[AF Android] Use rounded corners and elevation

This CL adds rounded corners and elevation to DropdownPopupWindowImpl.
It also adds a small util function to ApiCompatibilityUtils to
facilitate elevation.

Screenshots: https://docs.google.com/presentation/d/1cSW-l62jY_6HB3UA-KDg8JlguNrVJlncse9HL7xIhuU/edit?usp=sharing

BUG: 874077
Change-Id: Icd01731c2f7292d3ea1397e6790525af00bfa71d
Reviewed-on: https://chromium-review.googlesource.com/c/1265595Reviewed-by: Changwan Ryu <changwan@chromium.org>
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Tommy Martino <tmartino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598761}

base/android/java/src/org/chromium/base/ApiCompatibilityUtils.java

@@ -46,6 +46,7 @@ import android.view.WindowManager;
 import android.view.inputmethod.InputMethodSubtype;
 import android.view.textclassifier.TextClassifier;
 import android.widget.ImageView;
+import android.widget.PopupWindow;
 import android.widget.TextView;
 
 import java.io.File;
@@ -325,6 +326,17 @@ public class ApiCompatibilityUtils {
         return true;
     }
 
+    /**
+     * Set elevation if supported.
+     */
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    public static boolean setElevation(PopupWindow window, float elevationValue) {
+        if (!isElevationSupported()) return false;
+
+        window.setElevation(elevationValue);
+        return true;
+    }
+
     /**
      *  Gets an intent to start the Android system notification settings activity for an app.
      *

content/public/android/java/src/org/chromium/content/browser/input/SuggestionsPopupWindow.java

@@ -150,7 +150,7 @@ public abstract class SuggestionsPopupWindow
             // Set this on the content view instead of on the PopupWindow so we can retrieve the
             // padding later.
             mContentView.setBackground(ApiCompatibilityUtils.getDrawable(
-                    mContext.getResources(), R.drawable.dropdown_popup_background));
+                    mContext.getResources(), R.drawable.popup_bg));
         }
 
         // mPopupVerticalMargin is the minimum amount of space we want to have between the popup

ui/android/java/res/drawable/dropdown_popup_background.xml

-<?xml version="1.0" encoding="utf-8"?>
-
-<!-- Copyright 2014 The Chromium Authors. All rights reserved.
-
-     Use of this source code is governed by a BSD-style license that can be
-     found in the LICENSE file.
--->
-
-<selector xmlns:android="http://schemas.android.com/apk/res/android">
-    <item android:state_above_anchor="true"
-        android:drawable="@drawable/dropdown_popup_background_up" />
-    <item android:drawable="@drawable/dropdown_popup_background_down" />
-</selector>
\ No newline at end of file

ui/android/java/res/values-v17/styles.xml

@@ -8,7 +8,7 @@
 
 <resources xmlns:tools="http://schemas.android.com/tools">
     <style name="DropdownPopupWindow" parent="@android:style/Widget.ListPopupWindow">
-        <item name="android:popupBackground">@drawable/dropdown_popup_background</item>
+        <item name="android:popupBackground">@drawable/popup_bg</item>
     </style>
 
     <!-- Buttons -->

ui/android/java/res/values/dimens.xml

@@ -19,6 +19,8 @@
     <dimen name="dropdown_item_label_margin">10dp</dimen>
     <dimen name="dropdown_icon_margin">8dp</dimen>
     <dimen name="dropdown_vertical_margin">4dp</dimen>
+    <dimen name="dropdown_elevation">2dp</dimen>
+
     <dimen name="button_compat_corner_radius">4dp</dimen>
 
     <!-- Divider Dimensions -->

ui/android/java/src/org/chromium/ui/DropdownPopupWindowImpl.java

@@ -82,12 +82,14 @@ class DropdownPopupWindowImpl
 
         ViewRectProvider rectProvider = new ViewRectProvider(mAnchorView);
         rectProvider.setIncludePadding(true);
-        mBackground = ApiCompatibilityUtils.getDrawable(
-                context.getResources(), R.drawable.dropdown_popup_background);
+        mBackground =
+                ApiCompatibilityUtils.getDrawable(context.getResources(), R.drawable.popup_bg);
         mAnchoredPopupWindow = new AnchoredPopupWindow(
                 context, mAnchorView, mBackground, mContentView, rectProvider);
         mAnchoredPopupWindow.addOnDismissListener(onDismissLitener);
         mAnchoredPopupWindow.setLayoutObserver(this);
+        mAnchoredPopupWindow.setElevation(
+                context.getResources().getDimensionPixelSize(R.dimen.dropdown_elevation));
         Rect paddingRect = new Rect();
         mBackground.getPadding(paddingRect);
         rectProvider.setInsetPx(0, /* top= */ paddingRect.bottom, 0, /* bottom= */ paddingRect.top);
@@ -115,11 +117,8 @@ class DropdownPopupWindowImpl
     public void onPreLayoutChange(
             boolean positionBelow, int x, int y, int width, int height, Rect anchorRect) {
         mBackground.setBounds(anchorRect);
-        mAnchoredPopupWindow.setBackgroundDrawable(positionBelow
-                        ? ApiCompatibilityUtils.getDrawable(mContext.getResources(),
-                                  R.drawable.dropdown_popup_background_down)
-                        : ApiCompatibilityUtils.getDrawable(mContext.getResources(),
-                                  R.drawable.dropdown_popup_background_up));
+        mAnchoredPopupWindow.setBackgroundDrawable(
+                ApiCompatibilityUtils.getDrawable(mContext.getResources(), R.drawable.popup_bg));
     }
 
     /**

ui/android/java/src/org/chromium/ui/widget/AnchoredPopupWindow.java

@@ -20,6 +20,7 @@ import android.view.WindowManager;
 import android.widget.PopupWindow;
 import android.widget.PopupWindow.OnDismissListener;
 
+import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.base.ObserverList;
 import org.chromium.base.VisibleForTesting;
 
@@ -344,6 +345,13 @@ public class AnchoredPopupWindow implements OnTouchListener, RectProvider.Observ
         mPopupWindow.setBackgroundDrawable(background);
     }
 
+    /**
+     * Sets the elevation of the popup, if elevation is supported.
+     */
+    public void setElevation(float elevation) {
+        ApiCompatibilityUtils.setElevation(mPopupWindow, elevation);
+    }
+
     // RectProvider.Observer implementation.
     @Override
     public void onRectChanged() {