From c4385a0013bcc08cc949de41f4a5964520956c8e Mon Sep 17 00:00:00 2001
From: Navarum <48705414+navarum@users.noreply.github.com>
Date: Mon, 30 Dec 2019 05:15:17 -0800
Subject: [PATCH 1/4] Add support for multiple mouse buttons

---
 src/include/R_ext/GraphicsDevice.h |  1 +
 src/main/gevents.c                 | 31 ++++++++++++++++++++++--------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/src/include/R_ext/GraphicsDevice.h b/src/include/R_ext/GraphicsDevice.h
index d2604daf98..dbc0e2ad17 100644
--- a/src/include/R_ext/GraphicsDevice.h
+++ b/src/include/R_ext/GraphicsDevice.h
@@ -819,6 +819,7 @@ typedef enum {meMouseDown = 0,
 	      meMouseUp,
 	      meMouseMove} R_MouseEvent;
 
+#define mouseButtonMax 24
 #define leftButton   1
 #define middleButton 2
 #define rightButton  4
diff --git a/src/main/gevents.c b/src/main/gevents.c
index 8781e8ef17..1653e86697 100644
--- a/src/main/gevents.c
+++ b/src/main/gevents.c
@@ -208,11 +208,12 @@ do_getGraphicsEvent(SEXP call, SEXP op, SEXP args, SEXP env)
     return(result);
 }
 
+
 /* used in devWindows.c and cairoDevice */
 void doMouseEvent(pDevDesc dd, R_MouseEvent event,
 		  int buttons, double x, double y)
 {
-    int i;
+    int i, j;
     SEXP handler, bvec, sx, sy, temp, result;
 
     dd->gettingEvent = FALSE; /* avoid recursive calls */
@@ -226,16 +227,30 @@ void doMouseEvent(pDevDesc dd, R_MouseEvent event,
     if (TYPEOF(handler) == CLOSXP) {
 	SEXP s_which = install("which");
 	defineVar(s_which, ScalarInteger(ndevNumber(dd)+1), dd->eventEnv);
-	// Be portable: see PR#15793
-	int len = ((buttons & leftButton) != 0)
-	  + ((buttons & middleButton) != 0)
-	  + ((buttons & rightButton) != 0);
+    int len;
+    if(1) {
+		    /* RButtons = 1 << (event.xbutton.button - 1); */
+        len = 0;
+        for(j=0; j<mouseButtonMax; j++)
+            len += ((buttons & (1 << j)) != 0);
+    } else {
+        // Be portable: see PR#15793
+        len = ((buttons & leftButton) != 0)
+            + ((buttons & middleButton) != 0)
+            + ((buttons & rightButton) != 0);
+    }
 
 	PROTECT(bvec = allocVector(INTSXP, len));
 	i = 0;
-	if (buttons & leftButton) INTEGER(bvec)[i++] = 0;
-	if (buttons & middleButton) INTEGER(bvec)[i++] = 1;
-	if (buttons & rightButton) INTEGER(bvec)[i++] = 2;
+    if(1) {
+        for(j=0; j<mouseButtonMax; j++)
+            if(buttons & (1 << j))
+                INTEGER(bvec)[i++] = j;
+    } else {
+        if (buttons & leftButton) INTEGER(bvec)[i++] = 0;
+        if (buttons & middleButton) INTEGER(bvec)[i++] = 1;
+        if (buttons & rightButton) INTEGER(bvec)[i++] = 2;
+    }
 
 	PROTECT(sx = ScalarReal( (x - dd->left) / (dd->right - dd->left) ));
 	PROTECT(sy = ScalarReal((y - dd->bottom) / (dd->top - dd->bottom) ));
-- 
2.32.0