restore ability to save attachments (fixes #1455)

Author: kjk

src/EngineAll.h

@@ -60,6 +60,7 @@ const char* EngineMupdfGetPassword(EngineBase* engine);
 bool EngineMupdfSaveUpdated(EngineBase* engine, const char* path, const ShowErrorCb& showErrorFunc);
 Annotation* EngineMupdfGetAnnotationAtPos(EngineBase*, int pageNo, PointF pos, Annotation*);
 ByteSlice EngineMupdfLoadAttachment(EngineBase*, int attachmentNo);
+ByteSlice EngineMupdfLoadAnnotAttachment(EngineBase*, int objNum);
 TempStr EngineMupdfGetPdfInfo(const char* path);
 TempStr EngineMupdfGetPdfOutline(const char* path);
 

src/EngineBase.h

@@ -155,6 +155,7 @@ struct PageDestinationFile : IPageDestination {
 struct PageDestination : IPageDestination {
     char* value = nullptr;
     char* name = nullptr;
+    int embedObjNum = 0; // PDF object number for embedded file attachment annotations
 
     PageDestination() = default;
 

src/EngineMupdf.cpp

@@ -1355,6 +1355,31 @@ static ByteSlice PdfLoadAttachment(fz_context* ctx, pdf_document* doc, int no) {
     return res;
 }
 
+// load embedded file data from a file attachment annotation by PDF object number
+static ByteSlice PdfLoadAnnotationAttachment(fz_context* ctx, pdf_document* doc, int objNum) {
+    ByteSlice res;
+    fz_try(ctx) {
+        pdf_obj* obj = pdf_new_indirect(ctx, doc, objNum, 0);
+        pdf_obj* fs = pdf_dict_get(ctx, obj, PDF_NAME(FS));
+        if (!fs) {
+            pdf_drop_obj(ctx, obj);
+            break;
+        }
+        fz_buffer* buf = pdf_load_embedded_file_contents(ctx, fs);
+        if (buf) {
+            res.d = (u8*)memdup(buf->data, buf->len);
+            res.sz = buf->len;
+            fz_drop_buffer(ctx, buf);
+        }
+        pdf_drop_obj(ctx, obj);
+    }
+    fz_catch(ctx) {
+        fz_report_error(ctx);
+        logfa("PdfLoadAnnotationAttachment(objNum=%d) failed\n", objNum);
+    }
+    return res;
+}
+
 // Note: make sure to only call with ctxAccess
 static fz_outline* PdfLoadAttachments(fz_context* ctx, pdf_document* doc, const char* path) {
     fz_outline root{};
@@ -2725,9 +2750,9 @@ static void RebuildCommentsFromAnnotationsInner(fz_context* ctx, pdf_annot* anno
         logf("attachment: %s, num: %d\n", attname, num);
 
         auto dest = new PageDestination();
-        // TODO: kindDestinationAttachment ?
         dest->kind = kindDestinationLaunchEmbedded;
         dest->value = str::Dup(attname);
+        dest->embedObjNum = num;
 
         auto el = new PageElementDestination(dest);
         el->pageNo = pageNo;
@@ -3982,6 +4007,15 @@ ByteSlice EngineMupdfLoadAttachment(EngineBase* engine, int attachmentNo) {
     return res;
 }
 
+ByteSlice EngineMupdfLoadAnnotAttachment(EngineBase* engine, int objNum) {
+    EngineMupdf* epdf = AsEngineMupdf(engine);
+    if (!epdf->pdfdoc) {
+        return {};
+    }
+    ScopedCritSec scope(epdf->ctxAccess);
+    return PdfLoadAnnotationAttachment(epdf->Ctx(), epdf->pdfdoc, objNum);
+}
+
 // if an elements fully obscures another, remove it from the list
 static bool RemoveHeWhoFullyContains(Vec<Annotation*>& els) {
     int n = els.Size();

src/MainWindow.cpp

@@ -440,8 +440,24 @@ void LinkHandler::GotoLink(IPageDestination* dest) {
         return;
     }
     if (kindDestinationLaunchEmbedded == kind) {
-        // Not handled here. Must use context menu to trigger launching
-        // embedded files
+        PageDestination* pd = (PageDestination*)dest;
+        if (pd->embedObjNum > 0) {
+            EngineBase* engine = win->CurrentTab()->AsFixed()->GetEngine();
+            ByteSlice data = EngineMupdfLoadAnnotAttachment(engine, pd->embedObjNum);
+            if (!data.empty()) {
+                const char* fileName = pd->GetValue2();
+                logf("GotoLink: opening file attachment annotation '%s', objNum: %d, size: %d\n", fileName,
+                     pd->embedObjNum, (int)data.sz);
+                TempStr tmpDir = GetTempDirTemp();
+                if (tmpDir) {
+                    TempStr tmpPath = path::JoinTemp(tmpDir, path::GetBaseNameTemp(fileName));
+                    if (file::WriteFile(tmpPath, data)) {
+                        SumatraLaunchBrowser(tmpPath);
+                    }
+                }
+                str::Free(data.data());
+            }
+        }
         return;
     }
 

src/Menu.cpp

@@ -900,6 +900,10 @@ static MenuDef menuDefContext[] = {
         _TRN("Copy Co&mment"),
         CmdCopyComment,
     },
+    {
+        _TRN("Save Attachment"),
+        CmdSaveAttachment,
+    },
     {
         _TRN("&Image"),
         (UINT_PTR)menuDefContextImage,
@@ -1949,6 +1953,19 @@ void OnWindowContextMenu(MainWindow* win, int x, int y) {
     if (!pageEl || !pageEl->Is(kindPageElementComment) || !value) {
         MenuRemove(popup, CmdCopyComment);
     }
+    // show "Save Attachment" only for file attachment annotations
+    {
+        bool isFileAttachment = false;
+        if (pageEl && pageEl->Is(kindPageElementDest)) {
+            IPageDestination* elDest = pageEl->AsLink();
+            if (elDest && elDest->GetKind() == kindDestinationLaunchEmbedded) {
+                isFileAttachment = true;
+            }
+        }
+        if (!isFileAttachment) {
+            MenuRemove(popup, CmdSaveAttachment);
+        }
+    }
     {
         bool onImage = pageEl && pageEl->Is(kindPageElementImage);
         bool isImageEngine = tab && tab->GetEngineType() == kindEngineImage;
@@ -2122,6 +2139,25 @@ void OnWindowContextMenu(MainWindow* win, int x, int y) {
             return;
         }
 
+        case CmdSaveAttachment: {
+            if (pageEl && pageEl->Is(kindPageElementDest)) {
+                IPageDestination* elDest = pageEl->AsLink();
+                PageDestination* pd = (PageDestination*)elDest;
+                if (pd && pd->embedObjNum > 0) {
+                    ByteSlice data = EngineMupdfLoadAnnotAttachment(engine, pd->embedObjNum);
+                    if (!data.empty()) {
+                        const char* fileName = pd->GetValue2();
+                        TempStr dir = path::GetDirTemp(filePath);
+                        fileName = path::GetBaseNameTemp(fileName);
+                        TempStr dstPath = path::JoinTemp(dir, fileName);
+                        SaveDataToFile(win->hwndFrame, dstPath, data);
+                        str::Free(data.data());
+                    }
+                }
+            }
+            return;
+        }
+
         case CmdCopyImage: {
             if (pageEl) {
                 RenderedBitmap* bmp = dm->GetEngine()->GetImageForPageElement(pageEl);