Qt: Allow rebinding keyboard controls (#779)

* Initial input UI draft

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

* More keybinding work

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

* Nit

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

* More nits

Co-Authored-By: Paris Oplopoios <parisoplop@gmail.com>

---------

Co-authored-by: Paris Oplopoios <parisoplop@gmail.com>

src/core/services/hid.cpp

@@ -1,6 +1,8 @@
 #include "services/hid.hpp"
 
-#include <bit>
+#include <algorithm>
+#include <cctype>
+#include <unordered_map>
 
 #include "ipc.hpp"
 #include "kernel.hpp"
@@ -242,4 +244,61 @@ void HIDService::updateInputs(u64 currentTick) {
 			kernel.signalEvent(e.value());
 		}
 	}
-}
+}
+
+// Key serialization helpers
+namespace HID::Keys {
+	const char* keyToName(u32 key) {
+		static std::unordered_map<u32, const char*> keyMap = {
+			{A, "A"},
+			{B, "B"},
+			{Select, "Select"},
+			{Start, "Start"},
+			{Right, "D-Pad Right"},
+			{Left, "D-Pad Left"},
+			{Up, "D-Pad Up"},
+			{Down, "D-Pad Down"},
+			{R, "R"},
+			{L, "L"},
+			{X, "X"},
+			{Y, "Y"},
+			{ZL, "ZL"},
+			{ZR, "ZR"},
+			{CirclePadRight, "CirclePad Right"},
+			{CirclePadLeft, "CirclePad Left"},
+			{CirclePadUp, "CirclePad Up"},
+			{CirclePadDown, "CirclePad Down"},
+		};
+
+		auto it = keyMap.find(key);
+		return it != keyMap.end() ? it->second : "Unknown key";
+	}
+
+	u32 nameToKey(std::string name) {
+		static std::unordered_map<std::string, u32> keyMap = {
+			{"a", A},
+			{"b", B},
+			{"select", Select},
+			{"start", Start},
+			{"d-pad right", Right},
+			{"d-pad left", Left},
+			{"d-pad up", Up},
+			{"d-pad down", Down},
+			{"r", R},
+			{"l", L},
+			{"x", X},
+			{"y", Y},
+			{"zl", ZL},
+			{"zr", ZR},
+			{"circlepad right", CirclePadRight},
+			{"circlepad left", CirclePadLeft},
+			{"circlepad up", CirclePadUp},
+			{"circlepad down", CirclePadDown},
+		};
+
+		std::transform(name.begin(), name.end(), name.begin(), [](char c) { return std::tolower(c); });
+		auto it = keyMap.find(name);
+
+		return it != keyMap.end() ? it->second : HID::Keys::Null;
+	}
+}  // namespace HID::Keys

src/panda_qt/config_window.cpp

@@ -284,8 +284,8 @@ ConfigWindow::ConfigWindow(ConfigCallback configCallback, MainWindowCallback win
 	gpuLayout->addRow(tr("Light threshold for forcing shadergen"), lightShadergenThreshold);
 
 	// Audio settings
-	QGroupBox* spuGroupBox = new QGroupBox(tr("Audio Settings"), this);
-	QFormLayout* audioLayout = new QFormLayout(spuGroupBox);
+	QGroupBox* dspGroupBox = new QGroupBox(tr("Audio Settings"), this);
+	QFormLayout* audioLayout = new QFormLayout(dspGroupBox);
 	audioLayout->setHorizontalSpacing(20);
 	audioLayout->setVerticalSpacing(10);
 
@@ -344,6 +344,8 @@ ConfigWindow::ConfigWindow(ConfigCallback configCallback, MainWindowCallback win
 	volumeLayout->addWidget(volumeLabel);
 	audioLayout->addRow(tr("Audio device volume"), volumeLayout);
 
+	inputWindow = new InputWindow(this);
+
 	// Battery settings
 	QGroupBox* batGroupBox = new QGroupBox(tr("Battery Settings"), this);
 	QFormLayout* batLayout = new QFormLayout(batGroupBox);
@@ -381,7 +383,8 @@ ConfigWindow::ConfigWindow(ConfigCallback configCallback, MainWindowCallback win
 	addWidget(guiGroupBox, tr("Interface"), ":/docs/img/sparkling_icon.png", tr("User Interface settings"));
 	addWidget(genGroupBox, tr("General"), ":/docs/img/settings_icon.png", tr("General emulator settings"));
 	addWidget(gpuGroupBox, tr("Graphics"), ":/docs/img/display_icon.png", tr("Graphics emulation and output settings"));
-	addWidget(spuGroupBox, tr("Audio"), ":/docs/img/speaker_icon.png", tr("Audio emulation and output settings"));
+	addWidget(dspGroupBox, tr("Audio"), ":/docs/img/speaker_icon.png", tr("Audio emulation and output settings"));
+	addWidget(inputWindow, tr("Input"), ":/docs/img/gamepad_icon.png", tr("Keyboard & controller input settings"));
 	addWidget(batGroupBox, tr("Battery"), ":/docs/img/battery_icon.png", tr("Battery emulation settings"));
 	addWidget(sdcGroupBox, tr("SD Card"), ":/docs/img/sdcard_icon.png", tr("SD Card emulation settings"));
 

src/panda_qt/input_window.cpp

@@ -0,0 +1,127 @@
+#include "panda_qt/input_window.hpp"
+
+#include <QHBoxLayout>
+#include <QKeyEvent>
+#include <QLabel>
+#include <QPushButton>
+#include <QVBoxLayout>
+
+#include "input_mappings.hpp"
+#include "services/hid.hpp"
+
+InputWindow::InputWindow(QWidget* parent) : QDialog(parent) {
+	auto mainLayout = new QVBoxLayout(this);
+
+	QStringList actions = {
+		"A",
+		"B",
+		"X",
+		"Y",
+		"L",
+		"R",
+		"ZL",
+		"ZR",
+		"Start",
+		"Select",
+		"D-Pad Up",
+		"D-Pad Down",
+		"D-Pad Left",
+		"D-Pad Right",
+		"CirclePad Up",
+		"CirclePad Down",
+		"CirclePad Left",
+		"CirclePad Right",
+	};
+
+	for (const QString& action : actions) {
+		auto row = new QHBoxLayout();
+		row->addWidget(new QLabel(action));
+
+		auto button = new QPushButton(tr("Not set"));
+		buttonMap[action] = button;
+		keyMappings[action] = QKeySequence();
+
+		connect(button, &QPushButton::clicked, this, [=, this]() { startKeyCapture(action); });
+
+		row->addWidget(button);
+		mainLayout->addLayout(row);
+	}
+
+	auto resetButton = new QPushButton(tr("Reset Defaults"));
+	connect(resetButton, &QPushButton::pressed, this, [&]() {
+		// Restore the keymappings to the default ones for Qt
+		auto defaultMappings = InputMappings::defaultKeyboardMappings();
+		loadFromMappings(defaultMappings);
+
+		emit mappingsChanged();
+	});
+
+	mainLayout->addWidget(resetButton);
+	installEventFilter(this);
+}
+
+void InputWindow::startKeyCapture(const QString& action) {
+	waitingForAction = action;
+	grabKeyboard();
+}
+
+bool InputWindow::eventFilter(QObject* obj, QEvent* event) {
+	// If we're waiting for a button to be inputted, handle the keypress
+	if (!waitingForAction.isEmpty() && event->type() == QEvent::KeyPress) {
+		QKeyEvent* keyEvent = static_cast<QKeyEvent*>(event);
+		QKeySequence key(keyEvent->key());
+
+		// If this key is already bound to something else, unbind it
+		for (auto it = keyMappings.begin(); it != keyMappings.end(); ++it) {
+			if (it.key() != waitingForAction && it.value() == key) {
+				it.value() = QKeySequence();
+				buttonMap[it.key()]->setText(tr("Not set"));
+				break;
+			}
+		}
+
+		keyMappings[waitingForAction] = key;
+		buttonMap[waitingForAction]->setText(key.toString());
+
+		releaseKeyboard();
+		waitingForAction.clear();
+
+		emit mappingsChanged();
+		return true;
+	}
+
+	return false;
+}
+
+void InputWindow::loadFromMappings(const InputMappings& mappings) {
+	for (const auto& action : buttonMap.keys()) {
+		u32 key = HID::Keys::nameToKey(action.toStdString());
+
+		for (const auto& [scancode, mappedKey] : mappings) {
+			if (mappedKey == key) {
+				QKeySequence qkey(scancode);
+				keyMappings[action] = qkey;
+				buttonMap[action]->setText(qkey.toString());
+				break;
+			}
+		}
+	}
+}
+
+void InputWindow::applyToMappings(InputMappings& mappings) const {
+	// Clear existing keyboard mappings before mapping the buttons
+	mappings = InputMappings();
+
+	for (const auto& action : keyMappings.keys()) {
+		const QKeySequence& qkey = keyMappings[action];
+
+		if (!qkey.isEmpty()) {
+			InputMappings::Scancode scancode = qkey[0].key();
+			u32 key = HID::Keys::nameToKey(action.toStdString());
+
+			if (key != HID::Keys::Null) {
+				mappings.setMapping(scancode, key);
+			}
+		}
+	}
+}

src/panda_qt/main.cpp

@@ -1,7 +1,6 @@
 #include <QApplication>
 
 #include "panda_qt/main_window.hpp"
-#include "panda_qt/screen.hpp"
 
 int main(int argc, char *argv[]) {
 	QApplication app(argc, argv);

src/panda_qt/main_window.cpp

@@ -14,7 +14,7 @@
 #include "services/dsp.hpp"
 #include "version.hpp"
 
-MainWindow::MainWindow(QApplication* app, QWidget* parent) : QMainWindow(parent), keyboardMappings(InputMappings::defaultKeyboardMappings()) {
+MainWindow::MainWindow(QApplication* app, QWidget* parent) : QMainWindow(parent), keyboardMappings(InputMappings()) {
 	emu = new Emulator();
 
 	loadTranslation();
@@ -115,6 +115,13 @@ MainWindow::MainWindow(QApplication* app, QWidget* parent) : QMainWindow(parent)
 		[&]() { return this; }, emu->getConfig(), this
 	);
 
+	loadKeybindings();
+
+	connect(configWindow->getInputWindow(), &InputWindow::mappingsChanged, this, [&]() {
+		keybindingsChanged = true;
+		configWindow->getInputWindow()->applyToMappings(keyboardMappings);
+	});
+
 	auto args = QCoreApplication::arguments();
 	if (args.size() > 1) {
 		auto romPath = std::filesystem::current_path() / args.at(1).toStdU16String();
@@ -274,6 +281,10 @@ void MainWindow::closeEvent(QCloseEvent* event) {
 
 // Cleanup when the main window closes
 MainWindow::~MainWindow() {
+	if (keybindingsChanged) {
+		saveKeybindings();
+	}
+
 	delete emu;
 	delete menuBar;
 	delete aboutWindow;
@@ -766,3 +777,23 @@ void MainWindow::setupControllerSensors(SDL_GameController* controller) {
 		SDL_GameControllerSetSensorEnabled(controller, SDL_SENSOR_ACCEL, SDL_TRUE);
 	}
 }
+
+void MainWindow::loadKeybindings() {
+	auto mappings = InputMappings::deserialize(emu->getAppDataRoot() / "controls_qt.toml", "Qt", [](const std::string& name) {
+		return InputMappings::Scancode(QKeySequence(QString::fromStdString(name))[0].key());
+	});
+
+	if (mappings.has_value()) {
+		keyboardMappings = *mappings;
+	} else {
+		keyboardMappings = InputMappings::defaultKeyboardMappings();
+	}
+
+	configWindow->getInputWindow()->loadFromMappings(keyboardMappings);
+}
+
+void MainWindow::saveKeybindings() {
+	keyboardMappings.serialize(emu->getAppDataRoot() / "controls_qt.toml", "Qt", [](InputMappings::Scancode scancode) {
+		return QKeySequence(scancode).toString().toStdString();
+	});
+}

src/panda_qt/mappings.cpp

@@ -1,4 +1,5 @@
 #include <QKeyEvent>
+#include <QKeySequence>
 
 #include "input_mappings.hpp"
 

src/panda_sdl/mappings.cpp

@@ -1,7 +1,7 @@
-#include "input_mappings.hpp"
-
 #include <SDL.h>
 
+#include "input_mappings.hpp"
+
 InputMappings InputMappings::defaultKeyboardMappings() {
 	InputMappings mappings;
 	mappings.setMapping(SDLK_l, HID::Keys::A);