Open "near-by" .bib file

CHANGELOG.md

@@ -41,6 +41,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 - We added an importer for SSRN URLs. [#12021](https://github.com/JabRef/jabref/pull/12021)
 - We added a compare button to the duplicates in the citation relations tab to open the "Possible duplicate entries" window. [#11192](https://github.com/JabRef/jabref/issues/11192)
 - We added automatic browser extension install on Windows for Chrome and Edge. [#6076](https://github.com/JabRef/jabref/issues/6076)
+- We added support to automatically open a `.bib` file in the current/parent folder if no other library is opened. [koppor#377](https://github.com/koppor/jabref/issues/377)
 - We added a search bar for filtering keyboard shortcuts. [#11686](https://github.com/JabRef/jabref/issues/11686)
 - By double clicking on a local citation in the Citation Relations Tab you can now jump the linked entry. [#11955](https://github.com/JabRef/jabref/pull/11955)
 - We use the menu icon for background tasks as a progress indicator to visualise an import's progress when dragging and dropping several PDF files into the main table. [#12072](https://github.com/JabRef/jabref/pull/12072)

src/main/java/org/jabref/cli/ArgumentProcessor.java

@@ -99,7 +99,7 @@ public ArgumentProcessor(String[] args,
     }
 
     /**
-     * Will open a file (like {@link #importFile(String)}, but will also request JabRef to focus on this database.
+     * Will open a file (like {@link #importFile(String)}, but will also request JabRef to focus on this library.
      *
      * @return ParserResult with setToOpenTab(true)
      */

src/main/java/org/jabref/gui/frame/JabRefFrameViewModel.java

@@ -1,5 +1,8 @@
 package org.jabref.gui.frame;
 
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.sql.SQLException;
 import java.util.ArrayList;
@@ -30,18 +33,22 @@
 import org.jabref.logic.UiCommand;
 import org.jabref.logic.ai.AiService;
 import org.jabref.logic.importer.ImportCleanup;
+import org.jabref.logic.importer.OpenDatabase;
 import org.jabref.logic.importer.ParserResult;
 import org.jabref.logic.l10n.Localization;
+import org.jabref.logic.os.OS;
 import org.jabref.logic.shared.DatabaseNotSupportedException;
 import org.jabref.logic.shared.exception.InvalidDBMSConnectionPropertiesException;
 import org.jabref.logic.shared.exception.NotASharedDatabaseException;
 import org.jabref.logic.util.BackgroundTask;
 import org.jabref.logic.util.TaskExecutor;
+import org.jabref.logic.util.io.FileUtil;
 import org.jabref.model.database.BibDatabaseContext;
 import org.jabref.model.entry.BibEntry;
 import org.jabref.model.entry.BibEntryTypesManager;
 import org.jabref.model.util.FileUpdateMonitor;
 
+import org.jooq.lambda.Unchecked;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -146,9 +153,12 @@ public boolean close() {
     public void handleUiCommands(List<UiCommand> uiCommands) {
         LOGGER.debug("Handling UI commands {}", uiCommands);
         if (uiCommands.isEmpty()) {
+            checkForBibInUpperDir();
             return;
         }
 
+        assert !uiCommands.isEmpty();
+
         // Handle blank workspace
         boolean blank = uiCommands.stream().anyMatch(UiCommand.BlankWorkspace.class::isInstance);
 
@@ -180,6 +190,85 @@ public void handleUiCommands(List<UiCommand> uiCommands) {
                   });
     }
 
+    private void checkForBibInUpperDir() {
+        // "Open last edited databases" happened before this call
+        // Moreover, there is not any CLI command (especially, not opening any new tab)
+        // Thus, we check if there are any tabs open.
+        if (tabContainer.getLibraryTabs().isEmpty()) {
+            Optional<Path> firstBibFile = firstBibFile();
+            if (firstBibFile.isPresent()) {
+                ParserResult parserResult;
+                try {
+                    parserResult = OpenDatabase.loadDatabase(
+                            firstBibFile.get(),
+                            preferences.getImportFormatPreferences(),
+                            fileUpdateMonitor);
+                } catch (IOException e) {
+                    LOGGER.error("Could not open bib file {}", firstBibFile.get(), e);
+                    return;
+                }
+                List<ParserResult> librariesToOpen = new ArrayList<>(1);
+                librariesToOpen.add(parserResult);
+                openDatabases(librariesToOpen);
+            }
+        }
+    }
+
+    /// Use case: User starts `JabRef.bat` or `JabRef.exe`. JabRef should open a "close by" bib file.
+    /// By "close by" a `.bib` file in the current folder or one level up of `JabRef.exe`is meant.
+    ///
+    /// Paths:
+    ///   - `...\{example-dir}\JabRef\JabRef.exe` (Windows)
+    ///   - `.../{example-dir}/JabRef/bin/JabRef` (Linux)
+    ///   - `...\{example-dir}\JabRef\runtime\bin\JabRef.bat` (Windows)
+    ///
+    /// In the example, `...\{example-dir}\example.bib` should be found.
+    ///
+    /// We do NOT go up another level (i.e., everything in `...` is not found)
+    private Optional<Path> firstBibFile() {
+        Path absolutePath = Path.of(".").toAbsolutePath();
+        if (OS.LINUX && absolutePath.startsWith("/usr")) {
+            return Optional.empty();
+        }
+        if (OS.OS_X && absolutePath.startsWith("/Applications")) {
+            return Optional.empty();
+        }
+        if (OS.WINDOWS && absolutePath.startsWith("C:\\Program Files")) {
+            return Optional.empty();
+        }
+
+        boolean isJabRefExe = Files.exists(Path.of("JabRef.exe"));
+        boolean isJabRefBat = Files.exists(Path.of("JabRef.bat"));
+        boolean isJabRef = Files.exists(Path.of("JabRef"));
+
+        ArrayList<Path> dirsToCheck = new ArrayList<>(2);
+        dirsToCheck.add(Path.of(""));
+        if (isJabRefExe) {
+            dirsToCheck.add(Path.of("../"));       // directory above `JabRef.exe` directory
+        } else if (isJabRefBat) {
+            dirsToCheck.add(Path.of("../../../")); // directory above `runtime\bin\JabRef.bat`
+        } else if (isJabRef) {
+            dirsToCheck.add(Path.of("../..(/"));   // directory above `bin/JabRef` directory
+        }
+
+        // We want to check dirsToCheck only, not all subdirs (due to unnecessary disk i/o)
+        try {
+            return dirsToCheck.stream()
+                              .map(Path::toAbsolutePath)
+                              .flatMap(Unchecked.function(dir -> Files.list(dir)))
+                              .filter(path -> FileUtil.getFileExtension(path).equals(Optional.of("bib")))
+                              .findFirst();
+        } catch (UncheckedIOException ex) {
+            // Could be access denied exception - when this is started from the application directory
+            // Therefore log level "debug"
+            LOGGER.debug("Could not check for existing bib file {}", dirsToCheck, ex);
+            return Optional.empty();
+        }
+    }
+
+    /// Opens the libraries given in `parserResults`. This list needs to be modifiable, because invalidDatabases are removed.
+    ///
+    /// @param parserResults A modifiable list of parser results
     private void openDatabases(List<ParserResult> parserResults) {
         final List<ParserResult> toOpenTab = new ArrayList<>();