Added voice trigger ("show me a demo"); updated code style to match t…

…hat of other samples.

AndroidManifest.xml

@@ -1,6 +1,21 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 Google Inc.
+
+     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.
+-->
+
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.google.glass.samples.waveform"
+    package="com.google.android.glass.sample.waveform"
     android:versionCode="1"
     android:versionName="1.0" >
 
@@ -12,15 +27,17 @@
 
     <application
         android:allowBackup="true"
-        android:label="@string/app_name"
-        android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >
+        android:label="@string/app_name" >
+
         <activity
-            android:name="com.google.glass.samples.waveform.WaveformActivity"
-            android:label="@string/app_name" >
+            android:name="com.google.android.glass.sample.waveform.WaveformActivity" >
             <intent-filter>
-                <action android:name="android.intent.action.MAIN" />
+                <action android:name="com.google.android.glass.action.VOICE_TRIGGER" />
             </intent-filter>
+            <meta-data android:name="com.google.android.glass.VoiceTrigger"
+                android:resource="@xml/trigger_show_me_a_demo" />
         </activity>
+
     </application>
 
 </manifest>

README.md

@@ -1,48 +1,22 @@
-apk-waveform-sample
-=====================
+Waveform
+========
 
-A simple Glassware apk that receives audio input from the microphone and
-displays it on the screen as an animated waveform, along with the decibel
+This sample launches an immersion that receives audio input from the microphone
+and displays it on the screen as an animated waveform, along with the decibel
 level.
 
-## Prerequistes
+## Getting started
 
-* [Android SDK](http://developer.android.com/sdk/index.html) - This is needed for development.
-* [Glass](http://www.google.com/glass/start/how-to-get-one/) - You can push the code to an Android device but the goal of this project is to get started writing .apk for Glass.
+Check out our documentation to learn how to get started on
+https://developers.google.com/glass/develop/index
 
-## Importing and compiling the code
+## Running the sample on Glass
 
-Checkout the code into your filesystem and use your favorite IDE to import and compile the code.
+You can use your IDE to compile and install the sample or use
+[`adb`](https://developer.android.com/tools/help/adb.html)
+on the command line:
 
-### In Eclipse and ADT
+    $ adb install -r WaveformSample.apk
 
-1. Click **File > Import ... > Existing Android Code into Workspace**.
-2. Click **Browse**, select the location of the `apk-waveform-sample/` directory, and click **OK**.
-3. Select the **apk-waveform-sample** project to import it and select
-**Copy projects into workspace**.
-6. Click **Finish** to complete the import.
-
-### In Android Studio
-
-1. Checkout the sample to a location where you keep your Android
-development projects. A `apk-waveform-sample/` directory is created.
-2. Click **File > Import Project...**, select the location of the `apk-waveform-sample/` directory, and click **Next** until you see the **Finish** button.
-3. Click **Finish** to complete the import.
-
-
-## Turning on debug mode
-
-You'll need to turn on debug mode before you do any type of development on
-Glass. Go to **Settings > Device Info > Turn on debug** to enable it.
-
-## Push the .apk on Glass
-
-You can use your IDE to compile, push and run the .apk or use this command line with `adb`:
-
-    adb install -r apk-waveform-sample.apk
-
-## Run the .apk
-
-You can use your IDE to run the .apk or use this command line with `adb` when the Glass screen is **on**:
-
-    adb shell am start -n com.google.glass.samples.waveform/.WaveformActivity
+To start the sample, say "ok glass, show me a demo" from the Glass clock
+screen or use the touch menu.

res/layout/layout_waveform.xml

@@ -1,23 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 Google Inc.
+
+     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.
+-->
+
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:keepScreenOn="true"
-    android:background="@color/black"
-    tools:context=".WaveformActivity" >
+    android:layout_height="match_parent" >
 
-    <com.google.glass.samples.waveform.WaveformView
-        android:id="@+id/waveformView"
+    <com.google.android.glass.sample.waveform.WaveformView
+        android:id="@+id/waveform_view"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />
 
     <TextView
-        android:id="@+id/decibelView"
+        android:id="@+id/decibel_view"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="bottom|right"
         android:layout_marginRight="@dimen/footer_right_margin"
         android:layout_marginBottom="@dimen/footer_bottom_margin"
-        android:textSize="@dimen/footer_text_size" />
-    
+        android:textAppearance="?android:attr/textAppearanceSmall" />
+
 </FrameLayout>

res/values/dimens.xml

@@ -1,6 +1,22 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 Google Inc.
+
+     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.
+-->
+
 <resources>
+
     <dimen name="footer_right_margin">40px</dimen>
     <dimen name="footer_bottom_margin">29px</dimen>
-    <dimen name="footer_text_size">30px</dimen>
+
 </resources>

res/values/strings.xml

@@ -1,5 +1,24 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 Google Inc.
+
+     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.
+-->
+
 <resources>
+
     <string name="app_name">Waveform</string>
+    <string name="show_me_a_demo">show me a demo</string>
+
     <string name="decibel_format">%1$.1f dB</string>
+
 </resources>

res/xml/trigger_show_me_a_demo.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 Google Inc.
+
+     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.
+-->
+
+<trigger keyword="@string/show_me_a_demo" />

src/com/google/android/glass/sample/waveform/WaveformActivity.java

@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2013 Google Inc.
+ *
+ * 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.google.android.glass.sample.waveform;
+
+import android.app.Activity;
+import android.media.AudioFormat;
+import android.media.AudioRecord;
+import android.media.MediaRecorder.AudioSource;
+import android.os.Bundle;
+import android.widget.TextView;
+
+/**
+ * Receives audio input from the microphone and displays a visualization of that data as a waveform
+ * on the screen.
+ */
+public class WaveformActivity extends Activity {
+
+    // The sampling rate for the audio recorder.
+    private static final int SAMPLING_RATE = 44100;
+
+    private WaveformView mWaveformView;
+    private TextView mDecibelView;
+
+    private RecordingThread mRecordingThread;
+    private int mBufferSize;
+    private short[] mAudioBuffer;
+    private String mDecibelFormat;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.layout_waveform);
+
+        mWaveformView = (WaveformView) findViewById(R.id.waveform_view);
+        mDecibelView = (TextView) findViewById(R.id.decibel_view);
+
+        // Compute the minimum required audio buffer size and allocate the buffer.
+        mBufferSize = AudioRecord.getMinBufferSize(SAMPLING_RATE, AudioFormat.CHANNEL_IN_MONO,
+                AudioFormat.ENCODING_PCM_16BIT);
+        mAudioBuffer = new short[mBufferSize / 2];
+
+        mDecibelFormat = getResources().getString(R.string.decibel_format);
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        mRecordingThread = new RecordingThread();
+        mRecordingThread.start();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+
+        if (mRecordingThread != null) {
+            mRecordingThread.stopRunning();
+            mRecordingThread = null;
+        }
+    }
+
+    /**
+     * A background thread that receives audio from the microphone and sends it to the waveform
+     * visualizing view.
+     */
+    private class RecordingThread extends Thread {
+
+        private boolean mShouldContinue = true;
+
+        @Override
+        public void run() {
+            android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_AUDIO);
+
+            AudioRecord record = new AudioRecord(AudioSource.MIC, SAMPLING_RATE,
+                    AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, mBufferSize);
+            record.startRecording();
+
+            while (shouldContinue()) {
+                record.read(mAudioBuffer, 0, mBufferSize / 2);
+                mWaveformView.updateAudioData(mAudioBuffer);
+                updateDecibelLevel();
+            }
+
+            record.stop();
+            record.release();
+        }
+
+        /**
+         * Gets a value indicating whether the thread should continue running.
+         *
+         * @return true if the thread should continue running or false if it should stop
+         */
+        private synchronized boolean shouldContinue() {
+            return mShouldContinue;
+        }
+
+        /** Notifies the thread that it should stop running at the next opportunity. */
+        public synchronized void stopRunning() {
+            mShouldContinue = false;
+        }
+
+        /**
+         * Computes the decibel level of the current sound buffer and updates the appropriate text
+         * view.
+         */
+        private void updateDecibelLevel() {
+            // Compute the root-mean-squared of the sound buffer and then apply the formula for
+            // computing the decibel level, 20 * log_10(rms). This is an uncalibrated calculation
+            // that assumes no noise in the samples; with 16-bit recording, it can range from
+            // -90 dB to 0 dB.
+            double sum = 0;
+
+            for (short rawSample : mAudioBuffer) {
+                double sample = rawSample / 32768.0;
+                sum += sample * sample;
+            }
+
+            double rms = Math.sqrt(sum / mAudioBuffer.length);
+            final double db = 20 * Math.log10(rms);
+
+            // Update the text view on the main thread.
+            mDecibelView.post(new Runnable() {
+                @Override
+                public void run() {
+                    mDecibelView.setText(String.format(mDecibelFormat, db));
+                }
+            });
+        }
+    }
+}