Platform: fix AndroidApplication for Android < 4.0.

src/Magnum/Platform/AndroidApplication.h

@@ -433,18 +433,46 @@ class AndroidApplication::MouseEvent: public InputEvent {
             /**
              * Left mouse button. Note that this button is not set if only
              * touch or stylus event occured.
+             * @attention Available since Android 4.0 (API level 14), not
+             *      detectable in earlier versions.
              */
+            #if __ANDROID_API__ >= 14
             Left = AMOTION_EVENT_BUTTON_PRIMARY,
+            #else
+            Left = 1 << 0,
+            #endif
 
-            /** Middle mouse button or second stylus button */
+            /**
+             * Middle mouse button or second stylus button
+             * @attention Available since Android 4.0 (API level 14), not
+             *      detectable in earlier versions.
+             */
+            #if __ANDROID_API__ >= 14
             Middle = AMOTION_EVENT_BUTTON_TERTIARY,
+            #else
+            Middle = 1 << 1,
+            #endif
 
-            /** Right mouse button or first stylus button */
+            /**
+             * Right mouse button or first stylus button
+             * @attention Available since Android 4.0 (API level 14), not
+             *      detectable in earlier versions.
+             */
+            #if __ANDROID_API__ >= 14
             Right = AMOTION_EVENT_BUTTON_SECONDARY
+            #else
+            Right = 1 << 2
+            #endif
         };
 
         /** @brief Button */
-        Button button() { return Button(AMotionEvent_getButtonState(_event)); }
+        Button button() {
+            #if __ANDROID_API__ >= 14
+            return Button(AMotionEvent_getButtonState(_event));
+            #else
+            return Button::None;
+            #endif
+        }
 
         /** @brief Position */
         Vector2i position() {
@@ -474,14 +502,36 @@ class AndroidApplication::MouseMoveEvent: public InputEvent {
             /**
              * Left mouse button. Note that this button is not set if only
              * touch or stylus event occured.
+             * @attention Available since Android 4.0 (API level 14), not
+             *      detectable in earlier versions.
              */
+            #if __ANDROID_API__ >= 14
             Left = AMOTION_EVENT_BUTTON_PRIMARY,
+            #else
+            Left = 1 << 0,
+            #endif
 
-            /** Middle mouse button or second stylus button */
+            /**
+             * Middle mouse button or second stylus button
+             * @attention Available since Android 4.0 (API level 14), not
+             *      detectable in earlier versions.
+             */
+            #if __ANDROID_API__ >= 14
             Middle = AMOTION_EVENT_BUTTON_TERTIARY,
+            #else
+            Middle = 1 << 1,
+            #endif
 
-            /** Right mouse button or first stylus button */
+            /**
+             * Right mouse button or first stylus button
+             * @attention Available since Android 4.0 (API level 14), not
+             *      detectable in earlier versions.
+             */
+            #if __ANDROID_API__ >= 14
             Right = AMOTION_EVENT_BUTTON_SECONDARY
+            #else
+            Right = 1 << 2
+            #endif
         };
 
         /**
@@ -499,7 +549,11 @@ class AndroidApplication::MouseMoveEvent: public InputEvent {
 
         /** @brief Mouse buttons */
         Buttons buttons() const {
+            #if __ANDROID_API__ >= 14
             return Button(AMotionEvent_getButtonState(_event));
+            #else
+            return {};
+            #endif
         }
 
     private: