Support setting mouse cursor icon in Android N.

chrome/android/java/src/org/chromium/chrome/browser/omnibox/LocationBarLayout.java

 // Copyright 2015 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.
 
 package org.chromium.chrome.browser.omnibox;
 
 import static org.chromium.chrome.browser.toolbar.ToolbarPhone.URL_FOCUS_CHANGE_ANIMATION_DURATION_MS;
 
 import android.Manifest;
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.res.ColorStateList;
 import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.graphics.Color;
 import android.graphics.PorterDuff;
 import android.graphics.Rect;
 import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Parcelable;
 import android.os.SystemClock;
 import android.provider.Settings;
 import android.speech.RecognizerIntent;
 import android.support.annotation.IntDef;
 import android.text.InputType;
 import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.util.Pair;
 import android.util.SparseArray;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
+import android.view.PointerIcon;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.view.ViewStub;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.ListView;
 import android.widget.TextView;
 
@@ skipping 2237 matching lines @@
         if (mOmniboxResultsContainer != null) return;
 
         // Use the omnibox results container in the bottom sheet if it exists.
         int omniboxResultsContainerId = R.id.omnibox_results_container_stub;
         if (mBottomSheet != null) {
             omniboxResultsContainerId = R.id.bottom_omnibox_results_container_stub;
         }
 
         ViewStub overlayStub = (ViewStub) getRootView().findViewById(omniboxResultsContainerId);
         mOmniboxResultsContainer = (ViewGroup) overlayStub.inflate();
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            PointerIcon icon = PointerIcon.getSystemIcon(
+                    mOmniboxResultsContainer.getContext(), PointerIcon.TYPE_ARROW);
+            mOmniboxResultsContainer.setPointerIcon(icon);

[Ted C, 2017/07/21 00:15:25]

what is the default icon?  why do we need to set anything?

I guess this question applies all places.  If we don't set anything, is the
default icon null?  In which case, does it walk up the children to find a
non-null icon?

That seems like quite the crazy api to me.  Does that mean every child in our
code needs to set an arrow to prevent blending up the hierarchy?

[jaebaek, 2017/07/21 10:03:05]

In my implementation, onResolvePointerIcon method of CoordinatorLayoutForPointer
skips children that return null in onResolvePointerIcon. The reason behind this
is because of partially transparent views.

When SnackBar is shown, BottomContainer is not invisible but transparent except
the part for SnackBar. In the case, the pointer icon for the transparent part
must be the same with the one of CompositorViewHolder, while the one of SnackBar
is not. If onResolvePointerIcon of CoordinatorLayoutForPointer only checks
visibility (without null check), it chooses pointer icon of BottomContainer but
not the one for CompositorViewHolder. Thus, point icon is always default (i.e.,
null).

To solve this, I add null check in onResolvePointerIcon of
CoordinatorLayoutForPointer. Because of the null check, All its children must
return non-null in onResolvePointerIcon, when they are not transparent.

[Ted C, 2017/07/21 18:45:31]

Is BottomContainer the only issue?  Can that be made to wrap_contents?

Actually, I'm still confused why partially transparent views give us grief.

Looking at the android code link you sent:
https://github.com/android/platform_frameworks_base/blob/master/core/java/and...

For each child, it checks whether the point is within the view
(isTransformedTouchPointInView).  When a snackbar is showing,
the bottomcontainer has the one view.  If you're hovering over
the blank area.  The code above looks like it should just return
null as it should fall into "return super.onResolvePointerIcon"
since no view should have returned true for

Touch point calculation:
https://github.com/android/platform_frameworks_base/blob/master/core/java/and...
https://github.com/android/platform_frameworks_base/blob/master/core/java/and...

What about the default call in BottomContainer#onResolvePointerIcon
doesn't work?

[jaebaek, 2017/07/24 07:34:11]

I changed the layout_height of BottomContainer to wrap_content.

+        }
     }
 
     private void updateOmniboxResultsContainer() {
         if (mSuggestionsShown || mUrlHasFocus) {
             initOmniboxResultsContainer();
             updateOmniboxResultsContainerVisibility(true);
         } else if (mOmniboxResultsContainer != null) {
             updateFadingBackgroundView(false);
         }
     }
@@ skipping 253 matching lines @@
     public void setTitleToPageTitle() { }
 
     @Override
     public void setShowTitle(boolean showTitle) { }
 
     @Override
     public boolean mustQueryUrlBarLocationForSuggestions() {
         return DeviceFormFactor.isTablet();
     }
 }