Refactor Database and Database widgets (#2491)

The Database, DatabaseWidget, and DatabaseTabWidget classes share many responsibilities in inconsistent ways resulting in impenetrable and unmaintainable code and a diverse set of bugs and architecture restrictions. This patch reworks the architecture, responsibilities of, and dependencies between these classes.

The core changes are:

* Move loading and saving logic from widgets into the Database class
* Get rid of the DatabaseManagerStruct and move all the information contained in it into the Database
* Let database objects keep track of modifications and dirty/clean state instead of handing this to external widgets
* Move GUI interactions for loading and saving from the DatabaseTabWidget into the DatabaseWidget (resolves #2494 as a side-effect)
* Heavily clean up DatabaseTabWidget and degrade it to a slightly glorified QTabWidget
* Use QSharedPointers for all Database objects
* Remove the modifiedImmediate signal and replace it with a markAsModified() method
* Implement proper tabName() method instead of reading back titles from GUI widgets (resolves #1389 and its duplicates #2146 #855)
* Fix unwanted AES-KDF downgrade if database uses Argon2 and has CustomData
* Improve code

This patch is also the first major step towards solving issues #476 and #2322.

1 files changed, 79 insertions, 71 deletions

diff --git a/src/gui/DatabaseWidget.h b/src/gui/DatabaseWidget.h
index d0c4e2042..1a908cf19 100644
--- a/src/gui/DatabaseWidget.h
+++ b/src/gui/DatabaseWidget.h
@@ -1,6 +1,6 @@
 /*
+ *  Copyright (C) 2018 KeePassXC Team <team@keepassxc.org>
  *  Copyright (C) 2010 Felix Geyer <debfx@fobos.de>
- *  Copyright (C) 2017 KeePassXC Team <team@keepassxc.org>
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -29,7 +29,6 @@
 #include "gui/csvImport/CsvImportWizard.h"
 #include "gui/entry/EntryModel.h"
 
-class ChangeMasterKeyWidget;
 class DatabaseOpenWidget;
 class DatabaseSettingsDialog;
 class Database;
@@ -61,7 +60,7 @@ class DatabaseWidget : public QStackedWidget
     Q_OBJECT
 
 public:
-    enum Mode
+    enum class Mode
     {
         None,
         ImportMode,
@@ -70,35 +69,39 @@ public:
         LockedMode
     };
 
-    explicit DatabaseWidget(Database* db, QWidget* parent = nullptr);
+    explicit DatabaseWidget(QSharedPointer<Database> db, QWidget* parent = nullptr);
+    explicit DatabaseWidget(const QString& filePath, QWidget* parent = nullptr);
     ~DatabaseWidget();
-    Database* database();
-    bool dbHasKey() const;
-    bool canDeleteCurrentGroup() const;
-    bool isInSearchMode() const;
+
+    QSharedPointer<Database> database() const;
+
+    bool lock();
+    void prepareUnlock();
+    bool save(int attempt = 0);
+    bool saveAs();
+
+    DatabaseWidget::Mode currentMode() const;
+    bool isLocked() const;
+    bool isSearchActive() const;
+
     QString getCurrentSearch();
+    void refreshSearch();
+
+    GroupView* groupView();
+    EntryView* entryView();
+
     Group* currentGroup() const;
-    int addWidget(QWidget* w);
-    void setCurrentIndex(int index);
-    void setCurrentWidget(QWidget* widget);
-    DatabaseWidget::Mode currentMode() const;
-    void lock();
-    void updateFilePath(const QString& filePath);
+    bool canDeleteCurrentGroup() const;
+    bool isGroupSelected() const;
+    bool isRecycleBinSelected() const;
     int numberOfSelectedEntries() const;
+
     QStringList customEntryAttributes() const;
-    bool isGroupSelected() const;
-    bool isInEditMode() const;
     bool isEditWidgetModified() const;
-    QList<int> mainSplitterSizes() const;
-    void setMainSplitterSizes(const QList<int>& sizes);
-    QList<int> previewSplitterSizes() const;
-    void setPreviewSplitterSizes(const QList<int>& sizes);
     bool isUsernamesHidden() const;
     void setUsernamesHidden(bool hide);
     bool isPasswordsHidden() const;
     void setPasswordsHidden(bool hide);
-    QByteArray entryViewState() const;
-    bool setEntryViewState(const QByteArray& state) const;
     void clearAllWidgets();
     bool currentEntryHasFocus();
     bool currentEntryHasTitle();
@@ -107,31 +110,33 @@ public:
     bool currentEntryHasUrl();
     bool currentEntryHasNotes();
     bool currentEntryHasTotp();
-    GroupView* groupView();
-    EntryView* entryView();
-    void showUnlockDialog();
-    void closeUnlockDialog();
+
     void blockAutoReload(bool block = true);
-    void refreshSearch();
-    bool isRecycleBinSelected() const;
-    QString getDatabaseName() const;
-    void setDatabaseName(const QString& databaseName);
-    QString getDatabaseFileName() const;
-    void setDatabaseFileName(const QString& databaseFileName);
+
+    QByteArray entryViewState() const;
+    bool setEntryViewState(const QByteArray& state) const;
+    QList<int> mainSplitterSizes() const;
+    void setMainSplitterSizes(const QList<int>& sizes);
+    QList<int> previewSplitterSizes() const;
+    void setPreviewSplitterSizes(const QList<int>& sizes);
 
 signals:
+    // relayed Database signals
+    void databaseFilePathChanged(const QString& oldPath, const QString& newPath);
+    void databaseModified();
+    void databaseSaved();
+    void databaseUnlocked();
+    void databaseLocked();
+
     void closeRequest();
     void currentModeChanged(DatabaseWidget::Mode mode);
     void groupChanged();
     void entrySelectionChanged();
-    void databaseChanged(Database* newDb, bool unsavedChanges);
-    void databaseMerged(Database* mergedDb);
+    void databaseMerged(QSharedPointer<Database> mergedDb);
     void groupContextMenuRequested(const QPoint& globalPos);
     void entryContextMenuRequested(const QPoint& globalPos);
     void pressedEntry(Entry* selectedEntry);
     void pressedGroup(Group* selectedGroup);
-    void unlockedDatabase();
-    void lockedDatabase();
     void listModeAboutToActivate();
     void listModeActivated();
     void searchModeAboutToActivate();
@@ -142,6 +147,7 @@ signals:
     void clearSearch();
 
 public slots:
+    void replaceDatabase(QSharedPointer<Database> db);
     void createEntry();
     void cloneEntry();
     void deleteEntries();
@@ -167,15 +173,13 @@ public slots:
     void switchToGroupEdit();
     void switchToMasterKeyChange();
     void switchToDatabaseSettings();
+    void switchToOpenDatabase();
     void switchToOpenDatabase(const QString& filePath);
-    void switchToOpenDatabase(const QString& filePath, const QString& password, const QString& keyFile);
     void switchToCsvImport(const QString& filePath);
     void csvImportFinished(bool accepted);
     void switchToOpenMergeDatabase(const QString& filePath);
     void switchToOpenMergeDatabase(const QString& filePath, const QString& password, const QString& keyFile);
     void switchToImportKeepass1(const QString& filePath);
-    void databaseModified();
-    void databaseSaved();
     void emptyRecycleBin();
 
     // Search related slots
@@ -191,18 +195,24 @@ public slots:
     void showErrorMessage(const QString& errorMessage);
     void hideMessage();
 
+protected:
+    void closeEvent(QCloseEvent* event) override;
+    void showEvent(QShowEvent* event) override;
+
 private slots:
+    void updateFilePath(const QString& filePath);
     void entryActivationSignalReceived(Entry* entry, EntryModel::ModelColumn column);
     void switchBackToEntryEdit();
     void switchToHistoryView(Entry* entry);
-    void switchToEntryEdit(Entry* entry);
+    void switchToEntryEdit(Entry*);
     void switchToEntryEdit(Entry* entry, bool create);
     void switchToGroupEdit(Group* entry, bool create);
     void emitGroupContextMenuRequested(const QPoint& pos);
     void emitEntryContextMenuRequested(const QPoint& pos);
     void emitPressedGroup(Group* currentGroup);
     void emitEntrySelectionChanged();
-    void openDatabase(bool accepted);
+    void connectDatabaseSignals();
+    void loadDatabase(bool accepted);
     void mergeDatabase(bool accepted);
     void unlockDatabase(bool accepted);
     void emitCurrentModeChanged();
@@ -213,36 +223,38 @@ private slots:
     void unblockAutoReload();
 
 private:
+    int addChildWidget(QWidget* w);
     void setClipboardTextAndMinimize(const QString& text);
     void setIconFromParent();
-    void replaceDatabase(Database* db);
-
-    QPointer<Database> m_db;
-    QWidget* m_mainWidget;
-    EditEntryWidget* m_editEntryWidget;
-    EditEntryWidget* m_historyEditEntryWidget;
-    EditGroupWidget* m_editGroupWidget;
-    ChangeMasterKeyWidget* m_changeMasterKeyWidget;
-    CsvImportWizard* m_csvImportWizard;
-    DatabaseSettingsDialog* m_databaseSettingDialog;
-    DatabaseOpenWidget* m_databaseOpenWidget;
-    DatabaseOpenWidget* m_databaseOpenMergeWidget;
-    KeePass1OpenWidget* m_keepass1OpenWidget;
-    UnlockDatabaseWidget* m_unlockDatabaseWidget;
-    UnlockDatabaseDialog* m_unlockDatabaseDialog;
-    QSplitter* m_mainSplitter;
-    QSplitter* m_previewSplitter;
-    GroupView* m_groupView;
-    EntryView* m_entryView;
-    QLabel* m_searchingLabel;
-    Group* m_newGroup;
-    Entry* m_newEntry;
-    Group* m_newParent;
-    QString m_filePath;
+
+    QSharedPointer<Database> m_db;
+
+    QPointer<QWidget> m_mainWidget;
+    QPointer<QSplitter> m_mainSplitter;
+    QPointer<MessageWidget> m_messageWidget;
+    QPointer<EntryPreviewWidget> m_previewView;
+    QPointer<QSplitter> m_previewSplitter;
+    QPointer<QLabel> m_searchingLabel;
+    QPointer<CsvImportWizard> m_csvImportWizard;
+    QPointer<EditEntryWidget> m_editEntryWidget;
+    QPointer<EditGroupWidget> m_editGroupWidget;
+    QPointer<EditEntryWidget> m_historyEditEntryWidget;
+    QPointer<DatabaseSettingsDialog> m_databaseSettingDialog;
+    QPointer<DatabaseOpenWidget> m_databaseOpenWidget;
+    QPointer<DatabaseOpenWidget> m_databaseOpenMergeWidget;
+    QPointer<KeePass1OpenWidget> m_keepass1OpenWidget;
+    QPointer<UnlockDatabaseWidget> m_unlockDatabaseWidget;
+    QPointer<UnlockDatabaseDialog> m_unlockDatabaseDialog;
+    QPointer<GroupView> m_groupView;
+    QPointer<EntryView> m_entryView;
+
+    QPointer<Group> m_newGroup;
+    QPointer<Entry> m_newEntry;
+    QPointer<Group> m_newParent;
+
     QUuid m_groupBeforeLock;
     QUuid m_entryBeforeLock;
-    MessageWidget* m_messageWidget;
-    EntryPreviewWidget* m_previewView;
+
     QString m_databaseName;
     QString m_databaseFileName;
 
@@ -251,15 +263,11 @@ private:
     QString m_lastSearchText;
     bool m_searchLimitGroup;
 
-    // CSV import state
-    bool m_importingCsv;
-
     // Autoreload
     QFileSystemWatcher m_fileWatcher;
     QTimer m_fileWatchTimer;
     QTimer m_fileWatchUnblockTimer;
     bool m_ignoreAutoReload;
-    bool m_databaseModified;
 };
 
 #endif // KEEPASSX_DATABASEWIDGET_H