[Presentation API, Android] Implement starting a presentation via CreateRoute()

chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CreateRouteRequest.java

Index: chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CreateRouteRequest.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CreateRouteRequest.java b/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CreateRouteRequest.java
new file mode 100644
index 0000000000000000000000000000000000000000..49cb8385c621fb970e258f108044f0c8929c5a19
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/router/cast/CreateRouteRequest.java
@@ -0,0 +1,218 @@
+// 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.media.router.cast;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.support.v7.media.MediaRouter;
+
+import com.google.android.gms.cast.Cast;
+import com.google.android.gms.cast.CastDevice;
+import com.google.android.gms.common.ConnectionResult;
+import com.google.android.gms.common.api.GoogleApiClient;
+import com.google.android.gms.common.api.PendingResult;
+import com.google.android.gms.common.api.ResultCallback;
+import com.google.android.gms.common.api.Status;
+
+import org.chromium.base.Log;
+import org.chromium.chrome.browser.media.router.ChromeMediaRouter;
+
+/**
+ * Establishes a {@link MediaRoute} by starting a Cast application represented by the given
+ * presentation URL. Reports success or failure to {@link ChromeMediaRouter}.
+ * Since there're numerous asynchronous calls involved in getting the application to launch
+ * the class is implemented as a state machine.
+ */
+public class CreateRouteRequest implements GoogleApiClient.ConnectionCallbacks,
+        GoogleApiClient.OnConnectionFailedListener,
+        ResultCallback<Cast.ApplicationConnectionResult> {
+    private static final String TAG = "cr.MediaRouter";
+
+    private static final int STATE_IDLE = 0;
+    private static final int STATE_CONNECTING_TO_API = 1;
+    private static final int STATE_API_CONNECTION_SUSPENDED = 2;
+    private static final int STATE_LAUNCHING_APPLICATION = 3;
+    private static final int STATE_LAUNCH_SUCCEEDED = 4;
+    private static final int STATE_TERMINATED = 5;
+
+    private static final String ERROR_NEW_ROUTE_INVALID_SOURCE_URN = "Invalid source URN: %s";
+    private static final String ERROR_NEW_ROUTE_INVALID_SINK_URN = "Invalid sink URN: %s";
+    private static final String ERROR_NEW_ROUTE_LAUNCH_APPLICATION_FAILED =
+            "Launch application failed: %s, %s";
+    private static final String ERROR_NEW_ROUTE_LAUNCH_APPLICATION_FAILED_STATUS =
+            "Launch application failed with status: %s, %d, %s";
+    private static final String ERROR_NEW_ROUTE_CLIENT_CONNECTION_FAILED =
+            "GoogleApiClient connection failed: %d, %b";
+
+    private final MediaSource mMediaSource;
+    private final String mSinkId;
+    private final String mPresentationId;
+    private final int mRequestId;
+    private final ChromeMediaRouter mMediaRouter;
+
+    private GoogleApiClient mApiClient;
+    private MediaRouter.RouteInfo mRoute;
+    private int mState = STATE_IDLE;
+
+    /**
+     * Initializes the request.
+     * @param sourceUrn The URN defining the application to launch on the Cast device
+     * @param sinkUrn The URN identifying the selected Cast device
+     * @param presentationId The presentation id assigned to the route by {@link ChromeMediaRouter}
+     * @param requestId The id of the route creation request for tracking by
+     * {@link ChromeMediaRouter}
+     * @param router The instance of {@link ChromeMediaRouter} handling the request
+     */
+    public CreateRouteRequest(
+            String sourceUrn,
+            String sinkUrn,
+            String presentationId,
+            int requestId,
+            ChromeMediaRouter router) {
+        mMediaSource = MediaSource.from(sourceUrn);
+        mSinkId = sinkUrn;
+        mPresentationId = presentationId;
+        mRequestId = requestId;
+        mMediaRouter = router;
+    }
+
+    /**
+     * Starts the process of launching the application on the Cast device.
+     * @param androidMediaRouter Android's {@link MediaRouter} instance.
+     * @param applicationContext application context
+     * @param castApplicationListener {@link com.google.android.gms.cast.Cast.Listener}
+     * implementation provided by the caller.
+     */
+    public void start(
+            MediaRouter androidMediaRouter,
+            Context applicationContext,
+            Cast.Listener castApplicationListener) {
+        assert androidMediaRouter != null;
+        assert applicationContext != null;
+        assert castApplicationListener != null;
+        if (mState != STATE_IDLE) throwInvalidState();

[mlamouri (slow - plz ping), 2015/08/18 16:04:54]

nit: empty line after condition

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: empty line after condition

What happens if start() is called twice in JS?

[whywhat, 2015/08/18 20:06:32]

Done.
PresentationServiceImpl will reject the consequent start while one request is in
process.

+        if (mMediaSource == null) {
+            reportError(String.format(ERROR_NEW_ROUTE_INVALID_SOURCE_URN, mMediaSource.getUrn()));
+            return;
+        }
+        mRoute = null;

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: empty line before mRoute

[whywhat, 2015/08/18 20:06:32]

Done.

+        for (MediaRouter.RouteInfo route : androidMediaRouter.getRoutes()) {
+            MediaSink routeSink = MediaSink.fromRoute(route);
+            if (routeSink.getId().equals(mSinkId)) {
+                mRoute = route;
+                break;
+            }
+        }
+        if (mRoute == null) {

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: empty line between for() and if()

[whywhat, 2015/08/18 20:06:32]

Done.

+            reportError(String.format(ERROR_NEW_ROUTE_INVALID_SINK_URN, mSinkId));
+            return;
+        }
+        mApiClient = createApiClient(mRoute, castApplicationListener, applicationContext);

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: empty line after if()

[whywhat, 2015/08/18 20:06:32]

Done.

+        mApiClient.connect();
+        mState = STATE_CONNECTING_TO_API;
+    }
+
+    @Override
+    public void onConnected(Bundle connectionHint) {
+        if (mState != STATE_CONNECTING_TO_API && mState != STATE_API_CONNECTION_SUSPENDED) {
+            throwInvalidState();
+        }
+        if (mState == STATE_API_CONNECTION_SUSPENDED) {
+            // TODO(avayvod): figure out what needs to be reset at this point and reconnect

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: bug number

[whywhat, 2015/08/18 20:06:32]

Updated the comment. We don't need to have all this connection/reconnection
logic - it all should be handles by the Google Play Services now. Will look into
removing unnecessary code tomorrow.

+            return;
+        }
+        try {

[mlamouri (slow - plz ping), 2015/08/18 16:04:54]

nit: empty line before try{}

[whywhat, 2015/08/18 20:06:32]

Done.

+            launchApplication(mApiClient, mMediaSource.getApplicationId(), false)
+                    .setResultCallback(this);
+            mState = STATE_LAUNCHING_APPLICATION;
+        } catch (Exception e) {
+            reportError(String.format(ERROR_NEW_ROUTE_LAUNCH_APPLICATION_FAILED,
+                    mMediaSource.getApplicationId(), e));
+        }
+    }
+
+    @Override
+    public void onConnectionSuspended(int cause) {
+        mState = STATE_API_CONNECTION_SUSPENDED;
+        // TODO(avayvod): what to suspend here to be reconnected in {@link onConnected()}?

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: bug number?

[whywhat, 2015/08/18 20:06:32]

Ditto

+    }
+
+    @Override
+    public void onResult(Cast.ApplicationConnectionResult result) {
+        if (mState != STATE_LAUNCHING_APPLICATION) throwInvalidState();
+        Status status = result.getStatus();

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: empty line after condition

[whywhat, 2015/08/18 20:06:32]

Done.

+        if (status.isSuccess()) {

[mlamouri (slow - plz ping), 2015/08/18 16:04:54]

nit:
if (!status.isSuccess()) {
    reportError();
    return;
}

// do the real thing

[whywhat, 2015/08/18 20:06:32]

Done.

+            // TODO(avayvod): figure out if the commented info below is useful and should be kept.
+            // String applicationStatus = result.getApplicationStatus();
+            // ApplicationMetadata applicationMetadata =
+            // result.getApplicationMetadata();

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

shrug...

[whywhat, 2015/08/18 20:06:32]

Removed.

+            String sessionId = result.getSessionId();
+            boolean wasLaunched = result.getWasLaunched();
+            mState = STATE_LAUNCH_SUCCEEDED;
+            reportSuccess(sessionId, wasLaunched);
+        } else {
+            reportError(String.format(
+                    ERROR_NEW_ROUTE_LAUNCH_APPLICATION_FAILED_STATUS,
+                    mMediaSource.getApplicationId(),
+                    status.getStatusCode(),
+                    status.getStatusMessage()));
+        }
+    }
+
+    @Override
+    public void onConnectionFailed(ConnectionResult result) {
+        if (mState != STATE_CONNECTING_TO_API) throwInvalidState();

[mlamouri (slow - plz ping), 2015/08/18 16:04:54]

nit: empty line after condition

[whywhat, 2015/08/18 20:06:32]

Done.

+        // TODO(avayvod): figure out how to extend GoogleApiClientConnectionHelper here and
+        // try to resolve the problem (e.g. ask the user to update GPS).

[mlamouri (slow - plz ping), 2015/08/18 16:04:55]

nit: add bug number.

[whywhat, 2015/08/18 20:06:32]

Ditto. Hopefully will remove altogether.

+        reportError(String.format(
+                ERROR_NEW_ROUTE_CLIENT_CONNECTION_FAILED,
+                result.getErrorCode(),
+                result.hasResolution()));
+    }
+
+    private GoogleApiClient createApiClient(
+            MediaRouter.RouteInfo route, Cast.Listener listener, Context context) {
+        CastDevice selectedDevice = CastDevice.getFromBundle(route.getExtras());
+        Cast.CastOptions.Builder apiOptionsBuilder = Cast.CastOptions
+                .builder(selectedDevice, listener)
+                // TODO(avayvod): hide this behind the flag or remove
+                .setVerboseLoggingEnabled(true);
+        return new GoogleApiClient.Builder(context)
+                .addApi(Cast.API, apiOptionsBuilder.build())
+                .addConnectionCallbacks(this)
+                .addOnConnectionFailedListener(this)
+                .build();
+    }
+
+    private PendingResult<Cast.ApplicationConnectionResult> launchApplication(
+            GoogleApiClient apiClient,
+            String appId,
+            boolean relaunchIfRunning) {
+        return Cast.CastApi.launchApplication(apiClient, appId, relaunchIfRunning);
+    }
+
+    private void throwInvalidState() {
+        Log.e(TAG, "throwInvalidState: %d", mState);
+        throw new RuntimeException(String.format("Invalid state: %d", mState));
+    }
+
+    private void reportSuccess(String sessionId, boolean wasLaunched) {
+        if (mState != STATE_LAUNCH_SUCCEEDED) throwInvalidState();
+
+        String mediaRouteId = String.format(
+                "route:%s/%s/%s", mPresentationId, mSinkId, mMediaSource.getUrn());
+        mMediaRouter.onRouteCreated(mediaRouteId, mRequestId, sessionId, wasLaunched);
+        mState = STATE_TERMINATED;
+    }
+
+    private void reportError(String message) {
+        Log.e(TAG, "reportError: %s", message);
+        if (mState == STATE_TERMINATED) throwInvalidState();
+        assert mMediaRouter != null;
+        mMediaRouter.onRouteCreationError(message, mRequestId);
+        mState = STATE_TERMINATED;
+    }
+
+}