feat(qt): add custom screen layout editor

src/citra/config.cpp

@@ -160,7 +160,6 @@ void Config::ReadValues() {
         static_cast<Settings::LayoutOption>(sdl2_config->GetInteger("Layout", "layout_option", 0));
     Settings::values.swap_screen = sdl2_config->GetBoolean("Layout", "swap_screen", false);
     Settings::values.upright_screen = sdl2_config->GetBoolean("Layout", "upright_screen", false);
-    Settings::values.custom_layout = sdl2_config->GetBoolean("Layout", "custom_layout", false);
     Settings::values.custom_top_left =
         static_cast<u16>(sdl2_config->GetInteger("Layout", "custom_top_left", 0));
     Settings::values.custom_top_top =

src/citra_qt/CMakeLists.txt

@@ -79,6 +79,12 @@ add_executable(citra-qt
     configuration/configure_web.cpp
     configuration/configure_web.h
     configuration/configure_web.ui
+    configuration/custom_screen.cpp
+    configuration/custom_screen.h
+    configuration/custom_screen.ui
+    configuration/custom_screen_layout_editor.cpp
+    configuration/custom_screen_layout_editor.h
+    configuration/custom_screen_layout_editor.ui
     debugger/console.h
     debugger/console.cpp
     debugger/graphics/graphics.cpp

src/citra_qt/configuration/config.cpp

@@ -343,7 +343,6 @@ void Config::ReadLayoutValues() {
         static_cast<Settings::LayoutOption>(ReadSetting(QStringLiteral("layout_option")).toInt());
     Settings::values.swap_screen = ReadSetting(QStringLiteral("swap_screen"), false).toBool();
     Settings::values.upright_screen = ReadSetting(QStringLiteral("upright_screen"), false).toBool();
-    Settings::values.custom_layout = ReadSetting(QStringLiteral("custom_layout"), false).toBool();
     Settings::values.custom_top_left = ReadSetting(QStringLiteral("custom_top_left"), 0).toInt();
     Settings::values.custom_top_top = ReadSetting(QStringLiteral("custom_top_top"), 0).toInt();
     Settings::values.custom_top_right =
@@ -887,7 +886,6 @@ void Config::SaveLayoutValues() {
     WriteSetting(QStringLiteral("layout_option"), static_cast<int>(Settings::values.layout_option));
     WriteSetting(QStringLiteral("swap_screen"), Settings::values.swap_screen, false);
     WriteSetting(QStringLiteral("upright_screen"), Settings::values.upright_screen, false);
-    WriteSetting(QStringLiteral("custom_layout"), Settings::values.custom_layout, false);
     WriteSetting(QStringLiteral("custom_top_left"), Settings::values.custom_top_left, 0);
     WriteSetting(QStringLiteral("custom_top_top"), Settings::values.custom_top_top, 0);
     WriteSetting(QStringLiteral("custom_top_right"), Settings::values.custom_top_right, 400);

src/citra_qt/configuration/configure_enhancements.cpp

@@ -2,16 +2,41 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <cassert>
 #include <QColorDialog>
+#include <QPoint>
+#include <QString>
 #include "citra_qt/configuration/configure_enhancements.h"
+#include "core/3ds.h"
 #include "core/core.h"
 #include "core/settings.h"
 #include "ui_configure_enhancements.h"
 #include "video_core/renderer_opengl/post_processing_opengl.h"
 #include "video_core/renderer_opengl/texture_filters/texture_filterer.h"
 
+namespace {
+
+const QString g_top_screen_name{QObject::tr("Top")};
+const QString g_bottom_screen_name{QObject::tr("Bottom")};
+
+void AddScreens(CustomScreenLayoutEditor& layout_editor) {
+    layout_editor.addScreen(
+        g_top_screen_name, {0, 0, Core::kScreenTopWidth, Core::kScreenTopHeight},
+        {QPoint{Settings::values.custom_top_left, Settings::values.custom_top_top},
+         QPoint{Settings::values.custom_top_right - 1, Settings::values.custom_top_bottom - 1}});
+    layout_editor.addScreen(
+        g_bottom_screen_name,
+        {40, Core::kScreenTopHeight, Core::kScreenBottomWidth, Core::kScreenBottomHeight},
+        {QPoint{Settings::values.custom_bottom_left, Settings::values.custom_bottom_top},
+         QPoint{Settings::values.custom_bottom_right - 1,
+                Settings::values.custom_bottom_bottom - 1}});
+}
+
+} // namespace
+
 ConfigureEnhancements::ConfigureEnhancements(QWidget* parent)
-    : QWidget(parent), ui(std::make_unique<Ui::ConfigureEnhancements>()) {
+    : QWidget(parent), ui(std::make_unique<Ui::ConfigureEnhancements>()),
+      layout_editor(std::make_unique<CustomScreenLayoutEditor>(this)) {
     ui->setupUi(this);
 
     for (const auto& filter : OpenGL::TextureFilterer::GetFilterNames())
@@ -19,16 +44,19 @@ ConfigureEnhancements::ConfigureEnhancements(QWidget* parent)
 
     SetConfiguration();
 
-    ui->layoutBox->setEnabled(!Settings::values.custom_layout);
-
     ui->resolution_factor_combobox->setEnabled(Settings::values.use_hw_renderer);
 
+    AddScreens(*layout_editor);
+
     connect(ui->render_3d_combobox,
             static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged), this,
             [this](int currentIndex) {
                 updateShaders(static_cast<Settings::StereoRenderOption>(currentIndex));
             });
 
+    connect(ui->editor_button, &QPushButton::clicked, this,
+            [this] { layout_editor->showMaximized(); });
+
     connect(ui->bg_button, &QPushButton::clicked, this, [this] {
         const QColor new_bg_color = QColorDialog::getColor(bg_color);
         if (!new_bg_color.isValid()) {
@@ -113,6 +141,23 @@ void ConfigureEnhancements::ApplyConfiguration() {
     Settings::values.texture_filter_name = ui->texture_filter_combobox->currentText().toStdString();
     Settings::values.layout_option =
         static_cast<Settings::LayoutOption>(ui->layout_combobox->currentIndex());
+    {
+        const auto geometry = [this](const QString& screen_name) {
+            const auto* const screen{layout_editor->getScreen(screen_name)};
+            assert(screen);
+            return screen->geometry();
+        };
+        const QRect top_screen{geometry(g_top_screen_name)};
+        Settings::values.custom_top_left = top_screen.left();
+        Settings::values.custom_top_top = top_screen.top();
+        Settings::values.custom_top_right = top_screen.right() + 1;
+        Settings::values.custom_top_bottom = top_screen.bottom() + 1;
+        const QRect bottom_screen{geometry(g_bottom_screen_name)};
+        Settings::values.custom_bottom_left = bottom_screen.left();
+        Settings::values.custom_bottom_top = bottom_screen.top();
+        Settings::values.custom_bottom_right = bottom_screen.right() + 1;
+        Settings::values.custom_bottom_bottom = bottom_screen.bottom() + 1;
+    }
     Settings::values.swap_screen = ui->swap_screen->isChecked();
     Settings::values.upright_screen = ui->upright_screen->isChecked();
     Settings::values.dump_textures = ui->toggle_dump_textures->isChecked();

src/citra_qt/configuration/configure_enhancements.h

@@ -6,6 +6,7 @@
 
 #include <memory>
 #include <QWidget>
+#include "citra_qt/configuration/custom_screen_layout_editor.h"
 
 namespace Settings {
 enum class StereoRenderOption;
@@ -31,5 +32,6 @@ private:
     void updateTextureFilter(int index);
 
     std::unique_ptr<Ui::ConfigureEnhancements> ui;
+    std::unique_ptr<CustomScreenLayoutEditor> layout_editor;
     QColor bg_color;
 };

src/citra_qt/configuration/configure_enhancements.ui

@@ -216,6 +216,13 @@
       <string>Layout</string>
      </property>
      <layout class="QVBoxLayout" name="verticalLayout_3">
+      <item>
+       <widget class="QPushButton" name="editor_button">
+        <property name="text">
+         <string>Edit Custom Screen Layout</string>
+        </property>
+       </widget>
+      </item>
       <item>
        <layout class="QHBoxLayout" name="horizontalLayout_4">
         <item>
@@ -247,6 +254,11 @@
             <string>Side by Side</string>
            </property>
           </item>
+          <item>
+           <property name="text">
+            <string>Custom</string>
+           </property>
+          </item>
          </widget>
         </item>
        </layout>

src/citra_qt/configuration/custom_screen.cpp

@@ -0,0 +1,261 @@
+// Copyright 2019 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+#include <numeric>
+#include <utility>
+#include <QMouseEvent>
+#include <QMoveEvent>
+#include <QResizeEvent>
+#include <QSpinBox>
+#include <QtGlobal>
+#include "citra_qt/configuration/custom_screen.h"
+#include "common/diagnostic.h"
+#include "ui_custom_screen.h"
+
+CITRA_DIAGNOSTIC_IGNORE_SWITCH
+
+constexpr unsigned to_underlying(RectangleSides s) {
+    return static_cast<unsigned>(s);
+}
+
+constexpr RectangleSides operator|(RectangleSides l, RectangleSides r) {
+    return RectangleSides{to_underlying(l) | to_underlying(r)};
+}
+
+constexpr RectangleSides operator&(RectangleSides l, RectangleSides r) {
+    return RectangleSides{to_underlying(l) & to_underlying(r)};
+}
+
+CustomScreen::CustomScreen(QWidget* parent)
+    : QFrame(parent), ui(std::make_unique<Ui::CustomScreen>()) {
+    ui->setupUi(this);
+
+    const auto value_changed{QOverload<int>::of(&QSpinBox::valueChanged)};
+
+    connect(ui->left, value_changed, this, [this](int x) { move(x, y()); });
+    connect(ui->top, value_changed, this, [this](int y) { move(x(), y); });
+    connect(ui->width, value_changed, this, [this](int width) {
+        resize(width, height());
+        ui->width->setValue(this->width());
+    });
+    connect(ui->height, value_changed, this, [this](int height) {
+        resize(width(), height);
+        ui->height->setValue(this->height());
+    });
+}
+
+QString CustomScreen::name() const {
+    return ui->name->text();
+}
+
+void CustomScreen::setName(const QString& name) {
+    ui->name->setText(name);
+}
+
+namespace {
+
+bool IsClamped(int v, int lo, int hi) {
+    return lo <= v && v < hi;
+}
+
+} // namespace
+
+auto CustomScreen::SidesAt(QPoint pt) -> RectangleSides {
+    return RectangleSides{
+        (IsClamped(pt.x(), 0, lineWidth()) ? RectangleSides::left : RectangleSides{}) |
+        (IsClamped(pt.y(), 0, lineWidth()) ? RectangleSides::top : RectangleSides{}) |
+        (IsClamped(pt.x(), width() - lineWidth(), width()) ? RectangleSides::right
+                                                           : RectangleSides{}) |
+        (IsClamped(pt.y(), height() - lineWidth(), height()) ? RectangleSides::bottom
+                                                             : RectangleSides{})};
+}
+
+void CustomScreen::mousePressEvent(QMouseEvent* event) {
+    switch (event->buttons()) {
+    case Qt::MouseButton::LeftButton:
+        drag = {SidesAt(event->pos()), geometry(), event->globalPos()};
+        if (drag.sides == RectangleSides{})
+            setCursor(Qt::CursorShape::ClosedHandCursor);
+        return event->accept();
+    default:
+        return event->ignore();
+    }
+}
+
+void CustomScreen::mouseMoveEvent(QMouseEvent* event) {
+    switch (event->buttons()) {
+    case Qt::MouseButton::NoButton:
+        switch (SidesAt(event->pos())) {
+        case RectangleSides::left:
+        case RectangleSides::right:
+            setCursor(Qt::CursorShape::SizeHorCursor);
+            break;
+        case RectangleSides::top:
+        case RectangleSides::bottom:
+            setCursor(Qt::CursorShape::SizeVerCursor);
+            break;
+        case RectangleSides::top | RectangleSides::left:
+        case RectangleSides::bottom | RectangleSides::right:
+            setCursor(Qt::CursorShape::SizeFDiagCursor);
+            break;
+        case RectangleSides::top | RectangleSides::right:
+        case RectangleSides::bottom | RectangleSides::left:
+            setCursor(Qt::CursorShape::SizeBDiagCursor);
+            break;
+        default:
+            setCursor(Qt::CursorShape::OpenHandCursor);
+            break;
+        }
+        break;
+    case Qt::MouseButton::LeftButton:
+        drag(*this, event->globalPos());
+        break;
+    default:
+        return event->ignore();
+    }
+
+    event->accept();
+}
+
+namespace {
+
+bool HasSingleBit(unsigned x) {
+    return x != 0 && (x & (x - 1)) == 0;
+}
+
+unsigned BitWidth(unsigned x) {
+    return x == 0 ? 0 : 1 + static_cast<unsigned>(std::log2(x));
+}
+
+struct RectangleSideOffsets {
+    int sides[4]{};
+
+    int& operator[](RectangleSides s) {
+        assert(HasSingleBit(to_underlying(s)));
+        return sides[BitWidth(to_underlying(s)) - 1];
+    }
+
+    int& left() {
+        return operator[](RectangleSides::left);
+    }
+    int& top() {
+        return operator[](RectangleSides::top);
+    }
+    int& right() {
+        return operator[](RectangleSides::right);
+    }
+    int& bottom() {
+        return operator[](RectangleSides::bottom);
+    }
+};
+
+RectangleSides prev(RectangleSides side) {
+    assert(HasSingleBit(to_underlying(side)));
+    return side == RectangleSides::left ? RectangleSides::bottom
+                                        : RectangleSides{to_underlying(side) >> 1};
+}
+
+RectangleSides next(RectangleSides side) {
+    assert(HasSingleBit(to_underlying(side)));
+    return side == RectangleSides::bottom ? RectangleSides::left
+                                          : RectangleSides{to_underlying(side) << 1};
+}
+
+bool HaveEqualOutwardsDirectionSign(RectangleSides l, RectangleSides r) {
+    assert(l != r);
+    return (l | r) == (RectangleSides::top | RectangleSides::left) ||
+           (l | r) == (RectangleSides::bottom | RectangleSides::right);
+}
+
+void GrowAdjacents(double aspect_ratio, RectangleSideOffsets& offsets, RectangleSides side) {
+    assert(HasSingleBit(to_underlying(side)));
+    const int adjacent_growth{static_cast<int>(aspect_ratio * offsets[side])};
+    RectangleSides adjacent_sides[2]{prev(side), next(side)};
+    if (!HaveEqualOutwardsDirectionSign(side, adjacent_sides[0]))
+        std::swap(adjacent_sides[0], adjacent_sides[1]);
+    offsets[adjacent_sides[0]] = adjacent_growth / 2;
+    offsets[adjacent_sides[1]] = -adjacent_growth / 2;
+}
+
+int FurthestOffset(RectangleSides side, int l, int r) {
+    assert(HasSingleBit(to_underlying(side)));
+    return (side & (RectangleSides::top | RectangleSides::left)) != RectangleSides{}
+               ? std::min(l, r)
+               : std::max(l, r);
+}
+
+constexpr RectangleSides vertical_sides{RectangleSides::left | RectangleSides::right};
+constexpr RectangleSides horizontal_sides{RectangleSides::top | RectangleSides::bottom};
+
+[[maybe_unused]] bool IsCorner(RectangleSides sides) {
+    return HasSingleBit(to_underlying(sides & vertical_sides)) &&
+           HasSingleBit(to_underlying(sides & horizontal_sides));
+}
+
+void GrowCorner(double aspect_ratio, RectangleSideOffsets& offsets, RectangleSides corner) {
+    assert(IsCorner(corner));
+    const RectangleSides vertical_side{corner & vertical_sides};
+    const RectangleSides horizontal_side{corner & horizontal_sides};
+    int& vertical_offset{offsets[vertical_side]};
+    int& horizontal_offset{offsets[horizontal_side]};
+    const int adjust{HaveEqualOutwardsDirectionSign(vertical_side, horizontal_side) ? 1 : -1};
+    const int grown_vertical_offset{static_cast<int>(horizontal_offset * aspect_ratio) * adjust};
+    const int grown_horizontal_offset{static_cast<int>(vertical_offset / aspect_ratio) * adjust};
+    vertical_offset = FurthestOffset(vertical_side, vertical_offset, grown_vertical_offset);
+    horizontal_offset = FurthestOffset(horizontal_side, horizontal_offset, grown_horizontal_offset);
+}
+
+} // namespace
+
+void CustomScreen::Drag::operator()(CustomScreen& screen, QPoint move_position) const {
+    const auto drag_offset{move_position - press_position};
+
+    if (sides == RectangleSides{})
+        return screen.move(original_screen_geometry.topLeft() + drag_offset);
+
+    RectangleSideOffsets offsets{
+        (sides & RectangleSides::left) != RectangleSides{} ? drag_offset.x() : 0,
+        (sides & RectangleSides::top) != RectangleSides{} ? drag_offset.y() : 0,
+        (sides & RectangleSides::right) != RectangleSides{} ? drag_offset.x() : 0,
+        (sides & RectangleSides::bottom) != RectangleSides{} ? drag_offset.y() : 0};
+
+    if (screen.ui->keep_aspect_ratio->isChecked()) {
+        const double aspect_ratio{original_screen_geometry.width() * 1.0 /
+                                  original_screen_geometry.height()};
+        (HasSingleBit(to_underlying(sides)) ? GrowAdjacents : GrowCorner)(aspect_ratio, offsets,
+                                                                          sides);
+    }
+
+    screen.move(std::min(original_screen_geometry.x() + offsets.left(),
+                         original_screen_geometry.right() - screen.minimumWidth() + 1),
+                std::min(original_screen_geometry.y() + offsets.top(),
+                         original_screen_geometry.bottom() - screen.minimumHeight() + 1));
+    screen.resize(original_screen_geometry.width() + offsets.right() - offsets.left(),
+                  original_screen_geometry.height() + offsets.bottom() - offsets.top());
+}
+
+void CustomScreen::moveEvent(QMoveEvent*) {
+    move(std::max(0, x()), std::max(0, y()));
+    ui->left->setValue(x());
+    ui->top->setValue(y());
+}
+
+void CustomScreen::resizeEvent(QResizeEvent*) {
+    moveEvent(nullptr);
+    ui->width->setValue(width());
+    ui->height->setValue(height());
+
+#if !defined(NDEBUG)
+    const int num{width()};
+    const int den{height()};
+    const int gcd{std::gcd(num, den)};
+    ui->keep_aspect_ratio->setText(
+        tr("Keep aspect ratio (%1, %2:%3)").arg(1.0 * num / den).arg(num / gcd).arg(den / gcd));
+#endif
+}
+
+CustomScreen::~CustomScreen() {}

src/citra_qt/configuration/custom_screen.h

@@ -0,0 +1,57 @@
+// Copyright 2019 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <QFrame>
+#include <QPoint>
+#include <QRect>
+#include <QString>
+
+enum class RectangleSides : unsigned {
+    left = (1 << 0),
+    top = (1 << 1),
+    right = (1 << 2),
+    bottom = (1 << 3)
+};
+
+namespace Ui {
+class CustomScreen;
+}
+
+class CustomScreen : public QFrame {
+    Q_OBJECT
+
+public:
+    explicit CustomScreen(QWidget* parent = nullptr);
+    ~CustomScreen();
+
+    QString name() const;
+
+    void setName(const QString&);
+
+protected:
+    void mousePressEvent(QMouseEvent*) override;
+    void mouseMoveEvent(QMouseEvent*) override;
+
+    void moveEvent(QMoveEvent*) override;
+    void resizeEvent(QResizeEvent*) override;
+
+private:
+    RectangleSides SidesAt(QPoint);
+
+    struct Drag {
+        RectangleSides sides;
+        QRect original_screen_geometry;
+        QPoint press_position;
+
+        void operator()(CustomScreen& screen, QPoint move_position) const;
+    };
+
+    friend Drag;
+
+    std::unique_ptr<Ui::CustomScreen> ui;
+    Drag drag;
+};

src/citra_qt/configuration/custom_screen.ui

@@ -0,0 +1,146 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>CustomScreen</class>
+ <widget class="QFrame" name="CustomScreen">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="mouseTracking">
+   <bool>true</bool>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <property name="frameShape">
+   <enum>QFrame::StyledPanel</enum>
+  </property>
+  <property name="lineWidth">
+   <number>5</number>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout_4">
+   <property name="sizeConstraint">
+    <enum>QLayout::SetMinimumSize</enum>
+   </property>
+   <item>
+    <widget class="QLabel" name="name">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="text">
+      <string>TextLabel</string>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QCheckBox" name="keep_aspect_ratio">
+     <property name="text">
+      <string>Keep aspect ratio</string>
+     </property>
+     <property name="checked">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QFrame" name="frame">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="frameShape">
+      <enum>QFrame::StyledPanel</enum>
+     </property>
+     <property name="frameShadow">
+      <enum>QFrame::Raised</enum>
+     </property>
+     <layout class="QVBoxLayout" name="verticalLayout_6">
+      <item>
+       <layout class="QHBoxLayout" name="horizontalLayout_2">
+        <item>
+         <widget class="QLabel" name="label">
+          <property name="text">
+           <string>Left</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="left">
+          <property name="maximum">
+           <number>16777215</number>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+      <item>
+       <layout class="QHBoxLayout" name="horizontalLayout_3">
+        <item>
+         <widget class="QLabel" name="label_2">
+          <property name="text">
+           <string>Top</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="top">
+          <property name="maximum">
+           <number>16777215</number>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+      <item>
+       <layout class="QHBoxLayout" name="horizontalLayout">
+        <item>
+         <widget class="QLabel" name="label_3">
+          <property name="text">
+           <string>Width</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="width">
+          <property name="maximum">
+           <number>16777215</number>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+      <item>
+       <layout class="QHBoxLayout" name="horizontalLayout_4">
+        <item>
+         <widget class="QLabel" name="label_4">
+          <property name="text">
+           <string>Height</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QSpinBox" name="height">
+          <property name="maximum">
+           <number>16777215</number>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </item>
+     </layout>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>

src/citra_qt/configuration/custom_screen_layout_editor.cpp

@@ -0,0 +1,47 @@
+// Copyright 2019 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cstddef>
+#include <utility>
+#include <QMainWindow>
+#include <QPushButton>
+#include "citra_qt/configuration/custom_screen_layout_editor.h"
+#include "ui_custom_screen_layout_editor.h"
+
+CustomScreenLayoutEditor::CustomScreenLayoutEditor(QWidget* parent)
+    : QDialog(parent), ui(std::make_unique<Ui::CustomScreenLayoutEditor>()) {
+    ui->setupUi(this);
+
+    auto* const framebuffer = new QMainWindow;
+    ui->scroll_area->setWidget(framebuffer);
+
+    const auto set = [this](QRect RestorableScreen::*geometry) {
+        return [this, geometry] {
+            for (auto& s : screens)
+                s.screen->setGeometry(s.*geometry);
+        };
+    };
+
+    connect(ui->buttonBox->button(QDialogButtonBox::Reset), &QPushButton::clicked, this,
+            set(&RestorableScreen::reset_geometry));
+    connect(ui->buttonBox->button(QDialogButtonBox::RestoreDefaults), &QPushButton::clicked, this,
+            set(&RestorableScreen::default_geometry));
+}
+
+void CustomScreenLayoutEditor::addScreen(QString name, QRect default_geometry,
+                                         QRect current_geometry) {
+    auto s{std::make_unique<CustomScreen>(ui->scroll_area->widget())};
+    s->setGeometry(current_geometry);
+    s->setName(name);
+    screens.emplace_back(RestorableScreen{std::move(s), default_geometry});
+}
+
+CustomScreen* CustomScreenLayoutEditor::getScreen(QString name) const {
+    auto s{std::find_if(screens.begin(), screens.end(),
+                        [&](auto& s) { return s.screen->name() == name; })};
+    return s == screens.end() ? nullptr : s->screen.get();
+}
+
+CustomScreenLayoutEditor::~CustomScreenLayoutEditor() {}

src/citra_qt/configuration/custom_screen_layout_editor.h

@@ -0,0 +1,38 @@
+// Copyright 2019 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <vector>
+#include <QDialog>
+#include <QRect>
+#include <QString>
+#include "citra_qt/configuration/custom_screen.h"
+
+namespace Ui {
+class CustomScreenLayoutEditor;
+}
+
+class CustomScreenLayoutEditor : public QDialog {
+    Q_OBJECT
+
+public:
+    explicit CustomScreenLayoutEditor(QWidget* parent = nullptr);
+    ~CustomScreenLayoutEditor();
+
+    void addScreen(QString name, QRect default_geometry, QRect current_geometry);
+
+    CustomScreen* getScreen(QString name) const;
+
+private:
+    struct RestorableScreen {
+        std::unique_ptr<CustomScreen> screen;
+        QRect default_geometry;
+        QRect reset_geometry{screen->geometry()};
+    };
+
+    std::unique_ptr<Ui::CustomScreenLayoutEditor> ui;
+    std::vector<RestorableScreen> screens;
+};

src/citra_qt/configuration/custom_screen_layout_editor.ui

@@ -0,0 +1,81 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>CustomScreenLayoutEditor</class>
+ <widget class="QDialog" name="CustomScreenLayoutEditor">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>490</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Custom Screen Layout Editor</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QScrollArea" name="scroll_area">
+     <property name="widgetResizable">
+      <bool>true</bool>
+     </property>
+     <widget class="QWidget" name="scrollAreaWidgetContents">
+      <property name="geometry">
+       <rect>
+        <x>0</x>
+        <y>0</y>
+        <width>470</width>
+        <height>250</height>
+       </rect>
+      </property>
+     </widget>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok|QDialogButtonBox::Reset|QDialogButtonBox::RestoreDefaults</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>CustomScreenLayoutEditor</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>257</x>
+     <y>290</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>CustomScreenLayoutEditor</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>325</x>
+     <y>290</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>

src/citra_qt/main.cpp

@@ -301,6 +301,7 @@ void GMainWindow::InitializeWidgets() {
     actionGroup_ScreenLayouts->addAction(ui->action_Screen_Layout_Single_Screen);
     actionGroup_ScreenLayouts->addAction(ui->action_Screen_Layout_Large_Screen);
     actionGroup_ScreenLayouts->addAction(ui->action_Screen_Layout_Side_by_Side);
+    actionGroup_ScreenLayouts->addAction(ui->action_Screen_Layout_Custom);
 }
 
 void GMainWindow::InitializeDebugWidgets() {
@@ -734,6 +735,8 @@ void GMainWindow::ConnectMenuEvents() {
             &GMainWindow::ChangeScreenLayout);
     connect(ui->action_Screen_Layout_Side_by_Side, &QAction::triggered, this,
             &GMainWindow::ChangeScreenLayout);
+    connect(ui->action_Screen_Layout_Custom, &QAction::triggered, this,
+            &GMainWindow::ChangeScreenLayout);
     connect(ui->action_Screen_Layout_Swap_Screens, &QAction::triggered, this,
             &GMainWindow::OnSwapScreens);
     connect(ui->action_Screen_Layout_Upright_Screens, &QAction::triggered, this,
@@ -1664,6 +1667,8 @@ void GMainWindow::ChangeScreenLayout() {
         new_layout = Settings::LayoutOption::LargeScreen;
     } else if (ui->action_Screen_Layout_Side_by_Side->isChecked()) {
         new_layout = Settings::LayoutOption::SideScreen;
+    } else if (ui->action_Screen_Layout_Custom->isChecked()) {
+        new_layout = Settings::LayoutOption::Custom;
     }
 
     Settings::values.layout_option = new_layout;
@@ -1671,24 +1676,9 @@ void GMainWindow::ChangeScreenLayout() {
 }
 
 void GMainWindow::ToggleScreenLayout() {
-    Settings::LayoutOption new_layout = Settings::LayoutOption::Default;
+    Settings::values.layout_option =
-
+        static_cast<Settings::LayoutOption>((static_cast<int>(Settings::values.layout_option) + 1) %
-    switch (Settings::values.layout_option) {
+                                            (static_cast<int>(Settings::LayoutOption::Custom) + 1)),
-    case Settings::LayoutOption::Default:
-        new_layout = Settings::LayoutOption::SingleScreen;
-        break;
-    case Settings::LayoutOption::SingleScreen:
-        new_layout = Settings::LayoutOption::LargeScreen;
-        break;
-    case Settings::LayoutOption::LargeScreen:
-        new_layout = Settings::LayoutOption::SideScreen;
-        break;
-    case Settings::LayoutOption::SideScreen:
-        new_layout = Settings::LayoutOption::Default;
-        break;
-    }
-
-    Settings::values.layout_option = new_layout;
     SyncMenuUISettings();
     Settings::Apply();
 }
@@ -2387,6 +2377,8 @@ void GMainWindow::SyncMenuUISettings() {
                                                       Settings::LayoutOption::LargeScreen);
     ui->action_Screen_Layout_Side_by_Side->setChecked(Settings::values.layout_option ==
                                                       Settings::LayoutOption::SideScreen);
+    ui->action_Screen_Layout_Custom->setChecked(Settings::values.layout_option ==
+                                                Settings::LayoutOption::Custom);
     ui->action_Screen_Layout_Swap_Screens->setChecked(Settings::values.swap_screen);
     ui->action_Screen_Layout_Upright_Screens->setChecked(Settings::values.upright_screen);
 }

src/citra_qt/main.ui

@@ -125,6 +125,7 @@
      <addaction name="action_Screen_Layout_Single_Screen"/>
      <addaction name="action_Screen_Layout_Large_Screen"/>
      <addaction name="action_Screen_Layout_Side_by_Side"/>
+     <addaction name="action_Screen_Layout_Custom"/>
      <addaction name="separator"/>
      <addaction name="action_Screen_Layout_Upright_Screens"/>
      <addaction name="action_Screen_Layout_Swap_Screens"/>
@@ -461,6 +462,14 @@
     <string>Side by Side</string>
    </property>
   </action>
+  <action name="action_Screen_Layout_Custom">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Custom</string>
+   </property>
+  </action>
   <action name="action_Screen_Layout_Swap_Screens">
    <property name="checkable">
     <bool>true</bool>

src/common/diagnostic.h

@@ -0,0 +1,27 @@
+// Copyright 2019 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+// Adapted from
+// https://github.com/ericniebler/range-v3/blob/master/include/range/v3/detail/config.hpp#L185.
+#define CITRA_PRAGMA(X) _Pragma(#X)
+#if !CITRA_COMP_MSVC
+#define CITRA_DIAGNOSTIC_PUSH CITRA_PRAGMA(GCC diagnostic push)
+#define CITRA_DIAGNOSTIC_POP CITRA_PRAGMA(GCC diagnostic pop)
+#define CITRA_DIAGNOSTIC_IGNORE_PRAGMAS CITRA_PRAGMA(GCC diagnostic ignored "-Wpragmas")
+#define CITRA_DIAGNOSTIC_IGNORE(X)                                                                 \
+    CITRA_DIAGNOSTIC_IGNORE_PRAGMAS                                                                \
+    CITRA_PRAGMA(GCC diagnostic ignored "-Wunknown-pragmas")                                       \
+    CITRA_PRAGMA(GCC diagnostic ignored "-Wunknown-warning-option")                                \
+    CITRA_PRAGMA(GCC diagnostic ignored X)
+#define CITRA_DIAGNOSTIC_IGNORE_SWITCH CITRA_DIAGNOSTIC_IGNORE("-Wswitch")
+#else
+#define CITRA_DIAGNOSTIC_PUSH CITRA_PRAGMA(warning(push))
+#define CITRA_DIAGNOSTIC_POP CITRA_PRAGMA(warning(pop))
+#define CITRA_DIAGNOSTIC_IGNORE_PRAGMAS CITRA_PRAGMA(warning(disable : 4068))
+#define CITRA_DIAGNOSTIC_IGNORE(X)                                                                 \
+    CITRA_DIAGNOSTIC_IGNORE_PRAGMAS CITRA_PRAGMA(warning(disable : X))
+#define CITRA_DIAGNOSTIC_IGNORE_SWITCH
+#endif

src/core/frontend/emu_window.cpp

@@ -151,12 +151,12 @@ void EmuWindow::UpdateCurrentFramebufferLayout(unsigned width, unsigned height)
     const auto min_size =
         Layout::GetMinimumSizeFromLayout(layout_option, Settings::values.upright_screen);
 
-    if (Settings::values.custom_layout == true) {
-        layout = Layout::CustomFrameLayout(width, height);
-    } else {
     width = std::max(width, min_size.first);
     height = std::max(height, min_size.second);
     switch (layout_option) {
+    case Settings::LayoutOption::Custom:
+        layout = Layout::CustomFrameLayout(width, height);
+        break;
     case Settings::LayoutOption::SingleScreen:
         layout = Layout::SingleFrameLayout(width, height, Settings::values.swap_screen,
                                            Settings::values.upright_screen);
@@ -176,7 +176,6 @@ void EmuWindow::UpdateCurrentFramebufferLayout(unsigned width, unsigned height)
         break;
     }
     UpdateMinimumWindowSize(min_size);
-    }
     NotifyFramebufferLayoutChanged(layout);
 }
 

src/core/frontend/framebuffer_layout.cpp

@@ -286,13 +286,13 @@ FramebufferLayout CustomFrameLayout(u32 width, u32 height) {
 
 FramebufferLayout FrameLayoutFromResolutionScale(u32 res_scale) {
     FramebufferLayout layout;
-    if (Settings::values.custom_layout == true) {
+    int width, height;
+    switch (Settings::values.layout_option) {
+    case Settings::LayoutOption::Custom:
         layout = CustomFrameLayout(
             std::max(Settings::values.custom_top_right, Settings::values.custom_bottom_right),
             std::max(Settings::values.custom_top_bottom, Settings::values.custom_bottom_bottom));
-    } else {
+        break;
-        int width, height;
-        switch (Settings::values.layout_option) {
     case Settings::LayoutOption::SingleScreen:
         if (Settings::values.upright_screen) {
             if (Settings::values.swap_screen) {
@@ -359,7 +359,6 @@ FramebufferLayout FrameLayoutFromResolutionScale(u32 res_scale) {
                                     Settings::values.upright_screen);
         break;
     }
-    }
     return layout;
 }
 

src/core/settings.h

@@ -24,6 +24,7 @@ enum class LayoutOption {
     SingleScreen,
     LargeScreen,
     SideScreen,
+    Custom,
 };
 
 enum class MicInputType {
@@ -163,7 +164,6 @@ struct Values {
     LayoutOption layout_option;
     bool swap_screen;
     bool upright_screen;
-    bool custom_layout;
     u16 custom_top_left;
     u16 custom_top_top;
     u16 custom_top_right;