Document how to position a popup in the center of the window

This was already in Overlay's docs, but not Popup's, so this
patch moves the example to a .qdocinc and includes it in both places,
creating a new Popup Positioning section in the process.

Change-Id: I8e8438919fd849a8466b3a28133d22bb45f7dc19
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

3 files changed, 31 insertions, 19 deletions

diff --git a/src/imports/controls/doc/src/includes/qquickoverlay-popup-parent.qdocinc b/src/imports/controls/doc/src/includes/qquickoverlay-popup-parent.qdocinc
new file mode 100644
index 00000000..7ad8a003
--- /dev/null
+++ b/src/imports/controls/doc/src/includes/qquickoverlay-popup-parent.qdocinc
@@ -0,0 +1,20 @@
+The following example uses the attached \l {Overlay::overlay}{Overlay.overlay}
+property to position a popup in the center of the window, despite the position
+of the button that opens the popup:
+
+\code
+Button {
+    onClicked: popup.open()
+
+    Popup {
+        id: popup
+
+        parent: Overlay.overlay
+
+        x: (parent.width - width) / 2
+        y: (parent.height - height) / 2
+        width: 100
+        height: 100
+    }
+}
+\endcode
diff --git a/src/quicktemplates2/qquickoverlay.cpp b/src/quicktemplates2/qquickoverlay.cpp
index 38f7949e..fe61dae2 100644
--- a/src/quicktemplates2/qquickoverlay.cpp
+++ b/src/quicktemplates2/qquickoverlay.cpp
@@ -60,26 +60,9 @@ QT_BEGIN_NAMESPACE
     \l {Popup::dim}{dimmed} popup is visible.
 
     The overlay is an ordinary Item that covers the entire window. It can be used
-    as a visual parent to position a popup in scene coordinates. The following
-    example uses the attached \c overlay property to position a popup to the center
-    of the window, despite the position of the button that opens the popup.
+    as a visual parent to position a popup in scene coordinates.
 
-    \code
-    Button {
-        onClicked: popup.open()
-
-        Popup {
-            id: popup
-
-            parent: Overlay.overlay
-
-            x: (parent.width - width) / 2
-            y: (parent.height - height) / 2
-            width: 100
-            height: 100
-        }
-    }
-    \endcode
+    \include qquickoverlay-popup-parent.qdocinc
 
     \sa ApplicationWindow
 */
diff --git a/src/quicktemplates2/qquickpopup.cpp b/src/quicktemplates2/qquickpopup.cpp
index 207a886b..03328b43 100644
--- a/src/quicktemplates2/qquickpopup.cpp
+++ b/src/quicktemplates2/qquickpopup.cpp
@@ -168,6 +168,15 @@ QT_BEGIN_NAMESPACE
      }
     \endcode
 
+    \section1 Popup Positioning
+
+    Similar to items in Qt Quick, Popup's \l x and \l y coordinates are
+    relative to its parent. This means that opening a popup that is a
+    child of a \l Button, for example, will cause the popup to be positioned
+    relative to the button.
+
+    \include qquickoverlay-popup-parent.qdocinc
+
     \sa {Popup Controls}, {Customizing Popup}, ApplicationWindow
 */