Make Alt+Shift = right-button(brightness, or blue). Shift-without-Alt = edit alpha.

cmed/CMedit.C

@@ -399,17 +399,19 @@ int CMedit::handle(int ev) {
     dragfrom = x, dragval = y, dragamount = 0;
     draghue = ( (x - XMIN) * (x - (XMIN/4)) < 0 );	/* If dragging on hue strip */
 
-    if(Fl::event_state(FL_SHIFT)) {
+    if(Fl::event_state(FL_ALT | FL_SHIFT) == FL_SHIFT) {	/* Shift but not Alt: edit alpha */
 	dragfield = ALPHA;
     } else {
 	// Which button?  Take account of alt/meta modifiers too.
 	
 	int btn = 1;
 
-	if(Fl::event_state(FL_BUTTON2 | FL_ALT))
-	    btn = 2;
-	else if(Fl::event_state(FL_BUTTON3 | FL_META))
+	if(Fl::event_state(FL_ALT | FL_SHIFT) == (FL_ALT | FL_SHIFT))	/* Shift Alt: edit Right */
+	    btn = 3;
+	else if(Fl::event_state(FL_BUTTON3 | FL_META))			/* rightbutton or Meta: edit Right */
 	    btn = 3;
+	else if(Fl::event_state(FL_BUTTON2 | FL_ALT))			/* middlebutton or Alt (but not Shift Alt): edit Middle */
+	    btn = 2;
 
 	static CMfield btn2field[2][3] = {
 	    { RED, GREEN, BLUE },