cocoa: Fix Mouse Event tracking of button status

Within qcocoahelpers, make function cocoaButton2QtButton() handle
all button numbers. Within qnsview, call the function in several
places (eliminating duplicate, inefficient code).

Task-number: QTBUG-28567

Change-Id: Ibae2ae4e8a881b825a8862afb82aa80437751111
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>
Reviewed-by: Rick Stockton <rickstockton@reno-computerhelp.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.mm b/src/plugins/platforms/cocoa/qcocoahelpers.mm
index c6d6e35794..0c5d26054c 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.mm
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.mm
@@ -623,20 +623,17 @@ CGFloat qt_mac_get_scalefactor()
 
 Qt::MouseButton cocoaButton2QtButton(NSInteger buttonNum)
 {
-    switch (buttonNum) {
-    case 0:
+    if (buttonNum == 0)
         return Qt::LeftButton;
-    case 1:
+    if (buttonNum == 1)
         return Qt::RightButton;
-    case 2:
-        return Qt::MidButton;
-    case 3:
-        return Qt::XButton1;
-    case 4:
-        return Qt::XButton2;
-    default:
-        return Qt::NoButton;
+    if (buttonNum == 2)
+        return Qt::MiddleButton;
+    if (buttonNum >= 3 && buttonNum <= 31) { // handle XButton1 and higher via logical shift
+        return Qt::MouseButton(uint(Qt::MiddleButton) << (buttonNum - 3));
     }
+    // else error: buttonNum too high, or negative
+    return Qt::NoButton;
 }
 
 bool qt_mac_execute_apple_script(const char *script, long script_len, AEDesc *ret) {