Move parts of MappingCommon out of DolphinQt

Some of the functions in MappingCommon would be useful to use on
mobile in the future.

8 files changed, 204 insertions, 154 deletions

diff --git a/Source/Core/Common/StringUtil.h b/Source/Core/Common/StringUtil.h
index f008dc55bb..56fa756a46 100644
--- a/Source/Core/Common/StringUtil.h
+++ b/Source/Core/Common/StringUtil.h
@@ -235,6 +235,14 @@ inline bool IsPrintableCharacter(char c)
   return std::isprint(c, std::locale::classic());
 }
 
+/// Returns whether a character is a letter, i.e. whether 'a' <= c <= 'z' || 'A' <= c <= 'Z'
+/// is true. Use this instead of calling std::isalpha directly to ensure
+/// the C locale is being used and to avoid possibly undefined behaviour.
+inline bool IsAlpha(char c)
+{
+  return std::isalpha(c, std::locale::classic());
+}
+
 #ifdef _WIN32
 std::vector<std::string> CommandLineToUtf8Argv(const wchar_t* command_line);
 #endif
diff --git a/Source/Core/DolphinLib.props b/Source/Core/DolphinLib.props
index 79557b58c7..208ad54df7 100644
--- a/Source/Core/DolphinLib.props
+++ b/Source/Core/DolphinLib.props
@@ -482,6 +482,7 @@
     <ClInclude Include="InputCommon\ControllerInterface\DualShockUDPClient\DualShockUDPProto.h" />
     <ClInclude Include="InputCommon\ControllerInterface\evdev\evdev.h" />
     <ClInclude Include="InputCommon\ControllerInterface\ForceFeedback\ForceFeedbackDevice.h" />
+    <ClInclude Include="InputCommon\ControllerInterface\MappingCommon.h" />
     <ClInclude Include="InputCommon\ControllerInterface\Wiimote\WiimoteController.h" />
     <ClInclude Include="InputCommon\ControllerInterface\Win32\Win32.h" />
     <ClInclude Include="InputCommon\ControllerInterface\XInput\XInput.h" />
@@ -1069,6 +1070,7 @@
     <ClCompile Include="InputCommon\ControllerInterface\DInput\XInputFilter.cpp" />
     <ClCompile Include="InputCommon\ControllerInterface\DualShockUDPClient\DualShockUDPClient.cpp" />
     <ClCompile Include="InputCommon\ControllerInterface\ForceFeedback\ForceFeedbackDevice.cpp" />
+    <ClCompile Include="InputCommon\ControllerInterface\MappingCommon.cpp" />
     <ClCompile Include="InputCommon\ControllerInterface\Wiimote\WiimoteController.cpp" />
     <ClCompile Include="InputCommon\ControllerInterface\Win32\Win32.cpp" />
     <ClCompile Include="InputCommon\ControllerInterface\XInput\XInput.cpp" />
diff --git a/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp b/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp
index 6e178a2ed8..50492e0767 100644
--- a/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp
+++ b/Source/Core/DolphinQt/Config/Mapping/IOWindow.cpp
@@ -34,6 +34,7 @@
 #include "InputCommon/ControlReference/ExpressionParser.h"
 #include "InputCommon/ControllerEmu/ControllerEmu.h"
 #include "InputCommon/ControllerInterface/ControllerInterface.h"
+#include "InputCommon/ControllerInterface/MappingCommon.h"
 
 constexpr int SLIDER_TICK_COUNT = 100;
 
@@ -485,9 +486,10 @@ void IOWindow::AppendSelectedOption()
   if (m_option_list->currentRow() < 0)
     return;
 
-  m_expression_text->insertPlainText(MappingCommon::GetExpressionForControl(
-      m_option_list->item(m_option_list->currentRow(), 0)->text(), m_devq,
-      m_controller->GetDefaultDevice()));
+  m_expression_text->insertPlainText(
+      QString::fromStdString(ciface::MappingCommon::GetExpressionForControl(
+          m_option_list->item(m_option_list->currentRow(), 0)->text().toStdString(), m_devq,
+          m_controller->GetDefaultDevice())));
 }
 
 void IOWindow::OnDeviceChanged()
@@ -526,7 +528,7 @@ void IOWindow::OnDetectButtonPressed()
 {
   const auto expression =
       MappingCommon::DetectExpression(m_detect_button, g_controller_interface, {m_devq.ToString()},
-                                      m_devq, MappingCommon::Quote::Off);
+                                      m_devq, ciface::MappingCommon::Quote::Off);
 
   if (expression.isEmpty())
     return;
diff --git a/Source/Core/DolphinQt/Config/Mapping/MappingCommon.cpp b/Source/Core/DolphinQt/Config/Mapping/MappingCommon.cpp
index fde917c2b1..0fdcb376af 100644
--- a/Source/Core/DolphinQt/Config/Mapping/MappingCommon.cpp
+++ b/Source/Core/DolphinQt/Config/Mapping/MappingCommon.cpp
@@ -3,8 +3,7 @@
 
 #include "DolphinQt/Config/Mapping/MappingCommon.h"
 
-#include <tuple>
-#include <vector>
+#include <chrono>
 
 #include <QApplication>
 #include <QPushButton>
@@ -14,6 +13,7 @@
 
 #include "DolphinQt/QtUtils/BlockUserInputFilter.h"
 #include "InputCommon/ControlReference/ControlReference.h"
+#include "InputCommon/ControllerInterface/MappingCommon.h"
 
 #include "Common/Thread.h"
 
@@ -25,44 +25,10 @@ constexpr auto INPUT_DETECT_MAXIMUM_TIME = std::chrono::seconds(5);
 
 constexpr auto OUTPUT_TEST_TIME = std::chrono::seconds(2);
 
-// Pressing inputs at the same time will result in the & operator vs a hotkey expression.
-constexpr auto HOTKEY_VS_CONJUNCION_THRESHOLD = std::chrono::milliseconds(50);
-
-// Some devices (e.g. DS4) provide an analog and digital input for the trigger.
-// We prefer just the analog input for simultaneous digital+analog input detections.
-constexpr auto SPURIOUS_TRIGGER_COMBO_THRESHOLD = std::chrono::milliseconds(150);
-
-QString GetExpressionForControl(const QString& control_name,
-                                const ciface::Core::DeviceQualifier& control_device,
-                                const ciface::Core::DeviceQualifier& default_device, Quote quote)
-{
-  QString expr;
-
-  // non-default device
-  if (control_device != default_device)
-  {
-    expr += QString::fromStdString(control_device.ToString());
-    expr += QLatin1Char{':'};
-  }
-
-  // append the control name
-  expr += control_name;
-
-  if (quote == Quote::On)
-  {
-    // If our expression contains any non-alpha characters
-    // we should quote it
-    const QRegularExpression reg(QStringLiteral("[^a-zA-Z]"));
-    if (reg.match(expr).hasMatch())
-      expr = QStringLiteral("`%1`").arg(expr);
-  }
-
-  return expr;
-}
-
 QString DetectExpression(QPushButton* button, ciface::Core::DeviceContainer& device_container,
                          const std::vector<std::string>& device_strings,
-                         const ciface::Core::DeviceQualifier& default_device, Quote quote)
+                         const ciface::Core::DeviceQualifier& default_device,
+                         ciface::MappingCommon::Quote quote)
 {
   const auto filter = new BlockUserInputFilter(button);
 
@@ -83,7 +49,7 @@ QString DetectExpression(QPushButton* button, ciface::Core::DeviceContainer& dev
       device_container.DetectInput(device_strings, INPUT_DETECT_INITIAL_TIME,
                                    INPUT_DETECT_CONFIRMATION_TIME, INPUT_DETECT_MAXIMUM_TIME);
 
-  RemoveSpuriousTriggerCombinations(&detections);
+  ciface::MappingCommon::RemoveSpuriousTriggerCombinations(&detections);
 
   const auto timer = new QTimer(button);
 
@@ -100,7 +66,7 @@ QString DetectExpression(QPushButton* button, ciface::Core::DeviceContainer& dev
 
   button->setText(old_text);
 
-  return BuildExpression(detections, default_device, quote);
+  return QString::fromStdString(BuildExpression(detections, default_device, quote));
 }
 
 void TestOutput(QPushButton* button, OutputReference* reference)
@@ -118,97 +84,4 @@ void TestOutput(QPushButton* button, OutputReference* reference)
   button->setText(old_text);
 }
 
-void RemoveSpuriousTriggerCombinations(
-    std::vector<ciface::Core::DeviceContainer::InputDetection>* detections)
-{
-  const auto is_spurious = [&](auto& detection) {
-    return std::any_of(detections->begin(), detections->end(), [&](auto& d) {
-      // This is a suprious digital detection if a "smooth" (analog) detection is temporally near.
-      return &d != &detection && d.smoothness > 1 &&
-             abs(d.press_time - detection.press_time) < SPURIOUS_TRIGGER_COMBO_THRESHOLD;
-    });
-  };
-
-  detections->erase(std::remove_if(detections->begin(), detections->end(), is_spurious),
-                    detections->end());
-}
-
-QString
-BuildExpression(const std::vector<ciface::Core::DeviceContainer::InputDetection>& detections,
-                const ciface::Core::DeviceQualifier& default_device, Quote quote)
-{
-  std::vector<const ciface::Core::DeviceContainer::InputDetection*> pressed_inputs;
-
-  QStringList alternations;
-
-  const auto get_control_expression = [&](auto& detection) {
-    // Return the parent-most name if there is one for better hotkey strings.
-    // Detection of L/R_Ctrl will be changed to just Ctrl.
-    // Users can manually map L_Ctrl if they so desire.
-    const auto input = (quote == Quote::On) ?
-                           detection.device->GetParentMostInput(detection.input) :
-                           detection.input;
-
-    ciface::Core::DeviceQualifier device_qualifier;
-    device_qualifier.FromDevice(detection.device.get());
-
-    return MappingCommon::GetExpressionForControl(QString::fromStdString(input->GetName()),
-                                                  device_qualifier, default_device, quote);
-  };
-
-  bool new_alternation = false;
-
-  const auto handle_press = [&](auto& detection) {
-    pressed_inputs.emplace_back(&detection);
-    new_alternation = true;
-  };
-
-  const auto handle_release = [&]() {
-    if (!new_alternation)
-      return;
-
-    new_alternation = false;
-
-    QStringList alternation;
-    for (auto* input : pressed_inputs)
-      alternation.push_back(get_control_expression(*input));
-
-    const bool is_hotkey = pressed_inputs.size() >= 2 &&
-                           (pressed_inputs[1]->press_time - pressed_inputs[0]->press_time) >
-                               HOTKEY_VS_CONJUNCION_THRESHOLD;
-
-    if (is_hotkey)
-    {
-      alternations.push_back(QStringLiteral("@(%1)").arg(alternation.join(QLatin1Char('+'))));
-    }
-    else
-    {
-      alternation.sort();
-      alternations.push_back(alternation.join(QLatin1Char('&')));
-    }
-  };
-
-  for (auto& detection : detections)
-  {
-    // Remove since released inputs.
-    for (auto it = pressed_inputs.begin(); it != pressed_inputs.end();)
-    {
-      if (!((*it)->release_time > detection.press_time))
-      {
-        handle_release();
-        it = pressed_inputs.erase(it);
-      }
-      else
-        ++it;
-    }
-
-    handle_press(detection);
-  }
-
-  handle_release();
-
-  alternations.removeDuplicates();
-  return alternations.join(QLatin1Char('|'));
-}
-
 }  // namespace MappingCommon
diff --git a/Source/Core/DolphinQt/Config/Mapping/MappingCommon.h b/Source/Core/DolphinQt/Config/Mapping/MappingCommon.h
index aa96ad76d7..f1385ebb6b 100644
--- a/Source/Core/DolphinQt/Config/Mapping/MappingCommon.h
+++ b/Source/Core/DolphinQt/Config/Mapping/MappingCommon.h
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "InputCommon/ControllerInterface/CoreDevice.h"
+#include "InputCommon/ControllerInterface/MappingCommon.h"
 
 class QString;
 class OutputReference;
@@ -14,27 +15,11 @@ class QPushButton;
 
 namespace MappingCommon
 {
-enum class Quote
-{
-  On,
-  Off
-};
-
-QString GetExpressionForControl(const QString& control_name,
-                                const ciface::Core::DeviceQualifier& control_device,
-                                const ciface::Core::DeviceQualifier& default_device,
-                                Quote quote = Quote::On);
-
 QString DetectExpression(QPushButton* button, ciface::Core::DeviceContainer& device_container,
                          const std::vector<std::string>& device_strings,
                          const ciface::Core::DeviceQualifier& default_device,
-                         Quote quote = Quote::On);
+                         ciface::MappingCommon::Quote quote = ciface::MappingCommon::Quote::On);
 
 void TestOutput(QPushButton* button, OutputReference* reference);
 
-void RemoveSpuriousTriggerCombinations(std::vector<ciface::Core::DeviceContainer::InputDetection>*);
-
-QString BuildExpression(const std::vector<ciface::Core::DeviceContainer::InputDetection>&,
-                        const ciface::Core::DeviceQualifier& default_device, Quote quote);
-
 }  // namespace MappingCommon
diff --git a/Source/Core/InputCommon/CMakeLists.txt b/Source/Core/InputCommon/CMakeLists.txt
index 576e87e711..e600004cda 100644
--- a/Source/Core/InputCommon/CMakeLists.txt
+++ b/Source/Core/InputCommon/CMakeLists.txt
@@ -54,6 +54,8 @@ add_library(inputcommon
   ControllerInterface/ControllerInterface.h
   ControllerInterface/CoreDevice.cpp
   ControllerInterface/CoreDevice.h
+  ControllerInterface/MappingCommon.cpp
+  ControllerInterface/MappingCommon.h
   ControllerInterface/Wiimote/WiimoteController.cpp
   ControllerInterface/Wiimote/WiimoteController.h
   ControlReference/ControlReference.cpp
diff --git a/Source/Core/InputCommon/ControllerInterface/MappingCommon.cpp b/Source/Core/InputCommon/ControllerInterface/MappingCommon.cpp
new file mode 100644
index 0000000000..5adc8daf35
--- /dev/null
+++ b/Source/Core/InputCommon/ControllerInterface/MappingCommon.cpp
@@ -0,0 +1,149 @@
+// Copyright 2022 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "InputCommon/ControllerInterface/MappingCommon.h"
+
+#include <algorithm>
+#include <chrono>
+#include <string>
+#include <vector>
+
+#include <fmt/format.h>
+
+#include "Common/StringUtil.h"
+#include "InputCommon/ControllerInterface/CoreDevice.h"
+
+namespace ciface::MappingCommon
+{
+// Pressing inputs at the same time will result in the & operator vs a hotkey expression.
+constexpr auto HOTKEY_VS_CONJUNCION_THRESHOLD = std::chrono::milliseconds(50);
+
+// Some devices (e.g. DS4) provide an analog and digital input for the trigger.
+// We prefer just the analog input for simultaneous digital+analog input detections.
+constexpr auto SPURIOUS_TRIGGER_COMBO_THRESHOLD = std::chrono::milliseconds(150);
+
+std::string GetExpressionForControl(const std::string& control_name,
+                                    const ciface::Core::DeviceQualifier& control_device,
+                                    const ciface::Core::DeviceQualifier& default_device,
+                                    Quote quote)
+{
+  std::string expr;
+
+  // non-default device
+  if (control_device != default_device)
+  {
+    expr += control_device.ToString();
+    expr += ':';
+  }
+
+  // append the control name
+  expr += control_name;
+
+  if (quote == Quote::On)
+  {
+    // If our expression contains any non-alpha characters
+    // we should quote it
+    if (!std::all_of(expr.begin(), expr.end(), IsAlpha))
+      expr = fmt::format("`{}`", expr);
+  }
+
+  return expr;
+}
+
+std::string
+BuildExpression(const std::vector<ciface::Core::DeviceContainer::InputDetection>& detections,
+                const ciface::Core::DeviceQualifier& default_device, Quote quote)
+{
+  std::vector<const ciface::Core::DeviceContainer::InputDetection*> pressed_inputs;
+
+  std::vector<std::string> alternations;
+
+  const auto get_control_expression = [&](auto& detection) {
+    // Return the parent-most name if there is one for better hotkey strings.
+    // Detection of L/R_Ctrl will be changed to just Ctrl.
+    // Users can manually map L_Ctrl if they so desire.
+    const auto input = (quote == Quote::On) ?
+                           detection.device->GetParentMostInput(detection.input) :
+                           detection.input;
+
+    ciface::Core::DeviceQualifier device_qualifier;
+    device_qualifier.FromDevice(detection.device.get());
+
+    return MappingCommon::GetExpressionForControl(input->GetName(), device_qualifier,
+                                                  default_device, quote);
+  };
+
+  bool new_alternation = false;
+
+  const auto handle_press = [&](auto& detection) {
+    pressed_inputs.emplace_back(&detection);
+    new_alternation = true;
+  };
+
+  const auto handle_release = [&]() {
+    if (!new_alternation)
+      return;
+
+    new_alternation = false;
+
+    std::vector<std::string> alternation;
+    for (auto* input : pressed_inputs)
+      alternation.push_back(get_control_expression(*input));
+
+    const bool is_hotkey = pressed_inputs.size() >= 2 &&
+                           (pressed_inputs[1]->press_time - pressed_inputs[0]->press_time) >
+                               HOTKEY_VS_CONJUNCION_THRESHOLD;
+
+    if (is_hotkey)
+    {
+      alternations.push_back(fmt::format("@({})", JoinStrings(alternation, "+")));
+    }
+    else
+    {
+      std::sort(alternation.begin(), alternation.end());
+      alternations.push_back(JoinStrings(alternation, "&"));
+    }
+  };
+
+  for (auto& detection : detections)
+  {
+    // Remove since released inputs.
+    for (auto it = pressed_inputs.begin(); it != pressed_inputs.end();)
+    {
+      if (!((*it)->release_time > detection.press_time))
+      {
+        handle_release();
+        it = pressed_inputs.erase(it);
+      }
+      else
+        ++it;
+    }
+
+    handle_press(detection);
+  }
+
+  handle_release();
+
+  // Remove duplicates
+  std::sort(alternations.begin(), alternations.end());
+  alternations.erase(std::unique(alternations.begin(), alternations.end()), alternations.end());
+
+  return JoinStrings(alternations, "|");
+}
+
+void RemoveSpuriousTriggerCombinations(
+    std::vector<ciface::Core::DeviceContainer::InputDetection>* detections)
+{
+  const auto is_spurious = [&](auto& detection) {
+    return std::any_of(detections->begin(), detections->end(), [&](auto& d) {
+      // This is a suprious digital detection if a "smooth" (analog) detection is temporally near.
+      return &d != &detection && d.smoothness > 1 &&
+             abs(d.press_time - detection.press_time) < SPURIOUS_TRIGGER_COMBO_THRESHOLD;
+    });
+  };
+
+  detections->erase(std::remove_if(detections->begin(), detections->end(), is_spurious),
+                    detections->end());
+}
+
+}  // namespace ciface::MappingCommon
diff --git a/Source/Core/InputCommon/ControllerInterface/MappingCommon.h b/Source/Core/InputCommon/ControllerInterface/MappingCommon.h
new file mode 100644
index 0000000000..1822125557
--- /dev/null
+++ b/Source/Core/InputCommon/ControllerInterface/MappingCommon.h
@@ -0,0 +1,29 @@
+// Copyright 2022 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "InputCommon/ControllerInterface/CoreDevice.h"
+
+namespace ciface::MappingCommon
+{
+enum class Quote
+{
+  On,
+  Off
+};
+
+std::string GetExpressionForControl(const std::string& control_name,
+                                    const ciface::Core::DeviceQualifier& control_device,
+                                    const ciface::Core::DeviceQualifier& default_device,
+                                    Quote quote = Quote::On);
+
+std::string BuildExpression(const std::vector<ciface::Core::DeviceContainer::InputDetection>&,
+                            const ciface::Core::DeviceQualifier& default_device, Quote quote);
+
+void RemoveSpuriousTriggerCombinations(std::vector<ciface::Core::DeviceContainer::InputDetection>*);
+
+}  // namespace ciface::MappingCommon