[TextInputLayout] Exposed the style of the ExposedDropDownMenu

lib/java/com/google/android/material/textfield/DropdownMenuEndIconDelegate.java

@@ -32,7 +32,6 @@
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.LayerDrawable;
 import android.graphics.drawable.RippleDrawable;
-import android.graphics.drawable.StateListDrawable;
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
 import androidx.core.view.ViewCompat;
@@ -57,7 +56,6 @@
 import com.google.android.material.color.MaterialColors;
 import com.google.android.material.internal.TextWatcherAdapter;
 import com.google.android.material.shape.MaterialShapeDrawable;
-import com.google.android.material.shape.ShapeAppearanceModel;
 import com.google.android.material.textfield.TextInputLayout.AccessibilityDelegate;
 import com.google.android.material.textfield.TextInputLayout.BoxBackgroundMode;
 import com.google.android.material.textfield.TextInputLayout.OnEditTextAttachedListener;
@@ -144,7 +142,6 @@ public void onEditTextAttached(@NonNull TextInputLayout textInputLayout) {
           AutoCompleteTextView autoCompleteTextView =
               castAutoCompleteTextViewOrThrow(textInputLayout.getEditText());
 
-          setPopupBackground(autoCompleteTextView);
           addRippleEffect(autoCompleteTextView);
           setUpDropdownShowHideBehavior(autoCompleteTextView);
           autoCompleteTextView.setThreshold(0);
@@ -184,8 +181,6 @@ public void onEndIconChanged(@NonNull TextInputLayout textInputLayout, int previ
   private boolean dropdownPopupDirty = false;
   private boolean isEndIconChecked = false;
   private long dropdownPopupActivatedAt = Long.MAX_VALUE;
-  private StateListDrawable filledPopupBackground;
-  private MaterialShapeDrawable outlinedPopupBackground;
   @Nullable private AccessibilityManager accessibilityManager;
   private ValueAnimator fadeOutAnim;
   private ValueAnimator fadeInAnim;
@@ -196,45 +191,15 @@ public void onEndIconChanged(@NonNull TextInputLayout textInputLayout, int previ
 
   @Override
   void initialize() {
-    float popupCornerRadius =
-        context
-            .getResources()
-            .getDimensionPixelOffset(R.dimen.mtrl_shape_corner_size_small_component);
-    float exposedDropdownPopupElevation =
-        context
-            .getResources()
-            .getDimensionPixelOffset(R.dimen.mtrl_exposed_dropdown_menu_popup_elevation);
-    int exposedDropdownPopupVerticalPadding =
-        context
-            .getResources()
-            .getDimensionPixelOffset(R.dimen.mtrl_exposed_dropdown_menu_popup_vertical_padding);
-    // Background for the popups of the outlined variation and for the filled variation when it is
-    // being displayed above the layout.
-    MaterialShapeDrawable roundedCornersPopupBackground =
-        getPopUpMaterialShapeDrawable(
-            popupCornerRadius,
-            popupCornerRadius,
-            exposedDropdownPopupElevation,
-            exposedDropdownPopupVerticalPadding);
-    // Background for the popup of the filled variation when it is being displayed below the layout.
-    MaterialShapeDrawable roundedBottomCornersPopupBackground =
-        getPopUpMaterialShapeDrawable(
-            0,
-            popupCornerRadius,
-            exposedDropdownPopupElevation,
-            exposedDropdownPopupVerticalPadding);
-
-    outlinedPopupBackground = roundedCornersPopupBackground;
-    filledPopupBackground = new StateListDrawable();
-    filledPopupBackground.addState(
-        new int[] {android.R.attr.state_above_anchor}, roundedCornersPopupBackground);
-    filledPopupBackground.addState(new int[] {}, roundedBottomCornersPopupBackground);
-
-    // For lollipop+, the arrow icon changes orientation based on dropdown popup, otherwise it
-    // always points down.
-    int drawableResId =
-        IS_LOLLIPOP ? R.drawable.mtrl_dropdown_arrow : R.drawable.mtrl_ic_arrow_drop_down;
-    textInputLayout.setEndIconDrawable(AppCompatResources.getDrawable(context, drawableResId));
+
+    if (textInputLayout.getEndIconDrawable() == null) {
+      // For lollipop+, the arrow icon changes orientation based on dropdown popup, otherwise it
+      // always points down.
+      int drawableResId =
+          IS_LOLLIPOP ? R.drawable.mtrl_dropdown_arrow : R.drawable.mtrl_ic_arrow_drop_down;
+      textInputLayout.setEndIconDrawable(AppCompatResources.getDrawable(context, drawableResId));
+    }
+
     textInputLayout.setEndIconContentDescription(
         textInputLayout.getResources().getText(R.string.exposed_dropdown_menu_content_description));
     textInputLayout.setEndIconOnClickListener(
@@ -287,16 +252,11 @@ private void showHideDropdown(@Nullable AutoCompleteTextView editText) {
     }
   }
 
-  private void setPopupBackground(@NonNull AutoCompleteTextView editText) {
+  /*private void setPopupBackground(@NonNull AutoCompleteTextView editText) {
     if (IS_LOLLIPOP) {
-      int boxBackgroundMode = textInputLayout.getBoxBackgroundMode();
-      if (boxBackgroundMode == TextInputLayout.BOX_BACKGROUND_OUTLINE) {
-        editText.setDropDownBackgroundDrawable(outlinedPopupBackground);
-      } else if (boxBackgroundMode == TextInputLayout.BOX_BACKGROUND_FILLED) {
-        editText.setDropDownBackgroundDrawable(filledPopupBackground);
-      }
+      editText.setDropDownBackgroundDrawable(popupBackground);
     }
-  }
+  }*/
 
   /* Add ripple effect to non editable layouts. */
   private void addRippleEffect(@NonNull AutoCompleteTextView editText) {
@@ -410,21 +370,6 @@ public void onDismiss() {
     }
   }
 
-  private MaterialShapeDrawable getPopUpMaterialShapeDrawable(
-      float topCornerRadius, float bottomCornerRadius, float elevation, int verticalPadding) {
-    ShapeAppearanceModel shapeAppearanceModel =
-        ShapeAppearanceModel.builder()
-            .setTopLeftCornerSize(topCornerRadius)
-            .setTopRightCornerSize(topCornerRadius)
-            .setBottomLeftCornerSize(bottomCornerRadius)
-            .setBottomRightCornerSize(bottomCornerRadius)
-            .build();
-    MaterialShapeDrawable popupDrawable =
-        MaterialShapeDrawable.createWithElevationOverlay(context, elevation);
-    popupDrawable.setShapeAppearanceModel(shapeAppearanceModel);
-    popupDrawable.setPadding(0, verticalPadding, 0, verticalPadding);
-    return popupDrawable;
-  }
 
   private boolean isDropdownPopupActive() {
     long activeFor = System.currentTimeMillis() - dropdownPopupActivatedAt;

lib/java/com/google/android/material/textfield/MaterialAutoCompleteTextView.java

@@ -24,7 +24,9 @@
 import android.content.res.TypedArray;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
+import android.graphics.drawable.StateListDrawable;
 import android.os.Build.VERSION;
+import androidx.annotation.StyleRes;
 import androidx.appcompat.widget.AppCompatAutoCompleteTextView;
 import androidx.appcompat.widget.ListPopupWindow;
 import android.text.InputType;
@@ -41,6 +43,8 @@
 import androidx.annotation.Nullable;
 import com.google.android.material.internal.ManufacturerUtils;
 import com.google.android.material.internal.ThemeEnforcement;
+import com.google.android.material.shape.MaterialShapeDrawable;
+import com.google.android.material.shape.ShapeAppearanceModel;
 
 /**
  * A special sub-class of {@link android.widget.AutoCompleteTextView} that is auto-inflated so that
@@ -60,6 +64,19 @@ public class MaterialAutoCompleteTextView extends AppCompatAutoCompleteTextView
   @NonNull private final ListPopupWindow modalListPopup;
   @Nullable private final AccessibilityManager accessibilityManager;
   @NonNull private final Rect tempRect = new Rect();
+  private StateListDrawable popupBackground;
+  private int popupStartPadding;
+  private int popupTopPadding;
+  private int popupBottomPadding;
+  private int popupEndPadding;
+  private float popupElevation;
+  @StyleRes int popupShapeAppearanceResId;
+  @StyleRes int popupShapeAppearanceOverlayResId;
+  boolean enforceFlatTopCorners;
+
+  private static final int[] POPUP_ATTRS = {
+      android.R.attr.popupElevation
+  };
 
   public MaterialAutoCompleteTextView(@NonNull Context context) {
     this(context, null);
@@ -95,6 +112,15 @@ public MaterialAutoCompleteTextView(
       }
     }
 
+    TypedArray a =
+        context.obtainStyledAttributes(
+            attributeSet, POPUP_ATTRS, defStyleAttr, 0);
+    if (a.hasValue(0)) {
+      popupElevation = a.getDimension(0, 0);
+    }
+    a.recycle();
+    loadPopupAttributes(attributes);
+
     accessibilityManager =
         (AccessibilityManager) context.getSystemService(Context.ACCESSIBILITY_SERVICE);
 
@@ -127,9 +153,70 @@ public void onItemClick(AdapterView<?> parent, View selectedView, int position,
           }
         });
 
+    createPopupBackground();
+    setPopupBackground();
     attributes.recycle();
   }
 
+  private void loadPopupAttributes(@NonNull TypedArray a){
+
+    popupShapeAppearanceResId = a.getResourceId(R.styleable.MaterialAutoCompleteTextView_popupBackgroundShapeAppearance, 0);
+    popupShapeAppearanceOverlayResId =
+        a.getResourceId(R.styleable.MaterialAutoCompleteTextView_popupBackgroundShapeAppearanceOverlay, 0);
+
+    popupStartPadding = a.getDimensionPixelSize(R.styleable.MaterialAutoCompleteTextView_popupStartPadding, 0);
+    popupTopPadding = a.getDimensionPixelSize(R.styleable.MaterialAutoCompleteTextView_popupTopPadding, 0);
+    popupBottomPadding = a.getDimensionPixelSize(R.styleable.MaterialAutoCompleteTextView_popupBottomPadding, 0);
+    popupEndPadding = a.getDimensionPixelSize(R.styleable.MaterialAutoCompleteTextView_popupEndPadding, 0);
+
+    enforceFlatTopCorners = a.getBoolean(R.styleable.MaterialAutoCompleteTextView_enforceFlatTopCorners,false);
+  }
+
+  private void createPopupBackground() {
+
+    ShapeAppearanceModel popupShapeAppearanceModel = ShapeAppearanceModel.builder(
+        getContext(), popupShapeAppearanceResId, popupShapeAppearanceOverlayResId)
+        .build();
+
+    // Background for the popups of the outlined variation and for the filled variation when it is
+    // being displayed above the layout.
+    MaterialShapeDrawable defaultRoundedCornersPopupBackground =
+        createDefaultPopupMaterialShapeDrawable(popupShapeAppearanceModel);
+
+    MaterialShapeDrawable flatTopCornersPopupBackground = null;
+    popupBackground = new StateListDrawable();
+    if (enforceFlatTopCorners) {
+      ShapeAppearanceModel flatTopCornersShapeAppearanceModel =
+          ShapeAppearanceModel.builder(
+              getContext(), popupShapeAppearanceResId, popupShapeAppearanceOverlayResId)
+              .setTopLeftCornerSize(0)
+              .setTopRightCornerSize(0)
+              .build();
+
+      flatTopCornersPopupBackground =
+          createDefaultPopupMaterialShapeDrawable(flatTopCornersShapeAppearanceModel);
+
+      popupBackground.addState(
+          new int[] {android.R.attr.state_above_anchor}, defaultRoundedCornersPopupBackground);
+      popupBackground.addState(new int[] {}, flatTopCornersPopupBackground);
+    } else {
+      popupBackground.addState(new int[]{}, defaultRoundedCornersPopupBackground);
+    }
+  }
+
+  private MaterialShapeDrawable createDefaultPopupMaterialShapeDrawable(
+      ShapeAppearanceModel shapeAppearanceModel) {
+    MaterialShapeDrawable popupDrawable =
+        MaterialShapeDrawable.createWithElevationOverlay(getContext(), popupElevation);
+    popupDrawable.setShapeAppearanceModel(shapeAppearanceModel);
+    popupDrawable.setPadding(popupStartPadding, popupTopPadding, popupEndPadding, popupBottomPadding);
+    return popupDrawable;
+  }
+
+  private void setPopupBackground(){
+    setDropDownBackgroundDrawable(popupBackground);
+  }
+
   @Override
   public void showDropDown() {
     if (accessibilityManager != null && accessibilityManager.isTouchExplorationEnabled()) {

lib/java/com/google/android/material/textfield/res-public/values/public.xml

@@ -91,6 +91,13 @@
   <public name="passwordToggleTintMode" type="attr"/>
 
   <public name="textInputLayoutFocusedRectEnabled" type="attr"/>
+  <public name="popupBackgroundShapeAppearance" type="attr" />
+  <public name="popupBackgroundShapeAppearanceOverlay" type="attr"/>
+  <public name="enforceFlatTopCorners" type="attr"/>
+  <public name="popupTopPadding" type="attr"/>
+  <public name="popupBottomPadding" type="attr"/>
+  <public name="popupStartPadding" type="attr"/>
+  <public name="popupEndPadding" type="attr"/>
 
   <public name="Widget.Design.TextInputLayout" type="style"/>
   <public name="Widget.MaterialComponents.TextInputLayout.FilledBox" type="style"/>

lib/java/com/google/android/material/textfield/res/values-v21/styles.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2019 The Android Open Source Project
+  ~
+  ~ 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
+  ~
+  ~     https://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.
+  -->
+<resources xmlns:tools="http://schemas.android.com/tools">
+
+</resources>

lib/java/com/google/android/material/textfield/res/values/attrs.xml

@@ -268,6 +268,21 @@
 
   <declare-styleable name="MaterialAutoCompleteTextView" parent="AppCompatAutoCompleteTextView">
     <attr name="android:inputType"/>
+    <!-- Shape appearance style reference for DropDownMenu in MaterialAutoCompleteTextView. -->
+    <attr name="popupBackgroundShapeAppearance" format="reference" />
+    <!-- Shape appearance overlay style reference for DropDownMenu in  MaterialAutoCompleteTextView.
+     To be used to augment attributes declared in the popupBackgroundShapeAppearance. -->
+    <attr name="popupBackgroundShapeAppearanceOverlay" format="reference"/>
+    <!-- Whether the flat top corners should be used in DropDownMenu -->
+    <attr name="enforceFlatTopCorners" format="boolean"/>
+    <!-- Top padding for DropDownMenu in  MaterialAutoCompleteTextView. -->
+    <attr name="popupTopPadding" format="dimension"/>
+    <!-- Bottom padding for DropDownMenu in  MaterialAutoCompleteTextView. -->
+    <attr name="popupBottomPadding" format="dimension"/>
+    <!-- Start padding for DropDownMenu in  MaterialAutoCompleteTextView. -->
+    <attr name="popupStartPadding" format="dimension"/>
+    <!-- End padding for DropDownMenu in  MaterialAutoCompleteTextView. -->
+    <attr name="popupEndPadding" format="dimension"/>
   </declare-styleable>
 
 </resources>

lib/java/com/google/android/material/textfield/res/values/styles.xml

@@ -209,12 +209,19 @@
     <item name="android:textAppearance">?attr/textAppearanceSubtitle1</item>
     <item name="android:dropDownVerticalOffset">@dimen/mtrl_exposed_dropdown_menu_popup_vertical_offset</item>
     <item name="android:popupElevation" tools:ignore="NewApi">@dimen/mtrl_exposed_dropdown_menu_popup_elevation</item>
+    <item name="enforceFlatTopCorners">false</item>
+    <item name="popupBackgroundShapeAppearance">?attr/shapeAppearanceMediumComponent</item>
+    <item name="popupStartPadding">0dp</item>
+    <item name="popupTopPadding">@dimen/mtrl_exposed_dropdown_menu_popup_vertical_padding</item>
+    <item name="popupEndPadding">0dp</item>
+    <item name="popupBottomPadding">@dimen/mtrl_exposed_dropdown_menu_popup_vertical_padding</item>
   </style>
 
   <!-- Styles for the AutocompleteTextView to be used if an ExposedDropdownMenu style is being used. -->
   <style name="Widget.MaterialComponents.AutoCompleteTextView.FilledBox" parent="Base.Widget.MaterialComponents.AutoCompleteTextView">
     <item name="android:paddingTop">28dp</item>
     <item name="android:paddingBottom">12dp</item>
+    <item name="enforceFlatTopCorners">true</item>
   </style>
 
   <style name="Widget.MaterialComponents.AutoCompleteTextView.FilledBox.Dense">
@@ -316,4 +323,23 @@
     <item name="cornerSizeBottomRight">@dimen/mtrl_textinput_box_corner_radius_small</item>
   </style>
 
+  <!--
+  <style name="Widget.MaterialComponents.ExposedDropdownMenu" parent="android:Widget"/>
+
+  <style name="Base.Widget.MaterialComponents.ExposedDropdownMenu.TextInputLayout" parent="Widget.MaterialComponents.ExposedDropdownMenu">
+    <item name="endIconDrawable">@drawable/mtrl_ic_arrow_drop_down</item>
+    <item name="popupVerticalPadding">@dimen/mtrl_exposed_dropdown_menu_popup_vertical_padding</item>
+    <item name="popupElevation">@dimen/mtrl_exposed_dropdown_menu_popup_elevation</item>
+    <item name="enforceFlatTopCorners">false</item>
+    <item name="shapeAppearance">?attr/shapeAppearanceMediumComponent</item>
+  </style>
+
+  <style name="Widget.MaterialComponents.ExposedDropdownMenu.TextInputLayout" parent="Base.Widget.MaterialComponents.ExposedDropdownMenu.TextInputLayout"/>
+
+  <style name="Widget.MaterialComponents.ExposedDropdownMenu.TextInputLayout.FilledBox">
+    <item name="enforceFlatTopCorners">true</item>
+  </style>
+
+  <style name="Widget.MaterialComponents.ExposedDropdownMenu.TextInputLayout.OutlinedBox"/>
+  -->
 </resources>