Fix cross-page markup drag z-order, harden PDF encryption, refresh README

app/src/main/java/com/chethan616/clearpdf/ui/screen/PdfContinuousPage.kt

@@ -190,6 +190,11 @@ internal fun PdfContinuousPage(
     onMoveImageToPage: (fromPage: Int, img: PdfMarkup.ImageMarkup, toPage: Int) -> Boolean = { _, _, _ -> false }
 ) {
     var imageDragging by remember { mutableStateOf(false) }
+    // A dragged text box / shape / note can swing below this page's bottom edge toward the next
+    // page while still being moved. Compose doesn't clip a page's overlay to its own bounds, and
+    // the next page is a later LazyColumn item, so without raising this page too it drew on top
+    // of the markup being dragged over it.
+    var markupDragging by remember { mutableStateOf(false) }
     var draftPoints    by remember(page, activeTool) { mutableStateOf<List<Offset>>(emptyList()) }
     var draftRectStart by remember(page, activeTool) { mutableStateOf<Offset?>(null) }
     var draftRectEnd   by remember(page, activeTool) { mutableStateOf<Offset?>(null) }
@@ -245,9 +250,10 @@ internal fun PdfContinuousPage(
 
     Box(
         modifier
-            // While an image is dragged across a page boundary, this page draws above its
-            // neighbours so the image isn't hidden behind the next page.
-            .zIndex(if (imageDragging) 1f else 0f)
+            // While an image or a selected text box / shape / note is dragged across a page
+            // boundary, this page draws above its neighbours so the markup isn't hidden behind
+            // the next page.
+            .zIndex(if (imageDragging || markupDragging) 1f else 0f)
             .fillMaxWidth()
             .padding(vertical = 6.dp)
             // The placeholder is trimmed too, so the page keeps its height when the bitmap lands.
@@ -734,6 +740,7 @@ internal fun PdfContinuousPage(
                                 total = Offset.Zero
                                 val pPage = Offset(local.x + (bb?.left ?: 0f) - pad, local.y + (bb?.top ?: 0f) - pad)
                                 mode = if (bb != null && cur.isResizable() && (pPage - bb.bottomRight).getDistance() <= 64f) 2 else 1
+                                markupDragging = true
                                 onInteraction()
                             },
                             onDrag = { ch, drag ->
@@ -745,8 +752,8 @@ internal fun PdfContinuousPage(
                                 marks[selectedMarkupIndex] = if (mode == 2) m0.resizedFrom(b0, total) else m0.translated(total)
                                 onInteraction()
                             },
-                            onDragEnd = { mode = 0; frozen = null },
-                            onDragCancel = { mode = 0; frozen = null }
+                            onDragEnd = { mode = 0; frozen = null; markupDragging = false },
+                            onDragCancel = { mode = 0; frozen = null; markupDragging = false }
                         )
                     }
             )

app/src/main/java/com/chethan616/clearpdf/ui/viewmodel/PdfViewerViewModel.kt

@@ -287,6 +287,10 @@ class PdfViewerViewModel(private val openPdfUseCase: OpenPdfUseCase) : ViewModel
         // gives that race a head start.
         private const val PREFETCH_AHEAD = 2
         private const val PREFETCH_BEHIND = 1
+        // Above this, the on-open form/link scan is skipped outright rather than risking PDFBox's
+        // temp-file-backed load on a huge document for a feature (form fields, in-document links)
+        // that scanned books essentially never have.
+        private const val FORM_SCAN_SIZE_LIMIT_BYTES = 150L * 1024 * 1024
     }
 
     fun openPdf(context: Context, uri: Uri, password: String? = null) {
@@ -394,14 +398,24 @@ class PdfViewerViewModel(private val openPdfUseCase: OpenPdfUseCase) : ViewModel
                     renderedByOfficeEngine = renderedUri.path?.contains("/office-pdf/") == true
                 )
                 // Fillable fields and links, read off the main thread in one pass; most PDFs have
-                // no form and stay empty.
+                // no form and stay empty. This used to load the whole file into PDFBox's in-memory
+                // model unconditionally on every open — a multi-hundred-MB scanned book (all image
+                // XObjects, no forms) OOM'd right after opening, before the user did anything. Above
+                // FORM_SCAN_SIZE_LIMIT_BYTES skip the scan (forms/links are rare in huge scans and
+                // not worth the risk); below it, load through a temp-file-backed buffer instead of
+                // the heap.
                 val formDocUri = doc.uri
                 viewModelScope.launch {
                     val (widgets, links) = withContext(Dispatchers.IO) {
-                        runCatching {
+                        if (doc.sizeBytes > FORM_SCAN_SIZE_LIMIT_BYTES) {
+                            emptyMap<Int, List<com.kyant.pdfcore.form.PdfFormWidget>>() to emptyMap()
+                        } else runCatching {
                             com.kyant.pdfcore.internal.PdfBox.ensureInitialized(context)
                             context.contentResolver.openInputStream(formDocUri)?.use { input ->
-                                com.tom_roush.pdfbox.pdmodel.PDDocument.load(input).use { pd ->
+                                com.tom_roush.pdfbox.pdmodel.PDDocument.load(
+                                    input,
+                                    com.tom_roush.pdfbox.io.MemoryUsageSetting.setupTempFileOnly()
+                                ).use { pd ->
                                     val w = runCatching { com.kyant.pdfcore.form.PdfFormWidgets.read(pd) }.getOrDefault(emptyMap())
                                     val l = runCatching { com.kyant.pdfcore.link.PdfLinks.read(pd) }.getOrDefault(emptyMap())
                                     w to l

readme.md

@@ -8,6 +8,7 @@ Read and annotate PDFs, sign forms, work with Office documents, edit spreadsheet
 
 <p>
   <a href="https://github.com/Chethan616/ClearPDF/releases/latest"><strong>Download the latest ClearPDF</strong></a>
+  · <a href="https://apps.obtainium.imranr.dev/redirect?r=https://github.com/Chethan616/ClearPDF"><strong>Add to Obtainium</strong></a>
   · <a href="https://github.com/Chethan616/ClearPDF/releases">All releases</a>
   · <a href="https://github.com/Chethan616/ClearPDF/issues/new/choose">Report a problem or request a feature</a>
   · <a href="CONTRIBUTING.md">Contribute</a>
@@ -20,6 +21,8 @@ Read and annotate PDFs, sign forms, work with Office documents, edit spreadsheet
   <a href="LICENSE"><img src="https://img.shields.io/github/license/Chethan616/ClearPDF?style=flat-square&color=30D158" alt="MIT license"></a>
   <img src="https://img.shields.io/badge/Android-6.0%2B-3DDC84?style=flat-square&logo=android&logoColor=white" alt="Android 6.0 or newer">
   <a href="https://github.com/Chethan616/ClearPDF/actions/workflows/android.yml"><img src="https://img.shields.io/github/actions/workflow/status/Chethan616/ClearPDF/android.yml?branch=main&style=flat-square&label=Android%20build" alt="Android build status"></a>
+  <a href="https://apps.obtainium.imranr.dev/redirect?r=https://github.com/Chethan616/ClearPDF"><img src="https://img.shields.io/badge/Obtainium-Add%20repo-1B5E20?style=flat-square" alt="Add to Obtainium"></a>
+  <img src="https://img.shields.io/badge/GitHub%20Trending-%232-FF375F?style=flat-square" alt="Number 2 on GitHub Trending">
 </p>
 
 </div>
@@ -36,13 +39,17 @@ ClearPDF was featured by HowToMen. [Watch the video from 9:08](https://www.youtu
   <img src="screenshots/light%20home%20screen.jpg" width="24%" alt="ClearPDF home screen in light mode">
   <img src="screenshots/light%20pdf%20tools.jpg" width="24%" alt="ClearPDF PDF tools in light mode">
   <img src="screenshots/light%20settings%20screen.jpg" width="24%" alt="ClearPDF settings in light mode">
-  <img src="demo/3.jpg" width="24%" alt="ClearPDF PDF editing tools">
+  <img src="screenshots/docx%20editing.jpg" width="24%" alt="ClearPDF opening a Word document">
 </p>
 <p align="center">
   <img src="screenshots/dark%20home%20screen.jpg" width="24%" alt="ClearPDF home screen in dark mode">
   <img src="screenshots/dark%20pdf%20tools.jpg" width="24%" alt="ClearPDF PDF tools in dark mode">
   <img src="screenshots/dark%20settings%20screen.jpg" width="24%" alt="ClearPDF settings in dark mode">
-  <img src="demo/4.jpg" width="24%" alt="ClearPDF annotation tools">
+  <img src="screenshots/xlsx%20editing.jpg" width="24%" alt="ClearPDF editing a spreadsheet">
+</p>
+
+<p align="center">
+  <img src="screenshots/pdf_scroll.gif" width="40%" alt="Scrolling a PDF in the ClearPDF viewer">
 </p>
 
 Short walkthroughs: [onboarding](demo/1.mp4) · [PDF viewer](demo/2.mp4).
@@ -87,7 +94,7 @@ ClearPDF annotates PDFs and edits form fields, signatures, and pages, but it doe
 
 ## Download
 
-The current stable release is **V4 (app version 2.0.0)**. Open the [V4 release page](https://github.com/Chethan616/ClearPDF/releases/tag/v4) and choose the APK that matches your device:
+The current stable release is **V5.1 (app version 2.1.1)**. Open the [latest release page](https://github.com/Chethan616/ClearPDF/releases/latest) and choose the APK that matches your device:
 
 | APK suffix | Choose it for |
 |---|---|
@@ -96,7 +103,15 @@ The current stable release is **V4 (app version 2.0.0)**. Open the [V4 release p
 | <code>-x86_64.apk</code> or <code>-x86.apk</code> | x86-based emulators and devices |
 | <code>-universal.apk</code> | A larger package containing the release's supported ABIs |
 
-The GitHub APKs are the FOSS distribution. The optional Office engine is downloaded only when requested in Settings. For future builds, use the [latest release page](https://github.com/Chethan616/ClearPDF/releases/latest). You can also add the repository to [Obtainium](https://github.com/ImranR98/Obtainium) for release update notifications.
+The GitHub APKs are the FOSS distribution. The optional Office engine is downloaded only when requested in Settings.
+
+### Install via Obtainium
+
+[Obtainium](https://github.com/ImranR98/Obtainium) tracks this repository's releases and installs/updates the APK for you, no manual downloads.
+
+1. Open Obtainium → **Add App**.
+2. Paste `https://github.com/Chethan616/ClearPDF`, or tap **[Add to Obtainium](https://apps.obtainium.imranr.dev/redirect?r=https://github.com/Chethan616/ClearPDF)** on a device with Obtainium installed.
+3. Pick the APK suffix for your device from the table above when prompted.
 
 ## Privacy and network use