From 053e0ec2acf37c451a674251fa195351d8e4a143 Mon Sep 17 00:00:00 2001
From: Jakub Malinowski <jakubmal+github@gmail.com>
Date: Thu, 6 Jun 2024 17:35:28 +0200
Subject: [PATCH] Enable manual creation of screen view spans

---
 .../splunk/android/sample/FirstFragment.java  | 14 ++++++
 .../src/main/res/layout/fragment_first.xml    |  6 +++
 sample-app/src/main/res/values/strings.xml    |  1 +
 .../rum/ExplicitVisibleScreenNameTracker.java | 39 +++++++++++++++
 .../java/com/splunk/rum/NoOpSplunkRum.java    |  7 ++-
 .../java/com/splunk/rum/RumInitializer.java   | 14 +++++-
 .../main/java/com/splunk/rum/SplunkRum.java   | 25 +++++++++-
 .../com/splunk/rum/NoOpSplunkRumTest.java     |  3 ++
 .../java/com/splunk/rum/SplunkRumTest.java    | 48 +++++++++++++++++--
 9 files changed, 149 insertions(+), 8 deletions(-)
 create mode 100644 splunk-otel-android/src/main/java/com/splunk/rum/ExplicitVisibleScreenNameTracker.java

diff --git a/sample-app/src/main/java/com/splunk/android/sample/FirstFragment.java b/sample-app/src/main/java/com/splunk/android/sample/FirstFragment.java
index 756cad25..0ef2cf92 100644
--- a/sample-app/src/main/java/com/splunk/android/sample/FirstFragment.java
+++ b/sample-app/src/main/java/com/splunk/android/sample/FirstFragment.java
@@ -80,6 +80,10 @@ public void onViewCreated(@NonNull View view, Bundle savedInstanceState) {
                         NavHostFragment.findNavController(FirstFragment.this)
                                 .navigate(R.id.action_FirstFragment_to_SecondFragment));
 
+        binding.buttonScreenName.setOnClickListener(v -> {
+            SplunkRum.getInstance().setScreenName("custom-screen");
+        });
+
         binding.crash.setOnClickListener(v -> multiThreadCrashing());
 
         binding.httpMe.setOnClickListener(
@@ -184,12 +188,22 @@ public LiveData<String> getSessionId() {
     public void onDestroyView() {
         super.onDestroyView();
         binding = null;
+
+        SplunkRum.getInstance().setScreenName(null);
     }
 
     @Override
     public void onResume() {
         super.onResume();
         sessionId.postValue(splunkRum.getRumSessionId());
+
+        SplunkRum.getInstance().setScreenName("custom-resumed-name", "Resumed");
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        SplunkRum.getInstance().setScreenName(null);
     }
 
     @SuppressLint("AllowAllHostnameVerifier")
diff --git a/sample-app/src/main/res/layout/fragment_first.xml b/sample-app/src/main/res/layout/fragment_first.xml
index af78e301..4267f023 100644
--- a/sample-app/src/main/res/layout/fragment_first.xml
+++ b/sample-app/src/main/res/layout/fragment_first.xml
@@ -42,6 +42,12 @@
                 android:layout_height="wrap_content"
                 android:text="@string/next" />
 
+            <Button
+                android:id="@+id/button_screen_name"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/screen_name" />
+
             <Button
                 android:id="@+id/crash"
                 android:layout_width="wrap_content"
diff --git a/sample-app/src/main/res/values/strings.xml b/sample-app/src/main/res/values/strings.xml
index cbf89f97..dbebcf06 100644
--- a/sample-app/src/main/res/values/strings.xml
+++ b/sample-app/src/main/res/values/strings.xml
@@ -6,6 +6,7 @@
     <string name="second_fragment_label">Second Fragment</string>
     <string name="next">Next</string>
     <string name="previous">Previous</string>
+    <string name="screen_name">Custom screen name</string>
 
     <string name="hello_first_fragment">Hello first fragment</string>
     <string name="hello_second_fragment">Hello second fragment. Arg: %1$s</string>
diff --git a/splunk-otel-android/src/main/java/com/splunk/rum/ExplicitVisibleScreenNameTracker.java b/splunk-otel-android/src/main/java/com/splunk/rum/ExplicitVisibleScreenNameTracker.java
new file mode 100644
index 00000000..b49aa8b8
--- /dev/null
+++ b/splunk-otel-android/src/main/java/com/splunk/rum/ExplicitVisibleScreenNameTracker.java
@@ -0,0 +1,39 @@
+package com.splunk.rum;
+
+import androidx.annotation.Nullable;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+import io.opentelemetry.android.instrumentation.activity.VisibleScreenTracker;
+
+public class ExplicitVisibleScreenNameTracker extends VisibleScreenTracker {
+    private final AtomicReference<String> lastScreenName = new AtomicReference<>();
+    private final AtomicReference<String> previouslyLastScreenName = new AtomicReference<>();
+
+    public void setExplicitScreenName(String screenName) {
+        this.previouslyLastScreenName.set(this.lastScreenName.get());
+        this.lastScreenName.set(screenName);
+    }
+
+    @Nullable
+    @Override
+    public String getPreviouslyVisibleScreen() {
+        String screenName = previouslyLastScreenName.get();
+        if (screenName != null) {
+            return screenName;
+        }
+
+        return super.getPreviouslyVisibleScreen();
+    }
+
+    @Override
+    public String getCurrentlyVisibleScreen() {
+        String screenName = lastScreenName.get();
+        if (screenName != null) {
+            return screenName;
+        }
+
+        return super.getCurrentlyVisibleScreen();
+    }
+
+}
diff --git a/splunk-otel-android/src/main/java/com/splunk/rum/NoOpSplunkRum.java b/splunk-otel-android/src/main/java/com/splunk/rum/NoOpSplunkRum.java
index f1248889..d5a6e0f7 100644
--- a/splunk-otel-android/src/main/java/com/splunk/rum/NoOpSplunkRum.java
+++ b/splunk-otel-android/src/main/java/com/splunk/rum/NoOpSplunkRum.java
@@ -32,7 +32,7 @@ class NoOpSplunkRum extends SplunkRum {
     // passing null values here is fine, they'll never get used anyway
     @SuppressWarnings("NullAway")
     private NoOpSplunkRum() {
-        super(OpenTelemetryRum.noop(), null);
+        super(OpenTelemetryRum.noop(), null, null);
     }
 
     @Override
@@ -79,4 +79,9 @@ public void integrateWithBrowserRum(WebView webView) {
     void flushSpans() {
         // no-op
     }
+
+    @Override
+    public void setScreenName(String screenName) {
+        // no-op
+    }
 }
diff --git a/splunk-otel-android/src/main/java/com/splunk/rum/RumInitializer.java b/splunk-otel-android/src/main/java/com/splunk/rum/RumInitializer.java
index 62bd5c70..1a5f56e4 100644
--- a/splunk-otel-android/src/main/java/com/splunk/rum/RumInitializer.java
+++ b/splunk-otel-android/src/main/java/com/splunk/rum/RumInitializer.java
@@ -36,6 +36,7 @@
 import io.opentelemetry.android.OpenTelemetryRum;
 import io.opentelemetry.android.OpenTelemetryRumBuilder;
 import io.opentelemetry.android.RuntimeDetailsExtractor;
+import io.opentelemetry.android.ScreenAttributesSpanProcessor;
 import io.opentelemetry.android.config.OtelRumConfig;
 import io.opentelemetry.android.instrumentation.activity.VisibleScreenTracker;
 import io.opentelemetry.android.instrumentation.anr.AnrDetector;
@@ -52,6 +53,7 @@
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.resources.ResourceBuilder;
 import io.opentelemetry.sdk.trace.SpanLimits;
+import io.opentelemetry.sdk.trace.SpanProcessor;
 import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
 import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
@@ -86,7 +88,7 @@ class RumInitializer {
     }
 
     SplunkRum initialize(Looper mainLooper) {
-        VisibleScreenTracker visibleScreenTracker = new VisibleScreenTracker();
+        ExplicitVisibleScreenNameTracker visibleScreenTracker = new ExplicitVisibleScreenNameTracker();
 
         initializationEvents.begin();
 
@@ -98,6 +100,7 @@ SplunkRum initialize(Looper mainLooper) {
             config.disableNetworkChangeMonitoring();
         }
 
+        config.disableScreenAttributes();
         OpenTelemetryRumBuilder otelRumBuilder = OpenTelemetryRum.builder(application, config);
 
         otelRumBuilder.mergeResource(createSplunkResource());
@@ -193,6 +196,13 @@ SplunkRum initialize(Looper mainLooper) {
             installCrashReporter(otelRumBuilder);
         }
 
+        otelRumBuilder.addTracerProviderCustomizer(
+                (tracerProviderBuilder, app) -> {
+                    SpanProcessor screenAttributesAppender =
+                            new ScreenAttributesSpanProcessor(visibleScreenTracker);
+                    return tracerProviderBuilder.addSpanProcessor(screenAttributesAppender);
+                });
+
         // Lifecycle events instrumentation are always installed.
         installLifecycleInstrumentations(otelRumBuilder, visibleScreenTracker);
 
@@ -204,7 +214,7 @@ SplunkRum initialize(Looper mainLooper) {
                 builder.getConfigFlags(),
                 openTelemetryRum.getOpenTelemetry().getTracer(RUM_TRACER_NAME));
 
-        return new SplunkRum(openTelemetryRum, globalAttributeSupplier);
+        return new SplunkRum(openTelemetryRum, globalAttributeSupplier, visibleScreenTracker);
     }
 
     @NonNull
diff --git a/splunk-otel-android/src/main/java/com/splunk/rum/SplunkRum.java b/splunk-otel-android/src/main/java/com/splunk/rum/SplunkRum.java
index 90b59165..4d7273b9 100644
--- a/splunk-otel-android/src/main/java/com/splunk/rum/SplunkRum.java
+++ b/splunk-otel-android/src/main/java/com/splunk/rum/SplunkRum.java
@@ -16,6 +16,8 @@
 
 package com.splunk.rum;
 
+import static io.opentelemetry.android.RumConstants.LAST_SCREEN_NAME_KEY;
+import static io.opentelemetry.android.RumConstants.SCREEN_NAME_KEY;
 import static io.opentelemetry.api.common.AttributeKey.doubleKey;
 import static io.opentelemetry.api.common.AttributeKey.stringKey;
 
@@ -28,6 +30,7 @@
 import androidx.annotation.Nullable;
 import com.splunk.rum.internal.GlobalAttributesSupplier;
 import io.opentelemetry.android.OpenTelemetryRum;
+import io.opentelemetry.android.instrumentation.activity.VisibleScreenTracker;
 import io.opentelemetry.android.instrumentation.startup.AppStartupTimer;
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.AttributeKey;
@@ -72,15 +75,17 @@ public class SplunkRum {
 
     private final OpenTelemetryRum openTelemetryRum;
     private final GlobalAttributesSupplier globalAttributes;
+    private final ExplicitVisibleScreenNameTracker visibleScreenTracker;
 
     static {
         Handler handler = new Handler(Looper.getMainLooper());
         startupTimer.detectBackgroundStart(handler);
     }
 
-    SplunkRum(OpenTelemetryRum openTelemetryRum, GlobalAttributesSupplier globalAttributes) {
+    SplunkRum(OpenTelemetryRum openTelemetryRum, GlobalAttributesSupplier globalAttributes, ExplicitVisibleScreenNameTracker visibleScreenTracker) {
         this.openTelemetryRum = openTelemetryRum;
         this.globalAttributes = globalAttributes;
+        this.visibleScreenTracker = visibleScreenTracker;
     }
 
     /** Creates a new {@link SplunkRumBuilder}, used to set up a {@link SplunkRum} instance. */
@@ -113,6 +118,24 @@ static SplunkRum initialize(SplunkRumBuilder builder, Application application) {
         return INSTANCE;
     }
 
+    public void setScreenName(String screenName, String spanType) {
+        visibleScreenTracker.setExplicitScreenName(screenName);
+
+        if (screenName != null) {
+            Span span = getTracer()
+                    .spanBuilder(spanType)
+                    .setAttribute(COMPONENT_KEY, "ui")
+                    .startSpan();
+            span.setAttribute(SCREEN_NAME_KEY, screenName);
+            span.setAttribute(LAST_SCREEN_NAME_KEY, visibleScreenTracker.getPreviouslyVisibleScreen());
+            span.end();
+        }
+    }
+
+    public void setScreenName(String screenName) {
+        setScreenName(screenName, "Created");
+    }
+
     /** Returns {@code true} if the Splunk RUM library has been successfully initialized. */
     public static boolean isInitialized() {
         return INSTANCE != null;
diff --git a/splunk-otel-android/src/test/java/com/splunk/rum/NoOpSplunkRumTest.java b/splunk-otel-android/src/test/java/com/splunk/rum/NoOpSplunkRumTest.java
index 9d7263d2..12d48253 100644
--- a/splunk-otel-android/src/test/java/com/splunk/rum/NoOpSplunkRumTest.java
+++ b/splunk-otel-android/src/test/java/com/splunk/rum/NoOpSplunkRumTest.java
@@ -50,5 +50,8 @@ void doesNotThrow() {
 
         Location location = mock(Location.class);
         instance.updateLocation(location);
+
+        instance.setScreenName("explicit-screen-name");
+        instance.flushSpans();
     }
 }
diff --git a/splunk-otel-android/src/test/java/com/splunk/rum/SplunkRumTest.java b/splunk-otel-android/src/test/java/com/splunk/rum/SplunkRumTest.java
index 8602ffb3..70f7b0f4 100644
--- a/splunk-otel-android/src/test/java/com/splunk/rum/SplunkRumTest.java
+++ b/splunk-otel-android/src/test/java/com/splunk/rum/SplunkRumTest.java
@@ -17,11 +17,14 @@
 package com.splunk.rum;
 
 import static com.splunk.rum.SplunkRum.COMPONENT_KEY;
+import static io.opentelemetry.android.RumConstants.LAST_SCREEN_NAME_KEY;
+import static io.opentelemetry.android.RumConstants.SCREEN_NAME_KEY;
 import static io.opentelemetry.api.common.AttributeKey.longKey;
 import static io.opentelemetry.api.common.AttributeKey.stringKey;
 import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.eq;
@@ -70,8 +73,12 @@ public class SplunkRumTest {
     @Mock private OpenTelemetryRum openTelemetryRum;
     @Mock private GlobalAttributesSupplier globalAttributes;
 
+    private ExplicitVisibleScreenNameTracker screenNameTracker;
+
     @BeforeEach
     public void setup() {
+        screenNameTracker = new ExplicitVisibleScreenNameTracker();
+
         tracer = otelTesting.getOpenTelemetry().getTracer("testTracer");
         SplunkRum.resetSingletonForTest();
     }
@@ -148,7 +155,7 @@ void nonNullMethods() {
     void addEvent() {
         when(openTelemetryRum.getOpenTelemetry()).thenReturn(otelTesting.getOpenTelemetry());
 
-        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes);
+        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes, screenNameTracker);
 
         Attributes attributes = Attributes.of(stringKey("one"), "1", longKey("two"), 2L);
         splunkRum.addRumEvent("foo", attributes);
@@ -166,7 +173,7 @@ void addException() {
 
         when(openTelemetryRum.getOpenTelemetry()).thenReturn(testSdk);
 
-        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes);
+        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes, screenNameTracker);
 
         NullPointerException exception = new NullPointerException("oopsie");
         Attributes attributes = Attributes.of(stringKey("one"), "1", longKey("two"), 2L);
@@ -197,7 +204,7 @@ private OpenTelemetrySdk buildTestSdk(InMemorySpanExporter testExporter) {
     void createAndEnd() {
         when(openTelemetryRum.getOpenTelemetry()).thenReturn(otelTesting.getOpenTelemetry());
 
-        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes);
+        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes, screenNameTracker);
 
         Span span = splunkRum.startWorkflow("workflow");
         Span inner = tracer.spanBuilder("foo").startSpan();
@@ -255,7 +262,7 @@ void updateLocation() {
                 .when(globalAttributes)
                 .update(isA(Consumer.class));
 
-        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes);
+        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes, screenNameTracker);
 
         Location location = mock(Location.class);
         when(location.getLatitude()).thenReturn(42d);
@@ -274,4 +281,37 @@ void updateLocation() {
 
         assertTrue(updatedAttributes.get().isEmpty());
     }
+
+    @Test
+    void canSetScreenName() {
+        when(openTelemetryRum.getOpenTelemetry()).thenReturn(otelTesting.getOpenTelemetry());
+
+        SplunkRum splunkRum = new SplunkRum(openTelemetryRum, globalAttributes, screenNameTracker);
+        splunkRum.setScreenName("screen-1");
+        splunkRum.setScreenName("screen-2");
+
+        // pause and resume
+        splunkRum.setScreenName(null);
+        splunkRum.setScreenName("screen-2", "Resumed");
+
+        // exit the view with explicit screen names
+        // both last screen name and second last screen name have to be cleared, hence the doubled call
+        splunkRum.setScreenName(null);
+        splunkRum.setScreenName(null);
+
+        List<SpanData> spans = otelTesting.getSpans();
+        assertEquals(3, spans.size());
+
+        assertEquals("Created", spans.get(0).getName());
+        assertEquals("screen-1", spans.get(0).getAttributes().get(SCREEN_NAME_KEY));
+        assertNull(spans.get(0).getAttributes().get(LAST_SCREEN_NAME_KEY));
+
+        assertEquals("Created", spans.get(1).getName());
+        assertEquals("screen-2", spans.get(1).getAttributes().get(SCREEN_NAME_KEY));
+        assertEquals("screen-1", spans.get(1).getAttributes().get(LAST_SCREEN_NAME_KEY));
+
+        assertEquals("Resumed", spans.get(2).getName());
+        assertEquals("screen-2", spans.get(2).getAttributes().get(SCREEN_NAME_KEY));
+        assertNull(spans.get(2).getAttributes().get(LAST_SCREEN_NAME_KEY));
+    }
 }