src/video/winrt/SDL_winrtmouse.cpp
author Sam Lantinga <slouken@libsdl.org>
Thu, 04 Jun 2020 12:30:25 -0700
changeset 13898 aa9d7c43a982
parent 13696 ea20a7434b98
permissions -rw-r--r--
Fixed exception if getManifestEnvironmentVariables() is called without a current SDL activity
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 #include "../../SDL_internal.h"
    22 
    23 #if SDL_VIDEO_DRIVER_WINRT
    24 
    25 /*
    26  * Windows includes:
    27  */
    28 #include <Windows.h>
    29 #include <windows.ui.core.h>
    30 using namespace Windows::UI::Core;
    31 using Windows::UI::Core::CoreCursor;
    32 
    33 /*
    34  * SDL includes:
    35  */
    36 extern "C" {
    37 #include "SDL_assert.h"
    38 #include "../../events/SDL_mouse_c.h"
    39 #include "../../events/SDL_touch_c.h"
    40 #include "../SDL_sysvideo.h"
    41 #include "SDL_events.h"
    42 }
    43 
    44 #include "../../core/winrt/SDL_winrtapp_direct3d.h"
    45 #include "SDL_winrtvideo_cpp.h"
    46 #include "SDL_winrtmouse_c.h"
    47 
    48 
    49 extern "C" SDL_bool WINRT_UsingRelativeMouseMode = SDL_FALSE;
    50 
    51 
    52 static SDL_Cursor *
    53 WINRT_CreateSystemCursor(SDL_SystemCursor id)
    54 {
    55     SDL_Cursor *cursor;
    56     CoreCursorType cursorType = CoreCursorType::Arrow;
    57 
    58     switch(id)
    59     {
    60     default:
    61         SDL_assert(0);
    62         return NULL;
    63     case SDL_SYSTEM_CURSOR_ARROW:     cursorType = CoreCursorType::Arrow; break;
    64     case SDL_SYSTEM_CURSOR_IBEAM:     cursorType = CoreCursorType::IBeam; break;
    65     case SDL_SYSTEM_CURSOR_WAIT:      cursorType = CoreCursorType::Wait; break;
    66     case SDL_SYSTEM_CURSOR_CROSSHAIR: cursorType = CoreCursorType::Cross; break;
    67     case SDL_SYSTEM_CURSOR_WAITARROW: cursorType = CoreCursorType::Wait; break;
    68     case SDL_SYSTEM_CURSOR_SIZENWSE:  cursorType = CoreCursorType::SizeNorthwestSoutheast; break;
    69     case SDL_SYSTEM_CURSOR_SIZENESW:  cursorType = CoreCursorType::SizeNortheastSouthwest; break;
    70     case SDL_SYSTEM_CURSOR_SIZEWE:    cursorType = CoreCursorType::SizeWestEast; break;
    71     case SDL_SYSTEM_CURSOR_SIZENS:    cursorType = CoreCursorType::SizeNorthSouth; break;
    72     case SDL_SYSTEM_CURSOR_SIZEALL:   cursorType = CoreCursorType::SizeAll; break;
    73     case SDL_SYSTEM_CURSOR_NO:        cursorType = CoreCursorType::UniversalNo; break;
    74     case SDL_SYSTEM_CURSOR_HAND:      cursorType = CoreCursorType::Hand; break;
    75     }
    76 
    77     cursor = (SDL_Cursor *) SDL_calloc(1, sizeof(*cursor));
    78     if (cursor) {
    79         /* Create a pointer to a COM reference to a cursor.  The extra
    80            pointer is used (on top of the COM reference) to allow the cursor
    81            to be referenced by the SDL_cursor's driverdata field, which is
    82            a void pointer.
    83         */
    84         CoreCursor ^* theCursor = new CoreCursor^(nullptr);
    85         *theCursor = ref new CoreCursor(cursorType, 0);
    86         cursor->driverdata = (void *) theCursor;
    87     } else {
    88         SDL_OutOfMemory();
    89     }
    90 
    91     return cursor;
    92 }
    93 
    94 static SDL_Cursor *
    95 WINRT_CreateDefaultCursor()
    96 {
    97     return WINRT_CreateSystemCursor(SDL_SYSTEM_CURSOR_ARROW);
    98 }
    99 
   100 static void
   101 WINRT_FreeCursor(SDL_Cursor * cursor)
   102 {
   103     if (cursor->driverdata) {
   104         CoreCursor ^* theCursor = (CoreCursor ^*) cursor->driverdata;
   105         *theCursor = nullptr;       // Release the COM reference to the CoreCursor
   106         delete theCursor;           // Delete the pointer to the COM reference
   107     }
   108     SDL_free(cursor);
   109 }
   110 
   111 static int
   112 WINRT_ShowCursor(SDL_Cursor * cursor)
   113 {
   114     // TODO, WinRT, XAML: make WINRT_ShowCursor work when XAML support is enabled.
   115     if ( ! CoreWindow::GetForCurrentThread()) {
   116         return 0;
   117     }
   118 
   119     CoreWindow ^ coreWindow = CoreWindow::GetForCurrentThread();
   120     if (cursor) {
   121         CoreCursor ^* theCursor = (CoreCursor ^*) cursor->driverdata;
   122         coreWindow->PointerCursor = *theCursor;
   123     } else {
   124         // HACK ALERT: TL;DR - Hiding the cursor in WinRT/UWP apps is weird, and
   125         //   a Win32-style cursor resource file must be directly included in apps,
   126         //   otherwise hiding the cursor will cause mouse-motion data to never be
   127         //   received.
   128         //
   129         // Here's the lengthy explanation:
   130         //
   131         // There are two ways to hide a cursor in WinRT/UWP apps.
   132         // Both involve setting the WinRT CoreWindow's (which is somewhat analogous
   133         // to a Win32 HWND) 'PointerCursor' property.
   134         //
   135         // The first way to hide a cursor sets PointerCursor to nullptr.  This
   136         // is, arguably, the easiest to implement for an app.  It does have an
   137         // unfortunate side-effect: it'll prevent mouse-motion events from being
   138         // sent to the app (via CoreWindow).
   139         //
   140         // The second way to hide a cursor sets PointerCursor to a transparent
   141         // cursor.  This allows mouse-motion events to be sent to the app, but is
   142         // more difficult to set up, as:
   143         //   1. WinRT/UWP, while providing a few stock cursors, does not provide
   144         //      a completely transparent cursor.
   145         //   2. WinRT/UWP allows apps to provide custom-built cursors, but *ONLY*
   146         //      if they are linked directly inside the app, via Win32-style
   147         //      cursor resource files.  APIs to create cursors at runtime are
   148         //      not provided to apps, and attempting to link-to or use Win32
   149         //      cursor-creation APIs could cause an app to fail Windows Store
   150         //      certification.
   151         //
   152         // SDL can use either means of hiding the cursor.  It provides a Win32-style
   153         // set of cursor resource files in its source distribution, inside
   154         // src/main/winrt/.  If those files are linked to an SDL-for-WinRT/UWP app
   155         // (by including them in a MSVC project, for example), SDL will attempt to
   156         // use those, if and when the cursor is hidden via SDL APIs.  If those
   157         // files are not linked in, SDL will attempt to hide the cursor via the
   158         // 'set PointerCursor to nullptr' means (which, if you recall, causes
   159         // mouse-motion data to NOT be sent to the app!).
   160         //
   161         // Tech notes:
   162         //  - SDL's blank cursor resource uses a resource ID of 5000.
   163         //  - SDL's cursor resources consist of the following two files:
   164         //     - src/main/winrt/SDL2-WinRTResource_BlankCursor.cur -- cursor pixel data
   165         //     - src/main/winrt/SDL2-WinRTResources.rc             -- declares the cursor resource, and its ID (of 5000)
   166         //
   167 
   168         const unsigned int win32CursorResourceID = 5000;  
   169         CoreCursor ^ blankCursor = ref new CoreCursor(CoreCursorType::Custom, win32CursorResourceID);
   170 
   171         // Set 'PointerCursor' to 'blankCursor' in a way that shouldn't throw
   172         // an exception if the app hasn't loaded that resource.
   173         ABI::Windows::UI::Core::ICoreCursor * iblankCursor = reinterpret_cast<ABI::Windows::UI::Core::ICoreCursor *>(blankCursor);
   174         ABI::Windows::UI::Core::ICoreWindow * icoreWindow = reinterpret_cast<ABI::Windows::UI::Core::ICoreWindow *>(coreWindow);
   175         HRESULT hr = icoreWindow->put_PointerCursor(iblankCursor);
   176         if (FAILED(hr)) {
   177             // The app doesn't contain the cursor resource, or some other error
   178             // occurred.  Just use the other, but mouse-motion-preventing, means of
   179             // hiding the cursor.
   180             coreWindow->PointerCursor = nullptr;
   181         }
   182     }
   183     return 0;
   184 }
   185 
   186 static int
   187 WINRT_SetRelativeMouseMode(SDL_bool enabled)
   188 {
   189     WINRT_UsingRelativeMouseMode = enabled;
   190     return 0;
   191 }
   192 
   193 void
   194 WINRT_InitMouse(_THIS)
   195 {
   196     SDL_Mouse *mouse = SDL_GetMouse();
   197 
   198     /* DLudwig, Dec 3, 2012: WinRT does not currently provide APIs for
   199        the following features, AFAIK:
   200         - custom cursors  (multiple system cursors are, however, available)
   201         - programmatically moveable cursors
   202     */
   203 
   204 #if WINAPI_FAMILY != WINAPI_FAMILY_PHONE_APP
   205     //mouse->CreateCursor = WINRT_CreateCursor;
   206     mouse->CreateSystemCursor = WINRT_CreateSystemCursor;
   207     mouse->ShowCursor = WINRT_ShowCursor;
   208     mouse->FreeCursor = WINRT_FreeCursor;
   209     //mouse->WarpMouse = WINRT_WarpMouse;
   210     mouse->SetRelativeMouseMode = WINRT_SetRelativeMouseMode;
   211 
   212     SDL_SetDefaultCursor(WINRT_CreateDefaultCursor());
   213 #endif
   214 }
   215 
   216 void
   217 WINRT_QuitMouse(_THIS)
   218 {
   219 }
   220 
   221 #endif /* SDL_VIDEO_DRIVER_WINRT */
   222 
   223 /* vi: set ts=4 sw=4 expandtab: */