Add extra observer hooks for interesting internal processes (#2694)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

platform/android/MapLibreAndroidTestApp/src/main/AndroidManifest.xml

@@ -874,6 +874,18 @@
             <meta-data
                 android:name="android.support.PARENT_ACTIVITY"
                 android:value=".activity.FeatureOverviewActivity" />
+        </activity> <!-- Events -->
+        <activity
+            android:name="org.maplibre.android.testapp.activity.events.ObserverActivity"
+            android:description="@string/description_observer_activity"
+            android:exported="true"
+            android:label="@string/activity_observer_activity" >
+            <meta-data
+                android:name="@string/category"
+                android:value="@string/category_events" />
+            <meta-data
+                android:name="android.support.PARENT_ACTIVITY"
+                android:value=".activity.FeatureOverviewActivity" />
         </activity> <!-- TextureView -->
         <activity
             android:name=".activity.textureview.TextureViewDebugModeActivity"

platform/android/MapLibreAndroidTestApp/src/main/java/org/maplibre/android/testapp/activity/events/ObserverActivity.kt

@@ -0,0 +1,137 @@
+package org.maplibre.android.testapp.activity.events
+
+import android.app.ActivityManager
+import android.os.Build
+import android.os.Bundle
+import android.view.WindowManager
+import androidx.appcompat.app.AppCompatActivity
+import org.maplibre.android.MapLibre
+import org.maplibre.android.maps.MapView
+import org.maplibre.android.maps.Style
+import org.maplibre.android.tile.TileOperation
+import org.maplibre.android.testapp.R
+import org.maplibre.android.testapp.styles.TestStyles
+import timber.log.Timber
+import java.util.*
+import kotlin.time.TimeMark
+import kotlin.time.TimeSource
+import kotlin.time.TimeSource.Monotonic
+import org.maplibre.android.log.Logger
+import org.maplibre.android.log.Logger.INFO
+
+/**
+ * Test activity showcasing logging observer actions from the core
+ */
+class ObserverActivity : AppCompatActivity(),
+    MapView.OnPreCompileShaderListener,
+    MapView.OnPostCompileShaderListener,
+    MapView.OnTileActionListener,
+    MapView.OnGlyphsLoadedListener,
+    MapView.OnGlyphsRequestedListener,
+    MapView.OnSpriteLoadedListener,
+    MapView.OnSpriteRequestedListener {
+    private lateinit var mapView: MapView
+
+    companion object {
+        const val TAG = "ObserverActivity"
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_map_simple)
+        mapView = findViewById(R.id.mapView)
+        mapView.onCreate(savedInstanceState)
+        mapView.addOnPreCompileShaderListener(this)
+        mapView.addOnPostCompileShaderListener(this)
+        mapView.addOnTileActionListener(this)
+        mapView.addOnGlyphsLoadedListener(this)
+        mapView.addOnGlyphsRequestedListener(this)
+        mapView.addOnSpriteLoadedListener(this)
+        mapView.addOnSpriteRequestedListener(this)
+        mapView.getMapAsync {
+            it.setStyle(
+                Style.Builder().fromUri(TestStyles.getPredefinedStyleWithFallback("Streets"))
+            )
+        }
+    }
+
+    private val shaderTimes: HashMap<String, TimeMark> = HashMap()
+
+    public override fun onPreCompileShader(id: Int, type: Int, defines: String) {
+        shaderTimes["${id}-${type}-${defines}"] = TimeSource.Monotonic.markNow()
+        Logger.i(TAG, "A new shader is being compiled, shaderID:${id}, backend type:${type}, program configuration:${defines}")
+    }
+
+    public override fun onPostCompileShader(id: Int, type: Int, defines: String) {
+        val startTime = shaderTimes.get("${id}-${type}-${defines}")
+        if (startTime != null) {
+            Logger.i(TAG, "A shader has been compiled in ${startTime.elapsedNow()}, shaderID:${id}, backend type:${type}, program configuration:${defines}")
+        }
+    }
+
+    public override fun onGlyphsRequested(fontStack: Array<String>, rangeStart: Int, rangeEnd: Int) {
+        Logger.i(TAG, "Glyphs are being requested for the font stack $fontStack, ranging from $rangeStart to $rangeEnd")
+    }
+
+    public override fun onGlyphsLoaded(fontStack: Array<String>, rangeStart: Int, rangeEnd: Int) {
+        Logger.i(TAG, "Glyphs have been loaded for the font stack $fontStack, ranging from $rangeStart to $rangeEnd")
+    }
+
+    public override fun onSpriteRequested(id: String, url: String) {
+        Logger.i(TAG, "The sprite $id has been requested from $url")
+    }
+
+    public override fun onSpriteLoaded(id: String, url: String) {
+        Logger.i(TAG, "The sprite $id has been loaded from $url")
+    }
+
+    public override fun onTileAction(op: TileOperation, x: Int, y: Int, z: Int, wrap: Int, overscaledZ: Int, sourceID: String) {
+        val tile = "X:${x}, Y:${y}, Z:${z}, Wrap:${wrap}, OverscaledZ:${overscaledZ}, SourceID:${sourceID}"
+        when (op) {
+            TileOperation.RequestedFromCache -> Logger.i(TAG, "Requesting tile ${tile} from the cache")
+            TileOperation.RequestedFromNetwork -> Logger.i(TAG, "Requesting tile ${tile} from the network")
+            TileOperation.LoadFromCache -> Logger.i(TAG, "Loading tile ${tile}, requested from the cache")
+            TileOperation.LoadFromNetwork -> Logger.i(TAG, "Loading tile ${tile}, requested from the network")
+            TileOperation.StartParse -> Logger.i(TAG, "Parsing tile ${tile}")
+            TileOperation.EndParse -> Logger.i(TAG, "Completed parsing tile ${tile}")
+            TileOperation.Error -> Logger.e(TAG, "An error occured during proccessing for tile ${tile}")
+            TileOperation.Cancelled -> Logger.i(TAG, "Pending work on tile ${tile} was cancelled")
+            TileOperation.NullOp -> Logger.e(TAG, "An unknown tile operation was emitted for tile ${tile}")
+        }
+    }
+
+    override fun onStart() {
+        super.onStart()
+        mapView.onStart()
+    }
+
+    override fun onResume() {
+        super.onResume()
+        mapView.onResume()
+    }
+
+    override fun onPause() {
+        super.onPause()
+        mapView.onPause()
+    }
+
+    override fun onStop() {
+        super.onStop()
+        mapView.onStop()
+    }
+
+    override fun onLowMemory() {
+        super.onLowMemory()
+        mapView.onLowMemory()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        mapView.onDestroy()
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        mapView.onSaveInstanceState(outState)
+    }
+}

platform/android/MapLibreAndroidTestApp/src/main/res/values/categories.xml

@@ -13,6 +13,7 @@
     <string name="category_style">Styling</string>
     <string name="category_features">Features</string>
     <string name="category_storage">Storage</string>
+    <string name="category_events">Events</string>
     <string name="category_textureview">Texture View</string>
     <string name="category_location">Location</string>
     <string name="category_integration">_Integration</string>

platform/android/MapLibreAndroidTestApp/src/main/res/values/descriptions.xml

@@ -72,6 +72,7 @@
     <string name="description_map_snapshotter_local_style">Show how to load a local style with a Snapshot</string>
     <string name="description_camera_animator">Use Android SDK Animators to animate camera position changes</string>
     <string name="description_symbol_generator">Use Android SDK Views as symbols</string>
+    <string name="description_observer_activity">Use map observers to log map event information</string>
     <string name="description_textureview_debug">Use TextureView to render the map</string>
     <string name="description_textureview_resize">Resize a map rendered on a TextureView</string>
     <string name="description_textureview_animate">Animate a map rendered on a TextureView</string>

platform/android/MapLibreAndroidTestApp/src/main/res/values/titles.xml

@@ -68,6 +68,7 @@
     <string name="activity_map_snapshotter_local_style">Map Snapshot with local style</string>
     <string name="activity_camera_animator">Animator animation</string>
     <string name="activity_symbol_generator">SymbolGenerator</string>
+    <string name="activity_observer_activity">Log map observer events</string>
     <string name="activity_textureview_debug">TextureView debug</string>
     <string name="activity_textureview_resize">TextureView resize</string>
     <string name="activity_textureview_animate">TextureView animation</string>