system activity for scan always available setting

Takes user permission via a dialog to enable scans to be always available.

Bug: 8141918
Change-Id: I1e5e45e514726c2cbfd86e747123e477e00fd7ed

AndroidManifest.xml

@@ -1179,6 +1179,15 @@
             </intent-filter>
         </activity>
 
+        <activity android:name=".wifi.WifiScanModeActivity"
+                  android:excludeFromRecents="true"
+                  android:theme="@style/Transparent">
+            <intent-filter>
+                <action android:name="android.net.wifi.action.REQUEST_SCAN_ALWAYS_AVAILABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+        </activity>
+
         <activity android:name=".bluetooth.RequestPermissionHelperActivity"
                   android:label="@string/bluetooth_pairing_request"
                   android:excludeFromRecents="true"

res/values/strings.xml

@@ -1433,6 +1433,9 @@
     <!-- Do not translate.  Concise terminology for wifi with 802.1x EAP security -->
     <string name="wifi_security_eap">802.1x EAP</string>
 
+    <string name="wifi_scan_always_turnon_message">To improve location accuracy and for other purposes, <xliff:g id="app_name">%1$s</xliff:g> wants to turn on network scanning, even when Wi-Fi is off.\n\nAllow this for all apps that want to scan?</string>
+    <string name="wifi_scan_always_confirm_allow">Allow</string>
+    <string name="wifi_scan_always_confirm_deny">Deny</string>
 
     <!-- Button label to connect to a Wi-Fi network -->
     <string name="wifi_connect">Connect</string>

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

@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2013 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
+ *
+ *      http://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.
+ */
+
+package com.android.settings.wifi;
+
+import com.android.settings.R;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.app.Dialog;
+import android.app.DialogFragment;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.net.wifi.WifiManager;
+import android.os.Bundle;
+import android.provider.Settings;
+import android.util.Log;
+
+/**
+ * This activity requests users permission to allow scanning even when Wi-Fi is turned off
+ */
+public class WifiScanModeActivity extends Activity {
+    private DialogFragment mDialog;
+    private String mApp;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        Intent intent = getIntent();
+        if (savedInstanceState == null) {
+            if (intent != null && intent.getAction()
+                    .equals(WifiManager.ACTION_REQUEST_SCAN_ALWAYS_AVAILABLE)) {
+                mApp = getCallingPackage();
+            } else {
+                finish();
+                return;
+            }
+        } else {
+            mApp = savedInstanceState.getString("app");
+        }
+        createDialog();
+    }
+
+    private void createDialog() {
+        if (mDialog == null) {
+            mDialog = AlertDialogFragment.newInstance(mApp);
+            mDialog.show(getFragmentManager(), "dialog");
+        }
+    }
+
+    private void dismissDialog() {
+        if (mDialog != null) {
+            mDialog.dismiss();
+            mDialog = null;
+        }
+    }
+
+    private void doPositiveClick() {
+        Settings.Global.putInt(getContentResolver(),
+                Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE, 1);
+        setResult(RESULT_OK);
+        finish();
+    }
+
+    private void doNegativeClick() {
+        setResult(RESULT_CANCELED);
+        finish();
+    }
+
+    @Override
+    public void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        outState.putString("app", mApp);
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        dismissDialog();
+    }
+
+    public void onResume() {
+        super.onResume();
+        createDialog();
+    }
+
+    public static class AlertDialogFragment extends DialogFragment {
+        static AlertDialogFragment newInstance(String app) {
+            AlertDialogFragment frag = new AlertDialogFragment(app);
+            return frag;
+        }
+
+        private final String mApp;
+        public AlertDialogFragment(String app) {
+            super();
+            mApp = app;
+        }
+
+        public AlertDialogFragment() {
+            super();
+            mApp = null;
+        }
+
+        @Override
+        public Dialog onCreateDialog(Bundle savedInstanceState) {
+            return new AlertDialog.Builder(getActivity())
+                    .setMessage(getString(R.string.wifi_scan_always_turnon_message, mApp))
+                    .setPositiveButton(R.string.wifi_scan_always_confirm_allow,
+                            new DialogInterface.OnClickListener() {
+                                public void onClick(DialogInterface dialog, int whichButton) {
+                                    ((WifiScanModeActivity) getActivity()).doPositiveClick();
+                                }
+                            }
+                    )
+                    .setNegativeButton(R.string.wifi_scan_always_confirm_deny,
+                            new DialogInterface.OnClickListener() {
+                                public void onClick(DialogInterface dialog, int whichButton) {
+                                    ((WifiScanModeActivity) getActivity()).doNegativeClick();
+                                }
+                            }
+                    )
+                    .create();
+        }
+        @Override
+        public void onCancel(DialogInterface dialog) {
+            ((WifiScanModeActivity) getActivity()).doNegativeClick();
+        }
+    }
+}