3 files changed, 92 insertions, 7 deletions

diff --git a/src/yuzu/applets/qt_controller.cpp b/src/yuzu/applets/qt_controller.cpp
index 00aafb8f8..3b8317598 100644
--- a/src/yuzu/applets/qt_controller.cpp
+++ b/src/yuzu/applets/qt_controller.cpp
@@ -21,6 +21,7 @@
 #include "yuzu/configuration/configure_vibration.h"
 #include "yuzu/configuration/input_profiles.h"
 #include "yuzu/main.h"
+#include "yuzu/util/controller_navigation.h"
 
 namespace {
 
@@ -130,6 +131,8 @@ QtControllerSelectorDialog::QtControllerSelectorDialog(
         ui->checkboxPlayer7Connected, ui->checkboxPlayer8Connected,
     };
 
+    ui->labelError->setVisible(false);
+
     // Setup/load everything prior to setting up connections.
     // This avoids unintentionally changing the states of elements while loading them in.
     SetSupportedControllers();
@@ -141,6 +144,8 @@ QtControllerSelectorDialog::QtControllerSelectorDialog(
 
     LoadConfiguration();
 
+    controller_navigation = new ControllerNavigation(system.HIDCore(), this);
+
     for (std::size_t i = 0; i < NUM_PLAYERS; ++i) {
         SetExplainText(i);
         UpdateControllerIcon(i);
@@ -149,6 +154,8 @@ QtControllerSelectorDialog::QtControllerSelectorDialog(
 
         connect(player_groupboxes[i], &QGroupBox::toggled, [this, i](bool checked) {
             if (checked) {
+                // Hide eventual error message about number of controllers
+                ui->labelError->setVisible(false);
                 for (std::size_t index = 0; index <= i; ++index) {
                     connected_controller_checkboxes[index]->setChecked(checked);
                 }
@@ -197,6 +204,12 @@ QtControllerSelectorDialog::QtControllerSelectorDialog(
     connect(ui->buttonBox, &QDialogButtonBox::accepted, this,
             &QtControllerSelectorDialog::ApplyConfiguration);
 
+    connect(controller_navigation, &ControllerNavigation::TriggerKeyboardEvent,
+            [this](Qt::Key key) {
+                QKeyEvent* event = new QKeyEvent(QEvent::KeyPress, key, Qt::NoModifier);
+                QCoreApplication::postEvent(this, event);
+            });
+
     // Enhancement: Check if the parameters have already been met before disconnecting controllers.
     // If all the parameters are met AND only allows a single player,
     // stop the constructor here as we do not need to continue.
@@ -215,6 +228,7 @@ QtControllerSelectorDialog::QtControllerSelectorDialog(
 }
 
 QtControllerSelectorDialog::~QtControllerSelectorDialog() {
+    controller_navigation->UnloadController();
     system.HIDCore().DisableAllControllerConfiguration();
 }
 
@@ -287,6 +301,31 @@ void QtControllerSelectorDialog::CallConfigureInputProfileDialog() {
     dialog.exec();
 }
 
+void QtControllerSelectorDialog::keyPressEvent(QKeyEvent* evt) {
+    const auto num_connected_players = static_cast<int>(
+        std::count_if(player_groupboxes.begin(), player_groupboxes.end(),
+                      [](const QGroupBox* player) { return player->isChecked(); }));
+
+    const auto min_supported_players = parameters.enable_single_mode ? 1 : parameters.min_players;
+    const auto max_supported_players = parameters.enable_single_mode ? 1 : parameters.max_players;
+
+    if ((evt->key() == Qt::Key_Enter || evt->key() == Qt::Key_Return) && !parameters_met) {
+        // Display error message when trying to validate using "Enter" and "OK" button is disabled
+        ui->labelError->setVisible(true);
+        return;
+    } else if (evt->key() == Qt::Key_Left && num_connected_players > min_supported_players) {
+        // Remove a player if possible
+        connected_controller_checkboxes[num_connected_players - 1]->setChecked(false);
+        return;
+    } else if (evt->key() == Qt::Key_Right && num_connected_players < max_supported_players) {
+        // Add a player, if possible
+        ui->labelError->setVisible(false);
+        connected_controller_checkboxes[num_connected_players]->setChecked(true);
+        return;
+    }
+    QDialog::keyPressEvent(evt);
+}
+
 bool QtControllerSelectorDialog::CheckIfParametersMet() {
     // Here, we check and validate the current configuration against all applicable parameters.
     const auto num_connected_players = static_cast<int>(
diff --git a/src/yuzu/applets/qt_controller.h b/src/yuzu/applets/qt_controller.h
index 2fdc35857..7f0673d06 100644
--- a/src/yuzu/applets/qt_controller.h
+++ b/src/yuzu/applets/qt_controller.h
@@ -34,6 +34,8 @@ class HIDCore;
 enum class NpadStyleIndex : u8;
 } // namespace Core::HID
 
+class ControllerNavigation;
+
 class QtControllerSelectorDialog final : public QDialog {
     Q_OBJECT
 
@@ -46,6 +48,8 @@ public:
 
     int exec() override;
 
+    void keyPressEvent(QKeyEvent* evt) override;
+
 private:
     // Applies the current configuration.
     void ApplyConfiguration();
@@ -110,6 +114,8 @@ private:
 
     Core::System& system;
 
+    ControllerNavigation* controller_navigation = nullptr;
+
     // This is true if and only if all parameters are met. Otherwise, this is false.
     // This determines whether the "OK" button can be clicked to exit the applet.
     bool parameters_met{false};
diff --git a/src/yuzu/applets/qt_controller.ui b/src/yuzu/applets/qt_controller.ui
index 729e921ee..6f7cb3c13 100644
--- a/src/yuzu/applets/qt_controller.ui
+++ b/src/yuzu/applets/qt_controller.ui
@@ -2624,13 +2624,53 @@
           </spacer>
          </item>
          <item alignment="Qt::AlignBottom">
-          <widget class="QDialogButtonBox" name="buttonBox">
-           <property name="enabled">
-            <bool>true</bool>
-           </property>
-           <property name="standardButtons">
-            <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
-           </property>
+          <widget class="QWidget" name="closeButtons" native="true">
+           <layout class="QVBoxLayout" name="verticalLayout_46">
+            <property name="spacing">
+             <number>7</number>
+            </property>
+            <property name="leftMargin">
+             <number>0</number>
+            </property>
+            <property name="topMargin">
+             <number>0</number>
+            </property>
+            <property name="rightMargin">
+             <number>0</number>
+            </property>
+            <property name="bottomMargin">
+             <number>0</number>
+            </property>
+            <item>
+             <widget class="QLabel" name="labelError">
+              <property name="enabled">
+               <bool>true</bool>
+              </property>
+              <property name="styleSheet">
+               <string notr="true">QLabel { color : red; }</string>
+              </property>
+              <property name="text">
+               <string>Not enough controllers</string>
+              </property>
+              <property name="alignment">
+               <set>Qt::AlignCenter</set>
+              </property>
+              <property name="margin">
+               <number>0</number>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QDialogButtonBox" name="buttonBox">
+              <property name="enabled">
+               <bool>true</bool>
+              </property>
+              <property name="standardButtons">
+               <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
+              </property>
+             </widget>
+            </item>
+           </layout>
           </widget>
          </item>
         </layout>