Add Wi-Fi soft ap related Rpc methods. (#35)

* Add Wi-Fi soft ap related Rpc methods.
* Change wait util to accomodate lambda functions that throw exceptions, which interrupt the wait.

4 files changed, 127 insertions, 11 deletions

diff --git a/src/main/java/com/google/android/mobly/snippet/bundled/WifiManagerSnippet.java b/src/main/java/com/google/android/mobly/snippet/bundled/WifiManagerSnippet.java
index f4fa0c0..ba9569c 100644
--- a/src/main/java/com/google/android/mobly/snippet/bundled/WifiManagerSnippet.java
+++ b/src/main/java/com/google/android/mobly/snippet/bundled/WifiManagerSnippet.java
@@ -23,14 +23,17 @@ import android.content.IntentFilter;
 import android.net.wifi.ScanResult;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiManager;
+import android.os.Build;
 import android.support.annotation.Nullable;
 import android.support.test.InstrumentationRegistry;
 import com.google.android.mobly.snippet.Snippet;
+import com.google.android.mobly.snippet.bundled.utils.ApiVersionException;
 import com.google.android.mobly.snippet.bundled.utils.JsonDeserializer;
 import com.google.android.mobly.snippet.bundled.utils.JsonSerializer;
 import com.google.android.mobly.snippet.bundled.utils.Utils;
 import com.google.android.mobly.snippet.rpc.Rpc;
 import com.google.android.mobly.snippet.util.Log;
+import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -240,6 +243,106 @@ public class WifiManagerSnippet implements Snippet {
         return mJsonSerializer.toJson(mWifiManager.getDhcpInfo());
     }
 
+    private void verifyApiVersionForSoftAp() throws ApiVersionException {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
+            throw new ApiVersionException(
+                    "Soft AP APIs are not supported in Android versions >= N.");
+        }
+    }
+
+    @Rpc(description = "Check whether Wi-Fi Soft AP (hotspot) is enabled.")
+    public boolean wifiIsApEnabled() throws Throwable {
+        verifyApiVersionForSoftAp();
+        try {
+            return (boolean)
+                    mWifiManager
+                            .getClass()
+                            .getDeclaredMethod("isWifiApEnabled")
+                            .invoke(mWifiManager);
+        } catch (InvocationTargetException e) {
+            throw e.getCause();
+        }
+    }
+
+    /**
+     * Enable Wi-Fi Soft AP (hotspot).
+     *
+     * <p>Does not work for release N.
+     *
+     * @param configuration The same format as the param wifiNetworkConfig param for wifiConnect.
+     * @throws Throwable
+     */
+    @Rpc(description = "Enable Wi-Fi Soft AP (hotspot).")
+    public void wifiEnableSoftAp(@Nullable JSONObject configuration) throws Throwable {
+        verifyApiVersionForSoftAp();
+        // If no configuration is provided, the existing configuration would be used.
+        WifiConfiguration wifiConfiguration = null;
+        if (configuration != null) {
+            wifiConfiguration = JsonDeserializer.jsonToWifiConfig(configuration);
+            // Have to trim off the extra quotation marks since Soft AP logic interprets
+            // WifiConfiguration.SSID literally, unlike the WifiManager connection logic.
+            wifiConfiguration.SSID = JsonSerializer.trimQuotationMarks(wifiConfiguration.SSID);
+        }
+        boolean success;
+        try {
+            success =
+                    (boolean)
+                            mWifiManager
+                                    .getClass()
+                                    .getDeclaredMethod(
+                                            "setWifiApEnabled",
+                                            WifiConfiguration.class,
+                                            boolean.class)
+                                    .invoke(mWifiManager, wifiConfiguration, true);
+        } catch (InvocationTargetException e) {
+            throw e.getCause();
+        }
+        if (!success) {
+            throw new WifiManagerSnippetException("Failed to initiate turning on Wi-Fi Soft AP.");
+        }
+        if (!Utils.waitUntil(() -> wifiIsApEnabled() == true, 60)) {
+            throw new WifiManagerSnippetException(
+                    "Timed out after 60s waiting for Wi-Fi Soft AP state to turn on with configuration: "
+                            + configuration);
+        }
+    }
+
+    /**
+     * Disables Wi-Fi Soft AP (hotspot).
+     *
+     * <p>Does not work for release N.
+     *
+     * @throws Throwable
+     */
+    @Rpc(description = "Disable Wi-Fi Soft AP (hotspot).")
+    public void wifiDisableSoftAp() throws Throwable {
+        verifyApiVersionForSoftAp();
+        boolean success;
+        try {
+            success =
+                    (boolean)
+                            mWifiManager
+                                    .getClass()
+                                    .getDeclaredMethod(
+                                            "setWifiApEnabled",
+                                            WifiConfiguration.class,
+                                            boolean.class)
+                                    .invoke(
+                                            mWifiManager,
+                                            null, /* No configuration needed for disabling */
+                                            false);
+        } catch (InvocationTargetException e) {
+            throw e.getCause();
+        }
+        if (!success) {
+            throw new WifiManagerSnippetException("Failed to initiate turning off Wi-Fi Soft AP.");
+        }
+        if (!Utils.waitUntil(() -> wifiIsApEnabled() == false, 60)) {
+            throw new WifiManagerSnippetException(
+                    "Timed out after 60s waiting for Wi-Fi Soft AP state to turn off.");
+        }
+    }
+
     @Override
     public void shutdown() {}
 
diff --git a/src/main/java/com/google/android/mobly/snippet/bundled/utils/ApiVersionException.java b/src/main/java/com/google/android/mobly/snippet/bundled/utils/ApiVersionException.java
new file mode 100644
index 0000000..68f2a55
--- /dev/null
+++ b/src/main/java/com/google/android/mobly/snippet/bundled/utils/ApiVersionException.java
@@ -0,0 +1,8 @@
+package com.google.android.mobly.snippet.bundled.utils;
+
+/** Raised for when an Rpc call is not supported by the Android version used. */
+public class ApiVersionException extends Exception {
+    public ApiVersionException(String message) {
+        super(message);
+    }
+}
diff --git a/src/main/java/com/google/android/mobly/snippet/bundled/utils/JsonSerializer.java b/src/main/java/com/google/android/mobly/snippet/bundled/utils/JsonSerializer.java
index 0c1b7a3..45af4a4 100644
--- a/src/main/java/com/google/android/mobly/snippet/bundled/utils/JsonSerializer.java
+++ b/src/main/java/com/google/android/mobly/snippet/bundled/utils/JsonSerializer.java
@@ -55,7 +55,7 @@ public class JsonSerializer {
      *
      * @param originalString
      */
-    private static String trimQuotationMarks(String originalString) {
+    public static String trimQuotationMarks(String originalString) {
         String result = originalString;
         if (originalString.charAt(0) == '"'
                 && originalString.charAt(originalString.length() - 1) == '"') {
diff --git a/src/main/java/com/google/android/mobly/snippet/bundled/utils/Utils.java b/src/main/java/com/google/android/mobly/snippet/bundled/utils/Utils.java
index 00bfbd2..0ea5313 100644
--- a/src/main/java/com/google/android/mobly/snippet/bundled/utils/Utils.java
+++ b/src/main/java/com/google/android/mobly/snippet/bundled/utils/Utils.java
@@ -25,21 +25,26 @@ public final class Utils {
      * <p>This is often used to wait for asynchronous operations to finish and the system to reach a
      * desired state.
      *
+     * <p>If the predicate function throws an exception and interrupts the waiting, the exception
+     * will be wrapped in an {@link RuntimeException}.
+     *
      * @param predicate A lambda function that specifies the condition to wait for. This function
      *     should return true when the desired state has been reached.
      * @param timeout The number of seconds to wait for before giving up.
      * @return true if the operation finished before timeout, false otherwise.
-     * @throws InterruptedException
      */
-    public static boolean waitUntil(Utils.Predicate predicate, int timeout)
-            throws InterruptedException {
+    public static boolean waitUntil(Utils.Predicate predicate, int timeout) {
         timeout *= 10;
-        while (!predicate.waitCondition() && timeout >= 0) {
-            Thread.sleep(100);
-            timeout -= 1;
-        }
-        if (predicate.waitCondition()) {
-            return true;
+        try {
+            while (!predicate.waitCondition() && timeout >= 0) {
+                Thread.sleep(100);
+                timeout -= 1;
+            }
+            if (predicate.waitCondition()) {
+                return true;
+            }
+        } catch (Throwable e) {
+            throw new RuntimeException(e);
         }
         return false;
     }
@@ -49,6 +54,6 @@ public final class Utils {
      * going on.
      */
     public interface Predicate {
-        boolean waitCondition();
+        boolean waitCondition() throws Throwable;
     }
 }