Add custom reaction layout

- Add the custom reaction layout that only shows the expand UI after 2 lines. - It also enforces that the add more and expand buttons are always on the same line. - In LTR languages we want an incoming message's reactions to be LRT and outgoing to be RTL. - For RTL languages it should be the opposite.
2023-07-18 21:18:27 +01:00
parent 467ce70ba8
commit a1c482d673
3 changed files with 274 additions and 112 deletions
--- a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemEventRow.kt
+++ b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemEventRow.kt
@@ -291,7 +291,7 @@ private fun TimelineItemEventRowContent(
        if (event.reactionsState.reactions.isNotEmpty()) {
            TimelineItemReactions(
                reactionsState = event.reactionsState,
-                mainAxisAlignment = if (event.isMine) FlowMainAxisAlignment.End else FlowMainAxisAlignment.Start,
+                isOutgoing = event.isMine,
                onReactionClicked = onReactionClicked,
                onMoreReactionsClicked = { onMoreReactionsClicked(event) },
                modifier = Modifier
--- a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemReactionsLayout.kt
+++ b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemReactionsLayout.kt
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) 2023 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.messages.impl.timeline.components
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.AddReaction
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.MeasureResult
+import androidx.compose.ui.layout.Placeable
+import androidx.compose.ui.layout.SubcomposeLayout
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.IntOffset
+import androidx.compose.ui.unit.dp
+import io.element.android.features.messages.impl.R
+import io.element.android.libraries.designsystem.preview.DayNightPreviews
+import io.element.android.libraries.designsystem.preview.ElementPreview
+
+/**
+ * A flow layout for reactions that will show a collapse/expand button when the layout wraps over a defined number of rows.
+ * It displays an add more button when there are greater than 0 reactions and always displays the reaction and add more button
+ * on the same row (moving them both to a new row if necessary).
+ * @param itemSpacing The horizontal spacing between items
+ * @param rowSpacing The vertical spacing between rows
+ * @param expanded Whether the layout should display in expanded or collapsed state
+ * @param rowsBeforeCollapsible The number of rows before the collapse/expand button is shown
+ * @param expandButton The expand button
+ * @param addMoreButton The add more button
+ * @param reactions The reaction buttons
+ */
+@Composable
+fun TimelineItemReactionsLayout(
+    modifier: Modifier = Modifier,
+    itemSpacing: Dp = 0.dp,
+    rowSpacing: Dp = 0.dp,
+    expanded: Boolean = false,
+    rowsBeforeCollapsible: Int? = 2,
+    expandButton: @Composable () -> Unit,
+    addMoreButton: @Composable () -> Unit,
+    reactions: @Composable () -> Unit
+) {
+    SubcomposeLayout(modifier) { constraints ->
+        // Given the placeables and returns a structure representing
+        // how they should wrap on to multiple rows given the constraints max width.
+        fun calculateRows(measurables: List<Placeable>): List<List<Placeable>> {
+            val rows = mutableListOf<List<Placeable>>()
+            var currentRow = mutableListOf<Placeable>()
+            var rowX = 0
+
+            measurables.forEach { placeable ->
+                val horizontalSpacing = if (currentRow.isEmpty()) 0 else itemSpacing.toPx().toInt()
+                // If the current view does not fine on this row bump to the next
+                if (rowX + placeable.width > constraints.maxWidth) {
+                    rows.add(currentRow)
+                    currentRow = mutableListOf()
+                    rowX = 0
+                }
+                rowX += horizontalSpacing + placeable.width
+                currentRow.add(placeable)
+            }
+            // If there are items in the current row remember to append it to the returned value
+            if (currentRow.size > 0) {
+                rows.add(currentRow)
+            }
+            return rows
+        }
+
+        // Used to render the collapsed state, this takes the rows inputted and adds the extra button to the last row,
+        // removing only as many trailing reactions as needed to make space for it.
+        fun replaceTrailingItemsWithButtons(rowsIn: List<List<Placeable>>, expandButton: Placeable, addMoreButton: Placeable): List<List<Placeable>> {
+            val rows = rowsIn.toMutableList()
+            val lastRow = rows[rows.size - 1]
+            val buttonsWidth = expandButton.width + itemSpacing.toPx().toInt() + addMoreButton.width
+            var rowX = 0
+            lastRow.forEachIndexed { i, placeable ->
+                val horizontalSpacing = if (i == 0) 0 else itemSpacing.toPx().toInt()
+                rowX += placeable.width + horizontalSpacing
+                if (rowX > (constraints.maxWidth - (buttonsWidth + horizontalSpacing))) {
+                    val lastRowWithButton = lastRow.take(i) + listOf(expandButton, addMoreButton)
+                    rows[rows.size - 1] = lastRowWithButton
+                    return rows
+                }
+            }
+            val lastRowWithButton = lastRow + listOf(expandButton, addMoreButton)
+            rows[rows.size - 1] = lastRowWithButton
+            return rows
+        }
+
+        // To prevent the add more and expand buttons from wrapping on to separate lines.
+        // If there is one item on the last line, it moves the expand button down.
+        fun ensureCollapseAndAddMoreButtonsAreOnTheSameRow(rowsIn: List<List<Placeable>>): List<List<Placeable>> {
+            val lastRow = rowsIn.last().toMutableList()
+            if (lastRow.size != 1) {
+                return rowsIn
+            }
+            val rows = rowsIn.toMutableList()
+            val secondLastRow = rows[rows.size - 2].toMutableList()
+            val expandButtonPlaceable = secondLastRow.removeLast()
+            lastRow.add(0, expandButtonPlaceable)
+            rows[rows.size - 2] = secondLastRow
+            rows[rows.size - 1] = lastRow
+            return rows
+        }
+
+        /// Given a list of rows place them in the layout.
+        fun layoutRows(rows: List<List<Placeable>>): MeasureResult {
+            var width = 0
+            var height = 0
+            val placeables = rows.mapIndexed { i, row ->
+                var rowX = 0
+                var rowHeight = 0
+                val verticalSpacing = if (i == 0) 0 else rowSpacing.toPx().toInt()
+                val rowWithPoints = row.mapIndexed { j, placeable ->
+                    val horizontalSpacing = if (j == 0) 0 else itemSpacing.toPx().toInt()
+                    val point = IntOffset(rowX + horizontalSpacing, height + verticalSpacing)
+                    rowX += placeable.width + horizontalSpacing
+                    rowHeight = maxOf(rowHeight, placeable.height)
+                    Pair(placeable, point)
+                }
+                height += rowHeight + verticalSpacing
+                width = maxOf(width, rowX)
+                rowWithPoints
+            }.flatten()
+
+            return layout(width = width, height = height) {
+                placeables.forEach {
+                    val (placeable, origin) = it
+                    placeable.placeRelative(origin.x, origin.y)
+                }
+            }
+        }
+
+        val reactionsPlaceables = subcompose(0, reactions).map { it.measure(constraints) }
+        if (reactionsPlaceables.isEmpty()) {
+            return@SubcomposeLayout layoutRows(listOf())
+        }
+        val addMorePlaceable = subcompose(1, addMoreButton).first().measure(constraints)
+        val expandPlaceable = subcompose(2, expandButton).first().measure(constraints)
+
+        // Calculate the layout of the rows with the reactions button and add more button
+        val reactionsAndAddMore = calculateRows(reactionsPlaceables + listOf(addMorePlaceable))
+        // If we have extended beyond the defined number of rows we are showing the expand/collapse ui
+        if (rowsBeforeCollapsible?.let { reactionsAndAddMore.size > it } == true) {
+            if (expanded) {
+                // Show all subviews with the add more button at the end
+                var reactionsAndButtons = calculateRows(reactionsPlaceables + listOf(expandPlaceable, addMorePlaceable))
+                reactionsAndButtons = ensureCollapseAndAddMoreButtonsAreOnTheSameRow(reactionsAndButtons)
+                layoutRows(reactionsAndButtons)
+            } else {
+                // Truncate to `rowsBeforeCollapsible` number of rows and replace the reactions at the end of the last row with the buttons
+                val collapsedRows = reactionsAndAddMore.take(rowsBeforeCollapsible)
+                val collapsedRowsWithButtons = replaceTrailingItemsWithButtons(collapsedRows, expandPlaceable, addMorePlaceable)
+                layoutRows(collapsedRowsWithButtons)
+            }
+        } else {
+            // Otherwise we are just showing all items without the expand button
+            layoutRows(reactionsAndAddMore)
+        }
+    }
+}
+
+@DayNightPreviews
+@Composable
+internal fun TimelineItemReactionsLayoutPreview() = ElementPreview {
+    TimelineItemReactionsLayout(
+        expanded = false,
+        expandButton = {
+            MessagesReactionButton(
+                content = MessagesReactionsButtonContent.Text(
+                    text = stringResource(id = R.string.screen_room_timeline_less_reactions)
+                ),
+                onClick = { },
+            )
+        },
+        addMoreButton = {
+            MessagesReactionButton(
+                content = MessagesReactionsButtonContent.Icon(Icons.Outlined.AddReaction),
+                onClick = {}
+            )
+        },
+        reactions = {
+            io.element.android.features.messages.impl.timeline.aTimelineItemReactions(count = 18).reactions.forEach {
+                MessagesReactionButton(
+                    content = MessagesReactionsButtonContent.Reaction(
+                        it
+                    ),
+                    onClick = {}
+                )
+            }
+        }
+    )
+}
--- a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemReactionsView.kt
+++ b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/TimelineItemReactionsView.kt
@@ -19,18 +19,16 @@ package io.element.android.features.messages.impl.timeline.components
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.outlined.AddReaction
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.res.pluralStringResource
+import androidx.compose.ui.platform.LocalLayoutDirection
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.unit.dp
-import com.google.accompanist.flowlayout.FlowMainAxisAlignment
-import com.google.accompanist.flowlayout.FlowRow
 import io.element.android.features.messages.impl.R
 import io.element.android.features.messages.impl.timeline.aTimelineItemReactions
 import io.element.android.features.messages.impl.timeline.model.AggregatedReaction
@@ -38,162 +36,119 @@ import io.element.android.features.messages.impl.timeline.model.TimelineItemReac
 import io.element.android.libraries.designsystem.preview.DayNightPreviews
 import io.element.android.libraries.designsystem.preview.ElementPreview
 import kotlinx.collections.immutable.ImmutableList
-import kotlinx.collections.immutable.toPersistentList
-
-/**
- * The maximum number of items that can be displayed before some items will be hidden
- *
- * TODO The threshold should be based on the number of rows, rather than items.
- *       Once items would spill onto a third row, they should be hidden.
- *       Note this could be particularly worthwhile to handle reactions that are
- *       longer than a single character (as annotation keys are free text).
- */
-private const val COLLAPSE_ITEMS_THRESHOLD = 8

@Composable
 fun TimelineItemReactions(
    reactionsState: TimelineItemReactions,
-    mainAxisAlignment: FlowMainAxisAlignment,
+    isOutgoing: Boolean,
    onReactionClicked: (emoji: String) -> Unit,
    onMoreReactionsClicked: () -> Unit,
    modifier: Modifier = Modifier,
 ) {
    var expanded: Boolean by rememberSaveable { mutableStateOf(false) }

-    val reactions by remember(reactionsState, expanded) {
-        derivedStateOf {
-            val numToDisplay = if (expanded) {
-                reactionsState.reactions.count()
-            } else {
-                COLLAPSE_ITEMS_THRESHOLD
-            }
-            reactionsState.reactions.take(numToDisplay).toPersistentList()
-        }
+    // In LTR languages we want an incoming message's reactions to be LRT and outgoing to be RTL.
+    // For RTL languages it should be the opposite.
+    val reactionsLayoutDirection = if (!isOutgoing) LocalLayoutDirection.current
+    else if (LocalLayoutDirection.current == LayoutDirection.Ltr)
+        LayoutDirection.Rtl
+    else
+        LayoutDirection.Ltr
+
+    CompositionLocalProvider(LocalLayoutDirection provides reactionsLayoutDirection) {
+        TimelineItemReactionsView(
+            modifier = modifier,
+            reactions = reactionsState.reactions,
+            expanded = expanded,
+            onReactionClick = onReactionClicked,
+            onMoreReactionsClick = onMoreReactionsClicked,
+            onToggleExpandClick = { expanded = !expanded },
+        )
    }
-
-    val expandableState by remember {
-        derivedStateOf {
-            if (expanded) {
-                ExpandableState.Expanded
-            } else {
-                val hiddenItems = reactionsState.reactions.count() - reactions.count()
-                if (hiddenItems > 0) {
-                    ExpandableState.Collapsed(hidden = hiddenItems)
-                } else {
-                    ExpandableState.None
-                }
-            }
-        }
-    }
-
-    TimelineItemReactionsView(
-        modifier = modifier,
-        reactions = reactions,
-        expandableState = expandableState,
-        mainAxisAlignment = mainAxisAlignment,
-        onReactionClick = onReactionClicked,
-        onMoreReactionsClick = onMoreReactionsClicked,
-        onExpandClick = { expanded = true },
-        onCollapseClick = { expanded = false }
-    )
-}
-
-private sealed class ExpandableState {
-    object None: ExpandableState()
-    data class Collapsed(val hidden: Int): ExpandableState()
-    object Expanded : ExpandableState()
 }

@Composable
 private fun TimelineItemReactionsView(
    reactions: ImmutableList<AggregatedReaction>,
-    expandableState: ExpandableState,
-    mainAxisAlignment: FlowMainAxisAlignment,
+    expanded: Boolean,
    onReactionClick: (emoji: String) -> Unit,
    onMoreReactionsClick: () -> Unit,
-    onExpandClick: () -> Unit,
-    onCollapseClick: () -> Unit,
+    onToggleExpandClick: () -> Unit,
    modifier: Modifier = Modifier
-) =
-    FlowRow(
-        modifier = modifier,
-        mainAxisSpacing = 4.dp,
-        crossAxisSpacing = 4.dp,
-        mainAxisAlignment = mainAxisAlignment,
-    ) {
+) = TimelineItemReactionsLayout(
+    modifier = modifier,
+    itemSpacing = 4.dp,
+    rowSpacing = 4.dp,
+    expanded = expanded,
+    expandButton = {
+        MessagesReactionButton(
+            content = MessagesReactionsButtonContent.Text(
+                text = stringResource(id = if (expanded) R.string.screen_room_reactions_show_less else R.string.screen_room_reactions_show_more)
+            ),
+            onClick = onToggleExpandClick,
+        )
+    },
+    addMoreButton = {
+        MessagesReactionButton(
+            content = MessagesReactionsButtonContent.Icon(Icons.Outlined.AddReaction),
+            onClick = onMoreReactionsClick
+        )
+    },
+    reactions = {
        reactions.forEach { reaction ->
            MessagesReactionButton(
                content = MessagesReactionsButtonContent.Reaction(reaction = reaction),
                onClick = { onReactionClick(reaction.key) }
            )
        }
-        when (expandableState) {
-            ExpandableState.Expanded ->
-                MessagesReactionButton(
-                    content = MessagesReactionsButtonContent.Text(
-                        text = stringResource(id = R.string.screen_room_timeline_less_reactions)
-                    ),
-                    onClick = onCollapseClick,
-                )
-            is ExpandableState.Collapsed -> {
-                val hidden = expandableState.hidden
-                MessagesReactionButton(
-                    content = MessagesReactionsButtonContent.Text(
-                        text = pluralStringResource(id = R.plurals.screen_room_timeline_more_reactions, hidden, hidden)
-                    ),
-                    onClick = onExpandClick,
-                )
-            }
-            ExpandableState.None -> {
-                // No expand or collapse action available
-            }
-        }
-        MessagesReactionButton(
-            content = MessagesReactionsButtonContent.Icon(Icons.Outlined.AddReaction),
-            onClick = onMoreReactionsClick
-        )
    }
+)

@DayNightPreviews
@Composable
 fun TimelineItemReactionsViewPreview() = ElementPreview {
    ContentToPreview(
-        reactions = aTimelineItemReactions(count = 1).reactions,
-        expandableState = ExpandableState.None,
+        reactions = aTimelineItemReactions(count = 1).reactions
    )
 }

@DayNightPreviews
@Composable
-fun TimelineItemReactionsViewCollapsedPreview() = ElementPreview {
+fun TimelineItemReactionsViewFewPreview() = ElementPreview {
    ContentToPreview(
-        reactions = aTimelineItemReactions(count = 3).reactions,
-        expandableState = ExpandableState.Collapsed(hidden = 7),
+        reactions = aTimelineItemReactions(count = 3).reactions
    )
 }

@DayNightPreviews
@Composable
-fun TimelineItemReactionsViewExpandedPreview() = ElementPreview {
+fun TimelineItemReactionsViewIncomingPreview() = ElementPreview {
    ContentToPreview(
-        reactions = aTimelineItemReactions(count = 10).reactions,
-        expandableState = ExpandableState.Expanded,
+        reactions = aTimelineItemReactions(count = 18).reactions
+    )
+}
+
+@DayNightPreviews
+@Composable
+fun TimelineItemReactionsViewOutgoingPreview() = ElementPreview {
+    ContentToPreview(
+        reactions = aTimelineItemReactions(count = 18).reactions,
+        isOutgoing = true
    )
 }

@Composable
 private fun ContentToPreview(
    reactions: ImmutableList<AggregatedReaction>,
-    expandableState: ExpandableState
+    isOutgoing: Boolean = false
 ) {
-    TimelineItemReactionsView(
-        reactions = reactions,
-        expandableState = expandableState,
-        mainAxisAlignment = FlowMainAxisAlignment.Center,
-        onReactionClick = {},
-        onMoreReactionsClick = {},
-        onExpandClick = {},
-        onCollapseClick = {}
+    TimelineItemReactions(
+        reactionsState = TimelineItemReactions(
+            reactions
+        ),
+        isOutgoing = isOutgoing,
+        onReactionClicked = {},
+        onMoreReactionsClicked = {},
    )
 }