Setting “outside” bottom edge for MaterialCardView doesn't work as expected

Question

I'm trying to build a tooltip with shadow like the following image:

I was able to do so by using an Image as background . But I couldn't apply shadows to it. So, after searching I found this article , it uses MaterialCardView and applying MaterialShapeDrawable to it as a background .

I have tried the following code:

    val shapeDrawable = MaterialShapeDrawable()
    val shapeAppearanceModel =
        ShapeAppearanceModel.builder().setBottomEdge(TriangleEdgeTreatment(20f, false)).build()
    shapeDrawable.shapeAppearanceModel = shapeAppearanceModel
    materialDialog.background = shapeDrawable

XML file:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="@dimen/width_custom_marker"
    android:layout_height="100dp"
    android:padding="16dp"
    tools:ignore="Overdraw">

    <com.google.android.material.card.MaterialCardView
        android:id="@+id/materialCard"
        android:layout_width="@dimen/width_custom_marker"
        android:layout_height="50dp" />
</RelativeLayout>

My issue is that while setting the inside flag with false for this object TriangleEdgeTreatment(30f, true) it doesn't work as expected. However, setting the flag with true works properly.

TriangleEdgeTreatment(30f, false)

TriangleEdgeTreatment(30f, true)

Thanks in advance!

Answer 1

I can achieve it using:

  <LinearLayout
      android:clipChildren="false"
      android:clipToPadding="false"
      android:padding="16dp"
      ..>

        <com.google.android.material.card.MaterialCardView
         ../>

and applying the TriangleEdgeTreatment :

float size = getResources().getDimension(R.dimen.triangle_size); //16dp
TriangleEdgeTreatment triangleEdgeTreatment = new TriangleEdgeTreatment(size,false);

MaterialCardView cardView = findViewById(R.id.card);
cardView.setShapeAppearanceModel(cardView.getShapeAppearanceModel()
    .toBuilder()
    .setBottomEdge(triangleEdgeTreatment)
    .build());