Closes #399: Support "Hug Contents" for list widgets.

For rows and columns, let the Row() or Column() size itself based off its children, then inform the layout manager of this size so that the parent can resize if it is an autolayout parent.

This also fixes an issue where the modifier passed into DesignView was ignored for nodes that were laid out by the layout manager.

designcompose/src/main/java/com/android/designcompose/DesignFrame.kt

@@ -40,11 +40,13 @@ import androidx.compose.ui.geometry.toRect
 import androidx.compose.ui.graphics.BlendMode
 import androidx.compose.ui.graphics.Paint
 import androidx.compose.ui.graphics.withSaveLayer
+import androidx.compose.ui.layout.onSizeChanged
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.TextStyle
 import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.unit.dp
+import com.android.designcompose.serdegen.Dimension
 import com.android.designcompose.serdegen.GridLayoutType
 import com.android.designcompose.serdegen.GridSpan
 import com.android.designcompose.serdegen.ItemSpacing
@@ -193,9 +195,19 @@ internal fun DesignFrame(
                     if (style.overflow_node_id.isPresent)
                         overflowNodeId = style.overflow_node_id.get()
                 }
-                val rowSizeModifier = Modifier.layoutSizeToModifier(layout)
+
+                // If the widget is set to hug contents, don't give Row() a size and let it size
+                // itself. Then when the size is determined, inform the layout manager. Otherwise,
+                // get the fixed size from the layout manager and use it in a Modifier.
+                val hugContents = view.style.width is Dimension.Auto
+                val rowModifier =
+                    if (hugContents)
+                        Modifier.onSizeChanged {
+                            LayoutManager.setNodeSize(layoutId, it.width, it.height)
+                        }
+                    else Modifier.layoutSizeToModifier(layout)
                 Row(
-                    rowSizeModifier
+                    rowModifier
                         .then(layoutInfo.selfModifier)
                         .then(m)
                         .then(layoutInfo.marginModifier),
@@ -241,9 +253,19 @@ internal fun DesignFrame(
                     if (style.overflow_node_id.isPresent)
                         overflowNodeId = style.overflow_node_id.get()
                 }
-                val columnSizeModifier = Modifier.layoutSizeToModifier(layout)
+
+                // If the widget is set to hug contents, don't give Column() a size and let it size
+                // itself. Then when the size is determined, inform the layout manager. Otherwise,
+                // get the fixed size from the layout manager and use it in a Modifier.
+                val hugContents = view.style.height is Dimension.Auto
+                val columnModifier =
+                    if (hugContents)
+                        Modifier.onSizeChanged {
+                            LayoutManager.setNodeSize(layoutId, it.width, it.height)
+                        }
+                    else Modifier.layoutSizeToModifier(layout)
                 Column(
-                    columnSizeModifier
+                    columnModifier
                         .then(layoutInfo.selfModifier)
                         .then(m)
                         .then(layoutInfo.marginModifier),
@@ -594,7 +616,8 @@ internal fun DesignFrame(
             } else {
                 // Otherwise, use our custom layout to render the frame and to place its children
                 m = m.then(Modifier.layoutStyle(name, layoutId))
-                DesignFrameLayout(m, name, layoutId, layoutState) {
+                val frameModifier = layoutInfo.selfModifier.then(m)
+                DesignFrameLayout(frameModifier, name, layoutId, layoutState) {
                     Box(Modifier) // Need this for some reason
                     content()
                 }