp / 2.4f
+                4 -> size.dp / 2.2f
+                else -> error("Unsupported number of heroes: $numberOfAvatars")
+            }
+            val angleOffset = when (numberOfAvatars) {
+                2 -> PI
+                3 -> 7 * PI / 6
+                4 -> 13 * PI / 4
+                else -> error("Unsupported number of heroes: $numberOfAvatars")
+            }
+            Box(
+                modifier = modifier
+                    .size(size.dp)
+                    .semantics {
+                        this.contentDescription = contentDescription.orEmpty()
+                    },
+                contentAlignment = Alignment.Center,
+            ) {
+                limitedAvatars.forEachIndexed { index, heroAvatar ->
+                    val xOffset = (offsetRadius * cos(angle * index.toDouble() + angleOffset)).dp
+                    val yOffset = (offsetRadius * sin(angle * index.toDouble() + angleOffset)).dp
+                    Box(
+                        modifier = Modifier
+                            .size(heroAvatarSize)
+                            .offset(
+                                x = xOffset,
+                                y = yOffset,
+                            )
+                    ) {
+                        Avatar(
+                            avatarData = heroAvatar,
+                            forcedAvatarSize = heroAvatarSize,
+                            hideImage = hideAvatarImages,
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Preview(group = PreviewGroup.Avatars)
+@Composable
+internal fun AvatarClusterPreview() = ElementThemedPreview {
+    Row(
+        horizontalArrangement = Arrangement.spacedBy(8.dp)
+    ) {
+        repeat(6) { ngOfAvatars ->
+            AvatarCluster(
+                avatars = List(ngOfAvatars) { anAvatarData(it) }.toPersistentList(),
+            )
+        }
+    }
+}
+
+private fun anAvatarData(i: Int) = anAvatarData(
+    id = ('A' + i).toString(),
+    name = ('A' + i).toString()
+)

libraries/designsystem/src/main/kotlin/io/element/android/libraries/designsystem/components/avatar/RoomAvatar.kt

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.designsystem.components.avatar
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import kotlinx.collections.immutable.ImmutableList
+
+@Composable
+fun RoomAvatar(
+    avatarData: AvatarData,
+    heroes: ImmutableList<AvatarData>,
+    modifier: Modifier = Modifier,
+    isTombstoned: Boolean = false,
+    hideAvatarImage: Boolean = false,
+    contentDescription: String? = null,
+) {
+    when  {
+        isTombstoned -> {
+            TombstonedRoomAvatar(
+                size = avatarData.size,
+                modifier = modifier,
+                contentDescription = contentDescription
+            )
+        }
+        avatarData.url != null || heroes.isEmpty() -> {
+            Avatar(
+                avatarData = avatarData,
+                modifier = modifier,
+                contentDescription = contentDescription,
+                hideImage = hideAvatarImage
+            )
+        }
+        else -> {
+            AvatarCluster(
+                avatars = heroes,
+                modifier = modifier,
+                hideAvatarImages = hideAvatarImage,
+                contentDescription = contentDescription
+            )
+        }
+    }
+}