[Chromecast] Turn CastContentWindow into an abstract interface.

chromecast/browser/android/apk/src/org/chromium/chromecast/shell/CastContentWindowAndroid.java

+// Copyright 2016 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.chromecast.shell;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.Uri;
+import android.os.PatternMatcher;
+import android.support.v4.content.LocalBroadcastManager;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.Log;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.content_public.browser.WebContents;
+
+/**
+ * The Java component of CastContentWindowAndroid. This class is responsible for
+ * starting, stopping and monitoring CastWebContentsActivity.
+ *
+ * See chromecast/browser/cast_content_window_android.* for the native half.
+ */
+@JNINamespace("chromecast::shell")
+public class CastContentWindowAndroid {
+    private static final String TAG = "cr_CastContentWindowAndroid";
+    private static final boolean DEBUG = true;
+
+    // Note: CastContentWindowAndroid may outlive the native object. The native
+    // ref should be checked that it is not zero before it is used.
+    private long mNativeCastContentWindowAndroid;
+    private Context mContext;
+    private IntentFilter mActivityClosedIntentFilter;
+    private BroadcastReceiver mActivityClosedBroadcastReceiver;
+    private String mInstanceId;
+
+    private static int sInstanceId = 1;
+
+    @SuppressWarnings("unused")
+    @CalledByNative
+    private static CastContentWindowAndroid create(long nativeCastContentWindowAndroid) {
+        return new CastContentWindowAndroid(
+                nativeCastContentWindowAndroid, ContextUtils.getApplicationContext());
+    }
+
+    private CastContentWindowAndroid(long nativeCastContentWindowAndroid, Context context) {
+        mNativeCastContentWindowAndroid = nativeCastContentWindowAndroid;
+        mContext = context;
+        mInstanceId = Integer.toString(sInstanceId++);
+    }
+
+    private Uri getInstanceUri() {
+        Uri instanceUri = new Uri.Builder()
+                .scheme(CastWebContentsActivity.ACTION_DATA_SCHEME)
+                .authority(CastWebContentsActivity.ACTION_DATA_AUTHORITY)
+                .path(mInstanceId)
+                .build();
+        return instanceUri;
+    }
+
+    @SuppressWarnings("unused")
+    @CalledByNative
+    private void showWebContents(WebContents webContents) {
+        if (DEBUG) Log.d(TAG, "showWebContents");
+
+        Intent intent = new Intent(
+                Intent.ACTION_VIEW, getInstanceUri(), mContext, CastWebContentsActivity.class);
+
+        mActivityClosedBroadcastReceiver = new BroadcastReceiver() {
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                if (intent.getAction() == CastWebContentsActivity.ACTION_ACTIVITY_STOPPED) {
+                    onActivityStopped();
+                } else if (intent.getAction() == CastWebContentsActivity.ACTION_KEY_EVENT) {
+                    int keyCode =
+                            intent.getIntExtra(CastWebContentsActivity.ACTION_EXTRA_KEY_CODE, 0);
+                    onKeyDown(keyCode);
+                }
+            }
+        };
+        mActivityClosedIntentFilter = new IntentFilter();
+        mActivityClosedIntentFilter.addDataScheme(intent.getData().getScheme());
+        mActivityClosedIntentFilter.addDataAuthority(intent.getData().getAuthority(), null);
+        mActivityClosedIntentFilter.addDataPath(
+                intent.getData().getPath(), PatternMatcher.PATTERN_LITERAL);
+        mActivityClosedIntentFilter.addAction(CastWebContentsActivity.ACTION_ACTIVITY_STOPPED);
+        mActivityClosedIntentFilter.addAction(CastWebContentsActivity.ACTION_KEY_EVENT);
+        LocalBroadcastManager.getInstance(mContext).registerReceiver(
+                mActivityClosedBroadcastReceiver, mActivityClosedIntentFilter);
+
+        intent.putExtra(CastWebContentsActivity.ACTION_EXTRA_WEB_CONTENTS, webContents);
+        // FLAG_ACTIVITY_SINGLE_TOP will try to reuse existing activity.
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_MULTIPLE_TASK
+                | Intent.FLAG_ACTIVITY_SINGLE_TOP);
+        mContext.startActivity(intent);
+    }
+
+    @SuppressWarnings("unused")
+    @CalledByNative
+    private void onNativeDestroyed() {
+        assert mNativeCastContentWindowAndroid != 0;
+        mNativeCastContentWindowAndroid = 0;
+
+        // Note: there is a potential race condition when this function is called after
+        // showWebContents. If the stop intent is received after the start intent but before
+        // onCreate, the activity won't shutdown.
+        // TODO(derekjchow): Add a unittest to check this behaviour. Also consider using
+        // Instrumentation.startActivitySync to guarentee onCreate is run.
+
+        if (DEBUG) Log.d(TAG, "onNativeDestroyed");
+        Intent intent = new Intent(CastWebContentsActivity.ACTION_STOP_ACTIVITY, getInstanceUri());
+        LocalBroadcastManager.getInstance(mContext).sendBroadcastSync(intent);
+    }
+
+    private void onActivityStopped() {
+        if (DEBUG) Log.d(TAG, "onActivityStopped");
+        if (mNativeCastContentWindowAndroid != 0) {
+            nativeOnActivityStopped(mNativeCastContentWindowAndroid);
+        }
+    }
+
+    private void onKeyDown(int keyCode) {
+        if (DEBUG) Log.d(TAG, "onKeyDown");
+        if (mNativeCastContentWindowAndroid != 0) {
+            nativeOnKeyDown(mNativeCastContentWindowAndroid, keyCode);
+        }
+    }
+
+    private native void nativeOnActivityStopped(long nativeCastContentWindowAndroid);
+    private native void nativeOnKeyDown(long nativeCastContentWindowAndroid, int keyCode);
+}