[flexiglass] Prevents crash when disable flags are set

There's a crash when certain disable flags are set. It comes from the
measure policy of SingleShadeMeasurePolicy which assumes that certain
elements are laid out when they're not (because the disable flags makes
those elements disappear in runtime).

This CL only prevents the crash, it doesn't fix the positioning of the
UMO in these cases, that still needs to be tested and fixed properly.
See the test lines for how to fix it properly. This is tracked in
b/379162317.

Bug: 371545613
Test: manually verified that disabling certain disable flags doesn't
crash anymore. The commands used are:
$ adb shell cmd statusbar send-disable-flag quick-settings
$ adb shell cmd statusbar send-disable-flag statusbar-expansion
$ adb shell cmd statusbar send-disable-flag none
Flag: com.android.systemui.scene_container

Change-Id: Ie26bbb743f06e2eb1549e67b9a5a3c7ca0613857

1 files changed, 27 insertions, 20 deletions

diff --git a/packages/SystemUI/compose/features/src/com/android/systemui/shade/ui/composable/SingleShadeMeasurePolicy.kt b/packages/SystemUI/compose/features/src/com/android/systemui/shade/ui/composable/SingleShadeMeasurePolicy.kt
index 352d29e21987..74896482be88 100644
--- a/packages/SystemUI/compose/features/src/com/android/systemui/shade/ui/composable/SingleShadeMeasurePolicy.kt
+++ b/packages/SystemUI/compose/features/src/com/android/systemui/shade/ui/composable/SingleShadeMeasurePolicy.kt
@@ -25,7 +25,6 @@ import androidx.compose.ui.layout.Placeable
 import androidx.compose.ui.layout.layoutId
 import androidx.compose.ui.unit.Constraints
 import androidx.compose.ui.unit.offset
-import androidx.compose.ui.util.fastFirst
 import androidx.compose.ui.util.fastFirstOrNull
 import com.android.systemui.shade.ui.composable.SingleShadeMeasurePolicy.LayoutId
 import kotlin.math.max
@@ -60,18 +59,20 @@ class SingleShadeMeasurePolicy(
 
         val shadeHeaderPlaceable =
             measurables
-                .fastFirst { it.layoutId == LayoutId.ShadeHeader }
-                .measure(constraintsWithCutout)
+                .fastFirstOrNull { it.layoutId == LayoutId.ShadeHeader }
+                ?.measure(constraintsWithCutout)
         val mediaPlaceable =
             measurables
                 .fastFirstOrNull { it.layoutId == LayoutId.Media }
                 ?.measure(applyMediaConstraints(constraintsWithCutout, isMediaInRow))
         val quickSettingsPlaceable =
             measurables
-                .fastFirst { it.layoutId == LayoutId.QuickSettings }
-                .measure(constraintsWithCutout)
+                .fastFirstOrNull { it.layoutId == LayoutId.QuickSettings }
+                ?.measure(constraintsWithCutout)
         val notificationsPlaceable =
-            measurables.fastFirst { it.layoutId == LayoutId.Notifications }.measure(constraints)
+            measurables
+                .fastFirstOrNull { it.layoutId == LayoutId.Notifications }
+                ?.measure(constraints)
 
         val notificationsTop =
             calculateNotificationsTop(
@@ -84,23 +85,25 @@ class SingleShadeMeasurePolicy(
         onNotificationsTopChanged(notificationsTop)
 
         return layout(constraints.maxWidth, constraints.maxHeight) {
-            shadeHeaderPlaceable.placeRelative(x = insetsLeft, y = insetsTop)
-            quickSettingsPlaceable.placeRelative(
+            shadeHeaderPlaceable?.placeRelative(x = insetsLeft, y = insetsTop)
+            val statusBarHeaderHeight = shadeHeaderPlaceable?.height ?: 0
+            quickSettingsPlaceable?.placeRelative(
                 x = insetsLeft,
-                y = insetsTop + shadeHeaderPlaceable.height,
+                y = insetsTop + statusBarHeaderHeight,
             )
 
-            if (mediaPlaceable != null)
+            if (mediaPlaceable != null) {
+                val quickSettingsHeight = quickSettingsPlaceable?.height ?: 0
+
                 if (isMediaInRow) {
                     // mediaPlaceable height ranges from 0 to qsHeight. We want it to be centered
                     // vertically when it's smaller than the QS
-                    val mediaCenteringOffset =
-                        (quickSettingsPlaceable.height - mediaPlaceable.height) / 2
+                    val mediaCenteringOffset = (quickSettingsHeight - mediaPlaceable.height) / 2
                     mediaPlaceable.placeRelative(
                         x = insetsLeft + constraintsWithCutout.maxWidth / 2,
                         y =
                             insetsTop +
-                                shadeHeaderPlaceable.height +
+                                statusBarHeaderHeight +
                                 mediaCenteringOffset +
                                 mediaOffset(),
                         zIndex = mediaZIndex(),
@@ -108,30 +111,34 @@ class SingleShadeMeasurePolicy(
                 } else {
                     mediaPlaceable.placeRelative(
                         x = insetsLeft,
-                        y = insetsTop + shadeHeaderPlaceable.height + quickSettingsPlaceable.height,
+                        y = insetsTop + statusBarHeaderHeight + quickSettingsHeight,
                         zIndex = mediaZIndex(),
                     )
                 }
+            }
 
             // Notifications don't need to accommodate for horizontal insets
-            notificationsPlaceable.placeRelative(x = 0, y = notificationsTop)
+            notificationsPlaceable?.placeRelative(x = 0, y = notificationsTop)
         }
     }
 
     private fun calculateNotificationsTop(
-        statusBarHeaderPlaceable: Placeable,
-        quickSettingsPlaceable: Placeable,
+        statusBarHeaderPlaceable: Placeable?,
+        quickSettingsPlaceable: Placeable?,
         mediaPlaceable: Placeable?,
         insetsTop: Int,
         isMediaInRow: Boolean,
     ): Int {
         val mediaHeight = mediaPlaceable?.height ?: 0
+        val statusBarHeaderHeight = statusBarHeaderPlaceable?.height ?: 0
+        val quickSettingsHeight = quickSettingsPlaceable?.height ?: 0
+
         return insetsTop +
-            statusBarHeaderPlaceable.height +
+            statusBarHeaderHeight +
             if (isMediaInRow) {
-                max(quickSettingsPlaceable.height, mediaHeight)
+                max(quickSettingsHeight, mediaHeight)
             } else {
-                quickSettingsPlaceable.height + mediaHeight
+                quickSettingsHeight + mediaHeight
             }
     }