Only allow vertical resizing if it's supported by the widget

Bug: b/368056266
Test: atest ResizeableItemFrameViewModelTest
Flag: com.android.systemui.communal_widget_resizing
Change-Id: I6a72e68a69af744e2043d75b9cab578770d57777

4 files changed, 273 insertions, 107 deletions

diff --git a/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/CommunalHub.kt b/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/CommunalHub.kt
index 7fb4c537641b..f96217a1331b 100644
--- a/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/CommunalHub.kt
+++ b/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/CommunalHub.kt
@@ -16,6 +16,7 @@
 
 package com.android.systemui.communal.ui.compose
 
+import android.appwidget.AppWidgetProviderInfo
 import android.content.Context
 import android.content.res.Configuration
 import android.graphics.drawable.Icon
@@ -184,6 +185,9 @@ import com.android.systemui.communal.widgets.SmartspaceAppWidgetHostView
 import com.android.systemui.communal.widgets.WidgetConfigurator
 import com.android.systemui.res.R
 import com.android.systemui.statusbar.phone.SystemUIDialogFactory
+import kotlin.math.max
+import kotlin.math.min
+import kotlin.math.roundToInt
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 
@@ -646,10 +650,11 @@ private fun ObserveNewWidgetAddedEffect(
 private fun ResizableItemFrameWrapper(
     key: String,
     gridState: LazyGridState,
-    minItemSpan: Int,
     gridContentPadding: PaddingValues,
     verticalArrangement: Arrangement.Vertical,
     enabled: Boolean,
+    minHeightPx: Int,
+    maxHeightPx: Int,
     modifier: Modifier = Modifier,
     alpha: () -> Float = { 1f },
     onResize: (info: ResizeInfo) -> Unit = {},
@@ -661,19 +666,46 @@ private fun ResizableItemFrameWrapper(
         ResizableItemFrame(
             key = key,
             gridState = gridState,
-            minItemSpan = minItemSpan,
             gridContentPadding = gridContentPadding,
             verticalArrangement = verticalArrangement,
             enabled = enabled,
             alpha = alpha,
             modifier = modifier,
             onResize = onResize,
+            minHeightPx = minHeightPx,
+            maxHeightPx = maxHeightPx,
+            resizeMultiple = CommunalContentSize.HALF.span,
         ) {
             content(Modifier)
         }
     }
 }
 
+@Composable
+fun calculateWidgetSize(item: CommunalContentModel, isResizable: Boolean): WidgetSizeInfo {
+    val density = LocalDensity.current
+
+    return if (isResizable && item is CommunalContentModel.WidgetContent.Widget) {
+        with(density) {
+            val minHeightPx =
+                (min(item.providerInfo.minResizeHeight, item.providerInfo.minHeight)
+                    .coerceAtLeast(CommunalContentSize.HALF.dp().toPx().roundToInt()))
+
+            val maxHeightPx =
+                (if (item.providerInfo.maxResizeHeight > 0) {
+                        max(item.providerInfo.maxResizeHeight, item.providerInfo.minHeight)
+                    } else {
+                        Int.MAX_VALUE
+                    })
+                    .coerceIn(minHeightPx, CommunalContentSize.FULL.dp().toPx().roundToInt())
+
+            WidgetSizeInfo(minHeightPx, maxHeightPx)
+        }
+    } else {
+        WidgetSizeInfo(0, Int.MAX_VALUE)
+    }
+}
+
 @OptIn(ExperimentalFoundationApi::class)
 @Composable
 private fun BoxScope.CommunalHubLazyGrid(
@@ -748,6 +780,12 @@ private fun BoxScope.CommunalHubLazyGrid(
             val size = SizeF(Dimensions.CardWidth.value, item.size.dp().value)
             val selected = item.key == selectedKey.value
             val dpSize = DpSize(size.width.dp, size.height.dp)
+            val isResizable =
+                if (item is CommunalContentModel.WidgetContent.Widget) {
+                    item.providerInfo.resizeMode and AppWidgetProviderInfo.RESIZE_VERTICAL != 0
+                } else {
+                    false
+                }
 
             if (viewModel.isEditMode && dragDropState != null) {
                 val outlineAlpha by
@@ -756,10 +794,10 @@ private fun BoxScope.CommunalHubLazyGrid(
                         animationSpec = spring(stiffness = Spring.StiffnessMediumLow),
                         label = "Widget resizing outline alpha",
                     )
+                val widgetSizeInfo = calculateWidgetSize(item, isResizable)
                 ResizableItemFrameWrapper(
                     key = item.key,
                     gridState = gridState,
-                    minItemSpan = CommunalContentSize.HALF.span,
                     gridContentPadding = contentPadding,
                     verticalArrangement = itemArrangement,
                     enabled = selected,
@@ -773,6 +811,8 @@ private fun BoxScope.CommunalHubLazyGrid(
                             )
                         },
                     onResize = { resizeInfo -> contentListState.resize(index, resizeInfo) },
+                    minHeightPx = widgetSizeInfo.minHeightPx,
+                    maxHeightPx = widgetSizeInfo.maxHeightPx,
                 ) { modifier ->
                     DraggableItem(
                         modifier = modifier,
@@ -1657,6 +1697,8 @@ class Dimensions(val context: Context, val config: Configuration) {
     }
 }
 
+data class WidgetSizeInfo(val minHeightPx: Int, val maxHeightPx: Int)
+
 private object Colors {
     val DisabledColorFilter by lazy { disabledColorMatrix() }
 
diff --git a/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/ResizeableItemFrame.kt b/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/ResizeableItemFrame.kt
index ef62eb726e2b..9ffc1a626345 100644
--- a/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/ResizeableItemFrame.kt
+++ b/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/ResizeableItemFrame.kt
@@ -60,9 +60,11 @@ private fun UpdateGridLayoutInfo(
     viewModel: ResizeableItemFrameViewModel,
     key: String,
     gridState: LazyGridState,
-    minItemSpan: Int,
     gridContentPadding: PaddingValues,
     verticalArrangement: Arrangement.Vertical,
+    minHeightPx: Int,
+    maxHeightPx: Int,
+    resizeMultiple: Int,
 ) {
     val density = LocalDensity.current
     LaunchedEffect(
@@ -70,9 +72,11 @@ private fun UpdateGridLayoutInfo(
         viewModel,
         key,
         gridState,
-        minItemSpan,
         gridContentPadding,
         verticalArrangement,
+        minHeightPx,
+        maxHeightPx,
+        resizeMultiple,
     ) {
         val verticalItemSpacingPx = with(density) { verticalArrangement.spacing.toPx() }
         val verticalContentPaddingPx =
@@ -92,13 +96,15 @@ private fun UpdateGridLayoutInfo(
             )
             .collectLatest { (maxItemSpan, viewportHeightPx, itemInfo) ->
                 viewModel.setGridLayoutInfo(
-                    verticalItemSpacingPx,
-                    verticalContentPaddingPx,
-                    viewportHeightPx,
-                    maxItemSpan,
-                    minItemSpan,
-                    itemInfo?.row,
-                    itemInfo?.span,
+                    verticalItemSpacingPx = verticalItemSpacingPx,
+                    currentRow = itemInfo?.row,
+                    maxHeightPx = maxHeightPx,
+                    minHeightPx = minHeightPx,
+                    currentSpan = itemInfo?.span,
+                    resizeMultiple = resizeMultiple,
+                    totalSpans = maxItemSpan,
+                    viewportHeightPx = viewportHeightPx,
+                    verticalContentPaddingPx = verticalContentPaddingPx,
                 )
             }
     }
@@ -163,7 +169,6 @@ private fun BoxScope.DragHandle(
 fun ResizableItemFrame(
     key: String,
     gridState: LazyGridState,
-    minItemSpan: Int,
     gridContentPadding: PaddingValues,
     verticalArrangement: Arrangement.Vertical,
     modifier: Modifier = Modifier,
@@ -172,6 +177,9 @@ fun ResizableItemFrame(
     outlineColor: Color = LocalAndroidColorScheme.current.primary,
     cornerRadius: Dp = 37.dp,
     strokeWidth: Dp = 3.dp,
+    minHeightPx: Int = 0,
+    maxHeightPx: Int = Int.MAX_VALUE,
+    resizeMultiple: Int = 1,
     alpha: () -> Float = { 1f },
     onResize: (info: ResizeInfo) -> Unit = {},
     content: @Composable () -> Unit,
@@ -230,12 +238,14 @@ fun ResizableItemFrame(
             }
 
             UpdateGridLayoutInfo(
-                viewModel,
-                key,
-                gridState,
-                minItemSpan,
-                gridContentPadding,
-                verticalArrangement,
+                viewModel = viewModel,
+                key = key,
+                gridState = gridState,
+                gridContentPadding = gridContentPadding,
+                verticalArrangement = verticalArrangement,
+                minHeightPx = minHeightPx,
+                maxHeightPx = maxHeightPx,
+                resizeMultiple = resizeMultiple,
             )
             LaunchedEffect(viewModel) {
                 viewModel.resizeInfo.collectLatest { info -> onResizeUpdated(info) }
diff --git a/packages/SystemUI/multivalentTests/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModelTest.kt b/packages/SystemUI/multivalentTests/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModelTest.kt
index f0d88ab41ad4..55d68e67d461 100644
--- a/packages/SystemUI/multivalentTests/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModelTest.kt
+++ b/packages/SystemUI/multivalentTests/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModelTest.kt
@@ -26,7 +26,6 @@ import com.android.systemui.kosmos.testScope
 import com.android.systemui.lifecycle.activateIn
 import com.android.systemui.testKosmos
 import com.google.common.truth.Truth.assertThat
-import kotlin.time.Duration
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.TestScope
 import kotlinx.coroutines.test.runCurrent
@@ -53,10 +52,12 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
             verticalItemSpacingPx = 10f,
             verticalContentPaddingPx = verticalContentPaddingPx,
             viewportHeightPx = viewportHeightPx,
-            maxItemSpan = 1,
-            minItemSpan = 1,
-            currentSpan = 1,
             currentRow = 0,
+            currentSpan = 1,
+            maxHeightPx = Int.MAX_VALUE,
+            minHeightPx = 0,
+            resizeMultiple = 1,
+            totalSpans = 1,
         )
 
     @Before
@@ -79,7 +80,7 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
 
     @Test
     fun testSingleSpanGrid() =
-        testScope.runTest(timeout = Duration.INFINITE) {
+        testScope.runTest {
             updateGridLayout(singleSpanGrid)
 
             val topState = underTest.topDragState
@@ -98,8 +99,7 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testTwoSpanGrid_elementInFirstRow_sizeSingleSpan() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2))
-
+            updateGridLayout(singleSpanGrid.copy(currentRow = 0, totalSpans = 2))
             val topState = underTest.topDragState
             assertThat(topState.currentValue).isEqualTo(0)
             assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
@@ -116,8 +116,7 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testTwoSpanGrid_elementInSecondRow_sizeSingleSpan() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2, currentRow = 1))
-
+            updateGridLayout(singleSpanGrid.copy(currentRow = 1, totalSpans = 2))
             val topState = underTest.topDragState
             assertThat(topState.currentValue).isEqualTo(0)
             assertThat(topState.anchors.toList()).containsExactly(0 to 0f, -1 to -45f)
@@ -134,15 +133,17 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testTwoSpanGrid_elementInFirstRow_sizeTwoSpan() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2, currentSpan = 2))
+            val adjustedGridLayout = singleSpanGrid.copy(currentSpan = 2, totalSpans = 2)
+
+            updateGridLayout(adjustedGridLayout)
 
             val topState = underTest.topDragState
-            assertThat(topState.currentValue).isEqualTo(0)
             assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
+            assertThat(topState.currentValue).isEqualTo(0)
 
             val bottomState = underTest.bottomDragState
+            assertThat(bottomState.anchors.toList()).containsExactly(-1 to -45f, 0 to 0f)
             assertThat(bottomState.currentValue).isEqualTo(0)
-            assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f, -1 to -45f)
         }
 
     /**
@@ -151,7 +152,10 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testThreeSpanGrid_elementInMiddleRow_sizeOneSpan() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 3, currentRow = 1))
+            val adjustedGridLayout =
+                singleSpanGrid.copy(currentRow = 1, currentSpan = 1, totalSpans = 3)
+
+            updateGridLayout(adjustedGridLayout)
 
             val topState = underTest.topDragState
             assertThat(topState.currentValue).isEqualTo(0)
@@ -165,7 +169,10 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testThreeSpanGrid_elementInTopRow_sizeOneSpan() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 3))
+            val adjustedGridLayout =
+                singleSpanGrid.copy(currentRow = 0, currentSpan = 1, totalSpans = 3)
+
+            updateGridLayout(adjustedGridLayout)
 
             val topState = underTest.topDragState
             assertThat(topState.currentValue).isEqualTo(0)
@@ -177,16 +184,17 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
         }
 
     @Test
-    fun testSixSpanGrid_minSpanThree_itemInThirdRow_sizeThreeSpans() =
+    fun testSixSpanGrid_minSpanThree_itemInFourthRow_sizeThreeSpans() =
         testScope.runTest {
-            updateGridLayout(
+            val adjustedGridLayout =
                 singleSpanGrid.copy(
-                    maxItemSpan = 6,
                     currentRow = 3,
                     currentSpan = 3,
-                    minItemSpan = 3,
+                    resizeMultiple = 3,
+                    totalSpans = 6,
                 )
-            )
+
+            updateGridLayout(adjustedGridLayout)
 
             val topState = underTest.topDragState
             assertThat(topState.currentValue).isEqualTo(0)
@@ -200,7 +208,14 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testTwoSpanGrid_elementMovesFromFirstRowToSecondRow() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2))
+            val firstRowLayout =
+                singleSpanGrid.copy(
+                    currentRow = 0,
+                    currentSpan = 1,
+                    resizeMultiple = 1,
+                    totalSpans = 2,
+                )
+            updateGridLayout(firstRowLayout)
 
             val topState = underTest.topDragState
             val bottomState = underTest.bottomDragState
@@ -208,7 +223,8 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
             assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
             assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f, 1 to 45f)
 
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2, currentRow = 1))
+            val secondRowLayout = firstRowLayout.copy(currentRow = 1)
+            updateGridLayout(secondRowLayout)
 
             assertThat(topState.anchors.toList()).containsExactly(0 to 0f, -1 to -45f)
             assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f)
@@ -217,19 +233,21 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testTwoSpanGrid_expandElementFromBottom() = runTestWithSnapshots {
         val resizeInfo by collectLastValue(underTest.resizeInfo)
-        updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2))
 
-        assertThat(resizeInfo).isNull()
+        val adjustedGridLayout = singleSpanGrid.copy(resizeMultiple = 1, totalSpans = 2)
+
+        updateGridLayout(adjustedGridLayout)
+
         underTest.bottomDragState.anchoredDrag { dragTo(45f) }
+
         assertThat(resizeInfo).isEqualTo(ResizeInfo(1, DragHandle.BOTTOM))
     }
 
     @Test
     fun testThreeSpanGrid_expandMiddleElementUpwards() = runTestWithSnapshots {
         val resizeInfo by collectLastValue(underTest.resizeInfo)
-        updateGridLayout(singleSpanGrid.copy(maxItemSpan = 3, currentRow = 1))
+        updateGridLayout(singleSpanGrid.copy(currentRow = 1, totalSpans = 3))
 
-        assertThat(resizeInfo).isNull()
         underTest.topDragState.anchoredDrag { dragTo(-30f) }
         assertThat(resizeInfo).isEqualTo(ResizeInfo(1, DragHandle.TOP))
     }
@@ -237,7 +255,7 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testThreeSpanGrid_expandTopElementDownBy2Spans() = runTestWithSnapshots {
         val resizeInfo by collectLastValue(underTest.resizeInfo)
-        updateGridLayout(singleSpanGrid.copy(maxItemSpan = 3))
+        updateGridLayout(singleSpanGrid.copy(totalSpans = 3))
 
         assertThat(resizeInfo).isNull()
         underTest.bottomDragState.anchoredDrag { dragTo(60f) }
@@ -247,7 +265,7 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testTwoSpanGrid_shrinkElementFromBottom() = runTestWithSnapshots {
         val resizeInfo by collectLastValue(underTest.resizeInfo)
-        updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2, currentSpan = 2))
+        updateGridLayout(singleSpanGrid.copy(totalSpans = 2, currentSpan = 2))
 
         assertThat(resizeInfo).isNull()
         underTest.bottomDragState.anchoredDrag { dragTo(-45f) }
@@ -257,7 +275,7 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
     @Test
     fun testRowInfoBecomesNull_revertsBackToDefault() =
         testScope.runTest {
-            val gridLayout = singleSpanGrid.copy(maxItemSpan = 3, currentRow = 1)
+            val gridLayout = singleSpanGrid.copy(currentRow = 1, resizeMultiple = 1, totalSpans = 3)
             updateGridLayout(gridLayout)
 
             val topState = underTest.topDragState
@@ -266,44 +284,113 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
             val bottomState = underTest.bottomDragState
             assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f, 1 to 30f)
 
+            // Set currentRow to null to simulate the row info becoming null
             updateGridLayout(gridLayout.copy(currentRow = null))
             assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
             assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f)
         }
 
-    @Test(expected = IllegalArgumentException::class)
-    fun testIllegalState_maxSpanSmallerThanMinSpan() =
+    @Test
+    fun testEqualMaxAndMinHeight_cannotResize() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2, minItemSpan = 3))
+            val heightPx = 20
+            updateGridLayout(
+                singleSpanGrid.copy(maxHeightPx = heightPx, minHeightPx = heightPx, totalSpans = 2)
+            )
+
+            val topState = underTest.topDragState
+            val bottomState = underTest.bottomDragState
+
+            assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
+            assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f)
         }
 
-    @Test(expected = IllegalArgumentException::class)
-    fun testIllegalState_minSpanOfZero() =
+    @Test
+    fun testMinHeightTwoRows_canExpandButNotShrink() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 2, minItemSpan = 0))
+            val threeRowGrid =
+                singleSpanGrid.copy(
+                    maxHeightPx = 80,
+                    minHeightPx = 50,
+                    totalSpans = 3,
+                    currentSpan = 2,
+                    currentRow = 0,
+                )
+
+            updateGridLayout(threeRowGrid)
+
+            val topState = underTest.topDragState
+            val bottomState = underTest.bottomDragState
+            assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
+            assertThat(bottomState.anchors.toList()).containsAtLeast(0 to 0f, 1 to 30f)
         }
 
-    @Test(expected = IllegalArgumentException::class)
-    fun testIllegalState_maxSpanOfZero() =
+    @Test
+    fun testMaxHeightTwoRows_canShrinkButNotExpand() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 0, minItemSpan = 0))
+            val threeRowGrid =
+                singleSpanGrid.copy(
+                    maxHeightPx = 50,
+                    minHeightPx = 20,
+                    totalSpans = 3,
+                    currentSpan = 2,
+                    currentRow = 0,
+                )
+
+            updateGridLayout(threeRowGrid)
+
+            val topState = underTest.topDragState
+            val bottomState = underTest.bottomDragState
+
+            assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f, -1 to -30f)
+
+            assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
+        }
+
+    @Test
+    fun testMinHeightEqualToAvailableSpan_cannotResize() =
+        testScope.runTest {
+            val twoRowGrid =
+                singleSpanGrid.copy(
+                    minHeightPx = (viewportHeightPx - verticalContentPaddingPx.toInt()),
+                    totalSpans = 2,
+                    currentSpan = 2,
+                )
+
+            updateGridLayout(twoRowGrid)
+
+            val topState = underTest.topDragState
+            val bottomState = underTest.bottomDragState
+
+            assertThat(topState.anchors.toList()).containsExactly(0 to 0f)
+            assertThat(bottomState.anchors.toList()).containsExactly(0 to 0f)
         }
 
     @Test(expected = IllegalArgumentException::class)
-    fun testIllegalState_currentRowNotMultipleOfMinSpan() =
+    fun testIllegalState_maxHeightLessThanMinHeight() =
         testScope.runTest {
-            updateGridLayout(singleSpanGrid.copy(maxItemSpan = 6, minItemSpan = 3, currentSpan = 2))
+            updateGridLayout(singleSpanGrid.copy(maxHeightPx = 50, minHeightPx = 100))
         }
 
+    @Test(expected = IllegalArgumentException::class)
+    fun testIllegalState_currentSpanExceedsTotalSpans() =
+        testScope.runTest { updateGridLayout(singleSpanGrid.copy(currentSpan = 3, totalSpans = 2)) }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun testIllegalState_resizeMultipleZeroOrNegative() =
+        testScope.runTest { updateGridLayout(singleSpanGrid.copy(resizeMultiple = 0)) }
+
     private fun TestScope.updateGridLayout(gridLayout: GridLayout) {
         underTest.setGridLayoutInfo(
-            gridLayout.verticalItemSpacingPx,
-            gridLayout.verticalContentPaddingPx,
-            gridLayout.viewportHeightPx,
-            gridLayout.maxItemSpan,
-            gridLayout.minItemSpan,
-            gridLayout.currentRow,
-            gridLayout.currentSpan,
+            verticalItemSpacingPx = gridLayout.verticalItemSpacingPx,
+            currentRow = gridLayout.currentRow,
+            maxHeightPx = gridLayout.maxHeightPx,
+            minHeightPx = gridLayout.minHeightPx,
+            currentSpan = gridLayout.currentSpan,
+            resizeMultiple = gridLayout.resizeMultiple,
+            totalSpans = gridLayout.totalSpans,
+            viewportHeightPx = gridLayout.viewportHeightPx,
+            verticalContentPaddingPx = gridLayout.verticalContentPaddingPx,
         )
         runCurrent()
     }
@@ -332,9 +419,11 @@ class ResizeableItemFrameViewModelTest : SysuiTestCase() {
         val verticalItemSpacingPx: Float,
         val verticalContentPaddingPx: Float,
         val viewportHeightPx: Int,
-        val maxItemSpan: Int,
-        val minItemSpan: Int,
         val currentRow: Int?,
         val currentSpan: Int?,
+        val maxHeightPx: Int,
+        val minHeightPx: Int,
+        val resizeMultiple: Int,
+        val totalSpans: Int,
     )
 }
diff --git a/packages/SystemUI/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModel.kt b/packages/SystemUI/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModel.kt
index 87fcdd7b97ee..b4057c775341 100644
--- a/packages/SystemUI/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModel.kt
+++ b/packages/SystemUI/src/com/android/systemui/communal/ui/viewmodel/ResizeableItemFrameViewModel.kt
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package com.android.systemui.communal.ui.viewmodel
 
 import androidx.compose.foundation.gestures.AnchoredDraggableState
@@ -21,6 +20,10 @@ import androidx.compose.foundation.gestures.DraggableAnchors
 import androidx.compose.runtime.snapshotFlow
 import com.android.app.tracing.coroutines.coroutineScope
 import com.android.systemui.lifecycle.ExclusiveActivatable
+import kotlin.math.abs
+import kotlin.math.ceil
+import kotlin.math.floor
+import kotlin.math.sign
 import kotlinx.coroutines.awaitCancellation
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -50,14 +53,33 @@ data class ResizeInfo(
 }
 
 class ResizeableItemFrameViewModel : ExclusiveActivatable() {
-    private data class GridLayoutInfo(
-        val minSpan: Int,
-        val maxSpan: Int,
-        val heightPerSpanPx: Float,
-        val verticalItemSpacingPx: Float,
+    data class GridLayoutInfo(
         val currentRow: Int,
         val currentSpan: Int,
-    )
+        val maxHeightPx: Int,
+        val minHeightPx: Int,
+        val resizeMultiple: Int,
+        val totalSpans: Int,
+        private val heightPerSpanPx: Float,
+        private val verticalItemSpacingPx: Float,
+    ) {
+        fun getPxOffsetForResize(spans: Int): Int =
+            (spans * (heightPerSpanPx + verticalItemSpacingPx)).toInt()
+
+        private fun getSpansForPx(height: Int): Int =
+            ceil((height + verticalItemSpacingPx) / (heightPerSpanPx + verticalItemSpacingPx))
+                .toInt()
+                .coerceIn(resizeMultiple, totalSpans)
+
+        private fun roundDownToMultiple(spans: Int): Int =
+            floor(spans.toDouble() / resizeMultiple).toInt() * resizeMultiple
+
+        val maxSpans: Int
+            get() = roundDownToMultiple(getSpansForPx(maxHeightPx))
+
+        val minSpans: Int
+            get() = roundDownToMultiple(getSpansForPx(minHeightPx))
+    }
 
     /**
      * The layout information necessary in order to calculate the pixel offsets of the drag anchor
@@ -84,37 +106,44 @@ class ResizeableItemFrameViewModel : ExclusiveActivatable() {
      */
     fun setGridLayoutInfo(
         verticalItemSpacingPx: Float,
-        verticalContentPaddingPx: Float,
-        viewportHeightPx: Int,
-        maxItemSpan: Int,
-        minItemSpan: Int,
         currentRow: Int?,
+        maxHeightPx: Int,
+        minHeightPx: Int,
         currentSpan: Int?,
+        resizeMultiple: Int,
+        totalSpans: Int,
+        viewportHeightPx: Int,
+        verticalContentPaddingPx: Float,
     ) {
-        if (currentSpan == null || currentRow == null) {
+        if (currentRow == null || currentSpan == null) {
             gridLayoutInfo.value = null
             return
         }
-        require(maxItemSpan >= minItemSpan) {
-            "Maximum item span of $maxItemSpan cannot be less than the minimum span of $minItemSpan"
+        require(maxHeightPx >= minHeightPx) {
+            "Maximum item span of $maxHeightPx cannot be less than the minimum span of $minHeightPx"
         }
-        require(minItemSpan in 1..maxItemSpan) {
-            "Minimum span must be between 1 and $maxItemSpan, but was $minItemSpan"
+
+        require(currentSpan <= totalSpans) {
+            "Current span ($currentSpan) cannot exceed the total number of spans ($totalSpans)"
         }
-        require(currentSpan % minItemSpan == 0) {
-            "Current span of $currentSpan is not a multiple of the minimum span of $minItemSpan"
+
+        require(resizeMultiple > 0) {
+            "Resize multiple ($resizeMultiple) must be a positive integer"
         }
         val availableHeight = viewportHeightPx - verticalContentPaddingPx
-        val totalSpacing = verticalItemSpacingPx * ((maxItemSpan / minItemSpan) - 1)
-        val heightPerSpanPx = (availableHeight - totalSpacing) / maxItemSpan
+        val heightPerSpanPx =
+            (availableHeight - (totalSpans - 1) * verticalItemSpacingPx) / totalSpans
+
         gridLayoutInfo.value =
             GridLayoutInfo(
-                minSpan = minItemSpan,
-                maxSpan = maxItemSpan,
                 heightPerSpanPx = heightPerSpanPx,
                 verticalItemSpacingPx = verticalItemSpacingPx,
                 currentRow = currentRow,
                 currentSpan = currentSpan,
+                maxHeightPx = maxHeightPx.coerceAtMost(availableHeight.toInt()),
+                minHeightPx = minHeightPx,
+                resizeMultiple = resizeMultiple,
+                totalSpans = totalSpans,
             )
     }
 
@@ -123,50 +152,46 @@ class ResizeableItemFrameViewModel : ExclusiveActivatable() {
         layoutInfo: GridLayoutInfo?,
     ): DraggableAnchors<Int> {
 
-        if (layoutInfo == null || !isDragAllowed(handle, layoutInfo)) {
+        if (layoutInfo == null || (!isDragAllowed(handle, layoutInfo))) {
             return DraggableAnchors { 0 at 0f }
         }
-
-        val (
-            minItemSpan,
-            maxItemSpan,
-            heightPerSpanPx,
-            verticalSpacingPx,
-            currentRow,
-            currentSpan,
-        ) = layoutInfo
+        val currentRow = layoutInfo.currentRow
+        val currentSpan = layoutInfo.currentSpan
+        val minItemSpan = layoutInfo.minSpans
+        val maxItemSpan = layoutInfo.maxSpans
+        val totalSpans = layoutInfo.totalSpans
 
         // The maximum row this handle can be dragged to.
         val maxRow =
             if (handle == DragHandle.TOP) {
                 (currentRow + currentSpan - minItemSpan).coerceAtLeast(0)
             } else {
-                maxItemSpan
+                (currentRow + maxItemSpan).coerceAtMost(totalSpans)
             }
 
         // The minimum row this handle can be dragged to.
         val minRow =
             if (handle == DragHandle.TOP) {
-                0
+                (currentRow + currentSpan - maxItemSpan).coerceAtLeast(0)
             } else {
-                (currentRow + minItemSpan).coerceAtMost(maxItemSpan)
+                (currentRow + minItemSpan).coerceAtMost(totalSpans)
             }
 
         // The current row position of this handle
         val currentPosition = if (handle == DragHandle.TOP) currentRow else currentRow + currentSpan
 
         return DraggableAnchors {
-            for (targetRow in minRow..maxRow step minItemSpan) {
+            for (targetRow in minRow..maxRow step layoutInfo.resizeMultiple) {
                 val diff = targetRow - currentPosition
-                val spacing = diff / minItemSpan * verticalSpacingPx
-                diff at diff * heightPerSpanPx + spacing
+                val pixelOffset = (layoutInfo.getPxOffsetForResize(abs(diff)) * diff.sign).toFloat()
+                diff at pixelOffset
             }
         }
     }
 
     private fun isDragAllowed(handle: DragHandle, layoutInfo: GridLayoutInfo): Boolean {
-        val minItemSpan = layoutInfo.minSpan
-        val maxItemSpan = layoutInfo.maxSpan
+        val minItemSpan = layoutInfo.minSpans
+        val maxItemSpan = layoutInfo.maxSpans
         val currentRow = layoutInfo.currentRow
         val currentSpan = layoutInfo.currentSpan
         val atMinSize = currentSpan == minItemSpan