Add utils to reduce verbosity when working with InputManager and Stylus

Test: manual

Fixes: b/261843344
Change-Id: Idbb5705ace9ead1a1230358de5b571c766b6b39c

packages/SystemUI/shared/src/com/android/systemui/shared/hardware/InputDevice.kt

@@ -0,0 +1,39 @@
+/*
+ * 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.shared.hardware
+
+import android.view.InputDevice
+
+/**
+ * Returns true if [InputDevice] is electronic components to allow a user to use an active stylus in
+ * the host device or a passive stylus is detected by the host device.
+ */
+val InputDevice.isInternalStylusSource: Boolean
+    get() = isAnyStylusSource && !isExternal
+
+/** Returns true if [InputDevice] is an active stylus. */
+val InputDevice.isExternalStylusSource: Boolean
+    get() = isAnyStylusSource && isExternal
+
+/**
+ * Returns true if [InputDevice] supports any stylus source.
+ *
+ * @see InputDevice.isInternalStylusSource
+ * @see InputDevice.isExternalStylusSource
+ */
+val InputDevice.isAnyStylusSource: Boolean
+    get() = supportsSource(InputDevice.SOURCE_STYLUS)

packages/SystemUI/shared/src/com/android/systemui/shared/hardware/InputManager.kt

@@ -0,0 +1,69 @@
+/*
+ * 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.shared.hardware
+
+import android.hardware.input.InputManager
+import android.view.InputDevice
+
+/**
+ * Gets information about all input devices in the system and returns as a lazy [Sequence].
+ *
+ * For performance reasons, it is preferred to operate atop the returned [Sequence] to ensure each
+ * operation is executed on an element-per-element basis yet customizable.
+ *
+ * For example:
+ * ```kotlin
+ * val stylusDevices = inputManager.getInputDeviceSequence().filter {
+ *   it.supportsSource(InputDevice.SOURCE_STYLUS)
+ * }
+ *
+ * val hasInternalStylus = stylusDevices.any { it.isInternal }
+ * val hasExternalStylus = stylusDevices.any { !it.isInternal }
+ * ```
+ *
+ * @return a [Sequence] of [InputDevice].
+ */
+fun InputManager.getInputDeviceSequence(): Sequence<InputDevice> =
+    inputDeviceIds.asSequence().mapNotNull { getInputDevice(it) }
+
+/**
+ * Returns the first [InputDevice] matching the given predicate, or null if no such [InputDevice]
+ * was found.
+ */
+fun InputManager.findInputDevice(predicate: (InputDevice) -> Boolean): InputDevice? =
+    getInputDeviceSequence().find { predicate(it) }
+
+/**
+ * Returns true if [any] [InputDevice] matches with [predicate].
+ *
+ * For example:
+ * ```kotlin
+ * val hasStylusSupport = inputManager.hasInputDevice { it.isStylusSupport() }
+ * val hasStylusPen = inputManager.hasInputDevice { it.isStylusPen() }
+ * ```
+ */
+fun InputManager.hasInputDevice(predicate: (InputDevice) -> Boolean): Boolean =
+    getInputDeviceSequence().any { predicate(it) }
+
+/** Returns true if host device has any [InputDevice] where [InputDevice.isInternalStylusSource]. */
+fun InputManager.hasInternalStylusSource(): Boolean = hasInputDevice { it.isInternalStylusSource }
+
+/** Returns true if host device has any [InputDevice] where [InputDevice.isExternalStylusSource]. */
+fun InputManager.hasExternalStylusSource(): Boolean = hasInputDevice { it.isExternalStylusSource }
+
+/** Returns true if host device has any [InputDevice] where [InputDevice.isAnyStylusSource]. */
+fun InputManager.hasAnyStylusSource(): Boolean = hasInputDevice { it.isAnyStylusSource }