Map all pointer buttons to Qt::MouseButton

The mapping is slightly inspired by the mapping in QtWayland.
But the mapping in QtWayland seems wrong. E.g. there is a linux kernel
button called BTN_BACK which is not mapped to Qt::BackButton.

Anyway we are not really interested in the mapping being 100 % correct
for the case in KWin. KWin internally uses only very few mouse buttons
and all others are only relevant to figure out whether buttons are
pressed. The button code itself is passed to the seat with the native
code.

autotests/wayland/move_resize_window_test.cpp

@@ -510,17 +510,6 @@ void MoveResizeWindowTest::testPointerMoveEnd()
 
     // release the left button, should still have the window moving
     waylandServer()->backend()->pointerButtonReleased(BTN_LEFT, timestamp++);
-    QEXPECT_FAIL("BTN_SIDE", "Not yet mapped", Continue);
-    QEXPECT_FAIL("BTN_EXTRA", "Not yet mapped", Continue);
-    QEXPECT_FAIL("BTN_TASK", "Not yet mapped", Continue);
-    QEXPECT_FAIL("118", "Not yet mapped", Continue);
-    QEXPECT_FAIL("119", "Not yet mapped", Continue);
-    QEXPECT_FAIL("11a", "Not yet mapped", Continue);
-    QEXPECT_FAIL("11b", "Not yet mapped", Continue);
-    QEXPECT_FAIL("11c", "Not yet mapped", Continue);
-    QEXPECT_FAIL("11d", "Not yet mapped", Continue);
-    QEXPECT_FAIL("11e", "Not yet mapped", Continue);
-    QEXPECT_FAIL("11f", "Not yet mapped", Continue);
     QVERIFY(c->isMove());
 
     // but releasing the other button should now end moving

pointer_input.cpp

@@ -48,12 +48,43 @@ static Qt::MouseButton buttonToQtMouseButton(uint32_t button)
         return Qt::MiddleButton;
     case BTN_RIGHT:
         return Qt::RightButton;
+    case BTN_SIDE:
+        // in QtWayland mapped like that
+        return Qt::ExtraButton1;
+    case BTN_EXTRA:
+        // in QtWayland mapped like that
+        return Qt::ExtraButton2;
     case BTN_BACK:
-        return Qt::XButton1;
+        return Qt::BackButton;
     case BTN_FORWARD:
-        return Qt::XButton2;
-    }
-    return Qt::NoButton;
+        return Qt::ForwardButton;
+    case BTN_TASK:
+        return Qt::TaskButton;
+        // mapped like that in QtWayland
+    case 0x118:
+        return Qt::ExtraButton6;
+    case 0x119:
+        return Qt::ExtraButton7;
+    case 0x11a:
+        return Qt::ExtraButton8;
+    case 0x11b:
+        return Qt::ExtraButton9;
+    case 0x11c:
+        return Qt::ExtraButton10;
+    case 0x11d:
+        return Qt::ExtraButton11;
+    case 0x11e:
+        return Qt::ExtraButton12;
+    case 0x11f:
+        return Qt::ExtraButton13;
+    }
+    // all other values get mapped to ExtraButton24
+    // this is actually incorrect but doesn't matter in our usage
+    // KWin internally doesn't use these high extra buttons anyway
+    // it's only needed for recognizing whether buttons are pressed
+    // if multiple buttons are mapped to the value the evaluation whether
+    // buttons are pressed is correct and that's all we care about.
+    return Qt::ExtraButton24;
 }
 
 static bool screenContainsPos(const QPointF &pos)
@@ -357,11 +388,7 @@ void PointerInputRedirection::updateButton(uint32_t button, InputRedirection::Po
         if (it.value() == InputRedirection::PointerButtonReleased) {
             continue;
         }
-        Qt::MouseButton button = buttonToQtMouseButton(it.key());
-        // TODO: we need to map all buttons, otherwise checks for are buttons pressed fail
-        if (button != Qt::NoButton) {
-            m_qtButtons |= button;
-        }
+        m_qtButtons |= buttonToQtMouseButton(it.key());
     }
 
     emit m_input->pointerButtonStateChanged(button, state);