Initial commit

app/src/main/java/com/aryan/reader/epubreader/EpubReaderSystem.kt

@@ -0,0 +1,121 @@
+package com.aryan.reader.epubreader
+
+import timber.log.Timber
+import android.view.KeyEvent
+import android.view.View
+import android.view.Window
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.onPreviewKeyEvent
+import androidx.compose.ui.input.key.type
+import androidx.core.view.WindowCompat
+import androidx.core.view.WindowInsetsCompat
+import androidx.core.view.WindowInsetsControllerCompat
+import com.aryan.reader.RenderMode
+
+@Composable
+fun EpubReaderSystemUiController(
+    window: Window?,
+    view: View,
+    showBars: Boolean,
+    initialIsAppearanceLightStatusBars: Boolean,
+    initialSystemBarsBehavior: Int
+) {
+    val isDarkTheme = isSystemInDarkTheme()
+
+    // 1. Handle Immersive Mode (Enter/Exit)
+    DisposableEffect(window, view, initialIsAppearanceLightStatusBars, initialSystemBarsBehavior) {
+        if (window == null) {
+            Timber.w("Window is null, cannot control system UI.")
+            return@DisposableEffect onDispose {}
+        }
+        val insetsController = WindowCompat.getInsetsController(window, view)
+        Timber.d("Applying immersive mode.")
+
+        WindowCompat.setDecorFitsSystemWindows(window, false)
+        insetsController.hide(WindowInsetsCompat.Type.navigationBars())
+        insetsController.systemBarsBehavior = WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+
+        onDispose {
+            Timber.d("Restoring system UI.")
+            WindowCompat.setDecorFitsSystemWindows(window, true)
+            insetsController.show(WindowInsetsCompat.Type.navigationBars())
+            insetsController.isAppearanceLightStatusBars = initialIsAppearanceLightStatusBars
+            insetsController.systemBarsBehavior = initialSystemBarsBehavior
+        }
+    }
+
+    // 2. Handle Status Bar Appearance (Dark/Light theme)
+    LaunchedEffect(window, view, isDarkTheme) {
+        if (window != null) {
+            val insetsController = WindowCompat.getInsetsController(window, view)
+            insetsController.isAppearanceLightStatusBars = !isDarkTheme
+        }
+    }
+
+    // 3. Handle Show/Hide Bars dynamically
+    LaunchedEffect(showBars, window, view) {
+        if (window != null) {
+            val insetsController = WindowCompat.getInsetsController(window, view)
+            if (showBars) {
+                insetsController.show(WindowInsetsCompat.Type.navigationBars())
+            } else {
+                insetsController.hide(WindowInsetsCompat.Type.navigationBars())
+            }
+        }
+    }
+}
+
+fun Modifier.volumeScrollHandler(
+    volumeScrollEnabled: Boolean,
+    renderMode: RenderMode,
+    isTtsActive: Boolean,
+    isMusicActive: Boolean,
+    currentScrollY: Int,
+    currentScrollHeight: Int,
+    currentClientHeight: Int,
+    currentChapterIndex: Int,
+    totalChapters: Int,
+    onScrollBy: (Int) -> Unit,
+    onNavigateChapter: (offset: Int, scrollTarget: ChapterScrollPosition) -> Unit
+): Modifier = this.onPreviewKeyEvent { keyEvent ->
+    val shouldHandle = volumeScrollEnabled &&
+            renderMode == RenderMode.VERTICAL_SCROLL &&
+            !isTtsActive &&
+            !isMusicActive
+
+    if (!shouldHandle) return@onPreviewKeyEvent false
+
+    val isVolumeKey = keyEvent.nativeKeyEvent.keyCode == KeyEvent.KEYCODE_VOLUME_DOWN ||
+            keyEvent.nativeKeyEvent.keyCode == KeyEvent.KEYCODE_VOLUME_UP
+
+    if (!isVolumeKey) return@onPreviewKeyEvent false
+
+    if (keyEvent.type == KeyEventType.KeyDown) {
+        val direction = if (keyEvent.nativeKeyEvent.keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) 1 else -1
+        val isAtBottom = (currentScrollY + currentClientHeight) >= (currentScrollHeight - 2)
+
+        Timber.d("Dir: $direction, AtBottom: $isAtBottom, Y: $currentScrollY")
+
+        if (direction == -1 && currentScrollY == 0) {
+            // Top -> Prev Chapter
+            if (currentChapterIndex > 0) {
+                onNavigateChapter(-1, ChapterScrollPosition.END)
+            }
+        } else if (direction == 1 && isAtBottom) {
+            // Bottom -> Next Chapter
+            if (currentChapterIndex < totalChapters - 1) {
+                onNavigateChapter(1, ChapterScrollPosition.START)
+            }
+        } else {
+            // Scroll
+            val scrollAmount = (currentClientHeight * 0.25).toInt() * direction
+            onScrollBy(scrollAmount)
+        }
+    }
+    true
+}