Added Android custom cursor implementation

This is commented out in SDLActivity.java, with the note #CURSORIMPLEENTATION because it requires API 24, which is higher than the minimum required SDK

src/core/android/SDL_android.c

@@ -223,6 +223,9 @@ static jmethodID midClipboardHasText;
 static jmethodID midOpenAPKExpansionInputStream;
 static jmethodID midGetManifestEnvironmentVariables;
 static jmethodID midGetDisplayDPI;
+static jmethodID midCreateCustomCursor;
+static jmethodID midSetCustomCursor;
+static jmethodID midSetSystemCursor;
 
 /* audio manager */
 static jclass mAudioManagerClass;
@@ -332,7 +335,11 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(nativeSetupJNI)(JNIEnv* mEnv, jclass c
                                 "getManifestEnvironmentVariables", "()Z");
 
     midGetDisplayDPI = (*mEnv)->GetStaticMethodID(mEnv, mActivityClass, "getDisplayDPI", "()Landroid/util/DisplayMetrics;");
-    midGetDisplayDPI = (*mEnv)->GetStaticMethodID(mEnv, mActivityClass, "getDisplayDPI", "()Landroid/util/DisplayMetrics;");
+
+    /* Custom cursor implementation is only available on API 24 and above */
+    midCreateCustomCursor = (*mEnv)->GetStaticMethodID(mEnv, mActivityClass, "createCustomCursor", "([IIIII)I");
+    midSetCustomCursor = (*mEnv)->GetStaticMethodID(mEnv, mActivityClass, "setCustomCursor", "(I)V");
+    midSetSystemCursor = (*mEnv)->GetStaticMethodID(mEnv, mActivityClass, "setSystemCursor", "(I)V");
 
     if (!midGetNativeSurface ||
        !midSetActivityTitle || !midSetWindowStyle || !midSetOrientation || !midGetContext || !midIsAndroidTV || !midInputGetInputDeviceIds ||
@@ -2167,6 +2174,40 @@ void Android_JNI_GetManifestEnvironmentVariables(void)
     }
 }
 
+int Android_JNI_CreateCustomCursor(SDL_Surface *surface, int hot_x, int hot_y)
+{
+    JNIEnv *mEnv = Android_JNI_GetEnv();
+    int custom_cursor = 0;
+    if (midCreateCustomCursor) {
+        jintArray pixels;
+        pixels = (*mEnv)->NewIntArray(mEnv, surface->w * surface->h);
+        if (!pixels) {
+            return 0;
+        }
+        (*mEnv)->SetIntArrayRegion(mEnv, pixels, 0, surface->w * surface->h, (int *)surface->pixels);
+        custom_cursor = (*mEnv)->CallStaticIntMethod(mEnv, mActivityClass, midCreateCustomCursor, pixels, surface->w, surface->h, hot_x, hot_y);
+        (*mEnv)->DeleteLocalRef(mEnv, pixels);
+    }
+    return custom_cursor;
+}
+
+
+void Android_JNI_SetCustomCursor(int cursorID)
+{
+    JNIEnv *mEnv = Android_JNI_GetEnv();
+    if (midSetCustomCursor) {
+        (*mEnv)->CallStaticVoidMethod(mEnv, mActivityClass, midSetCustomCursor, cursorID);
+    }
+}
+
+void Android_JNI_SetSystemCursor(int cursorID)
+{
+    JNIEnv *mEnv = Android_JNI_GetEnv();
+    if (midSetSystemCursor) {
+        (*mEnv)->CallStaticVoidMethod(mEnv, mActivityClass, midSetSystemCursor, cursorID);
+    }
+}
+
 #endif /* __ANDROID__ */
 
 /* vi: set ts=4 sw=4 expandtab: */

src/core/android/SDL_android.h

@@ -102,6 +102,11 @@ JNIEXPORT void JNICALL SDL_Android_Init(JNIEnv* mEnv, jclass cls);
 #include "SDL_messagebox.h"
 int Android_JNI_ShowMessageBox(const SDL_MessageBoxData *messageboxdata, int *buttonid);
 
+/* Cursor support */
+int Android_JNI_CreateCustomCursor(SDL_Surface *surface, int hot_x, int hot_y);
+void Android_JNI_SetCustomCursor(int cursorID);
+void Android_JNI_SetSystemCursor(int cursorID);
+
 /* Ends C function definitions when using C++ */
 #ifdef __cplusplus
 /* *INDENT-OFF* */

src/video/android/SDL_androidmouse.c

@@ -42,12 +42,107 @@
 #define BUTTON_BACK 8
 #define BUTTON_FORWARD 16
 
+typedef struct
+{
+    int custom_cursor;
+    int system_cursor;
+
+} SDL_AndroidCursorData;
+
 /* Last known Android mouse button state (includes all buttons) */
 static int last_state;
 
+
+static SDL_Cursor *
+Android_WrapCursor(int custom_cursor, int system_cursor)
+{
+    SDL_Cursor *cursor;
+
+    cursor = SDL_calloc(1, sizeof(*cursor));
+    if (cursor) {
+        SDL_AndroidCursorData *data = (SDL_AndroidCursorData*)SDL_calloc(1, sizeof(*data));
+        if (data) {
+            data->custom_cursor = custom_cursor;
+            data->system_cursor = system_cursor;
+            cursor->driverdata = data;
+        } else {
+            SDL_free(cursor);
+            cursor = NULL;
+            SDL_OutOfMemory();
+        }
+    } else {
+        SDL_OutOfMemory();
+    }
+
+    return cursor;
+}
+
+static SDL_Cursor *
+Android_CreateDefaultCursor()
+{
+    return Android_WrapCursor(0, SDL_SYSTEM_CURSOR_ARROW);
+}
+
+static SDL_Cursor *
+Android_CreateCursor(SDL_Surface * surface, int hot_x, int hot_y)
+{
+    int custom_cursor;
+    SDL_Surface *converted;
+
+    converted = SDL_ConvertSurfaceFormat(surface, SDL_PIXELFORMAT_ARGB8888, 0);
+    if (!converted) {
+        return NULL;
+    }
+    custom_cursor = Android_JNI_CreateCustomCursor(converted, hot_x, hot_y);
+    SDL_FreeSurface(converted);
+    if (!custom_cursor) {
+        SDL_Unsupported();
+        return NULL;
+    }
+    return Android_WrapCursor(custom_cursor, 0);
+}
+
+static SDL_Cursor *
+Android_CreateSystemCursor(SDL_SystemCursor id)
+{
+    return Android_WrapCursor(0, id);
+}
+
+static void
+Android_FreeCursor(SDL_Cursor * cursor)
+{
+    SDL_free(cursor->driverdata);
+    SDL_free(cursor);
+}
+
+static int
+Android_ShowCursor(SDL_Cursor * cursor)
+{
+    if (cursor) {
+        SDL_AndroidCursorData *data = (SDL_AndroidCursorData*)cursor->driverdata;
+        if (data->custom_cursor) {
+            Android_JNI_SetCustomCursor(data->custom_cursor);
+        } else {
+            Android_JNI_SetSystemCursor(data->system_cursor);
+        }
+    } else {
+        Android_JNI_SetSystemCursor(-1);
+    }
+    return 0;
+}
+
 void
 Android_InitMouse(void)
 {
+    SDL_Mouse *mouse = SDL_GetMouse();
+
+    mouse->CreateCursor = Android_CreateCursor;
+    mouse->CreateSystemCursor = Android_CreateSystemCursor;
+    mouse->ShowCursor = Android_ShowCursor;
+    mouse->FreeCursor = Android_FreeCursor;
+
+    SDL_SetDefaultCursor(Android_CreateDefaultCursor());
+
     last_state = 0;
 }