Detect device form factor

Author: Semphris

android-project/app/src/main/java/org/libsdl/app/SDLActivity.java

@@ -1303,6 +1303,25 @@ public static boolean isVRHeadset() {
         return false;
     }
 
+    /**
+     * This method is called by SDL using JNI.
+     */
+    static String getDeviceFormFactor()
+    {
+        // TODO: WearOS
+        if (isAndroidTV()) {
+            return "tv";
+        } else if (isVRHeadset()) {
+            return "vr";
+        } else if (isTablet()) {
+            return "tablet";
+        //} else if (isAndroidAutomotive()) {
+        //    return "car";
+        } else {
+            return "phone";
+        }
+    }
+
     public static double getDiagonal()
     {
         DisplayMetrics metrics = new DisplayMetrics();

include/SDL3/SDL_system.h

@@ -620,6 +620,46 @@ extern SDL_DECLSPEC bool SDLCALL SDL_IsTablet(void);
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_IsTV(void);
 
+/**
+ * The possible form factors for a device.
+ *
+ * \since This enum is available since SDL 3.4.0.
+ *
+ * \sa SDL_GetDeviceFormFactor
+ */
+typedef enum SDL_FormFactor {
+    SDL_FORMFACTOR_UNKNOWN = 0,
+    SDL_FORMFACTOR_DESKTOP,
+    SDL_FORMFACTOR_LAPTOP,
+    SDL_FORMFACTOR_PHONE,
+    SDL_FORMFACTOR_TABLET,
+    SDL_FORMFACTOR_CONSOLE,
+    SDL_FORMFACTOR_HANDHELD,
+    SDL_FORMFACTOR_WATCH,
+    SDL_FORMFACTOR_TV,
+    SDL_FORMFACTOR_VR,
+    SDL_FORMFACTOR_CAR
+} SDL_FormFactor;
+
+/**
+ * Get the form factor of the current device.
+ *
+ * This function guesses what the device may be, but may report inaccurate or
+ * outright wrong results. For example, it may report a laptop as a desktop, or
+ * a car device as a phone.
+ *
+ * Depending on the usage, there may be different functions better suited for
+ * each purpose. For example, activating touch controls can be done by detecting
+ * the presence of a touchscreen rather than restricting to phones and tablets.
+ *
+ * \returns the best guess for the form factor of the current device.
+ *
+ * \since This function is available since SDL 3.4.0.
+ *
+ * \sa SDL_FormFactor
+ */
+extern SDL_DECLSPEC SDL_FormFactor SDLCALL SDL_GetDeviceFormFactor(void);
+
 /**
  * Application sandbox environment.
  *

src/SDL.c

@@ -769,25 +769,36 @@ const char *SDL_GetPlatform(void)
 
 bool SDL_IsTablet(void)
 {
-#ifdef SDL_PLATFORM_ANDROID
-    return SDL_IsAndroidTablet();
-#elif defined(SDL_PLATFORM_IOS)
-    extern bool SDL_IsIPad(void);
-    return SDL_IsIPad();
-#else
-    return false;
-#endif
+    return SDL_GetDeviceFormFactor() == SDL_FORMFACTOR_TABLET;
 }
 
 bool SDL_IsTV(void)
 {
+    return SDL_GetDeviceFormFactor() == SDL_FORMFACTOR_TV;
+}
+
+SDL_FormFactor SDL_GetDeviceFormFactor(void)
+{
+    /* TODO: SDL private platforms? */
 #ifdef SDL_PLATFORM_ANDROID
-    return SDL_IsAndroidTV();
+    return SDL_GetAndroidDeviceFormFactor();
 #elif defined(SDL_PLATFORM_IOS)
-    extern bool SDL_IsAppleTV(void);
-    return SDL_IsAppleTV();
+    extern bool SDL_GetUIKitDeviceFormFactor(void);
+    return SDL_GetUIKitDeviceFormFactor();
+#elif defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES) || defined(SDL_PLATFORM_PS2)
+    return SDL_FORMFACTOR_CONSOLE;
+#elif defined(SDL_PLATFORM_PSP) || defined(SDL_PLATFORM_VITA) || defined(SDL_PLATFORM_3DS)
+    return SDL_FORMFACTOR_HANDHELD;
+#elif defined(SDL_PLATFORM_QNXNTO)
+    /* TODO: QNX is used in BlackBerry phones and tablets, and in many embedded devices */
+    return SDL_FORMFACTOR_UNKNOWN;
+#elif defined(SDL_PLATFORM_WINGDK)
+    /* TODO: GDK can be either desktop Windows or XBox */
+    return SDL_FORMFACTOR_UNKNOWN;
+#elif defined(SDL_PLATFORM_HAIKU) || defined(SDL_PLATFORM_BSDI) || defined(SDL_PLATFORM_HPUX) || defined(SDL_PLATFORM_IRIX) || defined(SDL_PLATFORM_EMSCRIPTEN) || defined(SDL_PLATFORM_OS2) || defined(SDL_PLATFORM_OSF) || defined(SDL_PLATFORM_RISCOS) || defined(SDL_PLATFORM_SOLARIS) || defined(SDL_PLATFORM_WIN32)
+    return SDL_FORMFACTOR_DESKTOP;
 #else
-    return false;
+    return SDL_FORMFACTOR_UNKNOWN;
 #endif
 }
 

src/core/android/SDL_android.c

@@ -346,6 +346,7 @@ static jmethodID midClipboardSetText;
 static jmethodID midCreateCustomCursor;
 static jmethodID midDestroyCustomCursor;
 static jmethodID midGetContext;
+static jmethodID midGetDeviceFormFactor;
 static jmethodID midGetManifestEnvironmentVariables;
 static jmethodID midGetNativeSurface;
 static jmethodID midInitTouch;
@@ -635,6 +636,7 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(nativeSetupJNI)(JNIEnv *env, jclass cl
     midCreateCustomCursor = (*env)->GetStaticMethodID(env, mActivityClass, "createCustomCursor", "([IIIII)I");
     midDestroyCustomCursor = (*env)->GetStaticMethodID(env, mActivityClass, "destroyCustomCursor", "(I)V");
     midGetContext = (*env)->GetStaticMethodID(env, mActivityClass, "getContext", "()Landroid/content/Context;");
+    midGetDeviceFormFactor = (*env)->GetStaticMethodID(env, mActivityClass, "getDeviceFormFactor", "()Ljava/lang/String;");
     midGetManifestEnvironmentVariables = (*env)->GetStaticMethodID(env, mActivityClass, "getManifestEnvironmentVariables", "()Z");
     midGetNativeSurface = (*env)->GetStaticMethodID(env, mActivityClass, "getNativeSurface", "()Landroid/view/Surface;");
     midInitTouch = (*env)->GetStaticMethodID(env, mActivityClass, "initTouch", "()V");
@@ -667,6 +669,7 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(nativeSetupJNI)(JNIEnv *env, jclass cl
         !midCreateCustomCursor ||
         !midDestroyCustomCursor ||
         !midGetContext ||
+        !midGetDeviceFormFactor ||
         !midGetManifestEnvironmentVariables ||
         !midGetNativeSurface ||
         !midInitTouch ||
@@ -2821,4 +2824,37 @@ bool Android_JNI_OpenFileDialog(
     return true;
 }
 
+SDL_FormFactor SDL_GetAndroidDeviceFormFactor(void)
+{
+    JNIEnv *env = Android_JNI_GetEnv();
+    SDL_FormFactor form_factor = SDL_FORMFACTOR_UNKNOWN;
+    jstring string;
+
+    string = (*env)->CallStaticObjectMethod(env, mActivityClass, midGetDeviceFormFactor);
+    if (string) {
+        const char *utf = (*env)->GetStringUTFChars(env, string, 0);
+        if (utf) {
+            if (SDL_strcmp(utf, "tv") == 0) {
+                form_factor = SDL_FORMFACTOR_TV;
+            } else if (SDL_strcmp(utf, "tablet") == 0) {
+                form_factor = SDL_FORMFACTOR_TABLET;
+            } else if (SDL_strcmp(utf, "phone") == 0) {
+                form_factor = SDL_FORMFACTOR_PHONE;
+            } else if (SDL_strcmp(utf, "car") == 0) {
+                form_factor = SDL_FORMFACTOR_CAR;
+            } else if (SDL_strcmp(utf, "vr") == 0) {
+                form_factor = SDL_FORMFACTOR_VR;
+            } else if (SDL_strcmp(utf, "watch") == 0) {
+                form_factor = SDL_FORMFACTOR_WATCH;
+            } else {
+                form_factor = SDL_FORMFACTOR_UNKNOWN;
+            }
+            (*env)->ReleaseStringUTFChars(env, string, utf);
+        }
+        (*env)->DeleteLocalRef(env, string);
+    }
+
+    return form_factor;
+}
+
 #endif // SDL_PLATFORM_ANDROID

src/core/android/SDL_android.h

@@ -147,6 +147,7 @@ int SDL_GetAndroidSDKVersion(void);
 
 bool SDL_IsAndroidTablet(void);
 bool SDL_IsAndroidTV(void);
+SDL_FormFactor SDL_GetAndroidDeviceFormFactor(void);
 
 // File Dialogs
 bool Android_JNI_OpenFileDialog(SDL_DialogFileCallback callback, void* userdata,

src/dynapi/SDL_dynapi.sym

@@ -1242,6 +1242,7 @@ SDL3_0.0.0 {
     SDL_SetGPURenderStateFragmentUniforms;
     SDL_SetRenderGPUState;
     SDL_DestroyGPURenderState;
+    SDL_GetDeviceFormFactor;
     # extra symbols go here (don't modify this line)
   local: *;
 };

src/dynapi/SDL_dynapi_overrides.h

@@ -1267,3 +1267,4 @@
 #define SDL_SetGPURenderStateFragmentUniforms SDL_SetGPURenderStateFragmentUniforms_REAL
 #define SDL_SetRenderGPUState SDL_SetRenderGPUState_REAL
 #define SDL_DestroyGPURenderState SDL_DestroyGPURenderState_REAL
+#define SDL_GetDeviceFormFactor SDL_GetDeviceFormFactor_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -1275,3 +1275,4 @@ SDL_DYNAPI_PROC(SDL_GPURenderState*,SDL_CreateGPURenderState,(SDL_Renderer *a,SD
 SDL_DYNAPI_PROC(bool,SDL_SetGPURenderStateFragmentUniforms,(SDL_GPURenderState *a,Uint32 b,const void *c,Uint32 d),(a,b,c,d),return)
 SDL_DYNAPI_PROC(bool,SDL_SetRenderGPUState,(SDL_Renderer *a,SDL_GPURenderState *b),(a,b),return)
 SDL_DYNAPI_PROC(void,SDL_DestroyGPURenderState,(SDL_GPURenderState *a),(a),)
+SDL_DYNAPI_PROC(SDL_FormFactor,SDL_GetDeviceFormFactor,(void),(),return)

src/video/uikit/SDL_uikitvideo.m

@@ -301,14 +301,26 @@ void SDL_NSLog(const char *prefix, const char *text)
  * This doesn't really have anything to do with the interfaces of the SDL video
  * subsystem, but we need to stuff this into an Objective-C source code file.
  */
-bool SDL_IsIPad(void)
-{
-    return ([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPad);
-}
 
-bool SDL_IsAppleTV(void)
+bool SDL_GetUIKitDeviceFormFactor(void)
 {
-    return ([UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomTV);
+    // TODO: Apple Watch
+    switch ([UIDevice currentDevice].userInterfaceIdiom) {
+    case UIUserInterfaceIdiomPhone:
+        return SDL_FORMFACTOR_PHONE;
+    case UIUserInterfaceIdiomPad:
+        return SDL_FORMFACTOR_TABLET;
+    case UIUserInterfaceIdiomTV:
+        return SDL_FORMFACTOR_TV;
+    case UIUserInterfaceIdiomCarPlay:
+        return SDL_FORMFACTOR_CAR;
+    case UIUserInterfaceIdiomMac:
+        return SDL_FORMFACTOR_DESKTOP;
+    case UIUserInterfaceIdiomVision:
+        return SDL_FORMFACTOR_VR;
+    default:
+        return SDL_FORMFACTOR_UNKNOWN;
+    }
 }
 
 #endif // SDL_VIDEO_DRIVER_UIKIT