Pdf annotations fix (#99)

* Optimized high-res scale logic in PdfVerticalReader and adjusted layout padding in PdfViewerScreen

* Fixed position sync between both PDF reading modes

* Enabled annotation rendering in PDF tiles and improved scrolling state detection in `PdfVerticalReader` by introducing an `isDragging` flag.

app/src/main/java/com/aryan/reader/pdf/AnnotationDock.kt

@@ -67,8 +67,8 @@ fun AnnotationDock(
     canUndo: Boolean,
     canRedo: Boolean,
     lastPenTool: InkType,
-    lastHighlighterTool: InkType = InkType.HIGHLIGHTER,
     modifier: Modifier = Modifier,
+    lastHighlighterTool: InkType = InkType.HIGHLIGHTER,
     isSticky: Boolean = false,
     isMinimized: Boolean,
     onToggleMinimize: () -> Unit,

app/src/main/java/com/aryan/reader/pdf/PdfPageComposable.kt

@@ -1195,7 +1195,7 @@ internal fun PdfPageComposable(
                                     startY = -tileRenderY,
                                     drawSizeX = fullPageRenderWidth,
                                     drawSizeY = fullPageRenderHeight,
-                                    renderAnnot = false
+                                    renderAnnot = true
                                 )
 
                                 val newTile = PdfTile(tileBitmap, tileRect, tileId)

app/src/main/java/com/aryan/reader/pdf/PdfVerticalReader.kt

@@ -60,6 +60,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.Stable
@@ -234,6 +235,13 @@ internal fun PdfVerticalReader(
     activeToolThickness: Float = 0f
 ) {
     SideEffect { Timber.tag("PdfDrawPerf").v("LIST: PdfVerticalReader Recomposing.") }
+    DisposableEffect(state) {
+        onDispose {
+            state.scrollToPageHandler = null
+            state.snapToPageHandler = null
+            state.scrollByHandler = null
+        }
+    }
     var globalEraserPosition by remember { mutableStateOf<Offset?>(null) }
     BoxWithConstraints(modifier = modifier.fillMaxSize(), contentAlignment = Alignment.TopStart) {
         val imeInsets = WindowInsets.ime
@@ -399,6 +407,7 @@ internal fun PdfVerticalReader(
         var isFlinging by remember { mutableStateOf(false) }
         var isFastFlinging by remember { mutableStateOf(false) }
         var isInteracting by remember { mutableStateOf(false) }
+        var isDragging by remember { mutableStateOf(false) }
 
         LaunchedEffect(
             totalDocHeight, screenHeight, headerHeightPx, footerHeightPx, zoomAnimatable.value, isInteracting, isFlinging
@@ -596,16 +605,13 @@ internal fun PdfVerticalReader(
                     "VerticalReader Interaction State: isBusy=$isBusy (Interacting=$isInteracting, Flinging=$isFlinging, Fast=$isFastFlinging)"
                 )
 
-                if (isBusy) {
+                if (!isBusy) {
-                    highResScale = 1f
+                    delay(50)
-                } else {
-                    delay(20)
                     val target = zoomAnimatable.value
                     if (highResScale != target) {
-                        Timber.tag("PdfDrawPerf")
+                        Timber.tag("PdfDrawPerf").v("VerticalReader: Updating highResScale to $target")
-                            .v("VerticalReader: Updating highResScale to $target")
+                        highResScale = target
                     }
-                    highResScale = target
                 }
             }
         }
@@ -616,17 +622,8 @@ internal fun PdfVerticalReader(
         }
 
         LaunchedEffect(zoomAnimatable.value) {
-            if (!isInteracting && !isFlinging && zoomAnimatable.value != highResScale) {
+            if (!isInteracting && !(isFlinging && isFastFlinging)) {
-                highResScale = zoomAnimatable.value
+                if (highResScale != zoomAnimatable.value) {
-            }
-        }
-
-        LaunchedEffect(Unit) {
-            snapshotFlow { isInteracting }.collectLatest { interacting ->
-                if (interacting) {
-                    highResScale = 1f
-                } else {
-                    delay(350)
                     highResScale = zoomAnimatable.value
                 }
             }
@@ -938,6 +935,7 @@ internal fun PdfVerticalReader(
 
                         val down = awaitFirstDown(requireUnconsumed = false)
                         isInteracting = true
+                        isDragging = false
 
                         Timber.tag("PointerTypeDebug").d("VerticalReader: Input Type detected: ${down.type}")
 
@@ -1057,6 +1055,7 @@ internal fun PdfVerticalReader(
 
                                 if (shouldScroll) {
                                     panLocked = true
+                                    isDragging = true
                                     if (zoomChange != 1f || panChange != Offset.Zero) {
 
                                         var effectiveZoomChange = zoomChange
@@ -1114,6 +1113,7 @@ internal fun PdfVerticalReader(
                             Timber.tag("PdfTouchDebug").v("VerticalReader: Interaction ended")
                             isInteracting = false
                         }
+                        isDragging = false
 
                         val validFlingCondition = panLocked
 
@@ -1519,7 +1519,7 @@ internal fun PdfVerticalReader(
                                     onOcrStateChange = onOcrStateChange,
                                     onBookmarkClick = { onBookmarkClick(page.index) },
                                     isZoomEnabled = false,
-                                    isScrolling = isInteracting || (isFlinging && isFastFlinging),
+                                    isScrolling = isDragging || (isFlinging && isFastFlinging),
                                     isVerticalScroll = true,
                                     visualScaleProvider = currentScaleProvider,
                                     onDoubleTap = onDoubleTapLambda,

app/src/main/java/com/aryan/reader/pdf/PdfViewerScreen.kt

@@ -2196,10 +2196,16 @@ fun PdfViewerScreen(
     }
 
     LaunchedEffect(displayMode) {
-        coroutineScope.launch {
+        if (initialScrollDone) {
             if (displayMode == DisplayMode.VERTICAL_SCROLL) {
                 val pageToScroll = pagerState.currentPage
-                verticalReaderState.scrollToPage(pageToScroll)
+
+                var attempts = 0
+                while (verticalReaderState.snapToPageHandler == null && attempts < 50) {
+                    delay(16)
+                    attempts++
+                }
+                verticalReaderState.snapToPage(pageToScroll)
             } else {
                 val pageToScroll = verticalReaderState.currentPage
                 pagerState.scrollToPage(pageToScroll)
@@ -4124,9 +4130,6 @@ fun PdfViewerScreen(
                 Box(
                     modifier = Modifier
                         .fillMaxSize()
-                        .padding(
-                            top = verticalHeaderHeight, bottom = verticalFooterHeight
-                        )
                 ) {
                     when {
                         isLoadingDocument -> {
@@ -4605,8 +4608,8 @@ fun PdfViewerScreen(
                                 }
 
                                 DisplayMode.VERTICAL_SCROLL -> {
-                                    val headerHeight = 0.dp
+                                    val headerHeight = verticalHeaderHeight
-                                    val footerHeight = 0.dp
+                                    val footerHeight = verticalFooterHeight
 
                                     val currentSelectedTool by rememberUpdatedState(selectedTool)
                                     val currentStrokeColorState by rememberUpdatedState(