Enable X mouse buttons 6 and 7 for horizontal scrolling. (#367)

Author: nbriggs

src/xwinman.c

@@ -213,14 +213,8 @@ void getXsignaldata(DspInterface dsp)
             case Button3: PUTBASEBIT68K(EmRealUtilin68K, MOUSE_RIGHT, FALSE); break;
             case Button4: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_LEFT, FALSE); break;
             case Button5: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_LEFTMIDDLE, FALSE); break;
-#if 0
-            /* Button6 and Button7 are not defined, but these values are generated by
-               macOS for the left and right scrolling movements.
-               Leave them out for now, until we've sorted out the up and down scrolling.
-             */
-            case Button5 + 1: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHTMIDDLE, FALSE); break;
-            case Button5 + 2: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHT, FALSE); break;
-#endif
+            case Button5 + 1: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHT, FALSE); break;
+            case Button5 + 2: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHTMIDDLE, FALSE); break;
             default: break;
           }
           DoRing();
@@ -233,11 +227,8 @@ void getXsignaldata(DspInterface dsp)
             case Button3: PUTBASEBIT68K(EmRealUtilin68K, MOUSE_RIGHT, TRUE); break;
             case Button4: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_LEFT, TRUE); break;
             case Button5: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_LEFTMIDDLE, TRUE); break;
-#if 0
-            /* See above for key press */
-            case Button5 + 1: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHTMIDDLE, TRUE); break;
-            case Button5 + 2: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHT, TRUE); break;
-#endif
+            case Button5 + 1: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHT, TRUE); break;
+            case Button5 + 2: PUTBASEBIT68K(EmRealUtilin68K, KEYSET_RIGHTMIDDLE, TRUE); break;
             default: break;
           }
           DoRing();