[WifiSetup] Progress when wifi scanning

Use a custom empty view to show the status while wifi is scanning
or off. Cannot use android.R.id.empty because in phone portrait
layout the illustration is the listview header, which will be hidden
if the list is empty and we use ListView.setEmptyView.

Bug: 17183006
Change-Id: Ie8598303f4e61f87e078008fb7a03918ba92c9ef

src/com/android/settings/wifi/WifiSettings.java

@@ -321,8 +321,7 @@ public class WifiSettings extends RestrictedSettingsFragment
 
         prepareWifiAssistantCard();
 
-        mEmptyView = (TextView) getView().findViewById(android.R.id.empty);
-        getListView().setEmptyView(mEmptyView);
+        mEmptyView = initEmptyView();
         registerForContextMenu(getListView());
         setHasOptionsMenu(true);
     }
@@ -773,6 +772,12 @@ public class WifiSettings extends RestrictedSettingsFragment
         editor.apply();
     }
 
+    protected TextView initEmptyView() {
+        TextView emptyView = (TextView) getActivity().findViewById(android.R.id.empty);
+        getListView().setEmptyView(emptyView);
+        return emptyView;
+    }
+
     private void setOffMessage() {
         if (mEmptyView != null) {
             mEmptyView.setCompoundDrawablesWithIntrinsicBounds(0,

src/com/android/settings/wifi/WifiSettingsForSetupWizard.java

@@ -18,18 +18,19 @@ package com.android.settings.wifi;
 
 import android.content.Intent;
 import android.content.res.TypedArray;
+import android.database.DataSetObserver;
 import android.net.wifi.WifiConfiguration;
 import android.os.Bundle;
+import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
-import android.widget.ImageButton;
+import android.widget.AbsListView.LayoutParams;
+import android.widget.ListAdapter;
 import android.widget.ListView;
-import android.widget.PopupMenu;
-import android.widget.PopupMenu.OnMenuItemClickListener;
 import android.widget.TextView;
 
 import com.android.settings.R;
@@ -47,6 +48,11 @@ public class WifiSettingsForSetupWizard extends WifiSettings {
     // show a text regarding data charges when wifi connection is required during setup wizard
     protected static final String EXTRA_SHOW_WIFI_REQUIRED_INFO = "wifi_show_wifi_required_info";
 
+    private View mAddOtherNetworkItem;
+    private ListAdapter mAdapter;
+    private TextView mEmptyFooter;
+    private boolean mListLastEmpty = false;
+
     @Override
     public View onCreateView(final LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
@@ -60,9 +66,9 @@ public class WifiSettingsForSetupWizard extends WifiSettings {
             list.addHeaderView(header, null, false);
         }
 
-        final View other = inflater.inflate(R.layout.setup_wifi_add_network, list, false);
-        list.addFooterView(other, null, true);
-        other.setOnClickListener(new OnClickListener() {
+        mAddOtherNetworkItem = inflater.inflate(R.layout.setup_wifi_add_network, list, false);
+        list.addFooterView(mAddOtherNetworkItem, null, true);
+        mAddOtherNetworkItem.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View v) {
                 if (mWifiManager.isWifiEnabled()) {
@@ -92,6 +98,15 @@ public class WifiSettingsForSetupWizard extends WifiSettings {
         if (hasNextButton()) {
             getNextButton().setVisibility(View.GONE);
         }
+
+        mAdapter = getPreferenceScreen().getRootAdapter();
+        mAdapter.registerDataSetObserver(new DataSetObserver() {
+            @Override
+            public void onChanged() {
+                super.onChanged();
+                updateFooter();
+            }
+        });
     }
 
     @Override
@@ -133,4 +148,30 @@ public class WifiSettingsForSetupWizard extends WifiSettings {
         activity.networkSelected();
         super.connect(networkId);
     }
+
+    @Override
+    protected TextView initEmptyView() {
+        mEmptyFooter = new TextView(getActivity());
+        mEmptyFooter.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,
+                LayoutParams.MATCH_PARENT));
+        mEmptyFooter.setGravity(Gravity.CENTER);
+        mEmptyFooter.setCompoundDrawablesWithIntrinsicBounds(0,
+                R.drawable.ic_wifi_emptystate, 0,0);
+        return mEmptyFooter;
+    }
+
+    protected void updateFooter() {
+        final boolean isEmpty = mAdapter.isEmpty();
+        if (isEmpty != mListLastEmpty) {
+            final ListView list = getListView();
+            if (isEmpty) {
+                list.removeFooterView(mAddOtherNetworkItem);
+                list.addFooterView(mEmptyFooter, null, false);
+            } else {
+                list.removeFooterView(mEmptyFooter);
+                list.addFooterView(mAddOtherNetworkItem, null, true);
+            }
+            mListLastEmpty = isEmpty;
+        }
+    }
 }