Add functionality for Choose local file button

Added the functionality for `Choose local file` button to be able to go and select a local file from the device. The file was then displayed by using ExoPlayer inside PlayerView.

PiperOrigin-RevId: 693756565

demos/effect/build.gradle

@@ -74,6 +74,7 @@ dependencies {
     implementation 'androidx.compose.material3:material3'
     implementation 'com.google.android.material:material:' + androidxMaterialVersion
 
+    implementation project(modulePrefix + 'lib-exoplayer')
     implementation project(modulePrefix + 'lib-ui')
 
     // For detecting and debugging leaks only. LeakCanary is not needed for demo app to work.

demos/effect/src/main/AndroidManifest.xml

@@ -19,6 +19,8 @@
 
   <uses-sdk/>
   <uses-permission android:name="android.permission.INTERNET" />
+  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+  <uses-permission android:name="android.permission.READ_MEDIA_VIDEO"/>
 
   <application
       android:allowBackup="false"

demos/effect/src/main/java/androidx/media3/demo/effect/EffectActivity.kt

@@ -15,9 +15,14 @@
  */
 package androidx.media3.demo.effect
 
+import android.Manifest
+import android.net.Uri
 import android.os.Bundle
 import androidx.activity.ComponentActivity
+import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.compose.setContent
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.annotation.OptIn
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
@@ -31,14 +36,23 @@ import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.dimensionResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.viewinterop.AndroidView
+import androidx.core.content.ContextCompat
+import androidx.media3.common.MediaItem
+import androidx.media3.common.util.UnstableApi
+import androidx.media3.common.util.Util.SDK_INT
+import androidx.media3.exoplayer.ExoPlayer
 import androidx.media3.ui.PlayerView
 import kotlinx.coroutines.launch
 
@@ -53,6 +67,10 @@ class EffectActivity : ComponentActivity() {
   fun EffectDemo() {
     val snackbarHostState = remember { SnackbarHostState() }
     val coroutineScope = rememberCoroutineScope()
+    val context = LocalContext.current
+    val exoPlayer by remember {
+      mutableStateOf(ExoPlayer.Builder(context).build().apply { playWhenReady = true })
+    }
 
     Scaffold(
       modifier = Modifier.fillMaxSize(),
@@ -64,18 +82,17 @@ class EffectActivity : ComponentActivity() {
         horizontalAlignment = Alignment.CenterHorizontally,
       ) {
         InputChooser(
-          onButtonClick = {
-            coroutineScope.launch {
-              snackbarHostState.showSnackbar(message = "Button is not yet implemented.")
-            }
+          onException = { coroutineScope.launch { snackbarHostState.showSnackbar(it) } }
+        ) { uri ->
+          exoPlayer.apply {
+            setMediaItem(MediaItem.fromUri(uri))
+            prepare()
           }
-        )
-        PlayerScreen()
+        }
+        PlayerScreen(exoPlayer)
         Effects(
-          onButtonClick = {
-            coroutineScope.launch {
-              snackbarHostState.showSnackbar(message = "Button is not yet implemented.")
-            }
+          onException = { message ->
+            coroutineScope.launch { snackbarHostState.showSnackbar(message) }
           }
         )
       }
@@ -83,25 +100,76 @@ class EffectActivity : ComponentActivity() {
   }
 
   @Composable
-  fun InputChooser(onButtonClick: () -> Unit) {
+  fun InputChooser(onException: (String) -> Unit, onNewUri: (Uri) -> Unit) {
+    var showLocalFilePicker by remember { mutableStateOf(false) }
     Row(
       modifier = Modifier.padding(vertical = dimensionResource(id = R.dimen.small_padding)),
       horizontalArrangement = Arrangement.spacedBy(dimensionResource(id = R.dimen.small_padding)),
     ) {
-      Button(onClick = onButtonClick) {
+      Button(onClick = { onException("Button is not yet implemented.") }) {
         Text(text = stringResource(id = R.string.choose_preset_input))
       }
-      Button(onClick = onButtonClick) {
+      Button(onClick = { showLocalFilePicker = true }) {
         Text(text = stringResource(id = R.string.choose_local_file))
       }
     }
+    if (showLocalFilePicker) {
+      LocalFilePicker(
+        onException = {
+          onException(it)
+          showLocalFilePicker = false
+        }
+      ) { uri ->
+        onNewUri(uri)
+        showLocalFilePicker = false
+      }
+    }
+  }
+
+  @OptIn(UnstableApi::class)
+  @Composable
+  fun LocalFilePicker(onException: (String) -> Unit, onFileSelected: (Uri) -> Unit) {
+    val context = LocalContext.current
+    val localFilePickerLauncher =
+      rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.OpenDocument(),
+        onResult = { uri: Uri? ->
+          if (uri != null) {
+            onFileSelected(uri)
+          } else {
+            onException("File couldn't be opened. Please try again.")
+          }
+        },
+      )
+    val permissionLauncher =
+      rememberLauncherForActivityResult(
+        contract = ActivityResultContracts.RequestPermission(),
+        onResult = { isGranted: Boolean ->
+          if (isGranted) {
+            localFilePickerLauncher.launch(arrayOf("video/*"))
+          } else {
+            onException("Permission was not granted.")
+          }
+        },
+      )
+    LaunchedEffect(Unit) {
+      val permission =
+        if (SDK_INT >= 33) Manifest.permission.READ_MEDIA_VIDEO
+        else Manifest.permission.READ_EXTERNAL_STORAGE
+      val permissionCheck = ContextCompat.checkSelfPermission(context, permission)
+      if (permissionCheck == android.content.pm.PackageManager.PERMISSION_GRANTED) {
+        localFilePickerLauncher.launch(arrayOf("video/*"))
+      } else {
+        permissionLauncher.launch(permission)
+      }
+    }
   }
 
   @Composable
-  fun PlayerScreen() {
+  fun PlayerScreen(exoPlayer: ExoPlayer) {
     val context = LocalContext.current
     AndroidView(
-      factory = { PlayerView(context).apply {} },
+      factory = { PlayerView(context).apply { player = exoPlayer } },
       modifier =
         Modifier.height(dimensionResource(id = R.dimen.android_view_height))
           .padding(all = dimensionResource(id = R.dimen.small_padding)),
@@ -109,7 +177,9 @@ class EffectActivity : ComponentActivity() {
   }
 
   @Composable
-  fun Effects(onButtonClick: () -> Unit) {
-    Button(onClick = onButtonClick) { Text(text = stringResource(id = R.string.apply_effects)) }
+  fun Effects(onException: (String) -> Unit) {
+    Button(onClick = { onException("Button is not yet implemented.") }) {
+      Text(text = stringResource(id = R.string.apply_effects))
+    }
   }
 }