Release v0.8, minor README changes

No guarantes the read-only lookup is thread-safe so better
just lock there too

CHANGELOG.md

@@ -1,8 +1,50 @@
 # looqs: Release notes
+
+## 2022-10-22 - v0.8
+
+CHANGES:
+ - For new, not previously indexed files, start creating an additional index using sqlite's experimental trigram tokenizer. Thanks to that, we can now match substrings >= 3 of an unicode sequence. Results of the usual index are prioritized.
+ - GUI: Ensure order of previews matches ranking exactly. Previously, it depended simply on the time preview generators took, i. e. it was more or less a race.
+ - Report progress more often during indexing, so users don't get the impression that it's stuck when processing dirs with large documents.
+ - Fix a regression that caused phrase queries to be broken
+ - Minor improvements
+ - Add packages: Ubuntu 22.10.
+
+## 2022-09-10 - v0.7
+
+CHANGES:
+
+ - GUI: Add vertical scroll option, default to it. Most feedback considered horizontal scrolling unnatural.
+ - GUI: Previews: Improve plaintext preview snippet selection by prioritizing those which contain the most search terms
+ - GUI: Previews: Only highlight whole words, not parts in words.
+ - GUI: Previews: Don't treat text wrapped inside '<' '>' in plaintext files as HTMl tags which caused such text to get lost in previews.
+ - GUI: Avoid triggering preview generation in some cases even when previews tab is not the active one
+ - GUI: Implement a search history. Allow going up/down with arrow keys in the search field.
+ - GUI: Previews: Allow CTRL + mouse wheel to zoom in on previews
+ - General: Fix an incorrect sqlite query which caused the ranking information of search results to be lost. "All files" filter in the previews tab therefore now orders by the seemingly most relevant pages, across all documents.
+ - General: Fix handling of content search queries with prefix terms (those ending in '*').
+ - GUI: Show how many results are previewable.
+ - GUI: Refactor to improve stability of sandboxed IPC worker in order to avoid rare segfaults.
+
+## 2022-08-14 - v0.6
+This release features multiple fixes and enhancements.
+
+Bad news first: It drops a trivial trigger that appeared to work quite fine, but silently may cause "unpredictability" of the sqlite FTS5 index ( [9422a5b494](https://github.com/quitesimpleorg/looqs/commit/9422a5b494dabd0f1324dc2f92a34c3036137414) ). As a result, FTS queries may return weird and unexplainable results. This is not reasonably automatically recoverable by looqs. I strongly recommend creating a clean, new database. All previous versions are affected. To do that, go to "Settings" -> checking "Remove old database on save" -> "Save settings and restart". Alternatively, specify a new path to keep the old database.
+
+CHANGES:
+
+ - GUI: Add line numbers and context lines to plaintext previews
+ - GUI: Fix case where previews for old queries would have still been visible if new query would not create previews
+ - GUI: Add CTRL + F, CTRL+W, CTRL+Tab, CTRL+Shift+Tab shortcuts (see user manual)
+ - GUI: Add checkbox in "Settings" tab allowing to delete database.
+ - General: Fix wrong regexes that caused query errors with chars like -
+ - General: Drop trigger sending incomplete sqlite fts5 deletion command, causing undefined index behaviour
+
 ## 2022-07-30 - v0.5.1
 
 CHANGES:
-	- gui: Fix regression in implicit paths queries introduced in previous version
+
+ - gui: Fix regression in implicit paths queries introduced in previous version
 
 ## 2022-07-29 - v0.5
 This release features multiple fixes and enhancements.

HACKING.md

@@ -1,12 +1,7 @@
 # looqs - Hacking
 
 ## Introduction
-Without elaborating here, I hacked looqs because I was not satisfied with the state of desktop search on Linux.
-
-Originally a set of CLI python  scripts, it is now written in C++ and offers a GUI made using Qt. While a "web app" would have been an option, I prefer a desktop application for something like looqs. I chose Qt because I am more familiar with it than with any other GUI framework. To my knowledge, potential alternatives like GTK do not include as many "batteries" as Qt anyway, so the job presumably would have been harder there,
-at least for me.
-
-If you are interested in how to contribute, please see the file [CONTRIBUTING.md](CONTRIBUTING.md) which contains the instructions on how to submit patches etc.
+If you are interested on how to contribute, please see the file [CONTRIBUTING.md](CONTRIBUTING.md) which contains the instructions on how to submit patches etc.
 
 ## Security
 The architecture ensures that the parsing of documents and the preview generation is sandboxed by [exile.h](https://github.com/quitesimpleorg/exile.h). looqs uses a multi-process architecture to achieve this.
@@ -16,7 +11,8 @@ Qt code is considered trusted in this model. While one may critize this, it was
 Set the enviornment variable `LOOQS_DISABLE_SANDBOX=1` to disable sandboxing. It's intended for troublehshooting.
 
 ## Database
-The heart is sqlite, with the FTS5 extensions behind the full-text search. While FTS may not be sqlite's strong suit, I definitly did not want to run one of those oftenly recommended heavy (Java based) solutions. I explored other options like Postgresql, I've discard them due to some limitations back then.
+The heart is sqlite, with the FTS5 extensions behind the full-text search. While FTS may not be sqlite's strong suit, I definitely did not want to run one of those oftenly recommended heavy (Java based) solutions. I explored other options like Postgresql, I've discard them due to some limitations back then. It's also natural to use sqlite as it's
+used for metadata in general.
 
 Down the road, alternatives will be explored of course if sqlite should not suffice anymore.
 
@@ -27,7 +23,7 @@ looqs simply strips the tags and that seems to work fine so far. Naturally, this
 Naturally, looqs won't be able to index and render previews for everything. Such approach would create a huge bloated binary. In the future, there will be some plugin system of some sorts, either we will load .so objects or use subprocesses.
 
 ## Name
-looqs looks for files. You as the user can also look inside them. The 'k' in "looks" was replaced by a 'q'. Originally, I wanted my projects to have "qs" (for quitesimple) in their name. While abandoned now, this got us to looqs.
+looqs looks for files. You as the user can also look inside them. The 'k' in "looks" was replaced by a 'q'. Originally, I wanted my projects to have "qs" (for quitesimple) in their name. While that quirk is abandoned now, this got us to looqs.
 
 
 

README.md

@@ -1,10 +1,9 @@
 # looqs - Full-text search with previews for your files
-looqs is a tool that creates a full-text search index for your files. It allows you to look at previews where your
-search terms have been found, as shown in the screenshots below.
+looqs is a tool that creates a full-text search index for your files. It allows you to look at previews where your search terms have been found, as shown in the screenshots below.
 
 ## Screenshots
 ### Preview
-looqs allow you to look inside files. It marks what you have searched for.
+looqs allows you to look inside files. It highlights what you have searched for.
 
 ![Screenshot looqs](https://garage.quitesimple.org/assets/looqs/orwell.png)
 ![Screenshot looqs search fstream](https://garage.quitesimple.org/assets/looqs/fstream_write.png)
@@ -29,9 +28,12 @@ There is no need to write the long form of filters. There are also booleans avai
 The screenshots in this section may occasionally be slightly outdated, but they are usually recent enough to get an overall impression of the current state of the GUI.
 
 ## Current status
-Latest version: 2022-07-30, v0.5.1
+Latest version: 2022-10-22, v0.8
 
-Please see [Changelog](CHANGELOG.md) for a human readable list of changes.
+Please keep in mind: looqs is still at an early stage and may exhibit some weirdness and contain bugs.
+
+Please see [Changelog](CHANGELOG.md) for a human readable list of changes. For download instructions, see
+further down this document.
 
 
 ## Goals and principles
@@ -95,7 +97,7 @@ The GUI is located in `gui/looqs-gui`, the binary for the CLI is in `cli/looqs`
 ## Packages
 At this point, looqs is not in any official distro package repo, but I maintain some packages.
 
-### Ubuntu 22.04
+### Ubuntu 22.04, 22.10
 Latest release can be installed using apt from the repo.
 ```
 # First, obtain key, assume it's trusted.

USAGE.md

@@ -9,6 +9,8 @@ looqs is still at an early stage and may exhibit some weirdness and contain bugs
 ## Current Limitations and things to know
 You should be aware of the following:
 
+- Lags are to be expected for networked mount points such as SMB and NFS etc.
+
 - It may seem natural, but the GUI and CLI operate on the same database, so if you add files using the CLI, the GUI will know about them too.
 
 - If a file is listed in the "Search results" tab, it does not imply that a preview will be available in the "Previews" tab, as looqs can search more file formats than it can generate previews for currently.
@@ -26,6 +28,7 @@ Database default path: `$HOME/.local/share/quitesimple.org/looqs/looqs.sqlite`.
 ### First run
 You will be presented with an empty list. Go to the **"Index"** tab, add some directories and click **"Start indexing"**.
 
+### Indexing
 For large directories the progress bar is essentially just decoration. As long as you see the counters
 increase, everything is fine even if it seems the progress bar is stuck.
 
@@ -33,19 +36,34 @@ The indexing can be stopped. If you run it again you do not start from scratch,
 which files have been modified since they have been added to the index. Thus, files will
 only be reprocessed when necessary. Note that cancellation itself may take a moment as files finish processing.
 
+The counters increase in batches, therefore it's normal that it seems no progress is being made, particularly when processing lots of large documents. This aspect will be improved in a future version.
+
 ### Search
 The text field at the top is where you type your query. It can be selected quickly using **CTRL + L**. Filters are available, see this document at the end. By default, both the full path and the content are searched. Path names take precedence, i. e. they will appear the top of the list.
 
+**CTRL + F**: This is helpful shortcut if you want to perform several searches. Consider the following
+query: "p:(docs) c:(invoice credit card)". Press CTRL+F to highlight 'invoice credit card'. This way
+you can quickly perform content searches in paths containing 'docs'.
+
+**CTRL + W**: Removes the last filter. If we take above's example "p:(docs) c:(invoice credit card)" again, then CTRL + W kills "c:(invoice credit card)".
+
+The arrow keys (up and down) can be used to go back and forward in the search history.
+
 ### Configuring PDF viewer
 It's most convenient if, when you click on a preview, the PDF reader opens the page you clicked. For that, looqs needs to know which viewer you want to launch.
 
 It tries to auto detect some common viewers. You must set the value in the "Settings" tab yourself if the
 default does not work for you. In the command line options, "%f" represents the filepath, "%p" the page number.
 
-### Preview tab
-The preview tab shows previews. It marks your search keywords too. Click on a preview to open the file.
+### Previews tab
+The 'previews' tab shows previews. It marks your search keywords too. Click on a preview to open the file.
 A right click on a preview allows you to copy the file path, or to open the containing folder.
 
+When the combobox is set to "All previews", the previews are ordered by relevance from all documents/pages.
+
+By default, a vertical scrolling is active. In the settings, it can be changed to horizontal scroll, which may be
+preferred by users of (larger) wide screen monitors.
+
 ### Syncing index
 Over time, files get deleted or their content changes. Go to **looqs** -> **Sync index**. looqs will reindex the content of files which have been changed. Files that cannot be found anymore will be removed from the index.
 

cli/commandsearch.cpp

@@ -33,11 +33,18 @@ int CommandSearch::handle(QStringList arguments)
 
 	try
 	{
+
+		QHash<QString, bool> seenMap;
 		auto results = dbService->search(query);
 
-		for(SearchResult &result : results)
+		for(const SearchResult &result : results)
 		{
-			Logger::info() << result.fileData.absPath << Qt::endl;
+			const QString &absPath = result.fileData.absPath;
+			if(!seenMap.contains(absPath))
+			{
+				seenMap[absPath] = true;
+				Logger::info() << absPath << Qt::endl;
+			}
 		}
 	}
 	catch(LooqsGeneralException &e)

gui/ipcpreviewworker.cpp

@@ -1,16 +1,50 @@
 #include <QtConcurrent>
 #include "ipcpreviewworker.h"
 #include "previewgeneratormapfunctor.h"
-IPCPreviewWorker::IPCPreviewWorker()
+IPCPreviewWorker::IPCPreviewWorker(QLocalSocket *peer)
 {
+	this->peer = peer;
 	this->connect(&previewWorkerWatcher, &QFutureWatcher<QByteArray>::resultReadyAt, this,
-				  [this](int index) { emit previewGenerated(previewWorkerWatcher.resultAt(index)); });
-	connect(&previewWorkerWatcher, &QFutureWatcher<QByteArray>::finished, this, [this] { emit finished(); });
+				  [this](int index)
+				  {
+					  if(this->peer != nullptr)
+					  {
+						  QDataStream stream{this->peer};
+						  stream << previewWorkerWatcher.resultAt(index);
+						  this->peer->flush();
+					  }
+				  });
+	connect(&previewWorkerWatcher, &QFutureWatcher<QByteArray>::finished, this, &IPCPreviewWorker::shutdownSocket);
+	connect(this->peer, &QLocalSocket::disconnected, this, &IPCPreviewWorker::shutdownSocket);
 }
 
-void IPCPreviewWorker::start(RenderConfig config, const QVector<RenderTarget> &targets, QLocalSocket *peer)
+void IPCPreviewWorker::shutdownSocket()
+{
+	if(cleaned)
+	{
+		return;
+	}
+	cleaned = true;
+	if(this->peer != nullptr)
+	{
+		if(this->peer->state() == QLocalSocket::ConnectedState)
+		{
+			this->peer->flush();
+			this->peer->waitForBytesWritten();
+			this->peer->disconnectFromServer();
+			if(this->peer->state() != QLocalSocket::UnconnectedState)
+			{
+				this->peer->waitForDisconnected();
+			}
+		}
+		delete this->peer;
+		this->peer = nullptr;
+	}
+	emit finished();
+}
+
+void IPCPreviewWorker::start(RenderConfig config, const QVector<RenderTarget> &targets)
 {
-	stop();
 	auto mapFunctor = PreviewGeneratorMapFunctor();
 	mapFunctor.setRenderConfig(config);
 

gui/ipcpreviewworker.h

@@ -11,13 +11,21 @@ class IPCPreviewWorker : public QObject
 	Q_OBJECT
   private:
 	QFutureWatcher<QByteArray> previewWorkerWatcher;
+	QLocalSocket *peer;
+	bool cleaned = false;
 
   public:
-	IPCPreviewWorker();
-	void start(RenderConfig config, const QVector<RenderTarget> &targets, QLocalSocket *peer);
+	IPCPreviewWorker(QLocalSocket *peer);
+	void start(RenderConfig config, const QVector<RenderTarget> &targets);
 	void stop();
+	~IPCPreviewWorker()
+	{
+		delete this->peer;
+	}
+  private slots:
+	void shutdownSocket();
+
   signals:
-	void previewGenerated(QByteArray);
 	void finished();
 };
 

gui/ipcserver.cpp

@@ -18,8 +18,6 @@ IpcServer::IpcServer()
 	/* Only 1, we are doing work for the GUI, not a service for general availability */
 	this->spawningServer.setMaxPendingConnections(1);
 	connect(&this->spawningServer, &QLocalServer::newConnection, this, &IpcServer::spawnerNewConnection);
-	connect(&this->previewWorker, &IPCPreviewWorker::previewGenerated, this, &IpcServer::handlePreviewGenerated);
-	connect(&this->previewWorker, &IPCPreviewWorker::finished, this, [this] { this->currentSocket->flush(); });
 }
 
 bool IpcServer::startSpawner(QString socketPath)
@@ -31,8 +29,6 @@ bool IpcServer::startSpawner(QString socketPath)
 void IpcServer::spawnerNewConnection()
 {
 	QLocalSocket *socket = this->spawningServer.nextPendingConnection();
-	connect(socket, &QLocalSocket::disconnected, socket, &QLocalSocket::deleteLater);
-	this->currentSocket = socket;
 	if(socket != nullptr)
 	{
 		if(!socket->waitForReadyRead())
@@ -53,21 +49,22 @@ void IpcServer::spawnerNewConnection()
 				stream.startTransaction();
 				stream >> renderConfig >> targets;
 			} while(!stream.commitTransaction() && socket->state() == QLocalSocket::ConnectedState);
-
-			stream << targets.count();
-			socket->flush();
-			previewWorker.start(renderConfig, targets, socket);
+			if(socket->state() == QLocalSocket::ConnectedState)
+			{
+				stream << targets.count();
+				socket->flush();
+				IPCPreviewWorker *previewWorker = new IPCPreviewWorker(socket);
+				connect(previewWorker, &IPCPreviewWorker::finished, this, [previewWorker] { delete previewWorker; });
+				previewWorker->start(renderConfig, targets);
+			}
+			else
+			{
+				delete socket;
+			}
 		}
 		if(command == StopGeneratePreviews)
 		{
-			previewWorker.stop();
+			/* TODO: implement */
 		}
 	}
 }
-
-void IpcServer::handlePreviewGenerated(QByteArray ba)
-{
-	QDataStream stream{this->currentSocket};
-	stream << ba;
-	this->currentSocket->flush();
-}

gui/ipcserver.h

@@ -10,13 +10,10 @@ class IpcServer : public QObject
 {
 	Q_OBJECT
   private:
-	IPCPreviewWorker previewWorker;
 	QLocalServer spawningServer;
-	QLocalSocket *currentSocket = nullptr;
 	SaveFileResult addFile(QString file);
   private slots:
 	void spawnerNewConnection();
-	void handlePreviewGenerated(QByteArray ba);
 
   public:
 	IpcServer();

gui/mainwindow.cpp

@@ -15,6 +15,7 @@
 #include <QFileDialog>
 #include <QScreen>
 #include <QProgressDialog>
+#include <QDesktopWidget>
 #include "mainwindow.h"
 #include "ui_mainwindow.h"
 #include "clicklabel.h"
@@ -60,6 +61,10 @@ MainWindow::MainWindow(QWidget *parent, QString socketPath)
 	QString ignorePatterns = settings.value("ignorePatterns").toString();
 	ui->txtIgnorePatterns->setText(ignorePatterns);
 
+	QStringList searchHistoryList = settings.value(SETTINGS_KEY_SEARCHHISTORY).toStringList();
+	this->searchHistory = searchHistoryList.toVector();
+	this->currentSearchHistoryIndex = this->searchHistory.size();
+
 	ui->spinPreviewPage->setValue(1);
 	ui->spinPreviewPage->setMinimum(1);
 
@@ -70,6 +75,9 @@ MainWindow::MainWindow(QWidget *parent, QString socketPath)
 	policy.setRetainSizeWhenHidden(true);
 	ui->btnOpenFailed->setSizePolicy(policy);
 
+	ui->txtSearch->installEventFilter(this);
+	ui->scrollArea->viewport()->installEventFilter(this);
+
 	this->ipcClientThread.start();
 }
 
@@ -191,7 +199,14 @@ void MainWindow::connectSignals()
 	connect(ui->btnSaveSettings, &QPushButton::clicked, this, &MainWindow::saveSettings);
 	connect(ui->btnOpenFailed, &QPushButton::clicked, this, &MainWindow::exportFailedPaths);
 	connect(
-		ui->comboPreviewFiles, qOverload<int>(&QComboBox::currentIndexChanged), this, [&]() { makePreviews(1); },
+		ui->comboPreviewFiles, qOverload<int>(&QComboBox::currentIndexChanged), this,
+		[&]()
+		{
+			if(this->previewTabActive())
+			{
+				makePreviews(1);
+			}
+		},
 		Qt::QueuedConnection);
 	connect(&ipcPreviewClient, &IPCPreviewClient::previewReceived, this, &MainWindow::previewReceived,
 			Qt::QueuedConnection);
@@ -201,6 +216,7 @@ void MainWindow::connectSignals()
 				this->ui->previewProcessBar->setValue(this->ui->previewProcessBar->maximum());
 				this->ui->spinPreviewPage->setEnabled(true);
 				this->ui->comboPreviewFiles->setEnabled(true);
+				ui->txtSearch->setEnabled(true);
 			});
 	connect(&ipcPreviewClient, &IPCPreviewClient::error, this,
 			[this](QString msg)
@@ -341,6 +357,182 @@ bool MainWindow::indexerTabActive()
 	return ui->tabWidget->currentIndex() == 2;
 }
 
+void MainWindow::processShortcut(int key)
+{
+	if(key == Qt::Key_Tab || key == Qt::Key_Backtab)
+	{
+		int tabIndex = ui->tabWidget->currentIndex();
+		if(key == Qt::Key_Tab)
+		{
+			++tabIndex;
+		}
+		if(key == Qt::Key_Backtab)
+		{
+			--tabIndex;
+		}
+		tabIndex = tabIndex % ui->tabWidget->count();
+		if(tabIndex < 0)
+		{
+			tabIndex = ui->tabWidget->count() - 1;
+		}
+		ui->tabWidget->setCurrentIndex(tabIndex);
+	}
+	if(key == Qt::Key_L)
+	{
+		ui->txtSearch->setFocus();
+		ui->txtSearch->selectAll();
+	}
+	if(key == Qt::Key_W)
+	{
+		ui->txtSearch->setFocus();
+		QString currentText = ui->txtSearch->text().trimmed();
+		int index = currentText.lastIndexOf(QRegularExpression("[\\s\\)]"));
+		if(index != -1)
+		{
+			bool isFilter = (index == currentText.length() - 1);
+			currentText.remove(index + 1, currentText.length() - index - 1);
+			if(isFilter)
+			{
+				index = currentText.lastIndexOf(' ', index);
+				if(index == -1)
+				{
+					index = 0;
+				}
+				currentText.remove(index, currentText.length());
+			}
+			if(currentText.length() > 0)
+			{
+				currentText += ' ';
+			}
+			ui->txtSearch->setText(currentText);
+		}
+		else
+		{
+			ui->txtSearch->clear();
+		}
+	}
+	if(key == Qt::Key_F)
+	{
+		ui->txtSearch->setFocus();
+		QString currentText = ui->txtSearch->text().trimmed();
+		int index = currentText.lastIndexOf(')');
+		if(index != -1)
+		{
+			bool isFilter = (index == currentText.length() - 1);
+			if(!isFilter)
+			{
+				ui->txtSearch->setSelection(index + 2, ui->txtSearch->text().length() - index - 1);
+			}
+			else
+			{
+				int begin = currentText.lastIndexOf('(', index - 1);
+				if(begin != -1)
+				{
+					ui->txtSearch->setSelection(begin + 1, index - begin - 1);
+				}
+			}
+		}
+		else
+		{
+			int spaceIndex = currentText.lastIndexOf(' ');
+			int colonIndex = currentText.lastIndexOf(':');
+			if(colonIndex > spaceIndex)
+			{
+				int target = currentText.indexOf(' ', colonIndex);
+				if(target == -1)
+				{
+					target = ui->txtSearch->text().size() - colonIndex;
+				}
+				ui->txtSearch->setSelection(colonIndex + 1, target - 1);
+			}
+			else
+			{
+				ui->txtSearch->setSelection(spaceIndex + 1, ui->txtSearch->text().size() - spaceIndex - 1);
+			}
+		}
+	}
+}
+
+bool MainWindow::eventFilter(QObject *object, QEvent *event)
+{
+	if(object == ui->txtSearch && !searchHistory.empty())
+	{
+		if(event->type() == QEvent::KeyPress)
+		{
+			QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
+			if(keyEvent->key() == Qt::Key_Up)
+			{
+				if(this->currentSavedSearchText.isEmpty())
+				{
+					this->currentSavedSearchText = ui->txtSearch->text();
+				}
+				if(this->currentSearchHistoryIndex <= 0)
+				{
+					return true;
+				}
+				--this->currentSearchHistoryIndex;
+				QString text = this->searchHistory.at(this->currentSearchHistoryIndex);
+				ui->txtSearch->setText(text);
+				return true;
+			}
+			else if(keyEvent->key() == Qt::Key_Down)
+			{
+				if(this->currentSearchHistoryIndex == searchHistory.size() - 1)
+				{
+					if(!this->currentSavedSearchText.isEmpty())
+					{
+						ui->txtSearch->setText(this->currentSavedSearchText);
+						this->currentSavedSearchText.clear();
+						++this->currentSearchHistoryIndex;
+					}
+					return true;
+				}
+				if(this->currentSearchHistoryIndex < searchHistory.size() - 1)
+				{
+					++this->currentSearchHistoryIndex;
+					QString text = this->searchHistory.at(this->currentSearchHistoryIndex);
+					ui->txtSearch->setText(text);
+				}
+				return true;
+			}
+			else
+			{
+				this->currentSavedSearchText.clear();
+				/* Off by one on purpose so Key_Up decrements it again and lands at
+				 * the last entry */
+				this->currentSearchHistoryIndex = this->searchHistory.size();
+			}
+		}
+	}
+	if(object == ui->scrollArea->viewport())
+	{
+		if(event->type() == QEvent::Wheel)
+		{
+			QWheelEvent *wheelEvent = static_cast<QWheelEvent *>(event);
+			if(wheelEvent->modifiers() & Qt::ControlModifier)
+			{
+				if(wheelEvent->angleDelta().y() > 0)
+				{
+					if(ui->comboScale->currentIndex() < ui->comboScale->count() - 1)
+					{
+						ui->comboScale->setCurrentIndex(ui->comboScale->currentIndex() + 1);
+					}
+				}
+
+				else
+				{
+					if(ui->comboScale->currentIndex() > 0)
+					{
+						ui->comboScale->setCurrentIndex(ui->comboScale->currentIndex() - 1);
+					}
+				}
+				return true;
+			}
+		}
+	}
+	return QMainWindow::eventFilter(object, event);
+}
+
 void MainWindow::keyPressEvent(QKeyEvent *event)
 {
 	bool quit =
@@ -348,17 +540,15 @@ void MainWindow::keyPressEvent(QKeyEvent *event)
 	if(quit)
 	{
 		qApp->quit();
+		return;
 	}
 
 	if(event->modifiers() & Qt::ControlModifier)
 	{
-
-		if(event->key() == Qt::Key_L)
-		{
-			ui->txtSearch->setFocus();
-			ui->txtSearch->selectAll();
-		}
+		processShortcut(event->key());
+		return;
 	}
+
 	QWidget::keyPressEvent(event);
 }
 
@@ -404,10 +594,24 @@ void MainWindow::initSettingsTabs()
 	ui->txtSettingMountPaths->setText(mountPaths);
 	ui->spinSettingNumerPerPages->setValue(numPagesPerPreview);
 	ui->txtSettingDatabasePath->setText(databasePath);
+	bool horizontalScroll = settings.value(SETTINGS_KEY_PREVIEWS_SCROLL_HORIZONTALLY).toBool();
+	ui->radioScrollHorizontally->setChecked(horizontalScroll);
+	ui->radioScrollVertically->setChecked(!horizontalScroll);
 }
 
 void MainWindow::saveSettings()
 {
+	if(ui->chkRemoveOldDb->isChecked())
+	{
+		bool result = QFile::remove(Common::databasePath());
+		if(!result)
+		{
+			QMessageBox::critical(this, "Error removing database",
+								  "Failed to remove old database. Settings not saved.");
+			return;
+		}
+	}
+
 	QSettings settings;
 
 	QString pdfViewerCmd = ui->txtSettingPdfPreviewerCmd->text();
@@ -420,6 +624,7 @@ void MainWindow::saveSettings()
 	settings.setValue(SETTINGS_KEY_MOUNTPATHS, mountPaths);
 	settings.setValue(SETTINGS_KEY_PREVIEWSPERPAGE, ui->spinSettingNumerPerPages->value());
 	settings.setValue(SETTINGS_KEY_DBPATH, databasePath);
+	settings.setValue(SETTINGS_KEY_PREVIEWS_SCROLL_HORIZONTALLY, ui->radioScrollHorizontally->isChecked());
 
 	settings.sync();
 
@@ -438,11 +643,11 @@ void MainWindow::previewReceived(QSharedPointer<PreviewResult> preview, unsigned
 	{
 		QString docPath = preview->getDocumentPath();
 		auto previewPage = preview->getPage();
-
 		ClickLabel *headerLabel = new ClickLabel();
 		headerLabel->setText(QString("Path: ") + preview->getDocumentPath());
 
 		ClickLabel *label = dynamic_cast<ClickLabel *>(preview->createPreviewWidget());
+		label->setMaximumWidth(QApplication::desktop()->availableGeometry().width() - 200);
 
 		QVBoxLayout *previewLayout = new QVBoxLayout();
 
@@ -474,11 +679,29 @@ void MainWindow::previewReceived(QSharedPointer<PreviewResult> preview, unsigned
 		previewLayout->setMargin(0);
 		previewLayout->insertStretch(0, 1);
 		previewLayout->insertStretch(-1, 1);
+		previewLayout->setAlignment(Qt::AlignCenter);
 		QWidget *previewWidget = new QWidget();
 
 		previewWidget->setLayout(previewLayout);
 
-		ui->scrollAreaWidgetContents->layout()->addWidget(previewWidget);
+		QBoxLayout *layout = static_cast<QBoxLayout *>(ui->scrollAreaWidgetContents->layout());
+		int pos = previewOrder[docPath + QString::number(previewPage)];
+		if(pos <= layout->count())
+		{
+			layout->insertWidget(pos, previewWidget);
+			for(auto it = previewWidgetOrderCache.constKeyValueBegin();
+				it != previewWidgetOrderCache.constKeyValueEnd(); it++)
+			{
+				if(it->first <= layout->count())
+				{
+					layout->insertWidget(it->first, it->second);
+				}
+			}
+		}
+		else
+		{
+			previewWidgetOrderCache[pos] = previewWidget;
+		}
 	}
 }
 
@@ -495,6 +718,14 @@ void MainWindow::lineEditReturnPressed()
 		ui->tabWidget->setCurrentIndex(0);
 	}
 	// TODO: validate q;
+	while(this->searchHistory.size() > 30)
+	{
+		this->searchHistory.removeFirst();
+	}
+	this->searchHistory.append(q);
+	this->currentSearchHistoryIndex = this->searchHistory.size();
+	this->currentSavedSearchText.clear();
+
 	ui->treeResultsList->clear();
 	ui->lblSearchResults->setText("Searching...");
 	this->ui->txtSearch->setEnabled(false);
@@ -588,39 +819,48 @@ void MainWindow::lineEditReturnPressed()
 void MainWindow::handleSearchResults(const QVector<SearchResult> &results)
 {
 	this->previewableSearchResults.clear();
+	qDeleteAll(ui->scrollAreaWidgetContents->children());
+
 	ui->treeResultsList->clear();
 	ui->comboPreviewFiles->clear();
 	ui->comboPreviewFiles->addItem("All previews");
 	ui->comboPreviewFiles->setVisible(true);
+	ui->lblTotalPreviewPagesCount->setText("");
 
 	bool hasDeleted = false;
+	QHash<QString, bool> seenMap;
 	for(const SearchResult &result : results)
 	{
-		QFileInfo pathInfo(result.fileData.absPath);
+		const QString &absPath = result.fileData.absPath;
+		QFileInfo pathInfo(absPath);
 
-		QString fileName = pathInfo.fileName();
-		QTreeWidgetItem *item = new QTreeWidgetItem(ui->treeResultsList);
+		if(!seenMap.contains(absPath))
+		{
+			QString fileName = pathInfo.fileName();
+			QTreeWidgetItem *item = new QTreeWidgetItem(ui->treeResultsList);
 
-		QDateTime dt = QDateTime::fromSecsSinceEpoch(result.fileData.mtime);
-		item->setIcon(0, iconProvider.icon(pathInfo));
-		item->setText(0, fileName);
-		item->setText(1, result.fileData.absPath);
-		item->setText(2, dt.toString(Qt::ISODate));
-		item->setText(3, this->locale().formattedDataSize(result.fileData.size));
+			QDateTime dt = QDateTime::fromSecsSinceEpoch(result.fileData.mtime);
+			item->setIcon(0, iconProvider.icon(pathInfo));
+			item->setText(0, fileName);
+			item->setText(1, absPath);
+			item->setText(2, dt.toString(Qt::ISODate));
+			item->setText(3, this->locale().formattedDataSize(result.fileData.size));
+		}
 		bool exists = pathInfo.exists();
 		if(exists)
 		{
-			if(!result.wasContentSearch)
+			if(result.wasContentSearch)
 			{
-				continue;
-			}
-
-			if(!pathInfo.suffix().contains("htm")) // hack until we can preview them properly...
-			{
-				if(PreviewGenerator::get(pathInfo) != nullptr)
+				if(!pathInfo.suffix().contains("htm")) // hack until we can preview them properly...
 				{
-					this->previewableSearchResults.append(result);
-					ui->comboPreviewFiles->addItem(result.fileData.absPath);
+					if(PreviewGenerator::get(pathInfo) != nullptr)
+					{
+						this->previewableSearchResults.append(result);
+						if(!seenMap.contains(result.fileData.absPath))
+						{
+							ui->comboPreviewFiles->addItem(result.fileData.absPath);
+						}
+					}
 				}
 			}
 		}
@@ -628,7 +868,9 @@ void MainWindow::handleSearchResults(const QVector<SearchResult> &results)
 		{
 			hasDeleted = true;
 		}
+		seenMap[absPath] = true;
 	}
+
 	ui->treeResultsList->resizeColumnToContents(0);
 	ui->treeResultsList->resizeColumnToContents(1);
 	ui->treeResultsList->resizeColumnToContents(2);
@@ -642,6 +884,7 @@ void MainWindow::handleSearchResults(const QVector<SearchResult> &results)
 	}
 
 	QString statusText = "Results: " + QString::number(results.size()) + " files";
+	statusText += ", previewable: " + QString::number(this->previewableSearchResults.count());
 	if(hasDeleted)
 	{
 		statusText += " WARNING: Some files are inaccessible. No preview available for those. Index may be out of sync";
@@ -664,12 +907,22 @@ void MainWindow::makePreviews(int page)
 	}
 	qDeleteAll(ui->scrollAreaWidgetContents->children());
 
-	ui->scrollAreaWidgetContents->setLayout(new QHBoxLayout());
+	QSettings settings;
+	bool horizontalScroll = settings.value(SETTINGS_KEY_PREVIEWS_SCROLL_HORIZONTALLY, false).toBool();
+	if(horizontalScroll)
+	{
+		ui->scrollAreaWidgetContents->setLayout(new QHBoxLayout());
+	}
+	else
+	{
+		ui->scrollAreaWidgetContents->setLayout(new QVBoxLayout());
+		ui->scrollAreaWidgetContents->layout()->setAlignment(Qt::AlignCenter);
+	}
 	ui->previewProcessBar->setMaximum(this->previewableSearchResults.size());
 	processedPdfPreviews = 0;
 
 	QVector<QString> wordsToHighlight;
-	QRegularExpression extractor(R"#("([^"]*)"|((\p{L}|\p{N})+))#");
+	QRegularExpression extractor(R"#("([^"]*)"|([^\s]+))#");
 	for(const Token &token : this->contentSearchQuery.getTokens())
 	{
 		if(token.type == FILTER_CONTENT_CONTAINS)
@@ -701,6 +954,10 @@ void MainWindow::makePreviews(int page)
 	renderConfig.scaleY = QGuiApplication::primaryScreen()->physicalDotsPerInchY() * (currentScale / 100.);
 	renderConfig.wordsToHighlight = wordsToHighlight;
 
+	this->previewOrder.clear();
+	this->previewWidgetOrderCache.clear();
+
+	int previewPos = 0;
 	QVector<RenderTarget> targets;
 	for(SearchResult &sr : this->previewableSearchResults)
 	{
@@ -713,12 +970,9 @@ void MainWindow::makePreviews(int page)
 		}
 		RenderTarget renderTarget;
 		renderTarget.path = sr.fileData.absPath;
-
-		for(unsigned int pagenum : sr.pages)
-		{
-			renderTarget.page = (int)pagenum;
-			targets.append(renderTarget);
-		}
+		renderTarget.page = (int)sr.page;
+		targets.append(renderTarget);
+		this->previewOrder[renderTarget.path + QString::number(renderTarget.page)] = previewPos++;
 	}
 	int numpages = ceil(static_cast<double>(targets.size()) / previewsPerPage);
 	ui->spinPreviewPage->setMaximum(numpages);
@@ -732,6 +986,7 @@ void MainWindow::makePreviews(int page)
 	++this->currentPreviewGeneration;
 	this->ui->spinPreviewPage->setEnabled(false);
 	this->ui->comboPreviewFiles->setEnabled(false);
+	this->ui->txtSearch->setEnabled(false);
 	emit startIpcPreviews(renderConfig, targets);
 }
 
@@ -818,3 +1073,11 @@ MainWindow::~MainWindow()
 	delete this->indexer;
 	delete ui;
 }
+
+void MainWindow::closeEvent(QCloseEvent *event)
+{
+	QStringList list = this->searchHistory.toList();
+	QSettings settings;
+	settings.setValue(SETTINGS_KEY_SEARCHHISTORY, list);
+	settings.sync();
+}

gui/mainwindow.h

@@ -23,13 +23,6 @@ class MainWindow : public QMainWindow
 {
 	Q_OBJECT
 
-  public:
-	explicit MainWindow(QWidget *parent, QString socketPath);
-	~MainWindow();
-  signals:
-	void beginSearch(const QString &query);
-	void startPdfPreviewGeneration(QVector<SearchResult> paths, double scalefactor);
-
   private:
 	DatabaseFactory *dbFactory;
 	SqliteDbService *dbService;
@@ -37,32 +30,40 @@ class MainWindow : public QMainWindow
 	IPCPreviewClient ipcPreviewClient;
 	QThread ipcClientThread;
 	QThread syncerThread;
+	Indexer *indexer;
 	IndexSyncer *indexSyncer;
 	QProgressDialog progressDialog;
-
-	Indexer *indexer;
 	QFileIconProvider iconProvider;
-	bool previewDirty;
 	QSqlDatabase db;
 	QFutureWatcher<QVector<SearchResult>> searchWatcher;
-	void add(QString path, unsigned int page);
 	QVector<SearchResult> previewableSearchResults;
+	LooqsQuery contentSearchQuery;
+	QVector<QString> searchHistory;
+	int currentSearchHistoryIndex = 0;
+	QString currentSavedSearchText;
+	QHash<QString, int> previewOrder; /* Quick lookup for the order a preview should have */
+	QMap<int, QWidget *>
+		previewWidgetOrderCache /* Saves those that arrived out of order to be inserted later at the correct pos */;
+	bool previewDirty;
+	int previewsPerPage;
+	unsigned int processedPdfPreviews;
+	unsigned int currentPreviewGeneration = 1;
+
 	void connectSignals();
 	void makePreviews(int page);
 	bool previewTabActive();
 	bool indexerTabActive();
 	void keyPressEvent(QKeyEvent *event) override;
-	unsigned int processedPdfPreviews;
 	void handleSearchResults(const QVector<SearchResult> &results);
 	void handleSearchError(QString error);
-	LooqsQuery contentSearchQuery;
-	int previewsPerPage;
 	void createSearchResutlMenu(QMenu &menu, const QFileInfo &fileInfo);
 	void openDocument(QString path, int num);
 	void openFile(QString path);
-	unsigned int currentPreviewGeneration = 1;
 	void initSettingsTabs();
 	int currentSelectedScale();
+	void processShortcut(int key);
+	bool eventFilter(QObject *object, QEvent *event);
+
   private slots:
 	void lineEditReturnPressed();
 	void treeSearchItemActivated(QTreeWidgetItem *item, int i);
@@ -82,6 +83,16 @@ class MainWindow : public QMainWindow
 	void startIpcPreviews(RenderConfig config, const QVector<RenderTarget> &targets);
 	void stopIpcPreviews();
 	void beginIndexSync();
+
+  public:
+	explicit MainWindow(QWidget *parent, QString socketPath);
+	~MainWindow();
+  signals:
+	void beginSearch(const QString &query);
+	void startPdfPreviewGeneration(QVector<SearchResult> paths, double scalefactor);
+
+  protected:
+	void closeEvent(QCloseEvent *event) override;
 };
 
 #endif // MAINWINDOW_H

gui/mainwindow.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>1280</width>
-    <height>855</height>
+    <height>923</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -82,7 +82,7 @@
              <x>0</x>
              <y>0</y>
              <width>1244</width>
-             <height>565</height>
+             <height>633</height>
             </rect>
            </property>
            <layout class="QHBoxLayout" name="horizontalLayout"/>
@@ -165,7 +165,7 @@
           <item>
            <widget class="QComboBox" name="comboPreviewFiles">
             <property name="sizePolicy">
-             <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+             <sizepolicy hsizetype="Maximum" vsizetype="Fixed">
               <horstretch>0</horstretch>
               <verstretch>0</verstretch>
              </sizepolicy>
@@ -532,9 +532,29 @@
            <item>
             <widget class="QLineEdit" name="txtSettingDatabasePath"/>
            </item>
+           <item>
+            <widget class="QCheckBox" name="chkRemoveOldDb">
+             <property name="text">
+              <string>Remove old database on save</string>
+             </property>
+            </widget>
+           </item>
           </layout>
          </widget>
         </item>
+        <item>
+         <spacer name="verticalSpacer">
+          <property name="orientation">
+           <enum>Qt::Vertical</enum>
+          </property>
+          <property name="sizeHint" stdset="0">
+           <size>
+            <width>20</width>
+            <height>40</height>
+           </size>
+          </property>
+         </spacer>
+        </item>
         <item>
          <widget class="QGroupBox" name="Misc">
           <property name="title">
@@ -544,7 +564,7 @@
            <item>
             <layout class="QHBoxLayout" name="horizontalLayout_9">
              <item>
-              <widget class="QLabel" name="label_4">
+              <widget class="QLabel" name="lblMaxNumbersPreviewPages">
                <property name="text">
                 <string>Max number of previews per 'page' in 'Previews' tab: </string>
                </property>
@@ -568,22 +588,47 @@
              </item>
             </layout>
            </item>
+           <item>
+            <layout class="QHBoxLayout" name="horizontalLayout_8">
+             <item>
+              <widget class="QLabel" name="lblScrollModeForPreviews">
+               <property name="text">
+                <string>Scroll mode for previews:</string>
+               </property>
+              </widget>
+             </item>
+             <item>
+              <widget class="QRadioButton" name="radioScrollVertically">
+               <property name="text">
+                <string>Vertically</string>
+               </property>
+              </widget>
+             </item>
+             <item>
+              <widget class="QRadioButton" name="radioScrollHorizontally">
+               <property name="text">
+                <string>Horizontally</string>
+               </property>
+              </widget>
+             </item>
+             <item>
+              <spacer name="horizontalSpacer_6">
+               <property name="orientation">
+                <enum>Qt::Horizontal</enum>
+               </property>
+               <property name="sizeHint" stdset="0">
+                <size>
+                 <width>40</width>
+                 <height>20</height>
+                </size>
+               </property>
+              </spacer>
+             </item>
+            </layout>
+           </item>
           </layout>
          </widget>
         </item>
-        <item>
-         <spacer name="verticalSpacer">
-          <property name="orientation">
-           <enum>Qt::Vertical</enum>
-          </property>
-          <property name="sizeHint" stdset="0">
-           <size>
-            <width>20</width>
-            <height>40</height>
-           </size>
-          </property>
-         </spacer>
-        </item>
         <item>
          <widget class="QPushButton" name="btnSaveSettings">
           <property name="text">

gui/previewgenerator.cpp

@@ -1,20 +1,24 @@
 #include "../shared/common.h"
 #include "previewgenerator.h"
+#include <QMutexLocker>
 #include "previewgeneratorpdf.h"
 #include "previewgeneratorplaintext.h"
 #include "previewgeneratorodt.h"
 
 static PreviewGenerator *plainTextGenerator = new PreviewGeneratorPlainText();
 
-static QMap<QString, PreviewGenerator *> generators{
+static QHash<QString, PreviewGenerator *> generators{
 	{"pdf", new PreviewGeneratorPdf()}, {"txt", plainTextGenerator},  {"md", plainTextGenerator},
 	{"py", plainTextGenerator},			{"java", plainTextGenerator}, {"js", plainTextGenerator},
 	{"cpp", plainTextGenerator},		{"c", plainTextGenerator},	  {"sql", plainTextGenerator},
 	{"odt", new PreviewGeneratorOdt()}};
 
+static QMutex generatorsMutex;
 PreviewGenerator *PreviewGenerator::get(QFileInfo &info)
 {
+	QMutexLocker locker(&generatorsMutex);
 	PreviewGenerator *result = generators.value(info.suffix(), nullptr);
+	locker.unlock();
 	if(result == nullptr)
 	{
 		if(Common::isTextFile(info))

gui/previewgeneratorpdf.cpp

@@ -1,15 +1,18 @@
 #include <QMutexLocker>
 #include <QPainter>
+#include <QRegularExpression>
 #include "previewgeneratorpdf.h"
 
 static QMutex cacheMutex;
 
 Poppler::Document *PreviewGeneratorPdf::document(QString path)
 {
+	QMutexLocker locker(&cacheMutex);
 	if(documentcache.contains(path))
 	{
 		return documentcache.value(path);
 	}
+	locker.unlock();
 	Poppler::Document *result = Poppler::Document::load(path);
 	if(result == nullptr)
 	{
@@ -17,7 +20,8 @@ Poppler::Document *PreviewGeneratorPdf::document(QString path)
 		return nullptr;
 	}
 	result->setRenderHint(Poppler::Document::TextAntialiasing);
-	QMutexLocker locker(&cacheMutex);
+
+	locker.relock();
 	documentcache.insert(path, result);
 	locker.unlock();
 	return result;
@@ -45,7 +49,12 @@ QSharedPointer<PreviewResult> PreviewGeneratorPdf::generate(RenderConfig config,
 	QImage img = pdfPage->renderToImage(config.scaleX, config.scaleY);
 	for(QString &word : config.wordsToHighlight)
 	{
-		QList<QRectF> rects = pdfPage->search(word, Poppler::Page::SearchFlag::IgnoreCase);
+		QList<QRectF> rects =
+			pdfPage->search(word, Poppler::Page::SearchFlag::IgnoreCase | Poppler::Page::SearchFlag::WholeWords);
+		if(rects.empty())
+		{
+			rects = pdfPage->search(word, Poppler::Page::SearchFlag::IgnoreCase);
+		}
 		for(QRectF &rect : rects)
 		{
 			QPainter painter(&img);

gui/previewgeneratorplaintext.cpp

@@ -1,7 +1,9 @@
 #include <QTextStream>
+#include <QRegularExpression>
 
 #include "previewgeneratorplaintext.h"
 #include "previewresultplaintext.h"
+#include "../shared/limitqueue.h"
 
 QString PreviewGeneratorPlainText::generatePreviewText(QString content, RenderConfig config, QString fileName)
 {
@@ -14,14 +16,13 @@ QString PreviewGeneratorPlainText::generatePreviewText(QString content, RenderCo
 
 	QHash<QString, int> countmap;
 
-	const unsigned int maxSnippets = 7;
 	unsigned int currentSnippets = 0;
 	for(QString &word : config.wordsToHighlight)
 	{
 
 		int lastPos = 0;
 		int index = content.indexOf(word, lastPos, Qt::CaseInsensitive);
-		while(index != -1 && currentSnippets < maxSnippets)
+		while(index != -1 && currentSnippets < MAX_SNIPPETS)
 		{
 			countmap[word] = countmap.value(word, 0) + 1;
 
@@ -57,17 +58,15 @@ QString PreviewGeneratorPlainText::generatePreviewText(QString content, RenderCo
 		++i;
 	}
 
-	for(QString &word : config.wordsToHighlight)
-	{
-		resulText.replace(word, "<span style=\"background-color: yellow;\">" + word + "</span>", Qt::CaseInsensitive);
-	}
-
+	resulText = resulText.toHtmlEscaped();
 	QString header = "<b>" + fileName + "</b> ";
 	for(QString &word : config.wordsToHighlight)
 	{
+		resulText.replace(word, "<span style=\"background-color: yellow;\">" + word + "</span>", Qt::CaseInsensitive);
 		header += word + ": " + QString::number(countmap[word]) + " ";
 	}
-	if(currentSnippets == maxSnippets)
+
+	if(currentSnippets == MAX_SNIPPETS)
 	{
 		header += "(truncated)";
 	}
@@ -77,6 +76,189 @@ QString PreviewGeneratorPlainText::generatePreviewText(QString content, RenderCo
 	return header + resulText.replace("\n", "<br>").mid(0, 1000);
 }
 
+struct Snippet
+{
+	/* Contains each line number and line of the snippet*/
+	QString snippetText;
+
+	/* How many times a word occurs in the snippetText */
+	QHash<QString, int> wordCountMap;
+};
+
+QString PreviewGeneratorPlainText::generateLineBasedPreviewText(QTextStream &in, RenderConfig config, QString fileName)
+{
+	QVector<Snippet> snippets;
+	const int contextLinesCount = 2;
+	LimitQueue<QString> queue(contextLinesCount);
+	QString currentLine;
+	currentLine.reserve(512);
+
+	/* How many lines to read after a line with a match (like grep -A ) */
+	int justReadLinesCount = -1;
+
+	struct Snippet currentSnippet;
+
+	auto appendLine = [&currentSnippet, &config](int lineNumber, QString &line)
+	{
+		int foundWordsCount = 0;
+		for(QString &word : config.wordsToHighlight)
+		{
+			QRegularExpression searchRegex("\\b" + word + "\\b");
+			bool containsRegex = line.contains(searchRegex);
+			bool contains = false;
+			if(!containsRegex)
+			{
+				contains = line.contains(word, Qt::CaseInsensitive);
+			}
+			if(containsRegex || contains)
+			{
+				currentSnippet.wordCountMap[word] = currentSnippet.wordCountMap.value(word, 0) + 1;
+				QString replacementString = "<span style=\"background-color: yellow;\">" + word + "</span>";
+				if(containsRegex)
+				{
+					line.replace(searchRegex, replacementString);
+				}
+				else
+				{
+					line.replace(word, replacementString, Qt::CaseInsensitive);
+				}
+				++foundWordsCount;
+			}
+		}
+		currentSnippet.snippetText.append(QString("<b>%1</b>%2<br>").arg(lineNumber).arg(line));
+		return foundWordsCount;
+	};
+
+	unsigned int lineCount = 0;
+	while(in.readLineInto(&currentLine))
+	{
+		currentLine = currentLine.toHtmlEscaped();
+		++lineCount;
+		bool matched = false;
+		if(justReadLinesCount > 0)
+		{
+
+			int result = appendLine(lineCount, currentLine);
+			if(justReadLinesCount == 1 && result > 0)
+			{
+				justReadLinesCount = contextLinesCount;
+			}
+			else
+			{
+				--justReadLinesCount;
+			}
+
+			continue;
+		}
+		if(justReadLinesCount == 0)
+		{
+			currentSnippet.snippetText += "---<br>";
+			justReadLinesCount = -1;
+			snippets.append(currentSnippet);
+			currentSnippet = {};
+		}
+		for(QString &word : config.wordsToHighlight)
+		{
+			if(currentLine.contains(word, Qt::CaseInsensitive))
+			{
+				matched = true;
+				break;
+			}
+		}
+		if(matched)
+		{
+			while(queue.size() > 0)
+			{
+				int queuedLineCount = lineCount - queue.size();
+				QString queuedLine = queue.dequeue();
+				appendLine(queuedLineCount, queuedLine);
+			}
+			appendLine(lineCount, currentLine);
+			justReadLinesCount = contextLinesCount;
+		}
+		else
+		{
+			queue.enqueue(currentLine);
+		}
+	}
+
+	if(!currentSnippet.snippetText.isEmpty())
+	{
+		currentSnippet.snippetText += "---<br>";
+		snippets.append(currentSnippet);
+	}
+
+	std::sort(snippets.begin(), snippets.end(),
+			  [](Snippet &a, Snippet &b)
+			  {
+				  int differentWordsA = 0;
+				  int totalWordsA = 0;
+				  int differentWordsB = 0;
+				  int totalWordsB = 0;
+				  for(int count : a.wordCountMap.values())
+				  {
+					  if(count > 0)
+					  {
+						  ++differentWordsA;
+					  }
+					  totalWordsA += count;
+				  }
+				  for(int count : b.wordCountMap.values())
+				  {
+					  if(count > 0)
+					  {
+						  ++differentWordsB;
+					  }
+					  totalWordsB += count;
+				  }
+
+				  if(differentWordsA > differentWordsB)
+				  {
+					  return true;
+				  }
+				  if(differentWordsA == differentWordsB)
+				  {
+					  return totalWordsA > totalWordsB;
+				  }
+				  return false;
+			  });
+
+	QString resultText = "";
+
+	unsigned int snippetsCount = 0;
+
+	QString header = "<b>" + fileName + "</b> ";
+
+	QHash<QString, int> totalWordCountMap;
+	bool isTruncated = false;
+	for(Snippet &snippet : snippets)
+	{
+		if(snippetsCount++ < MAX_SNIPPETS)
+		{
+			resultText += snippet.snippetText;
+		}
+		else
+		{
+			isTruncated = true;
+		}
+		for(auto it = snippet.wordCountMap.keyValueBegin(); it != snippet.wordCountMap.keyValueEnd(); it++)
+		{
+			totalWordCountMap[it->first] = totalWordCountMap.value(it->first, 0) + it->second;
+		}
+	}
+	if(isTruncated)
+	{
+		header += "(truncated) ";
+	}
+	for(QString &word : config.wordsToHighlight)
+	{
+		header += word + ": " + QString::number(totalWordCountMap[word]) + " ";
+	}
+	header += "<hr>";
+
+	return header + resultText;
+}
+
 QSharedPointer<PreviewResult> PreviewGeneratorPlainText::generate(RenderConfig config, QString documentPath,
 																  unsigned int page)
 {
@@ -87,9 +269,7 @@ QSharedPointer<PreviewResult> PreviewGeneratorPlainText::generate(RenderConfig c
 		return QSharedPointer<PreviewResultPlainText>(result);
 	}
 	QTextStream in(&file);
-
-	QString content = in.readAll();
 	QFileInfo info{documentPath};
-	result->setText(generatePreviewText(content, config, info.fileName()));
+	result->setText(generateLineBasedPreviewText(in, config, info.fileName()));
 	return QSharedPointer<PreviewResultPlainText>(result);
 }

gui/previewgeneratorplaintext.h

@@ -1,12 +1,17 @@
 #ifndef PREVIEWGENERATORPLAINTEXT_H
 #define PREVIEWGENERATORPLAINTEXT_H
+#include <QTextStream>
 #include "previewgenerator.h"
 
 class PreviewGeneratorPlainText : public PreviewGenerator
 {
+  protected:
+	const unsigned int MAX_SNIPPETS = 7;
+
   public:
 	using PreviewGenerator::PreviewGenerator;
 	QString generatePreviewText(QString content, RenderConfig config, QString fileName);
+	QString generateLineBasedPreviewText(QTextStream &in, RenderConfig config, QString fileName);
 	QSharedPointer<PreviewResult> generate(RenderConfig config, QString documentPath, unsigned int page);
 };
 

shared/common.h

@@ -9,6 +9,8 @@
 #define SETTINGS_KEY_EXCLUDEDPATHS "excludedpaths"
 #define SETTINGS_KEY_MOUNTPATHS "mountpaths"
 #define SETTINGS_KEY_PREVIEWSPERPAGE "previewsPerPage"
+#define SETTINGS_KEY_SEARCHHISTORY "searchhistory"
+#define SETTINGS_KEY_PREVIEWS_SCROLL_HORIZONTALLY "horizontalscroll"
 
 namespace Common
 {

shared/indexer.cpp

@@ -152,12 +152,14 @@ void Indexer::processFileScanResult(FileScanResult result)
 		++this->currentIndexResult.erroredPaths;
 	}
 
-	if(currentScanProcessedCount++ == progressReportThreshold)
+	QTime currentTime = QTime::currentTime();
+	if(currentScanProcessedCount++ == progressReportThreshold || this->lastProgressReportTime.secsTo(currentTime) >= 10)
 	{
 		emit indexProgress(this->currentIndexResult.total(), this->currentIndexResult.addedPaths,
 						   this->currentIndexResult.skippedPaths, this->currentIndexResult.erroredPaths,
 						   this->dirScanner->pathCount());
 		currentScanProcessedCount = 0;
+		this->lastProgressReportTime = currentTime;
 	}
 }
 

shared/indexer.h

@@ -72,6 +72,8 @@ class Indexer : public QObject
 	IndexResult currentIndexResult;
 	void launchWorker(ConcurrentQueue<QString> &queue, int batchsize);
 
+	QTime lastProgressReportTime = QTime::currentTime();
+
   public:
 	bool isRunning();
 

shared/limitqueue.h

@@ -0,0 +1,48 @@
+#ifndef LIMITQUEUE_H
+#define LIMITQUEUE_H
+#include <QQueue>
+
+template <class T> class LimitQueue
+{
+  protected:
+	QQueue<T> queue;
+	int limit = 0;
+
+  public:
+	LimitQueue();
+	LimitQueue(int limit)
+	{
+		this->limit = limit;
+	}
+
+	void enqueue(const T &t)
+	{
+		if(queue.size() == limit)
+		{
+			queue.dequeue();
+		}
+		queue.enqueue(t);
+	}
+
+	int size()
+	{
+		return queue.size();
+	}
+
+	T dequeue()
+	{
+		return queue.dequeue();
+	}
+
+	void setLimit(int limit)
+	{
+		this->limit = limit;
+	}
+
+	void clear()
+	{
+		queue.clear();
+	}
+};
+
+#endif // LIMITQUEUE_H

shared/looqsquery.cpp

@@ -180,9 +180,8 @@ LooqsQuery LooqsQuery::build(QString expression, TokenType loneWordsTokenType, b
 
 	QStringList loneWords;
 	LooqsQuery result;
-	QRegularExpression rx(
-		"((?<filtername>(\\.|\\w)+):(?<args>\\((?<innerargs>[^\\)]+)\\)|([\\p{L}\\p{N},])+)|(?<boolean>AND|OR)"
-		"|(?<negation>!)|(?<bracket>\\(|\\))|(?<loneword>[\"\\p{L}\\p{N}]+))");
+	QRegularExpression rx("((?<filtername>(\\.|\\w)+):(?<args>\\((?<innerargs>[^\\)]+)\\)|([^\\s])+)|(?<boolean>AND|OR)"
+						  "|(?<negation>!)|(?<bracket>\\(|\\))|(?<loneword>[^\\s]+))");
 	QRegularExpressionMatchIterator i = rx.globalMatch(expression);
 	auto previousWasBool = [&result] { return !result.tokens.empty() && ((result.tokens.last().type & BOOL) == BOOL); };
 	auto previousWas = [&result](TokenType t) { return !result.tokens.empty() && (result.tokens.last().type == t); };

shared/migrations/3.sql

@@ -0,0 +1 @@
+DROP trigger content_ad;

shared/migrations/4.sql

@@ -0,0 +1,3 @@
+CREATE VIRTUAL TABLE fts_trigram USING fts5(content, content='',tokenize="trigram");
+ALTER TABLE content ADD COLUMN fts_trigramid integer;
+CREATE INDEX content_fts_trigramid ON content (fts_trigramid);

shared/migrations/migrations.qrc

@@ -2,5 +2,7 @@
     <qresource prefix="/looqs-migrations">
         <file>1.sql</file>
         <file>2.sql</file>
+        <file>3.sql</file>
+        <file>4.sql</file>
     </qresource>
 </RCC>

shared/searchresult.h

@@ -6,7 +6,7 @@ class SearchResult
 {
   public:
 	FileData fileData;
-	QVector<unsigned int> pages;
+	unsigned int page;
 	bool wasContentSearch = false;
 };
 

shared/shared.pro

@@ -77,6 +77,7 @@ HEADERS += sqlitesearch.h \
     filescanworker.h \
     indexer.h \
     indexsyncer.h \
+    limitqueue.h \
     logger.h \
     looqsgeneralexception.h \
     looqsquery.h \

shared/sqlitedbservice.cpp

@@ -110,6 +110,44 @@ unsigned int SqliteDbService::getFiles(QVector<FileData> &results, QString wildC
 	return processedRows;
 }
 
+bool SqliteDbService::insertToFTS(bool useTrigrams, QSqlDatabase &db, int fileid, QVector<PageData> &pageData)
+{
+	QString ftsInsertStatement;
+	QString contentInsertStatement;
+	if(useTrigrams)
+	{
+		ftsInsertStatement = "INSERT INTO fts_trigram(content) VALUES(?)";
+		contentInsertStatement = "INSERT INTO content(fileid, page, fts_trigramid) VALUES(?, ?, last_insert_rowid())";
+	}
+	else
+	{
+		ftsInsertStatement = "INSERT INTO fts(content) VALUES(?)";
+		contentInsertStatement = "INSERT INTO content(fileid, page, ftsid) VALUES(?, ?, last_insert_rowid())";
+	}
+
+	for(const PageData &data : pageData)
+	{
+		QSqlQuery ftsQuery(db);
+		ftsQuery.prepare(ftsInsertStatement);
+		ftsQuery.addBindValue(data.content);
+		if(!ftsQuery.exec())
+		{
+			Logger::error() << "Failed fts insertion " << ftsQuery.lastError() << Qt::endl;
+			return false;
+		}
+		QSqlQuery contentQuery(db);
+		contentQuery.prepare(contentInsertStatement);
+		contentQuery.addBindValue(fileid);
+		contentQuery.addBindValue(data.pagenumber);
+		if(!contentQuery.exec())
+		{
+			Logger::error() << "Failed content insertion " << contentQuery.lastError() << Qt::endl;
+			return false;
+		}
+	}
+	return true;
+}
+
 SaveFileResult SqliteDbService::saveFile(QFileInfo fileInfo, QVector<PageData> &pageData)
 {
 	QString absPath = fileInfo.absoluteFilePath();
@@ -149,24 +187,18 @@ SaveFileResult SqliteDbService::saveFile(QFileInfo fileInfo, QVector<PageData> &
 	}
 
 	int lastid = inserterQuery.lastInsertId().toInt();
-	for(const PageData &data : pageData)
+	if(!insertToFTS(false, db, lastid, pageData))
 	{
-		QSqlQuery ftsQuery(db);
-		ftsQuery.prepare("INSERT INTO fts(content) VALUES(?)");
-		ftsQuery.addBindValue(data.content);
-		ftsQuery.exec();
-		QSqlQuery contentQuery(db);
-		contentQuery.prepare("INSERT INTO content(fileid, page, ftsid) VALUES(?, ?, last_insert_rowid())");
-		contentQuery.addBindValue(lastid);
-		contentQuery.addBindValue(data.pagenumber);
-		if(!contentQuery.exec())
-		{
-			db.rollback();
-			Logger::error() << "Failed content insertion " << contentQuery.lastError() << Qt::endl;
-			return DBFAIL;
-		}
+		db.rollback();
+		Logger::error() << "Failed to insert data to FTS index " << Qt::endl;
+		return DBFAIL;
+	}
+	if(!insertToFTS(true, db, lastid, pageData))
+	{
+		db.rollback();
+		Logger::error() << "Failed to insert data to FTS index " << Qt::endl;
+		return DBFAIL;
 	}
-
 	if(!db.commit())
 	{
 		db.rollback();

shared/sqlitedbservice.h

@@ -13,6 +13,7 @@ class SqliteDbService
 {
   private:
 	DatabaseFactory *dbFactory = nullptr;
+	bool insertToFTS(bool useTrigrams, QSqlDatabase &db, int fileid, QVector<PageData> &pageData);
 
   public:
 	SqliteDbService(DatabaseFactory &dbFactory);

shared/sqlitesearch.cpp

@@ -78,12 +78,16 @@ QString SqliteSearch::escapeFtsArgument(QString ftsArg)
 		if(value.isEmpty())
 		{
 			value = m.captured(2);
+			if(value.endsWith('*'))
+			{
+				value = value.mid(0, value.size() - 1);
+			}
+			result += "\"" + value + "\"* ";
 		}
 		else
 		{
-			value = "\"\"" + value + "\"\"";
+			result += "\"" + value + "\" ";
 		}
-		result += "\"" + value + "\" ";
 	}
 	return result;
 }
@@ -137,9 +141,7 @@ QPair<QString, QVector<QString>> SqliteSearch::createSql(const Token &token)
 	}
 	if(token.type == FILTER_CONTENT_CONTAINS)
 	{
-		return {" content.id IN (SELECT fts.ROWID FROM fts WHERE fts.content MATCH ? ORDER BY "
-				"rank) ",
-				{escapeFtsArgument(value)}};
+		return {" fts MATCH ? ", {escapeFtsArgument(value)}};
 	}
 	throw LooqsGeneralException("Unknown token passed (should not happen)");
 }
@@ -159,26 +161,14 @@ QSqlQuery SqliteSearch::makeSqlQuery(const LooqsQuery &query)
 	auto tokens = query.getTokens();
 	for(const Token &token : tokens)
 	{
-		if(token.type == FILTER_CONTENT_CONTAINS)
-		{
-			if(!ftsAlreadyJoined)
-			{
-				joinSql += " INNER JOIN fts ON content.ftsid = fts.ROWID ";
-				ftsAlreadyJoined = true;
-			}
-			whereSql += " fts.content MATCH ? ";
-			bindValues.append(escapeFtsArgument(token.value));
-		}
-		else
-		{
-			auto sql = createSql(token);
-			whereSql += sql.first;
-			bindValues.append(sql.second);
-		}
+		auto sql = createSql(token);
+		whereSql += sql.first;
+		bindValues.append(sql.second);
 	}
 
 	QString prepSql;
 	QString sortSql = createSortSql(query.getSortConditions());
+	int bindIterations = 1;
 	if(isContentSearch)
 	{
 		if(sortSql.isEmpty())
@@ -186,13 +176,24 @@ QSqlQuery SqliteSearch::makeSqlQuery(const LooqsQuery &query)
 			if(std::find_if(tokens.begin(), tokens.end(),
 							[](const Token &t) -> bool { return t.type == FILTER_CONTENT_CONTAINS; }) != tokens.end())
 			{
-				sortSql = "ORDER BY rank";
+				sortSql = "ORDER BY prio, rank";
 			}
 		}
+		QString whereSqlTrigram = whereSql;
+		whereSqlTrigram.replace("fts MATCH", "fts_trigram MATCH"); // A bit dirty...
 		prepSql =
-			"SELECT file.path AS path, group_concat(content.page) AS pages, file.mtime AS mtime, file.size AS size, "
-			"file.filetype AS filetype FROM file INNER JOIN content ON file.id = content.fileid " +
-			joinSql + " WHERE 1=1 AND " + whereSql + " GROUP BY file.path  " + sortSql;
+			"SELECT DISTINCT path, page, mtime, size, filetype FROM ("
+			"SELECT file.path AS path,  content.page AS page, file.mtime AS mtime, file.size AS size, "
+			"file.filetype AS filetype, 0 AS prio, fts.rank AS rank FROM file INNER JOIN content ON file.id = "
+			"content.fileid "
+			"INNER JOIN fts ON content.ftsid = fts.ROWID WHERE 1=1 AND " +
+			whereSql +
+			"UNION ALL SELECT file.path AS path,  content.page AS page, file.mtime AS mtime, file.size AS size, "
+			"file.filetype AS filetype, 1 as prio, fts_trigram.rank AS rank FROM file INNER JOIN content ON file.id = "
+			"content.fileid " +
+			"INNER JOIN fts_trigram ON content.fts_trigramid = fts_trigram.ROWID WHERE 1=1 AND " + whereSqlTrigram +
+			" ) " + sortSql;
+		++bindIterations;
 	}
 	else
 	{
@@ -200,7 +201,7 @@ QSqlQuery SqliteSearch::makeSqlQuery(const LooqsQuery &query)
 		{
 			sortSql = "ORDER BY file.mtime DESC";
 		}
-		prepSql = "SELECT file.path AS path, '0' as pages,  file.mtime AS mtime, file.size AS size, file.filetype AS "
+		prepSql = "SELECT file.path AS path, '0' as page,  file.mtime AS mtime, file.size AS size, file.filetype AS "
 				  "filetype FROM file WHERE  1=1 AND " +
 				  whereSql + " " + sortSql;
 	}
@@ -212,11 +213,14 @@ QSqlQuery SqliteSearch::makeSqlQuery(const LooqsQuery &query)
 
 	QSqlQuery dbquery(*db);
 	dbquery.prepare(prepSql);
-	for(const QString &value : bindValues)
+	for(int i = 0; i < bindIterations; i++)
 	{
-		if(value != "")
+		for(const QString &value : bindValues)
 		{
-			dbquery.addBindValue(value);
+			if(value != "")
+			{
+				dbquery.addBindValue(value);
+			}
 		}
 	}
 	return dbquery;
@@ -243,15 +247,7 @@ QVector<SearchResult> SqliteSearch::search(const LooqsQuery &query)
 		result.fileData.mtime = dbQuery.value("mtime").toUInt();
 		result.fileData.size = dbQuery.value("size").toUInt();
 		result.fileData.filetype = dbQuery.value("filetype").toChar();
-		QString pages = dbQuery.value("pages").toString();
-		QStringList pagesList = pages.split(",");
-		for(QString &page : pagesList)
-		{
-			if(page != "")
-			{
-				result.pages.append(page.toUInt());
-			}
-		}
+		result.page = dbQuery.value("page").toUInt();
 		result.wasContentSearch = contentSearch;
 		results.append(result);
 	}