Add gamepad navigation support for everything except context menus and dialogs

app/app.pro

@@ -108,7 +108,8 @@ SOURCES += \
     streaming/streamutils.cpp \
     backend/autoupdatechecker.cpp \
     path.cpp \
-    settings/mappingmanager.cpp
+    settings/mappingmanager.cpp \
+    gui/sdlgamepadkeynavigation.cpp
 
 HEADERS += \
     utils.h \
@@ -130,7 +131,8 @@ HEADERS += \
     streaming/streamutils.h \
     backend/autoupdatechecker.h \
     path.h \
-    settings/mappingmanager.h
+    settings/mappingmanager.h \
+    gui/sdlgamepadkeynavigation.h
 
 # Platform-specific renderers and decoders
 ffmpeg {

app/gui/AppView.qml

@@ -3,8 +3,8 @@ import QtQuick.Dialogs 1.2
 import QtQuick.Controls 2.2
 
 import AppModel 1.0
-
 import ComputerManager 1.0
+import SdlGamepadKeyNavigation 1.0
 
 GridView {
     property int computerIndex
@@ -36,12 +36,18 @@ GridView {
         currentIndex = -1
     }
 
+    SdlGamepadKeyNavigation {
+        id: gamepadKeyNav
+    }
+
     onVisibleChanged: {
         if (visible) {
             appModel.computerLost.connect(computerLost)
+            gamepadKeyNav.enable()
         }
         else {
             appModel.computerLost.disconnect(computerLost)
+            gamepadKeyNav.disable()
         }
     }
 
@@ -119,20 +125,25 @@ GridView {
             anchors.fill: parent
             acceptedButtons: Qt.RightButton
             onClicked: {
-                // Right click
+                // popup() ensures the menu appears under the mouse cursor
-                appContextMenu.open()
+                appContextMenu.popup()
             }
         }
 
+        Keys.onMenuPressed: {
+            // We must use open() here so the menu is positioned on
+            // the ItemDelegate and not where the mouse cursor is
+            appContextMenu.open()
+        }
+
         Menu {
             id: appContextMenu
-            MenuItem {
+            NavigableMenuItem {
                 text: model.running ? "Resume Game" : "Launch Game"
                 onTriggered: {
                     appContextMenu.close()
                     launchOrResumeSelectedApp()
                 }
-                height: visible ? implicitHeight : 0
             }
             NavigableMenuItem {
                 text: "Quit Game"
@@ -142,7 +153,6 @@ GridView {
                     quitAppDialog.open()
                 }
                 visible: model.running
-                height: visible ? implicitHeight : 0
             }
         }
     }

app/gui/NavigableMenuItem.qml

@@ -2,6 +2,10 @@ import QtQuick 2.0
 import QtQuick.Controls 2.2
 
 MenuItem {
+    // Ensure focus can't be given to an invisible item
+    enabled: visible
+    height: visible ? implicitHeight : 0
+
     Keys.onReturnPressed: {
         triggered()
     }

app/gui/PcView.qml

@@ -8,6 +8,7 @@ import ComputerModel 1.0
 
 import ComputerManager 1.0
 import StreamingPreferences 1.0
+import SdlGamepadKeyNavigation 1.0
 
 GridView {
     property ComputerModel computerModel : createModel()
@@ -32,6 +33,19 @@ GridView {
         id: prefs
     }
 
+    SdlGamepadKeyNavigation {
+        id: gamepadKeyNav
+    }
+
+    onVisibleChanged: {
+        if (visible) {
+            gamepadKeyNav.enable()
+        }
+        else {
+            gamepadKeyNav.disable()
+        }
+    }
+
     Component.onCompleted: {
         // Setup signals on CM
         ComputerManager.computerAddCompleted.connect(addComplete)
@@ -144,7 +158,6 @@ GridView {
                 text: "Wake PC"
                 onTriggered: computerModel.wakeComputer(index)
                 visible: !model.addPc && !model.online && model.wakeable
-                height: visible ? implicitHeight : 0
             }
             NavigableMenuItem {
                 text: "Delete PC"
@@ -185,6 +198,7 @@ GridView {
                     }
                 }
             } else if (!model.online) {
+                // Using open() here because it may be activated by keyboard
                 pcContextMenu.open()
             }
         }
@@ -193,12 +207,20 @@ GridView {
             anchors.fill: parent
             acceptedButtons: Qt.RightButton;
             onClicked: {
-                // right click
+                if (!model.addPc) {
-                if (!model.addPc) { // but only for actual PCs, not the add-pc option
+                    // popup() ensures the menu appears under the mouse cursor
-                    pcContextMenu.open()
+                    pcContextMenu.popup()
                 }
             }
         }
+
+        Keys.onMenuPressed: {
+            if (!model.addPc) {
+                // We must use open() here so the menu is positioned on
+                // the ItemDelegate and not where the mouse cursor is
+                pcContextMenu.open()
+            }
+        }
     }
 
     MessageDialog {

app/gui/SettingsView.qml

@@ -3,6 +3,7 @@ import QtQuick.Controls 2.2
 
 import StreamingPreferences 1.0
 import ComputerManager 1.0
+import SdlGamepadKeyNavigation 1.0
 
 ScrollView {
     id: settingsPage
@@ -12,6 +13,25 @@ ScrollView {
         id: prefs
     }
 
+    // The StackView will trigger a visibility change when
+    // we're pushed onto it, causing our onVisibleChanged
+    // routine to run, but only if we start as invisible
+    visible: false
+
+    SdlGamepadKeyNavigation {
+        id: gamepadKeyNav
+    }
+
+    onVisibleChanged: {
+        if (visible) {
+            gamepadKeyNav.setSettingsMode(true)
+            gamepadKeyNav.enable()
+        }
+        else {
+            gamepadKeyNav.disable()
+        }
+    }
+
     Component.onDestruction: {
         prefs.save()
     }

app/gui/main.qml

@@ -43,6 +43,10 @@ ApplicationWindow {
                 stackView.pop()
             }
         }
+
+        Keys.onMenuPressed: {
+            settingsButton.clicked()
+        }
     }
 
     onVisibilityChanged: {

app/gui/sdlgamepadkeynavigation.cpp

@@ -0,0 +1,177 @@
+#include "sdlgamepadkeynavigation.h"
+
+#include <QKeyEvent>
+#include <QGuiApplication>
+#include <QWindow>
+
+#include "settings/mappingmanager.h"
+
+SdlGamepadKeyNavigation::SdlGamepadKeyNavigation()
+    : m_Enabled(false),
+      m_SettingsMode(false)
+{
+    m_PollingTimer = new QTimer(this);
+    connect(m_PollingTimer, SIGNAL(timeout()), this, SLOT(onPollingTimerFired()));
+}
+
+SdlGamepadKeyNavigation::~SdlGamepadKeyNavigation()
+{
+    disable();
+}
+
+void SdlGamepadKeyNavigation::enable()
+{
+    if (m_Enabled) {
+        return;
+    }
+
+    // We have to initialize and uninitialize this in enable()/disable()
+    // because we need to get out of the way of the Session class. If it
+    // doesn't get to reinitialize the GC subsystem, it won't get initial
+    // arrival events. Additionally, there's a race condition between
+    // our QML objects being destroyed and SDL being deinitialized that
+    // this solves too.
+    if (SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER) != 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER) failed: %s",
+                     SDL_GetError());
+        return;
+    }
+
+    MappingManager mappingManager;
+    mappingManager.applyMappings();
+
+    // Drop all pending gamepad add events. SDL will generate these for us
+    // on first init of the GC subsystem. We can't depend on them due to
+    // overlapping lifetimes of SdlGamepadKeyNavigation instances, so we
+    // will attach ourselves.
+    SDL_FlushEvent(SDL_CONTROLLERDEVICEADDED);
+
+    // Open all currently attached game controllers
+    for (int i = 0; i < SDL_NumJoysticks(); i++) {
+        if (SDL_IsGameController(i)) {
+            SDL_GameController* gc = SDL_GameControllerOpen(i);
+            if (gc != nullptr) {
+                m_Gamepads.append(gc);
+            }
+        }
+    }
+
+    // Poll every 50 ms for a new joystick event
+    m_PollingTimer->start(50);
+
+    m_Enabled = true;
+}
+
+void SdlGamepadKeyNavigation::disable()
+{
+    if (!m_Enabled) {
+        return;
+    }
+
+    m_PollingTimer->stop();
+
+    while (!m_Gamepads.isEmpty()) {
+        SDL_GameControllerClose(m_Gamepads[0]);
+        m_Gamepads.removeAt(0);
+    }
+
+    SDL_QuitSubSystem(SDL_INIT_GAMECONTROLLER);
+
+    m_Enabled = false;
+}
+
+void SdlGamepadKeyNavigation::onPollingTimerFired()
+{
+    SDL_Event event;
+
+    while (SDL_PollEvent(&event)) {
+        switch (event.type) {
+        case SDL_CONTROLLERBUTTONDOWN:
+        case SDL_CONTROLLERBUTTONUP:
+        {
+            QEvent::Type type =
+                    event.type == SDL_CONTROLLERBUTTONDOWN ?
+                        QEvent::Type::KeyPress : QEvent::Type::KeyRelease;
+
+            switch (event.cbutton.button) {
+            case SDL_CONTROLLER_BUTTON_DPAD_UP:
+                if (m_SettingsMode) {
+                    // Back-tab
+                    sendKey(type, Qt::Key_Tab, Qt::ShiftModifier);
+                }
+                else {
+                    sendKey(type, Qt::Key_Up);
+                }
+                break;
+            case SDL_CONTROLLER_BUTTON_DPAD_DOWN:
+                if (m_SettingsMode) {
+                    sendKey(type, Qt::Key_Tab);
+                }
+                else {
+                    sendKey(type, Qt::Key_Down);
+                }
+                break;
+            case SDL_CONTROLLER_BUTTON_DPAD_LEFT:
+                sendKey(type, Qt::Key_Left);
+                if (m_SettingsMode) {
+                    // Some settings controls respond to left/right (like the slider)
+                    // and others respond to up/down (like combo boxes). They seem to
+                    // be mutually exclusive though so let's just send both.
+                    sendKey(type, Qt::Key_Up);
+                }
+                break;
+            case SDL_CONTROLLER_BUTTON_DPAD_RIGHT:
+                sendKey(type, Qt::Key_Right);
+                if (m_SettingsMode) {
+                    // Some settings controls respond to left/right (like the slider)
+                    // and others respond to up/down (like combo boxes). They seem to
+                    // be mutually exclusive though so let's just send both.
+                    sendKey(type, Qt::Key_Down);
+                }
+                break;
+            case SDL_CONTROLLER_BUTTON_A:
+                if (m_SettingsMode) {
+                    sendKey(type, Qt::Key_Space);
+                }
+                else {
+                    sendKey(type, Qt::Key_Return);
+                }
+                break;
+            case SDL_CONTROLLER_BUTTON_B:
+                sendKey(type, Qt::Key_Escape);
+                break;
+            case SDL_CONTROLLER_BUTTON_X:
+            case SDL_CONTROLLER_BUTTON_Y:
+            case SDL_CONTROLLER_BUTTON_START:
+                sendKey(type, Qt::Key_Menu);
+                break;
+            default:
+                break;
+            }
+            break;
+        }
+        case SDL_CONTROLLERDEVICEADDED:
+            SDL_GameController* gc = SDL_GameControllerOpen(event.cdevice.which);
+            if (gc != nullptr) {
+                m_Gamepads.append(gc);
+            }
+            break;
+        }
+    }
+}
+
+void SdlGamepadKeyNavigation::sendKey(QEvent::Type type, Qt::Key key, Qt::KeyboardModifiers modifiers)
+{
+    QGuiApplication* app = static_cast<QGuiApplication*>(QGuiApplication::instance());
+    QWindow* focusWindow = app->focusWindow();
+    if (focusWindow != nullptr) {
+        QKeyEvent keyPressEvent(type, key, modifiers);
+        app->sendEvent(focusWindow, &keyPressEvent);
+    }
+}
+
+void SdlGamepadKeyNavigation::setSettingsMode(bool settingsMode)
+{
+    m_SettingsMode = settingsMode;
+}

app/gui/sdlgamepadkeynavigation.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <QTimer>
+#include <QEvent>
+
+#include <SDL.h>
+
+class SdlGamepadKeyNavigation : public QObject
+{
+    Q_OBJECT
+
+public:
+    SdlGamepadKeyNavigation();
+
+    ~SdlGamepadKeyNavigation();
+
+    Q_INVOKABLE void enable();
+
+    Q_INVOKABLE void disable();
+
+    Q_INVOKABLE void setSettingsMode(bool settingsMode);
+
+private:
+    void sendKey(QEvent::Type type, Qt::Key key, Qt::KeyboardModifiers modifiers = Qt::NoModifier);
+
+private slots:
+    void onPollingTimerFired();
+
+private:
+    QTimer* m_PollingTimer;
+    QList<SDL_GameController*> m_Gamepads;
+    bool m_Enabled;
+    bool m_SettingsMode;
+};

app/main.cpp

@@ -24,6 +24,7 @@
 #include "backend/autoupdatechecker.h"
 #include "streaming/session.h"
 #include "settings/streamingpreferences.h"
+#include "gui/sdlgamepadkeynavigation.h"
 
 #if !defined(QT_DEBUG) && defined(Q_OS_WIN32)
 // Log to file for release Windows builds
@@ -288,6 +289,7 @@ int main(int argc, char *argv[])
     qmlRegisterType<ComputerModel>("ComputerModel", 1, 0, "ComputerModel");
     qmlRegisterType<AppModel>("AppModel", 1, 0, "AppModel");
     qmlRegisterType<StreamingPreferences>("StreamingPreferences", 1, 0, "StreamingPreferences");
+    qmlRegisterType<SdlGamepadKeyNavigation>("SdlGamepadKeyNavigation", 1, 0, "SdlGamepadKeyNavigation");
     qmlRegisterUncreatableType<Session>("Session", 1, 0, "Session", "Session cannot be created from QML");
     qmlRegisterSingletonType<ComputerManager>("ComputerManager", 1, 0,
                                               "ComputerManager",
@@ -338,6 +340,10 @@ int main(int argc, char *argv[])
                      SDL_GetError());
     }
 
+    // Use atexit() to ensure SDL_Quit() is called. This avoids
+    // racing with object destruction where SDL may be used.
+    atexit(SDL_Quit);
+
     // Avoid the default behavior of changing the timer resolution to 1 ms.
     // We don't want this all the time that Moonlight is open. We will set
     // it manually when we start streaming.
@@ -345,7 +351,5 @@ int main(int argc, char *argv[])
 
     int err = app.exec();
 
-    SDL_Quit();
-
     return err;
 }