Merge pull request #13434 from JosJuice/android-non-blocking-input-detection

Android: Don't use separate thread for MotionAlertDialog

4 files changed, 110 insertions, 28 deletions

diff --git a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/model/InputDetector.kt b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/model/InputDetector.kt
new file mode 100644
index 0000000000..e180814a58
--- /dev/null
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/model/InputDetector.kt
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package org.dolphinemu.dolphinemu.features.input.model
+
+import androidx.annotation.Keep
+
+/**
+ * Waits for the user to press inputs, and reports which inputs were pressed.
+ *
+ * The caller is responsible for forwarding input events from Android to ControllerInterface
+ * and then calling [update].
+ */
+class InputDetector {
+    @Keep
+    private val pointer: Long
+
+    constructor() {
+        pointer = createNew()
+    }
+
+    @Keep
+    private constructor(pointer: Long) {
+        this.pointer = pointer
+    }
+
+    external fun finalize()
+
+    private external fun createNew(): Long
+
+    /**
+     * Starts a detection session.
+     *
+     * @param defaultDevice The device to detect inputs from.
+     * @param allDevices Whether to also detect inputs from devices other than the specified one.
+     */
+    external fun start(defaultDevice: String, allDevices: Boolean)
+
+    /**
+     * Checks what inputs are currently pressed and updates internal state.
+     *
+     * During a detection session, this should be called after each call to
+     * [ControllerInterface.dispatchKeyEvent] and [ControllerInterface#dispatchGenericMotionEvent].
+     */
+    external fun update()
+
+    /**
+     * Returns whether a detection session has finished.
+     *
+     * A detection session can end once the user has pressed and released an input or once a timeout
+     * has been reached.
+     */
+    external fun isComplete(): Boolean
+
+    /**
+     * Returns the result of a detection session.
+     *
+     * The result of each detection session is only returned once. If this method is called more
+     * than once without starting a new detection session, the second call onwards will return an
+     * empty string.
+     *
+     * @param defaultDevice The device to detect inputs from. Should normally be the same as the one
+     *                      passed to [start].
+     *
+     * @return The input(s) pressed by the user in the form of an InputCommon expression,
+     *         or an empty string if there were no inputs.
+     */
+    external fun takeResults(defaultDevice: String): String
+}
diff --git a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/model/MappingCommon.kt b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/model/MappingCommon.kt
index 32775a7ebc..622f4f5515 100644
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/model/MappingCommon.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/model/MappingCommon.kt
@@ -2,23 +2,7 @@
 
 package org.dolphinemu.dolphinemu.features.input.model
 
-import org.dolphinemu.dolphinemu.features.input.model.controlleremu.EmulatedController
-
 object MappingCommon {
-    /**
-     * Waits until the user presses one or more inputs or until a timeout,
-     * then returns the pressed inputs.
-     *
-     * When this is being called, a separate thread must be calling ControllerInterface's
-     * dispatchKeyEvent and dispatchGenericMotionEvent, otherwise no inputs will be registered.
-     *
-     * @param controller The device to detect inputs from.
-     * @param allDevices Whether to also detect inputs from devices other than the specified one.
-     * @return The input(s) pressed by the user in the form of an InputCommon expression,
-     * or an empty string if there were no inputs.
-     */
-    external fun detectInput(controller: EmulatedController, allDevices: Boolean): String
-
     external fun getExpressionForControl(
         control: String,
         device: String,
diff --git a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/ui/MotionAlertDialog.kt b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/ui/MotionAlertDialog.kt
index ff4a278f4c..12f3ffb138 100644
--- a/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/ui/MotionAlertDialog.kt
+++ b/Source/Android/app/src/main/java/org/dolphinemu/dolphinemu/features/input/ui/MotionAlertDialog.kt
@@ -3,12 +3,16 @@
 package org.dolphinemu.dolphinemu.features.input.ui
 
 import android.app.Activity
+import android.os.Looper
+import android.os.Handler
 import android.view.InputDevice
 import android.view.KeyEvent
 import android.view.MotionEvent
 import androidx.appcompat.app.AlertDialog
+import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import org.dolphinemu.dolphinemu.R
 import org.dolphinemu.dolphinemu.features.input.model.ControllerInterface
-import org.dolphinemu.dolphinemu.features.input.model.MappingCommon
+import org.dolphinemu.dolphinemu.features.input.model.InputDetector
 import org.dolphinemu.dolphinemu.features.input.model.view.InputMappingControlSetting
 
 /**
@@ -24,21 +28,21 @@ class MotionAlertDialog(
     private val setting: InputMappingControlSetting,
     private val allDevices: Boolean
 ) : AlertDialog(activity) {
+    private val handler = Handler(Looper.getMainLooper())
+    private val inputDetector: InputDetector = InputDetector()
     private var running = false
 
     override fun onStart() {
         super.onStart()
-
         running = true
-        Thread {
-            val result = MappingCommon.detectInput(setting.controller, allDevices)
-            activity.runOnUiThread {
-                if (running) {
-                    setting.value = result
-                    dismiss()
-                }
-            }
-        }.start()
+        inputDetector.start(setting.controller.getDefaultDevice(), allDevices)
+        periodicUpdate()
+        if (running == false) {
+            MaterialAlertDialogBuilder(activity)
+                .setMessage(R.string.input_binding_disconnected_device)
+                .setPositiveButton(R.string.ok, null)
+                .show()
+        }
     }
 
     override fun onStop() {
@@ -48,9 +52,11 @@ class MotionAlertDialog(
 
     override fun dispatchKeyEvent(event: KeyEvent): Boolean {
         ControllerInterface.dispatchKeyEvent(event)
+        updateInputDetector()
         if (event.keyCode == KeyEvent.KEYCODE_BACK && event.isLongPress) {
             // Special case: Let the user cancel by long-pressing Back (intended for non-touch devices)
             setting.clearValue()
+            running = false
             dismiss()
         }
         return true
@@ -63,6 +69,29 @@ class MotionAlertDialog(
         }
 
         ControllerInterface.dispatchGenericMotionEvent(event)
+        updateInputDetector()
         return true
     }
+
+    private fun updateInputDetector() {
+        if (running) {
+            if (inputDetector.isComplete()) {
+                setting.value = inputDetector.takeResults(setting.controller.getDefaultDevice())
+                running = false
+
+                // Quirk: If this method has been called from onStart, calling dismiss directly
+                // doesn't seem to do anything. As a workaround, post a call to dismiss instead.
+                handler.post(this::dismiss)
+            } else {
+                inputDetector.update()
+            }
+        }
+    }
+
+    private fun periodicUpdate() {
+        updateInputDetector()
+        if (running) {
+            handler.postDelayed(this::periodicUpdate, 10)
+        }
+    }
 }
diff --git a/Source/Android/app/src/main/res/values/strings.xml b/Source/Android/app/src/main/res/values/strings.xml
index e10a781114..c0b33237af 100644
--- a/Source/Android/app/src/main/res/values/strings.xml
+++ b/Source/Android/app/src/main/res/values/strings.xml
@@ -54,7 +54,8 @@
 
     <string name="input_binding">Input Binding</string>
     <string name="input_binding_description">Press or move an input to bind it to %1$s.</string>
-    <string name="input_binding_no_device">You need to select a device first!</string>
+    <string name="input_binding_no_device">You need to select a device first.</string>
+    <string name="input_binding_disconnected_device">The selected device is disconnected.\n\nPlease reconnect the device or select a different device.</string>
     <string name="input_configure_input">Configure Input</string>
     <string name="input_configure_output">Configure Output</string>
     <string name="input_expression">Expression</string>