Take into account input shaping in findRealWindow

In previous commits we took into account bound shaping, but X also
supports input shaping, so make sure it's inside both input and bounding
shaping to consider the position as inside a window

My tests show that when unset Bound Shaping and Input Shaping return the
rectangle of the window itself, so we need to be inside both of the
rectangle sets to consider the position as a dragabble position for the
window

Change-Id: I77973e51168d2a6d274d166f29f32e1bc02c32c3
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

1 files changed, 24 insertions, 16 deletions

diff --git a/src/plugins/platforms/xcb/qxcbdrag.cpp b/src/plugins/platforms/xcb/qxcbdrag.cpp
index 0e3807cd7b..a0736d81f1 100644
--- a/src/plugins/platforms/xcb/qxcbdrag.cpp
+++ b/src/plugins/platforms/xcb/qxcbdrag.cpp
@@ -215,6 +215,26 @@ translateCoordinates(QXcbConnection *c, xcb_window_t from, xcb_window_t to, int
     return xcb_translate_coordinates_reply(c->xcb_connection(), cookie, 0);
 }
 
+static
+bool windowInteractsWithPosition(xcb_connection_t *connection, const QPoint & pos, xcb_window_t w, int shapeType)
+{
+    bool interacts = true;
+    xcb_shape_get_rectangles_reply_t *reply = xcb_shape_get_rectangles_reply(connection, xcb_shape_get_rectangles(connection, w, shapeType), NULL);
+    if (reply) {
+        xcb_rectangle_t *rectangles = xcb_shape_get_rectangles_rectangles(reply);
+        if (rectangles) {
+            interacts = false;
+            const int nRectangles = xcb_shape_get_rectangles_rectangles_length(reply);
+            for (int i = 0; !interacts && i < nRectangles; ++i) {
+                interacts = QRect(rectangles[i].x, rectangles[i].y, rectangles[i].width, rectangles[i].height).contains(pos);
+            }
+        }
+        free(reply);
+    }
+
+    return interacts;
+}
+
 xcb_window_t QXcbDrag::findRealWindow(const QPoint & pos, xcb_window_t w, int md)
 {
     if (w == shapedPixmapWindow()->handle()->winId())
@@ -242,22 +262,10 @@ xcb_window_t QXcbDrag::findRealWindow(const QPoint & pos, xcb_window_t w, int md
                 bool isAware = reply && reply->type != XCB_NONE;
                 free(reply);
                 if (isAware) {
-                    xcb_xfixes_region_t region = xcb_generate_id(xcb_connection());
-                    xcb_xfixes_create_region_from_window(xcb_connection(), region, w, XCB_SHAPE_SK_BOUNDING);
-                    xcb_xfixes_fetch_region_reply_t *reply = xcb_xfixes_fetch_region_reply(xcb_connection(), xcb_xfixes_fetch_region(xcb_connection(), region), NULL);
-                    if (reply) {
-                        xcb_rectangle_t *rectangles = xcb_xfixes_fetch_region_rectangles(reply);
-                        if (rectangles) {
-                            windowContainsMouse = false;
-                            const int nRectangles = xcb_xfixes_fetch_region_rectangles_length(reply);
-                            for (int i = 0; !windowContainsMouse && i < nRectangles; ++i) {
-                                windowContainsMouse = QRect(rectangles[i].x, rectangles[i].y, rectangles[i].width, rectangles[i].height).contains(pos);
-                            }
-                        }
-                        free(reply);
-                    }
-                    xcb_xfixes_destroy_region(xcb_connection(), region);
-
+                    // When ShapeInput and ShapeBounding are not set they return a single rectangle with the geometry of the window, this is why we
+                    // need an && here so that in the case one is set and the other is not we still get the correct result.
+                    windowContainsMouse = windowInteractsWithPosition(xcb_connection(), pos, w, XCB_SHAPE_SK_INPUT) &&
+                                          windowInteractsWithPosition(xcb_connection(), pos, w, XCB_SHAPE_SK_BOUNDING);
                     if (windowContainsMouse)
                         return w;
                 }