Plaftorm: Add cursor management support

src/Magnum/Platform/GlfwApplication.cpp

@@ -549,6 +549,8 @@ void GlfwApplication::setupCallbacks() {
 
 GlfwApplication::~GlfwApplication() {
     glfwDestroyWindow(_window);
+    for(auto& cursor: _cursors)
+        glfwDestroyCursor(cursor);
     glfwTerminate();
 }
 
@@ -603,6 +605,41 @@ int GlfwApplication::exec() {
     return _exitCode;
 }
 
+void GlfwApplication::setCursor(Cursor cursor) {
+    CORRADE_INTERNAL_ASSERT(UnsignedInt(cursor) < Containers::arraySize(_cursors));
+
+    _cursor = cursor;
+
+    if(cursor == Cursor::Hidden) {
+        glfwSetInputMode(_window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
+        return;
+    } else if(cursor == Cursor::HiddenLocked) {
+        glfwSetInputMode(_window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
+        return;
+    } else {
+        glfwSetInputMode(_window, GLFW_CURSOR, GLFW_CURSOR_NORMAL);
+    }
+
+    if(!_cursors[UnsignedInt(cursor)]) {
+        constexpr Int CursorMap[] {
+            GLFW_ARROW_CURSOR,
+            GLFW_IBEAM_CURSOR,
+            GLFW_CROSSHAIR_CURSOR,
+            GLFW_HRESIZE_CURSOR,
+            GLFW_VRESIZE_CURSOR,
+            GLFW_HAND_CURSOR
+        };
+
+        _cursors[UnsignedInt(cursor)] = glfwCreateStandardCursor(CursorMap[UnsignedInt(cursor)]);
+    }
+
+    glfwSetCursor(_window, _cursors[UnsignedInt(cursor)]);
+}
+
+GlfwApplication::Cursor GlfwApplication::cursor() {
+    return _cursor;
+}
+
 auto GlfwApplication::MouseMoveEvent::buttons() -> Buttons {
     if(!_buttons) {
         _buttons = Buttons{};

src/Magnum/Platform/GlfwApplication.h

@@ -487,6 +487,33 @@ class GlfwApplication {
         /** @{ @name Mouse handling */
 
     public:
+        /**
+         * @brief Cursor type
+         *
+         * @see @ref setCursor()
+         */
+        enum class Cursor : UnsignedInt {
+            Arrow,          /**< Arrow */
+            TextInput,      /**< Text input */
+            Crosshair,      /**< Crosshair */
+            ResizeWE,       /**< Double arrow pointing west and east */
+            ResizeNS,       /**< Double arrow pointing north and south */
+            Hand,           /**< Hand */
+            Hidden,         /**< Hidden */
+            HiddenLocked    /**< Hidden and locked */
+        };
+
+    public:
+        /**
+         * @brief Set the cursor to the @p type
+         */
+        void setCursor(Cursor cursor);
+
+        /**
+         * @brief Get the current cursor type
+         */
+        Cursor cursor();
+
         /** @brief Warp mouse cursor to given coordinates */
         void warpCursor(const Vector2i& position) {
             glfwSetCursorPos(_window, Double(position.x()), Double(position.y()));
@@ -577,6 +604,9 @@ class GlfwApplication {
 
         void setupCallbacks();
 
+        GLFWcursor* _cursors[8]{};
+        Cursor _cursor = Cursor::Arrow;
+
         /* These are saved from command-line arguments */
         bool _verboseLog{};
         Implementation::GlfwDpiScalingPolicy _commandLineDpiScalingPolicy{};

src/Magnum/Platform/Sdl2Application.cpp

@@ -684,6 +684,11 @@ Sdl2Application::~Sdl2Application() {
     #endif
     #endif
 
+    #ifndef CORRADE_TARGET_EMSCRIPTEN
+    for(auto& cursor: _cursors)
+        SDL_FreeCursor(cursor);
+    #endif
+
     #ifndef CORRADE_TARGET_EMSCRIPTEN
     SDL_DestroyWindow(_window);
     #endif
@@ -880,6 +885,64 @@ bool Sdl2Application::mainLoopIteration() {
     return !(_flags & Flag::Exit);
 }
 
+#ifndef CORRADE_TARGET_EMSCRIPTEN
+void Sdl2Application::setCursor(Cursor cursor) {
+    CORRADE_INTERNAL_ASSERT(UnsignedInt(cursor) < Containers::arraySize(_cursors));
+
+    if(cursor == Cursor::Hidden) {
+        SDL_ShowCursor(SDL_DISABLE);
+        SDL_SetWindowGrab(_window, SDL_FALSE);
+        SDL_SetRelativeMouseMode(SDL_FALSE);
+        return;
+    } else if(cursor == Cursor::HiddenLocked) {
+        SDL_SetWindowGrab(_window, SDL_TRUE);
+        SDL_SetRelativeMouseMode(SDL_TRUE);
+        return;
+    } else {
+        SDL_ShowCursor(SDL_ENABLE);
+        SDL_SetWindowGrab(_window, SDL_FALSE);
+        SDL_SetRelativeMouseMode(SDL_FALSE);
+    }
+
+    if(!_cursors[UnsignedInt(cursor)]) {
+        constexpr SDL_SystemCursor CursorMap[] {
+            SDL_SYSTEM_CURSOR_ARROW,
+            SDL_SYSTEM_CURSOR_IBEAM,
+            SDL_SYSTEM_CURSOR_WAIT,
+            SDL_SYSTEM_CURSOR_CROSSHAIR,
+            SDL_SYSTEM_CURSOR_WAITARROW,
+            SDL_SYSTEM_CURSOR_SIZENWSE,
+            SDL_SYSTEM_CURSOR_SIZENESW,
+            SDL_SYSTEM_CURSOR_SIZEWE,
+            SDL_SYSTEM_CURSOR_SIZENS,
+            SDL_SYSTEM_CURSOR_SIZEALL,
+            SDL_SYSTEM_CURSOR_NO,
+            SDL_SYSTEM_CURSOR_HAND
+        };
+
+        _cursors[UnsignedInt(cursor)] = SDL_CreateSystemCursor(CursorMap[UnsignedInt(cursor)]);
+    }
+
+    SDL_SetCursor(_cursors[UnsignedInt(cursor)]);
+}
+
+Sdl2Application::Cursor Sdl2Application::cursor() {
+    if(SDL_GetRelativeMouseMode())
+        return Cursor::HiddenLocked;
+    else if(!SDL_ShowCursor(SDL_QUERY))
+        return Cursor::Hidden;
+
+    SDL_Cursor* cursor = SDL_GetCursor();
+
+    if(cursor)
+        for(UnsignedInt i = 0; i < sizeof(_cursors); i++)
+            if(_cursors[i] == cursor)
+                return Cursor(i);
+
+    return Cursor::Arrow;
+}
+#endif
+
 void Sdl2Application::setMouseLocked(bool enabled) {
     /** @todo Implement this in Emscripten */
     #ifndef CORRADE_TARGET_EMSCRIPTEN

src/Magnum/Platform/Sdl2Application.h

@@ -832,6 +832,48 @@ class Sdl2Application {
         /** @{ @name Mouse handling */
 
     public:
+        #ifndef CORRADE_TARGET_EMSCRIPTEN
+        /**
+         * @brief Cursor type
+         *
+         * @see @ref setCursor()
+         */
+        enum class Cursor : UnsignedInt {
+            Arrow,          /**< Arrow */
+            TextInput,      /**< Text input */
+            Wait,           /**< Wait */
+            Crosshair,      /**< Crosshair */
+            WaitArrow,      /**< Small wait cursor */
+            ResizeNWSE,     /**< Double arrow pointing northwest and southeast */
+            ResizeNESW,     /**< Double arrow pointing northeast and southwest */
+            ResizeWE,       /**< Double arrow pointing west and east */
+            ResizeNS,       /**< Double arrow pointing north and south */
+            ResizeAll,      /**< Four pointed arrow pointing north, south, east, and west */
+            No,             /**< Slashed circle or crossbones */
+            Hand,           /**< Hand */
+            Hidden,         /**< Hidden */
+            HiddenLocked    /**< Hidden and locked */
+        };
+        #endif
+
+    public:
+        #ifndef CORRADE_TARGET_EMSCRIPTEN
+        /**
+         * @brief Set the cursor to the @p type
+         */
+        void setCursor(Cursor cursor);
+
+        /**
+         * @brief Get the current cursor type
+         */
+        Cursor cursor();
+        #endif
+
+        /** @brief Warp mouse cursor to given coordinates */
+        void warpCursor(const Vector2i& position) {
+            SDL_WarpMouseInWindow(_window, position.x(), position.y());
+        }
+
         /** @brief Whether mouse is locked */
         bool isMouseLocked() const { return SDL_GetRelativeMouseMode(); }
 
@@ -1015,6 +1057,10 @@ class Sdl2Application {
         typedef Containers::EnumSet<Flag> Flags;
         CORRADE_ENUMSET_FRIEND_OPERATORS(Flags)
 
+        #ifndef CORRADE_TARGET_EMSCRIPTEN
+        SDL_Cursor* _cursors[14]{};
+        #endif
+
         /* These are saved from command-line arguments */
         bool _verboseLog{};
         Implementation::Sdl2DpiScalingPolicy _commandLineDpiScalingPolicy{};