Alt+Space hotkey, tray icon

README.md

@@ -28,7 +28,7 @@ Do `tar -jxvf file.tar.bz2` in docsets directory to enable given docset.
 
 ## TODO
 
- * Alt+Space / configurable hotkey for showing Zeal + tray icon
+ * Configuration (customisable hotkey instead of hardcoded Alt+Space, remember window size, etc.)
  * Search enhancements - some ideas:
    1. Allow selecting subset of docsets to search in.
    2. Substring match in case current startswith matching doesn't return anything.

zeal/main.cpp

@@ -1,11 +1,84 @@
 #include "mainwindow.h"
 #include <QApplication>
+#include <QLocalSocket>
+
+#include <string>
+#include <iostream>
+#include <X11/Xlib.h>
+#include <X11/keysym.h>
+
+using namespace std;
+
+void run_grabkey();
 
 int main(int argc, char *argv[])
 {
-    QApplication a(argc, argv);
-    MainWindow w;
-    w.show();
-    
-    return a.exec();
+    if(argc > 1 && argv[1] == string("--grabkey")) {
+        run_grabkey();
+        return -1;  // infinite loop - shouldn't terminate
+    } else {
+        // detect already running instance
+        QLocalSocket socket;
+        socket.connectToServer(serverName);
+        if (socket.waitForConnected(500)) {
+            cerr << "Already running. Terminating." << endl;
+            return -1; // Exit already a process running
+        }
+
+        QApplication a(argc, argv);
+        MainWindow w;
+        w.show();
+        return a.exec();
+    }
+}
+
+void run_grabkey()
+{
+    Display *display = XOpenDisplay(NULL);
+
+    unsigned int AltMask = 0;
+
+    XModifierKeymap *xmk = XGetModifierMapping(display);
+    if(xmk) {
+        KeyCode altKeyCode = XKeysymToKeycode(display, XK_Alt_L);
+        KeyCode *c = xmk->modifiermap;
+        int m, k;
+        for(m = 0; m < 8; m++) {
+            for(k = 0; k < xmk->max_keypermod; k++, c++)
+            {
+                if(*c == NoSymbol) {
+                    continue;
+                }
+                if(*c == altKeyCode) {
+                    AltMask = (1 << m);
+                }
+            }
+        }
+        XFreeModifiermap (xmk);
+    }
+
+    if(AltMask == 0) {
+        cout << "failed" << endl;
+    } else {
+        cout << "ok" << endl;
+    }
+
+    KeyCode hotKey = XKeysymToKeycode(display, XStringToKeysym("space"));
+    XGrabKey(display, hotKey, AnyModifier, DefaultRootWindow(display), True, GrabModeSync, GrabModeSync);
+
+    XEvent e;
+    for(;;)
+    {
+        XNextEvent(display, &e);
+        if(e.type == KeyPress){
+            if(e.xkey.keycode == hotKey && e.xkey.state & AltMask)
+            {
+                cout << "1" << endl;
+                XAllowEvents(display, AsyncKeyboard, e.xkey.time);
+            } else {
+                XAllowEvents(display, ReplayKeyboard, e.xkey.time);
+                XFlush(display);
+            }
+        }
+    }
 }

zeal/mainwindow.cpp

@@ -9,12 +9,48 @@ using namespace std;
 
 #include <QStandardPaths>
 #include <QMessageBox>
+#include <QSystemTrayIcon>
+#include <QLocalSocket>
 #include <QDir>
 
+const QString serverName = "zeal_process_running";
+
 MainWindow::MainWindow(QWidget *parent) :
     QMainWindow(parent),
     ui(new Ui::MainWindow)
 {
+    // server for detecting already running instances
+    localServer = new QLocalServer(this);
+    connect(localServer, &QLocalServer::newConnection, [&]() {
+        bringToFront();
+    });
+    QLocalServer::removeServer(serverName);  // remove in case previous instance crashed
+    localServer->listen(serverName);
+
+    // initialise icons
+    setWindowIcon(QIcon::fromTheme("edit-find"));
+    createTrayIcon();
+
+    // initialise key grabber
+    keyGrabber.setParent(this);
+    keyGrabber.start(qApp->applicationFilePath(), {"--grabkey"});
+    connect(&keyGrabber, &QProcess::readyRead, [&]() {
+        char buf[100];
+        keyGrabber.readLine(buf, sizeof(buf));
+        if(QString(buf) == "failed\n") {
+            QMessageBox::warning(this, "grabkey process init failed",
+                                 QString("Failed to grab keyboard - Alt+Space will not work."));
+        }
+        //first = false;
+        if(QString(buf) == "1\n") {
+            if(isVisible()) hide();
+            else {
+                bringToFront();
+            }
+        }
+    });
+
+    // initialise docsets
     auto dataLocation = QStandardPaths::writableLocation(QStandardPaths::DataLocation);
     auto dataDir = QDir(dataLocation);
     if(!dataDir.cd("docsets")) {
@@ -28,6 +64,8 @@ MainWindow::MainWindow(QWidget *parent) :
             }
         }
     }
+
+    // initialise ui
     ui->setupUi(this);
     ui->lineEdit->setTreeView(ui->treeView);
     ui->treeView->setModel(&zealList);
@@ -53,4 +91,34 @@ MainWindow::MainWindow(QWidget *parent) :
 MainWindow::~MainWindow()
 {
     delete ui;
+    delete localServer;
+    keyGrabber.terminate();
+    keyGrabber.waitForFinished(500);
+}
+
+void MainWindow::createTrayIcon()
+{
+    auto trayIconMenu = new QMenu(this);
+    auto quitAction = trayIconMenu->addAction("&Quit");
+    connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
+    auto trayIcon = new QSystemTrayIcon(this);
+    trayIcon->setContextMenu(trayIconMenu);
+    trayIcon->setIcon(QIcon::fromTheme("edit-find"));
+    trayIcon->setToolTip("Zeal");
+    connect(trayIcon, &QSystemTrayIcon::activated, [&](QSystemTrayIcon::ActivationReason reason) {
+        if(reason == QSystemTrayIcon::Trigger || reason == QSystemTrayIcon::DoubleClick) {
+            if(isVisible()) hide();
+            else show();
+        }
+    });
+    trayIcon->show();
+}
+
+void MainWindow::bringToFront()
+{
+    show();
+    setWindowState( (windowState() & ~Qt::WindowMinimized) | Qt::WindowActive);
+    raise();
+    activateWindow();
+    ui->lineEdit->setFocus();
 }

zeal/mainwindow.h

@@ -2,6 +2,8 @@
 #define MAINWINDOW_H
 
 #include <QMainWindow>
+#include <QProcess>
+#include <QLocalServer>
 #include "zeallistmodel.h"
 #include "zealsearchmodel.h"
 
@@ -9,6 +11,8 @@ namespace Ui {
 class MainWindow;
 }
 
+extern const QString serverName;
+
 class MainWindow : public QMainWindow
 {
     Q_OBJECT
@@ -18,9 +22,13 @@ public:
     ~MainWindow();
     
 private:
+    void bringToFront();
     Ui::MainWindow *ui;
     ZealListModel zealList;
     ZealSearchModel zealSearch;
+    QProcess keyGrabber;
+    QLocalServer *localServer;
+    void createTrayIcon();
 };
 
 #endif // MAINWINDOW_H