Fix for issue 6966: open all files of multiple entries (#7709)

* Fix #7416

* sync with origin

* core functions implemented

* moved function to OpenExternalFileAction; fixed a bug about checking if there is any linked file present; modified CHANGELOG.md; added javadoc

* remove dialog

* (incomplete) open all linked files of an entry; rewrite the boolean binding; question: open a large number of files

* Dialog: ask user whether to continue when opening more than 10 files

* fixed a bug: wrong position of the codes of dialog

* Modified binding; changed a variable name

CHANGELOG.md

@@ -22,6 +22,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We added a feature that allows the user to copy highlighted text in the preview window. [#6962](https://github.com/JabRef/jabref/issues/6962)
 - We added a feature that allows you to create new BibEntry via paste arxivId [#2292](https://github.com/JabRef/jabref/issues/2292)
 - We added a feature that allows the user to choose whether to trust the target site when unable to find a valid certification path from the file download site. [#7616](https://github.com/JabRef/jabref/issues/7616)
+- We added a feature that allows the user to open all linked files of multiple selected entries by "Open file" option. [#6966](https://github.com/JabRef/jabref/issues/6966)
 - We added a keybinding preset for new entries. [#7705](https://github.com/JabRef/jabref/issues/7705)
 
 ### Changed

src/main/java/org/jabref/gui/actions/ActionHelper.java

@@ -81,6 +81,18 @@ public static BooleanExpression isFilePresentForSelectedEntry(StateManager state
         return BooleanExpression.booleanExpression(fileIsPresent);
     }
 
+    /**
+     * Check if at least one of the selected entries has linked files
+     * <br>
+     * Used in {@link org.jabref.gui.maintable.OpenExternalFileAction} when multiple entries selected
+     * @param stateManager manager for the state of the GUI
+     * @return a boolean binding
+     */
+    public static BooleanExpression hasLinkedFileForSelectedEntries(StateManager stateManager) {
+        return BooleanExpression.booleanExpression(EasyBind.reduce(stateManager.getSelectedEntries(),
+                entries -> entries.anyMatch(entry -> !entry.getFiles().isEmpty())));
+    }
+
     public static BooleanExpression isOpenMultiDatabase(TabPane tabbedPane) {
         return Bindings.size(tabbedPane.getTabs()).greaterThan(1);
     }

src/main/java/org/jabref/gui/maintable/OpenExternalFileAction.java

@@ -1,5 +1,6 @@
 package org.jabref.gui.maintable;
 
+import java.util.LinkedList;
 import java.util.List;
 
 import org.jabref.gui.DialogService;
@@ -11,10 +12,13 @@
 import org.jabref.gui.fieldeditors.LinkedFileViewModel;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.model.entry.BibEntry;
+import org.jabref.model.entry.LinkedFile;
 import org.jabref.preferences.PreferencesService;
 
 public class OpenExternalFileAction extends SimpleCommand {
 
+    private final int FILES_LIMIT = 10;
+
     private final DialogService dialogService;
     private final StateManager stateManager;
     private final PreferencesService preferencesService;
@@ -24,32 +28,51 @@ public OpenExternalFileAction(DialogService dialogService, StateManager stateMan
         this.stateManager = stateManager;
         this.preferencesService = preferencesService;
 
-        this.executable.bind(ActionHelper.isFilePresentForSelectedEntry(stateManager, preferencesService)
-                                         .and(ActionHelper.needsEntriesSelected(1, stateManager)));
+        this.executable.bind(ActionHelper.hasLinkedFileForSelectedEntries(stateManager)
+                .and(ActionHelper.needsEntriesSelected(stateManager))
+        );
     }
 
+    /**
+     * Open all linked files of the selected entries. If opening too many files, pop out a dialog to ask the user if to continue.
+     * <br>
+     * If some selected entries have linked file and others do not, ignore the latter.
+     */
     @Override
     public void execute() {
         stateManager.getActiveDatabase().ifPresent(databaseContext -> {
             final List<BibEntry> selectedEntries = stateManager.getSelectedEntries();
 
-            if (selectedEntries.size() != 1) {
-                dialogService.notify(Localization.lang("This operation requires exactly one item to be selected."));
-                return;
+            List<LinkedFileViewModel> linkedFileViewModelList = new LinkedList<>();
+            LinkedFileViewModel linkedFileViewModel;
+
+            for (BibEntry entry:selectedEntries) {
+                for (LinkedFile linkedFile:entry.getFiles()) {
+                    linkedFileViewModel = new LinkedFileViewModel(
+                            linkedFile,
+                            entry,
+                            databaseContext,
+                            Globals.TASK_EXECUTOR,
+                            dialogService,
+                            preferencesService.getXmpPreferences(),
+                            preferencesService.getFilePreferences(),
+                            ExternalFileTypes.getInstance());
+
+                    linkedFileViewModelList.add(linkedFileViewModel);
+                }
+            }
+
+            // ask the user when detecting # of files > FILES_LIMIT
+            if (linkedFileViewModelList.size() > FILES_LIMIT) {
+                boolean continueOpening = dialogService.showConfirmationDialogAndWait(Localization.lang("Opening large number of files"),
+                        Localization.lang("You are about to open %0 files. Continue?", Integer.toString(linkedFileViewModelList.size())),
+                        Localization.lang("Continue"), Localization.lang("Cancel"));
+                if (!continueOpening) {
+                    return;
+                }
             }
 
-            final BibEntry entry = selectedEntries.get(0);
-
-            LinkedFileViewModel linkedFileViewModel = new LinkedFileViewModel(
-                    entry.getFiles().get(0),
-                    entry,
-                    databaseContext,
-                    Globals.TASK_EXECUTOR,
-                    dialogService,
-                    preferencesService.getXmpPreferences(),
-                    preferencesService.getFilePreferences(),
-                    ExternalFileTypes.getInstance());
-            linkedFileViewModel.open();
+            linkedFileViewModelList.forEach(LinkedFileViewModel::open);
         });
     }
 }

src/main/resources/l10n/JabRef_en.properties

@@ -1428,6 +1428,9 @@ Clears\ the\ field\ completely.=Clears the field completely.
 Directory\ not\ found=Directory not found
 Main\ file\ directory\ not\ set.\ Check\ the\ preferences\ (linked\ files)\ or\ the\ library\ properties.=Main file directory not set. Check the preferences (linked files) or the library properties.
 This\ operation\ requires\ exactly\ one\ item\ to\ be\ selected.=This operation requires exactly one item to be selected.
+Opening\ large\ number\ of\ files=Opening large number of files
+You\ are\ about\ to\ open\ %0\ files.\ Continue?=You are about to open %0 files. Continue?
+Continue=Continue
 Importing\ in\ %0\ format=Importing in %0 format
 Female\ name=Female name
 Female\ names=Female names