Large revamp to bring it closer to the Android tutorial 2.

gst-sdk/tutorials/xcode iOS/Tutorial 2/GStreamerBackend.h

@@ -3,12 +3,7 @@
 
 @interface GStreamerBackend : NSObject
 
-@property (nonatomic,assign) id delegate;
+-(id) init:(id) uiDelegate;
-
--(NSString*) getGStreamerVersion;
-
--(BOOL) initializePipeline;
-
 -(void) play;
 -(void) pause;
 -(void) stop;

gst-sdk/tutorials/xcode iOS/Tutorial 2/GStreamerBackend.m

@@ -3,16 +3,33 @@
 #include <gst/gst.h>
 
 @interface GStreamerBackend()
--(void)notifyError:(gchar*) message;
+-(void)setUIMessage:(gchar*) message;
--(void)notifyEos;
+-(void)app_function;
--(void) _poll_gst_bus;
+-(void)check_initialization_complete;
 @end
 
 @implementation GStreamerBackend {
-    GstElement *pipeline;
+    id delegate;           /* Class that we use to interact with the user interface */
+    GstElement *pipeline;  /* The running pipeline */
+    GMainContext *context; /* GLib context used to run the main loop */
+    GMainLoop *main_loop;  /* GLib main loop */
+    gboolean initialized;  /* To avoid informing the UI multiple times about the initialization */
 }
 
-@synthesize delegate;
+-(id) init:(id) uiDelegate
+{
+    if (self = [super init])
+    {
+        self->delegate = uiDelegate;
+
+        /* Start the bus monitoring task */
+        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+            [self app_function];
+        });
+    }
+
+    return self;
+}
 
 -(void) dealloc
 {
@@ -23,95 +40,120 @@
     }
 }
 
--(void)notifyError:(gchar*) message
+-(void)setUIMessage:(gchar*) message
 {
     NSString *string = [NSString stringWithUTF8String:message];
-    if(delegate && [delegate respondsToSelector:@selector(gstreamerError:from:)])
+    if(delegate && [delegate respondsToSelector:@selector(gstreamerSetUIMessage:)])
     {
-        [delegate gstreamerError:string from:self];
+        [delegate gstreamerSetUIMessage:string];
     }
 }
 
--(void)notifyEos
+/* Retrieve errors from the bus and show them on the UI */
+static void error_cb (GstBus *bus, GstMessage *msg, GStreamerBackend *self)
 {
-    if(delegate && [delegate respondsToSelector:@selector(gstreamerEosFrom)])
+    GError *err;
-    {
+    gchar *debug_info;
-        [delegate gstreamerEosFrom:self];
+    gchar *message_string;
+    
+    gst_message_parse_error (msg, &err, &debug_info);
+    message_string = g_strdup_printf ("Error received from element %s: %s", GST_OBJECT_NAME (msg->src), err->message);
+    g_clear_error (&err);
+    g_free (debug_info);
+    [self setUIMessage:message_string];
+    g_free (message_string);
+    gst_element_set_state (self->pipeline, GST_STATE_NULL);
+}
+
+/* Notify UI about pipeline state changes */
+static void state_changed_cb (GstBus *bus, GstMessage *msg, GStreamerBackend *self)
+{
+    GstState old_state, new_state, pending_state;
+    gst_message_parse_state_changed (msg, &old_state, &new_state, &pending_state);
+    /* Only pay attention to messages coming from the pipeline, not its children */
+    if (GST_MESSAGE_SRC (msg) == GST_OBJECT (self->pipeline)) {
+        gchar *message = g_strdup_printf("State changed to %s", gst_element_state_get_name(new_state));
+        [self setUIMessage:message];
+        g_free (message);
     }
 }
 
--(void) _poll_gst_bus
+/* Check if all conditions are met to report GStreamer as initialized.
+ * These conditions will change depending on the application */
+-(void) check_initialization_complete
+{
+    if (!initialized && main_loop) {
+        GST_DEBUG ("Initialization complete, notifying application.");
+        if (delegate && [delegate respondsToSelector:@selector(gstreamerInitialized)])
+        {
+            [delegate gstreamerInitialized];
+        }
+        initialized = TRUE;
+    }
+}
+
+/* Main method for the native code. This is executed on its own thread. */
+-(void) app_function
 {
     GstBus *bus;
-    GstMessage *msg;
+    GSource *bus_source;
-    
-    /* Wait until error or EOS */
-    bus = gst_element_get_bus (self->pipeline);
-    msg = gst_bus_timed_pop_filtered(bus, GST_CLOCK_TIME_NONE,
-                                     (GstMessageType) (GST_MESSAGE_ERROR | GST_MESSAGE_EOS));
-    gst_object_unref(bus);
-    
-    switch (GST_MESSAGE_TYPE(msg)) {
-        case GST_MESSAGE_EOS:
-            [self stop];
-            [self notifyEos];
-            NSLog(@"EOS");
-            break;
-        case GST_MESSAGE_ERROR: {
-            GError *gerr = NULL;
-            gchar *debug;
-            
-            gst_message_parse_error(msg, &gerr, &debug);
-            
-            [self stop];
-            NSLog(@"Error %s - %s", gerr->message, debug, nil);
-            [self notifyError:gerr->message];
-            g_free(debug);
-            g_error_free(gerr);
-        }
-            break;
-        default:
-            break;
-    }
-}
-
--(BOOL) initializePipeline
-{
     GError *error = NULL;
 
-    if (pipeline)
+    GST_DEBUG ("Creating pipeline");
-        return YES;
 
+    /* Create our own GLib Main Context and make it the default one */
+    context = g_main_context_new ();
+    g_main_context_push_thread_default(context);
+    
+    /* Build pipeline */
     pipeline = gst_parse_launch("audiotestsrc ! audioconvert ! audioresample ! autoaudiosink", &error);
     if (error) {
         gchar *message = g_strdup_printf("Unable to build pipeline: %s", error->message);
         g_clear_error (&error);
-        [self notifyError:message];
+        [self setUIMessage:message];
         g_free (message);
-        return NO;
+        return;
     }
     
-    /* start the bus polling. This will the bus being continuously polled */
+    /* Instruct the bus to emit signals for each received message, and connect to the interesting signals */
-    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+    bus = gst_element_get_bus (pipeline);
-        while (1) {
+    bus_source = gst_bus_create_watch (bus);
-            [self _poll_gst_bus];
+    g_source_set_callback (bus_source, (GSourceFunc) gst_bus_async_signal_func, NULL, NULL);
-        }
+    g_source_attach (bus_source, context);
-    });
+    g_source_unref (bus_source);
+    g_signal_connect (G_OBJECT (bus), "message::error", (GCallback)error_cb, (__bridge void *)self);
+    g_signal_connect (G_OBJECT (bus), "message::state-changed", (GCallback)state_changed_cb, (__bridge void *)self);
+    gst_object_unref (bus);
     
-    return YES;
+    /* Create a GLib Main Loop and set it to run */
+    GST_DEBUG ("Entering main loop...");
+    main_loop = g_main_loop_new (context, FALSE);
+    [self check_initialization_complete];
+    g_main_loop_run (main_loop);
+    GST_DEBUG ("Exited main loop");
+    g_main_loop_unref (main_loop);
+    main_loop = NULL;
+    
+    /* Free resources */
+    g_main_context_pop_thread_default(context);
+    g_main_context_unref (context);
+    gst_element_set_state (pipeline, GST_STATE_NULL);
+    gst_object_unref (pipeline);
+    
+    return;
 }
 
 -(void) play
 {
     if(gst_element_set_state(pipeline, GST_STATE_PLAYING) == GST_STATE_CHANGE_FAILURE) {
-        [self notifyError:"Failed to set pipeline to playing"];
+        [self setUIMessage:"Failed to set pipeline to playing"];
     }
 }
 
 -(void) pause
 {
     if(gst_element_set_state(pipeline, GST_STATE_PAUSED) == GST_STATE_CHANGE_FAILURE) {
-        [self notifyError:"Failed to set pipeline to paused"];
+        [self setUIMessage:"Failed to set pipeline to paused"];
     }
 }
 
@@ -121,13 +163,5 @@
         gst_element_set_state(pipeline, GST_STATE_NULL);
 }
 
--(NSString*) getGStreamerVersion
-{
-    char *str = gst_version_string();
-    NSString *version = [NSString stringWithUTF8String:str];
-    g_free(str);
-    return version;
-}
-
 @end
 

gst-sdk/tutorials/xcode iOS/Tutorial 2/GStreamerBackendDelegate.h

@@ -3,7 +3,7 @@
 @protocol GStreamerBackendDelegate <NSObject>
 
 @optional
--(void) gstreamerError:(NSString *)message from:(id)sender;
+-(void) gstreamerInitialized;
--(void) gstreamerEosFrom:(id)sender;
+-(void) gstreamerSetUIMessage:(NSString *)message;
 
 @end

gst-sdk/tutorials/xcode iOS/Tutorial 2/ViewController.h

@@ -2,13 +2,16 @@
 #import "GStreamerBackendDelegate.h"
 
 @interface ViewController : UIViewController <GStreamerBackendDelegate> {
+    IBOutlet UILabel *message_label;
+    IBOutlet UIButton *play_button;
+    IBOutlet UIButton *pause_button;
 }
 
 -(IBAction) play:(id)sender;
 -(IBAction) pause:(id)sender;
 
 /* From GStreamerBackendDelegate */
--(void) gstreamerError:(NSString *)message from:(id)sender;
+-(void) gstreamerInitialized;
--(void) gstreamerEosFrom:(id)sender;
+-(void) gstreamerSetUIMessage:(NSString *)message;
 
 @end

gst-sdk/tutorials/xcode iOS/Tutorial 2/ViewController.m

@@ -13,14 +13,11 @@
 - (void)viewDidLoad
 {
     [super viewDidLoad];
-	// Do any additional setup after loading the view, typically from a nib.
     
-    gst_backend = [[GStreamerBackend alloc] init];
+    play_button.enabled = FALSE;
+    pause_button.enabled = FALSE;
 
-    if (![gst_backend initializePipeline]) {
+    gst_backend = [[GStreamerBackend alloc] init:self];
-        
-    }
-    gst_backend.delegate = self;
 }
 
 - (void)didReceiveMemoryWarning
@@ -39,28 +36,19 @@
     [gst_backend pause];
 }
 
--(void) gstreamerError:(NSString *)message from:(id)sender
+-(void) gstreamerInitialized
 {
-    NSLog(@"Error %@", message, nil);
-    
-    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"GStreamer error"
-                                                    message:message
-                                                   delegate:nil
-                                          cancelButtonTitle:@"OK"
-                                          otherButtonTitles:nil];
     dispatch_async(dispatch_get_main_queue(), ^{
-        /* make sure it runs from the main thread */
+        play_button.enabled = TRUE;
-        [alert show];
+        pause_button.enabled = TRUE;
+        message_label.text = @"Ready";
     });
 }
 
--(void) gstreamerEosFrom:(id)sender
+-(void) gstreamerSetUIMessage:(NSString *)message
 {
-    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"EOS" message:@"End of stream" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
-    
     dispatch_async(dispatch_get_main_queue(), ^{
-        /* make sure it runs from the main thread */
+        message_label.text = message;
-        [alert show];
     });
 }
 

gst-sdk/tutorials/xcode iOS/Tutorial 2/en.lproj/MainStoryboard_iPad.storyboard

@@ -12,17 +12,26 @@
                         <rect key="frame" x="0.0" y="20" width="768" height="1004"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
-                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="nMR-rP-TAZ" userLabel="Buttons">
+                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="nMR-rP-TAZ" userLabel="Content">
                                 <subviews>
-                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="elU-wp-Qp2">
+                                    <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" text="Initializing..." textAlignment="center" lineBreakMode="wordWrap" numberOfLines="0" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" preferredMaxLayoutWidth="688" translatesAutoresizingMaskIntoConstraints="NO" id="UBA-ZM-cSe" userLabel="Message">
+                                        <fontDescription key="fontDescription" type="system" pointSize="24"/>
+                                        <color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
+                                        <nil key="highlightedColor"/>
+                                    </label>
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="elU-wp-Qp2" userLabel="Play">
                                         <constraints>
-                                            <constraint firstAttribute="width" constant="180" type="user" id="uTI-bm-bpQ"/>
+                                            <constraint firstAttribute="height" constant="100" type="user" id="4hh-98-fyR"/>
+                                            <constraint firstAttribute="width" constant="400" type="user" id="uTI-bm-bpQ"/>
                                         </constraints>
-                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="15"/>
+                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="32"/>
                                         <state key="normal" title="Play">
                                             <color key="titleColor" red="0.19607843459999999" green="0.30980393290000002" blue="0.52156865600000002" alpha="1" colorSpace="calibratedRGB"/>
                                             <color key="titleShadowColor" white="0.5" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
+                                        <state key="disabled">
+                                            <color key="titleColor" white="0.66666666666666663" alpha="1" colorSpace="calibratedWhite"/>
+                                        </state>
                                         <state key="highlighted">
                                             <color key="titleColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
@@ -30,15 +39,19 @@
                                             <action selector="play:" destination="2" eventType="touchUpInside" id="Rji-r8-PDd"/>
                                         </connections>
                                     </button>
-                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="w2M-v5-UAa">
+                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="w2M-v5-UAa" userLabel="Pause">
                                         <constraints>
-                                            <constraint firstAttribute="width" constant="180" type="user" id="S8q-2J-07k"/>
+                                            <constraint firstAttribute="height" constant="100" type="user" id="L6h-G1-RwS"/>
+                                            <constraint firstAttribute="width" constant="400" type="user" id="S8q-2J-07k"/>
                                         </constraints>
-                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="15"/>
+                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="32"/>
                                         <state key="normal" title="Pause">
                                             <color key="titleColor" red="0.19607843459999999" green="0.30980393290000002" blue="0.52156865600000002" alpha="1" colorSpace="calibratedRGB"/>
                                             <color key="titleShadowColor" white="0.5" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
+                                        <state key="disabled">
+                                            <color key="titleColor" white="0.66666666666666663" alpha="1" colorSpace="calibratedWhite"/>
+                                        </state>
                                         <state key="highlighted">
                                             <color key="titleColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
@@ -47,28 +60,53 @@
                                         </connections>
                                     </button>
                                 </subviews>
-                                <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                                <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                 <constraints>
+                                    <constraint firstItem="elU-wp-Qp2" firstAttribute="top" secondItem="UBA-ZM-cSe" secondAttribute="bottom" constant="8" symbolic="YES" type="user" id="18h-11-jhy"/>
+                                    <constraint firstItem="w2M-v5-UAa" firstAttribute="top" secondItem="elU-wp-Qp2" secondAttribute="bottom" constant="8" symbolic="YES" type="user" id="6GJ-37-EcB"/>
                                     <constraint firstAttribute="centerX" secondItem="w2M-v5-UAa" secondAttribute="centerX" type="user" id="7jU-ts-TJx"/>
+                                    <constraint firstAttribute="trailing" secondItem="UBA-ZM-cSe" secondAttribute="trailing" constant="20" symbolic="YES" type="user" id="EkQ-sA-oVc"/>
                                     <constraint firstAttribute="centerX" secondItem="elU-wp-Qp2" secondAttribute="centerX" type="user" id="EuX-Nw-e9K"/>
-                                    <constraint firstAttribute="bottom" secondItem="w2M-v5-UAa" secondAttribute="bottom" constant="20" symbolic="YES" type="default" id="Rdi-ax-p63"/>
+                                    <constraint firstAttribute="bottom" secondItem="w2M-v5-UAa" secondAttribute="bottom" constant="20" symbolic="YES" type="default" id="LCr-Rv-UZs"/>
-                                    <constraint firstItem="w2M-v5-UAa" firstAttribute="top" secondItem="elU-wp-Qp2" secondAttribute="bottom" constant="8" symbolic="YES" type="default" id="ZJv-bm-2N8"/>
+                                    <constraint firstItem="UBA-ZM-cSe" firstAttribute="top" secondItem="nMR-rP-TAZ" secondAttribute="top" constant="20" symbolic="YES" type="user" id="nNG-sn-bRM"/>
-                                    <constraint firstItem="elU-wp-Qp2" firstAttribute="top" secondItem="nMR-rP-TAZ" secondAttribute="top" constant="20" symbolic="YES" type="default" id="etT-xj-mf4"/>
+                                    <constraint firstItem="UBA-ZM-cSe" firstAttribute="leading" secondItem="nMR-rP-TAZ" secondAttribute="leading" constant="20" symbolic="YES" type="user" id="pJE-Vl-N8j"/>
                                 </constraints>
                             </view>
                         </subviews>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
                         <constraints>
                             <constraint firstItem="nMR-rP-TAZ" firstAttribute="leading" secondItem="5" secondAttribute="leading" constant="20" symbolic="YES" type="user" id="E7n-88-e9Y"/>
-                            <constraint firstAttribute="centerY" secondItem="nMR-rP-TAZ" secondAttribute="centerY" type="user" id="VKP-3B-S4N"/>
+                            <constraint firstAttribute="centerX" secondItem="nMR-rP-TAZ" secondAttribute="centerX" type="user" id="SAT-T4-FL2"/>
-                            <constraint firstAttribute="centerX" secondItem="nMR-rP-TAZ" secondAttribute="centerX" type="user" id="cFL-r5-ip5"/>
+                            <constraint firstAttribute="centerY" secondItem="nMR-rP-TAZ" secondAttribute="centerY" type="user" id="SfA-hs-2KS"/>
+                            <constraint firstItem="nMR-rP-TAZ" firstAttribute="top" secondItem="5" secondAttribute="top" priority="1" constant="20" symbolic="YES" type="user" id="XdK-Aa-fKA"/>
                         </constraints>
                     </view>
+                    <connections>
+                        <outlet property="message_label" destination="UBA-ZM-cSe" id="o2e-1J-nKs"/>
+                        <outlet property="pause_button" destination="w2M-v5-UAa" id="PKY-tN-Lod"/>
+                        <outlet property="play_button" destination="elU-wp-Qp2" id="C54-Xz-aIt"/>
+                    </connections>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="3" sceneMemberID="firstResponder"/>
             </objects>
         </scene>
     </scenes>
+    <classes>
+        <class className="NSLayoutConstraint" superclassName="NSObject">
+            <source key="sourceIdentifier" type="project" relativePath="./Classes/NSLayoutConstraint.h"/>
+        </class>
+        <class className="ViewController" superclassName="UIViewController">
+            <source key="sourceIdentifier" type="project" relativePath="./Classes/ViewController.h"/>
+            <relationships>
+                <relationship kind="action" name="pause:"/>
+                <relationship kind="action" name="play:"/>
+                <relationship kind="outlet" name="label" candidateClass="UILabel"/>
+                <relationship kind="outlet" name="message_label" candidateClass="UILabel"/>
+                <relationship kind="outlet" name="pause_button" candidateClass="UIButton"/>
+                <relationship kind="outlet" name="play_button" candidateClass="UIButton"/>
+            </relationships>
+        </class>
+    </classes>
     <simulatedMetricsContainer key="defaultSimulatedMetrics">
         <simulatedStatusBarMetrics key="statusBar" statusBarStyle="blackTranslucent"/>
         <simulatedOrientationMetrics key="orientation"/>

gst-sdk/tutorials/xcode iOS/Tutorial 2/en.lproj/MainStoryboard_iPhone.storyboard

@@ -1,89 +1,98 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="2.0" toolsVersion="3084" systemVersion="11G63" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" initialViewController="pxQ-Ha-9Mf">
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="2.0" toolsVersion="3084" systemVersion="11G63" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" initialViewController="kYn-Hr-MJq">
     <dependencies>
         <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="2083"/>
     </dependencies>
     <scenes>
         <!--View Controller-->
-        <scene sceneID="Vig-3P-QBd">
+        <scene sceneID="3nc-d3-XH9">
             <objects>
-                <viewController id="pxQ-Ha-9Mf" customClass="ViewController" sceneMemberID="viewController">
+                <viewController id="kYn-Hr-MJq" customClass="ViewController" sceneMemberID="viewController">
-                    <view key="view" contentMode="scaleToFill" id="OMs-0e-qTd">
+                    <view key="view" contentMode="scaleToFill" id="JOS-rK-Hts">
                         <rect key="frame" x="0.0" y="20" width="320" height="548"/>
                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                         <subviews>
-                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="GxN-0E-u6U" userLabel="Buttons">
+                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="pac-D3-jCF" userLabel="Content">
                                 <subviews>
-                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="vb0-jC-MBX">
+                                    <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" text="Initializing..." textAlignment="center" lineBreakMode="wordWrap" numberOfLines="0" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" preferredMaxLayoutWidth="240" translatesAutoresizingMaskIntoConstraints="NO" id="8wd-E5-Owx" userLabel="Message">
+                                        <fontDescription key="fontDescription" type="system" pointSize="16"/>
+                                        <color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
+                                        <nil key="highlightedColor"/>
+                                    </label>
+                                    <button opaque="NO" contentMode="scaleToFill" enabled="NO" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="uVI-yQ-geg" userLabel="Play">
                                         <constraints>
-                                            <constraint firstAttribute="width" constant="180" type="user" id="JWj-Ts-QpO"/>
+                                            <constraint firstAttribute="height" constant="100" type="user" id="D1U-D7-pGb"/>
+                                            <constraint firstAttribute="width" constant="200" type="user" id="H9m-EA-1Y9"/>
                                         </constraints>
-                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="15"/>
+                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="24"/>
                                         <state key="normal" title="Play">
                                             <color key="titleColor" red="0.19607843459999999" green="0.30980393290000002" blue="0.52156865600000002" alpha="1" colorSpace="calibratedRGB"/>
                                             <color key="titleShadowColor" white="0.5" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
+                                        <state key="disabled">
+                                            <color key="titleColor" white="0.66666666666666663" alpha="1" colorSpace="calibratedWhite"/>
+                                        </state>
                                         <state key="highlighted">
                                             <color key="titleColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
                                         <connections>
-                                            <action selector="play:" destination="pxQ-Ha-9Mf" eventType="touchUpInside" id="720-pe-ZQg"/>
+                                            <action selector="play:" destination="kYn-Hr-MJq" eventType="touchUpInside" id="lem-QX-Nov"/>
                                         </connections>
                                     </button>
-                                    <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="eNS-GM-32O">
+                                    <button opaque="NO" contentMode="scaleToFill" enabled="NO" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="w5n-dd-01i" userLabel="Pause">
                                         <constraints>
-                                            <constraint firstAttribute="width" constant="180" type="user" id="qyb-TL-L8J"/>
+                                            <constraint firstAttribute="height" constant="100" type="user" id="heT-S6-HPW"/>
+                                            <constraint firstAttribute="width" constant="200" type="user" id="zY8-bB-SYS"/>
                                         </constraints>
-                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="15"/>
+                                        <fontDescription key="fontDescription" type="boldSystem" pointSize="24"/>
                                         <state key="normal" title="Pause">
                                             <color key="titleColor" red="0.19607843459999999" green="0.30980393290000002" blue="0.52156865600000002" alpha="1" colorSpace="calibratedRGB"/>
                                             <color key="titleShadowColor" white="0.5" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
+                                        <state key="disabled">
+                                            <color key="titleColor" white="0.66666666666666663" alpha="1" colorSpace="calibratedWhite"/>
+                                        </state>
                                         <state key="highlighted">
                                             <color key="titleColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                         </state>
                                         <connections>
-                                            <action selector="pause:" destination="pxQ-Ha-9Mf" eventType="touchUpInside" id="prA-YD-hYl"/>
+                                            <action selector="pause:" destination="kYn-Hr-MJq" eventType="touchUpInside" id="eZ6-M4-XBq"/>
                                         </connections>
                                     </button>
                                 </subviews>
-                                <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                                <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                                 <constraints>
-                                    <constraint firstItem="vb0-jC-MBX" firstAttribute="top" secondItem="GxN-0E-u6U" secondAttribute="top" constant="20" symbolic="YES" type="default" id="06u-Jm-lfM"/>
+                                    <constraint firstAttribute="centerX" secondItem="uVI-yQ-geg" secondAttribute="centerX" type="user" id="2Wc-AU-tx5"/>
-                                    <constraint firstAttribute="centerX" secondItem="eNS-GM-32O" secondAttribute="centerX" type="user" id="Sep-Aj-htp"/>
+                                    <constraint firstItem="8wd-E5-Owx" firstAttribute="leading" secondItem="pac-D3-jCF" secondAttribute="leading" constant="20" symbolic="YES" type="user" id="3rd-sw-9RW"/>
-                                    <constraint firstAttribute="centerX" secondItem="vb0-jC-MBX" secondAttribute="centerX" type="user" id="gmk-PR-KdB"/>
+                                    <constraint firstAttribute="centerX" secondItem="w5n-dd-01i" secondAttribute="centerX" type="user" id="3se-ej-QVc"/>
-                                    <constraint firstItem="eNS-GM-32O" firstAttribute="top" secondItem="vb0-jC-MBX" secondAttribute="bottom" constant="8" symbolic="YES" type="default" id="lun-xW-CAi"/>
+                                    <constraint firstAttribute="trailing" secondItem="8wd-E5-Owx" secondAttribute="trailing" constant="20" symbolic="YES" type="user" id="FyO-Cv-ZON"/>
-                                    <constraint firstAttribute="bottom" secondItem="eNS-GM-32O" secondAttribute="bottom" constant="20" symbolic="YES" type="default" id="xWq-oD-d5F"/>
+                                    <constraint firstItem="uVI-yQ-geg" firstAttribute="top" secondItem="8wd-E5-Owx" secondAttribute="bottom" constant="8" symbolic="YES" type="user" id="Lte-nX-y3p"/>
+                                    <constraint firstItem="w5n-dd-01i" firstAttribute="top" secondItem="uVI-yQ-geg" secondAttribute="bottom" constant="8" symbolic="YES" type="user" id="Tqh-LF-05e"/>
+                                    <constraint firstItem="8wd-E5-Owx" firstAttribute="top" secondItem="pac-D3-jCF" secondAttribute="top" constant="20" symbolic="YES" type="user" id="dXW-gd-gnP"/>
+                                    <constraint firstAttribute="bottom" secondItem="w5n-dd-01i" secondAttribute="bottom" constant="20" symbolic="YES" type="default" id="dbq-X8-9Im"/>
                                 </constraints>
                             </view>
                         </subviews>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
                         <constraints>
-                            <constraint firstItem="GxN-0E-u6U" firstAttribute="leading" secondItem="OMs-0e-qTd" secondAttribute="leading" constant="20" symbolic="YES" type="user" id="H5s-xz-Nfc"/>
+                            <constraint firstItem="pac-D3-jCF" firstAttribute="top" secondItem="JOS-rK-Hts" secondAttribute="top" priority="1" constant="20" symbolic="YES" type="user" id="77r-Ci-q9w"/>
-                            <constraint firstAttribute="centerX" secondItem="GxN-0E-u6U" secondAttribute="centerX" type="user" id="dKd-jH-42g"/>
+                            <constraint firstItem="pac-D3-jCF" firstAttribute="top" secondItem="JOS-rK-Hts" secondAttribute="top" priority="1" constant="20" symbolic="YES" type="user" id="MGJ-u0-MAG"/>
-                            <constraint firstAttribute="centerY" secondItem="GxN-0E-u6U" secondAttribute="centerY" type="user" id="x24-bd-at0"/>
+                            <constraint firstAttribute="centerX" secondItem="pac-D3-jCF" secondAttribute="centerX" type="user" id="Y2t-0q-fAJ"/>
+                            <constraint firstItem="pac-D3-jCF" firstAttribute="leading" secondItem="JOS-rK-Hts" secondAttribute="leading" constant="20" symbolic="YES" type="user" id="dPX-1l-W4G"/>
+                            <constraint firstAttribute="centerY" secondItem="pac-D3-jCF" secondAttribute="centerY" type="user" id="pxX-Qj-nAV"/>
                         </constraints>
                     </view>
                     <simulatedStatusBarMetrics key="simulatedStatusBarMetrics"/>
+                    <connections>
+                        <outlet property="message_label" destination="8wd-E5-Owx" id="7Xw-cg-3hH"/>
+                        <outlet property="pause_button" destination="w5n-dd-01i" id="lHm-u3-mcA"/>
+                        <outlet property="play_button" destination="uVI-yQ-geg" id="vI5-ma-lhA"/>
+                    </connections>
                 </viewController>
-                <placeholder placeholderIdentifier="IBFirstResponder" id="3Wk-O5-Z1z" sceneMemberID="firstResponder"/>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="25z-hu-OZW" sceneMemberID="firstResponder"/>
             </objects>
-            <point key="canvasLocation" x="423" y="158"/>
         </scene>
     </scenes>
-    <classes>
-        <class className="NSLayoutConstraint" superclassName="NSObject">
-            <source key="sourceIdentifier" type="project" relativePath="./Classes/NSLayoutConstraint.h"/>
-        </class>
-        <class className="ViewController" superclassName="UIViewController">
-            <source key="sourceIdentifier" type="project" relativePath="./Classes/ViewController.h"/>
-            <relationships>
-                <relationship kind="action" name="pause:"/>
-                <relationship kind="action" name="play:"/>
-                <relationship kind="outlet" name="label" candidateClass="UILabel"/>
-            </relationships>
-        </class>
-    </classes>
     <simulatedMetricsContainer key="defaultSimulatedMetrics">
         <simulatedStatusBarMetrics key="statusBar"/>
         <simulatedOrientationMetrics key="orientation"/>