Add logging utilities for development with Kotlin

Test: manual
Flag: not needed

Fixes: b/274509846
Change-Id: I5d800d1bf94fbcbee85dfa706d7a43c92bbc4164

6 files changed, 148 insertions, 57 deletions

diff --git a/packages/SystemUI/src-debug/com/android/systemui/log/DebugLogger.kt b/packages/SystemUI/src-debug/com/android/systemui/log/DebugLogger.kt
new file mode 100644
index 000000000000..af29b05a3fb1
--- /dev/null
+++ b/packages/SystemUI/src-debug/com/android/systemui/log/DebugLogger.kt
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * 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.android.systemui.log
+
+import android.os.Build
+import android.util.Log
+import android.util.Log.LOG_ID_MAIN
+
+/**
+ * A simplified debug logger built as a wrapper around Android's [Log]. Internal for development.
+ *
+ * The main advantages are:
+ * - Sensible defaults, automatically retrieving the class name from the call-site (i.e., tag);
+ * - The messages are purged from source on release builds (keep in mind they are visible on AOSP);
+ * - Lazily evaluate Strings for zero impact in production builds or when disabled;
+ *
+ * Usage example:
+ * ```kotlin
+ * // Logging a message:
+ * debugLog { "message" }
+ *
+ * // Logging an error:
+ * debugLog(error = exception) { "message" }
+ *
+ * // Logging the current stack trace, for debugging:
+ * debugLog(error = Throwable()) { "message" }
+ * ```
+ */
+object DebugLogger {
+
+    /**
+     * Log a debug message, with sensible defaults.
+     *
+     * For example:
+     * ```kotlin
+     * val one = 1
+     * debugLog { "message#$one" }
+     * ```
+     *
+     * The output will be: `D/NoteTaskController: message#1`
+     *
+     * Beware, the [debugLog] content is **REMOVED FROM SOURCE AND BINARY** in Release builds.
+     *
+     * @param enabled: whether or not the message should be logged. By default, it is
+     *   [Build.IS_DEBUGGABLE].
+     * @param priority: type of this log. By default, it is [Log.DEBUG].
+     * @param tag: identifies the source of a log. By default, it is the receiver's simple name.
+     * @param error: a [Throwable] to log.
+     * @param message: a lazily evaluated message you wish to log.
+     */
+    inline fun Any.debugLog(
+        enabled: Boolean = Build.IS_DEBUGGABLE,
+        priority: Int = Log.DEBUG,
+        tag: String = this::class.simpleName.orEmpty(),
+        error: Throwable? = null,
+        message: () -> String,
+    ) {
+        if (enabled) {
+            if (error == null) {
+                Log.println(priority, tag, message())
+            } else {
+                Log.printlns(LOG_ID_MAIN, priority, tag, message(), error)
+            }
+        }
+    }
+}
diff --git a/packages/SystemUI/src-release/com/android/systemui/log/DebugLogger.kt b/packages/SystemUI/src-release/com/android/systemui/log/DebugLogger.kt
new file mode 100644
index 000000000000..2764a1fdfe3d
--- /dev/null
+++ b/packages/SystemUI/src-release/com/android/systemui/log/DebugLogger.kt
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * 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.android.systemui.log
+
+import android.os.Build
+import android.util.Log
+
+/** An empty logger for release builds. */
+object DebugLogger {
+
+    @JvmName("logcatMessage")
+    inline fun Any.debugLog(
+        enabled: Boolean = Build.IS_DEBUGGABLE,
+        priority: Int = Log.DEBUG,
+        tag: String = this::class.simpleName.orEmpty(),
+        error: Throwable? = null,
+        message: () -> String,
+    ) {
+        // no-op.
+    }
+}
diff --git a/packages/SystemUI/src/com/android/systemui/notetask/NoteTaskController.kt b/packages/SystemUI/src/com/android/systemui/notetask/NoteTaskController.kt
index d4052f54b3da..f288b06678a7 100644
--- a/packages/SystemUI/src/com/android/systemui/notetask/NoteTaskController.kt
+++ b/packages/SystemUI/src/com/android/systemui/notetask/NoteTaskController.kt
@@ -31,15 +31,14 @@ import android.content.Intent
 import android.content.pm.PackageManager
 import android.content.pm.ShortcutManager
 import android.graphics.drawable.Icon
-import android.os.Build
 import android.os.UserHandle
 import android.os.UserManager
-import android.util.Log
 import android.widget.Toast
 import androidx.annotation.VisibleForTesting
 import com.android.systemui.R
 import com.android.systemui.dagger.SysUISingleton
 import com.android.systemui.devicepolicy.areKeyguardShortcutsDisabled
+import com.android.systemui.log.DebugLogger.debugLog
 import com.android.systemui.notetask.NoteTaskRoleManagerExt.createNoteShortcutInfoAsUser
 import com.android.systemui.notetask.NoteTaskRoleManagerExt.getDefaultRoleHolderAsUser
 import com.android.systemui.notetask.shortcut.LaunchNoteTaskManagedProfileProxyActivity
@@ -92,10 +91,10 @@ constructor(
         if (info.launchMode != NoteTaskLaunchMode.AppBubble) return
 
         if (isExpanding) {
-            logDebug { "onBubbleExpandChanged - expanding: $info" }
+            debugLog { "onBubbleExpandChanged - expanding: $info" }
             eventLogger.logNoteTaskOpened(info)
         } else {
-            logDebug { "onBubbleExpandChanged - collapsing: $info" }
+            debugLog { "onBubbleExpandChanged - collapsing: $info" }
             eventLogger.logNoteTaskClosed(info)
         }
     }
@@ -168,14 +167,14 @@ constructor(
             isKeyguardLocked &&
                 devicePolicyManager.areKeyguardShortcutsDisabled(userId = user.identifier)
         ) {
-            logDebug { "Enterprise policy disallows launching note app when the screen is locked." }
+            debugLog { "Enterprise policy disallows launching note app when the screen is locked." }
             return
         }
 
         val info = resolver.resolveInfo(entryPoint, isKeyguardLocked, user)
 
         if (info == null) {
-            logDebug { "Default notes app isn't set" }
+            debugLog { "Default notes app isn't set" }
             showNoDefaultNotesAppToast()
             return
         }
@@ -184,7 +183,7 @@ constructor(
 
         try {
             // TODO(b/266686199): We should handle when app not available. For now, we log.
-            logDebug { "onShowNoteTask - start: $info on user#${user.identifier}" }
+            debugLog { "onShowNoteTask - start: $info on user#${user.identifier}" }
             when (info.launchMode) {
                 is NoteTaskLaunchMode.AppBubble -> {
                     val intent = createNoteTaskIntent(info)
@@ -192,7 +191,7 @@ constructor(
                         Icon.createWithResource(context, R.drawable.ic_note_task_shortcut_widget)
                     bubbles.showOrHideAppBubble(intent, user, icon)
                     // App bubble logging happens on `onBubbleExpandChanged`.
-                    logDebug { "onShowNoteTask - opened as app bubble: $info" }
+                    debugLog { "onShowNoteTask - opened as app bubble: $info" }
                 }
                 is NoteTaskLaunchMode.Activity -> {
                     if (activityManager.isInForeground(info.packageName)) {
@@ -200,20 +199,20 @@ constructor(
                         val intent = createHomeIntent()
                         context.startActivityAsUser(intent, user)
                         eventLogger.logNoteTaskClosed(info)
-                        logDebug { "onShowNoteTask - closed as activity: $info" }
+                        debugLog { "onShowNoteTask - closed as activity: $info" }
                     } else {
                         val intent = createNoteTaskIntent(info)
                         context.startActivityAsUser(intent, user)
                         eventLogger.logNoteTaskOpened(info)
-                        logDebug { "onShowNoteTask - opened as activity: $info" }
+                        debugLog { "onShowNoteTask - opened as activity: $info" }
                     }
                 }
             }
-            logDebug { "onShowNoteTask - success: $info" }
+            debugLog { "onShowNoteTask - success: $info" }
         } catch (e: ActivityNotFoundException) {
-            logDebug { "onShowNoteTask - failed: $info" }
+            debugLog { "onShowNoteTask - failed: $info" }
         }
-        logDebug { "onShowNoteTask - completed: $info" }
+        debugLog { "onShowNoteTask - completed: $info" }
     }
 
     @VisibleForTesting
@@ -253,7 +252,7 @@ constructor(
             PackageManager.DONT_KILL_APP,
         )
 
-        logDebug { "setNoteTaskShortcutEnabled - completed: $isEnabled" }
+        debugLog { "setNoteTaskShortcutEnabled - completed: $isEnabled" }
     }
 
     /**
@@ -352,11 +351,6 @@ private fun createNoteTaskIntent(info: NoteTaskInfo): Intent =
         }
     }
 
-/** [Log.println] a [Log.DEBUG] message, only when [Build.IS_DEBUGGABLE]. */
-private inline fun Any.logDebug(message: () -> String) {
-    if (Build.IS_DEBUGGABLE) Log.d(this::class.java.simpleName.orEmpty(), message())
-}
-
 /** Creates an [Intent] which forces the current app to background by calling home. */
 private fun createHomeIntent(): Intent =
     Intent(Intent.ACTION_MAIN).apply {
diff --git a/packages/SystemUI/src/com/android/systemui/notetask/shortcut/LaunchNoteTaskActivity.kt b/packages/SystemUI/src/com/android/systemui/notetask/shortcut/LaunchNoteTaskActivity.kt
index 0f38d32e0b64..8ca13b9776bb 100644
--- a/packages/SystemUI/src/com/android/systemui/notetask/shortcut/LaunchNoteTaskActivity.kt
+++ b/packages/SystemUI/src/com/android/systemui/notetask/shortcut/LaunchNoteTaskActivity.kt
@@ -18,12 +18,11 @@ package com.android.systemui.notetask.shortcut
 
 import android.content.Context
 import android.content.Intent
-import android.os.Build
 import android.os.Bundle
 import android.os.UserHandle
 import android.os.UserManager
-import android.util.Log
 import androidx.activity.ComponentActivity
+import com.android.systemui.log.DebugLogger.debugLog
 import com.android.systemui.notetask.NoteTaskController
 import com.android.systemui.notetask.NoteTaskEntryPoint
 import com.android.systemui.settings.UserTracker
@@ -68,7 +67,7 @@ constructor(
         val mainUser: UserHandle? = userManager.mainUser
         if (userManager.isManagedProfile) {
             if (mainUser == null) {
-                logDebug { "Can't find the main user. Skipping the notes app launch." }
+                debugLog { "Can't find the main user. Skipping the notes app launch." }
             } else {
                 controller.startNoteTaskProxyActivityForUser(mainUser)
             }
@@ -89,8 +88,3 @@ constructor(
         }
     }
 }
-
-/** [Log.println] a [Log.DEBUG] message, only when [Build.IS_DEBUGGABLE]. */
-private inline fun Any.logDebug(message: () -> String) {
-    if (Build.IS_DEBUGGABLE) Log.d(this::class.java.simpleName.orEmpty(), message())
-}
diff --git a/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt b/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt
index 412b3150489c..27aaa6828036 100644
--- a/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt
+++ b/packages/SystemUI/src/com/android/systemui/stylus/StylusManager.kt
@@ -22,7 +22,6 @@ import android.content.Context
 import android.hardware.BatteryState
 import android.hardware.input.InputManager
 import android.hardware.input.InputSettings
-import android.os.Build
 import android.os.Handler
 import android.util.ArrayMap
 import android.util.Log
@@ -35,6 +34,7 @@ import com.android.systemui.dagger.SysUISingleton
 import com.android.systemui.dagger.qualifiers.Background
 import com.android.systemui.flags.FeatureFlags
 import com.android.systemui.flags.Flags
+import com.android.systemui.log.DebugLogger.debugLog
 import com.android.systemui.shared.hardware.hasInputDevice
 import com.android.systemui.shared.hardware.isInternalStylusSource
 import java.util.concurrent.CopyOnWriteArrayList
@@ -81,7 +81,7 @@ constructor(
     fun startListener() {
         handler.post {
             if (hasStarted) return@post
-            logDebug { "Listener has started." }
+            debugLog { "Listener has started." }
 
             hasStarted = true
             isInUsiSession =
@@ -109,7 +109,7 @@ constructor(
 
         val device: InputDevice = inputManager.getInputDevice(deviceId) ?: return
         if (!device.supportsSource(InputDevice.SOURCE_STYLUS)) return
-        logDebug {
+        debugLog {
             "Stylus InputDevice added: $deviceId ${device.name}, " +
                 "External: ${device.isExternal}"
         }
@@ -134,7 +134,7 @@ constructor(
 
         val device: InputDevice = inputManager.getInputDevice(deviceId) ?: return
         if (!device.supportsSource(InputDevice.SOURCE_STYLUS)) return
-        logDebug { "Stylus InputDevice changed: $deviceId ${device.name}" }
+        debugLog { "Stylus InputDevice changed: $deviceId ${device.name}" }
 
         val currAddress: String? = device.bluetoothAddress
         val prevAddress: String? = inputDeviceAddressMap[deviceId]
@@ -155,7 +155,7 @@ constructor(
         if (!hasStarted) return
 
         if (!inputDeviceAddressMap.contains(deviceId)) return
-        logDebug { "Stylus InputDevice removed: $deviceId" }
+        debugLog { "Stylus InputDevice removed: $deviceId" }
 
         unregisterBatteryListener(deviceId)
 
@@ -180,7 +180,7 @@ constructor(
 
             val isCharging = String(value) == "true"
 
-            logDebug {
+            debugLog {
                 "Charging state metadata changed for device $inputDeviceId " +
                     "${device.address}: $isCharging"
             }
@@ -199,7 +199,7 @@ constructor(
         handler.post {
             if (!hasStarted) return@post
 
-            logDebug {
+            debugLog {
                 "Battery state changed for $deviceId. " +
                     "batteryState present: ${batteryState.isPresent}, " +
                     "capacity: ${batteryState.capacity}"
@@ -247,7 +247,7 @@ constructor(
         if (!featureFlags.isEnabled(Flags.TRACK_STYLUS_EVER_USED)) return
         if (InputSettings.isStylusEverUsed(context)) return
 
-        logDebug { "Stylus used for the first time." }
+        debugLog { "Stylus used for the first time." }
         InputSettings.setStylusEverUsed(context, true)
         executeStylusCallbacks { cb -> cb.onStylusFirstUsed() }
     }
@@ -264,7 +264,7 @@ constructor(
         val hasBtConnection = if (inputDeviceBtSessionIdMap.isEmpty()) 0 else 1
 
         if (batteryStateValid && usiSessionId == null) {
-            logDebug { "USI battery newly present, entering new USI session: $deviceId" }
+            debugLog { "USI battery newly present, entering new USI session: $deviceId" }
             usiSessionId = instanceIdSequence.newInstanceId()
             uiEventLogger.logWithInstanceIdAndPosition(
                 StylusUiEvent.USI_STYLUS_BATTERY_PRESENCE_FIRST_DETECTED,
@@ -274,7 +274,7 @@ constructor(
                 hasBtConnection,
             )
         } else if (!batteryStateValid && usiSessionId != null) {
-            logDebug { "USI battery newly absent, exiting USI session: $deviceId" }
+            debugLog { "USI battery newly absent, exiting USI session: $deviceId" }
             uiEventLogger.logWithInstanceIdAndPosition(
                 StylusUiEvent.USI_STYLUS_BATTERY_PRESENCE_REMOVED,
                 0,
@@ -291,7 +291,7 @@ constructor(
         btAddress: String,
         btConnected: Boolean
     ) {
-        logDebug {
+        debugLog {
             "Bluetooth stylus ${if (btConnected) "connected" else "disconnected"}:" +
                 " $deviceId $btAddress"
         }
@@ -386,9 +386,3 @@ constructor(
         val TAG = StylusManager::class.simpleName.orEmpty()
     }
 }
-
-private inline fun logDebug(message: () -> String) {
-    if (Build.IS_DEBUGGABLE) {
-        Log.d(StylusManager.TAG, message())
-    }
-}
diff --git a/packages/SystemUI/src/com/android/systemui/stylus/StylusUsiPowerUI.kt b/packages/SystemUI/src/com/android/systemui/stylus/StylusUsiPowerUI.kt
index 21b0efadb8d5..6eddd9eb7ad2 100644
--- a/packages/SystemUI/src/com/android/systemui/stylus/StylusUsiPowerUI.kt
+++ b/packages/SystemUI/src/com/android/systemui/stylus/StylusUsiPowerUI.kt
@@ -26,7 +26,6 @@ import android.content.Intent
 import android.content.IntentFilter
 import android.hardware.BatteryState
 import android.hardware.input.InputManager
-import android.os.Build
 import android.os.Bundle
 import android.os.Handler
 import android.os.UserHandle
@@ -40,6 +39,7 @@ import com.android.internal.logging.UiEventLogger
 import com.android.systemui.R
 import com.android.systemui.dagger.SysUISingleton
 import com.android.systemui.dagger.qualifiers.Background
+import com.android.systemui.log.DebugLogger.debugLog
 import com.android.systemui.shared.hardware.hasInputDevice
 import com.android.systemui.shared.hardware.isAnyStylusSource
 import com.android.systemui.util.NotificationChannels
@@ -110,7 +110,7 @@ constructor(
 
             inputDeviceId = deviceId
             batteryCapacity = batteryState.capacity
-            logDebug {
+            debugLog {
                 "Updating notification battery state to $batteryCapacity " +
                     "for InputDevice $deviceId."
             }
@@ -130,14 +130,14 @@ constructor(
         handler.post updateSuppressed@{
             if (suppressed == suppress) return@updateSuppressed
 
-            logDebug { "Updating notification suppression to $suppress." }
+            debugLog { "Updating notification suppression to $suppress." }
             suppressed = suppress
             refresh()
         }
     }
 
     private fun hideNotification() {
-        logDebug { "Cancelling USI low battery notification." }
+        debugLog { "Cancelling USI low battery notification." }
         instanceId = null
         notificationManager.cancel(USI_NOTIFICATION_ID)
     }
@@ -160,7 +160,7 @@ constructor(
                 .setAutoCancel(true)
                 .build()
 
-        logDebug { "Show or update USI low battery notification at $batteryCapacity." }
+        debugLog { "Show or update USI low battery notification at $batteryCapacity." }
         logUiEvent(StylusUiEvent.STYLUS_LOW_BATTERY_NOTIFICATION_SHOWN)
         notificationManager.notify(USI_NOTIFICATION_ID, notification)
     }
@@ -188,12 +188,12 @@ constructor(
             override fun onReceive(context: Context, intent: Intent) {
                 when (intent.action) {
                     ACTION_DISMISSED_LOW_BATTERY -> {
-                        logDebug { "USI low battery notification dismissed." }
+                        debugLog { "USI low battery notification dismissed." }
                         logUiEvent(StylusUiEvent.STYLUS_LOW_BATTERY_NOTIFICATION_DISMISSED)
                         updateSuppression(true)
                     }
                     ACTION_CLICKED_LOW_BATTERY -> {
-                        logDebug { "USI low battery notification clicked." }
+                        debugLog { "USI low battery notification clicked." }
                         logUiEvent(StylusUiEvent.STYLUS_LOW_BATTERY_NOTIFICATION_CLICKED)
                         updateSuppression(true)
                         if (inputDeviceId == null) return
@@ -263,9 +263,3 @@ constructor(
         @VisibleForTesting const val KEY_SETTINGS_FRAGMENT_ARGS = ":settings:show_fragment_args"
     }
 }
-
-private inline fun logDebug(message: () -> String) {
-    if (Build.IS_DEBUGGABLE) {
-        Log.d(StylusUsiPowerUI.TAG, message())
-    }
-}