Revamp/document custom-extension example

This is a very useful example which was unfortunately
undocumented.

It also needed some clean-up in the code, and as part of
writing the documentation, it became clear that it would be
an easier demonstration to follow if the QML client was
more similar to the C++ client, so that they were simply two
implementations of the same spec.

Fixes: QTBUG-110919
Change-Id: Ia4476cda34056e28722af6639f95d8c87819681a
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

7 files changed, 34 insertions, 16 deletions

diff --git a/examples/wayland/custom-extension/compositor/CMakeLists.txt b/examples/wayland/custom-extension/compositor/CMakeLists.txt
index 4a946e6a6..bb70cf106 100644
--- a/examples/wayland/custom-extension/compositor/CMakeLists.txt
+++ b/examples/wayland/custom-extension/compositor/CMakeLists.txt
@@ -14,6 +14,7 @@ set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/wayland/custom-extension/composit
 
 find_package(Qt6 REQUIRED COMPONENTS Core Gui Qml WaylandCompositor)
 
+qt6_policy(SET QTP0001 NEW)
 qt_add_executable(custom-extension-compositor
     customextension.cpp customextension.h
     main.cpp
@@ -50,6 +51,11 @@ qt6_add_resources(custom-extension-compositor "compositor"
         ${compositor_resource_files}
 )
 
+qt6_add_qml_module(custom-extension-compositor
+  URI io.qt.examples.customextension
+  VERSION 1.0
+)
+
 install(TARGETS custom-extension-compositor
     RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
     BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
diff --git a/examples/wayland/custom-extension/compositor/compositor.pro b/examples/wayland/custom-extension/compositor/compositor.pro
index 283ccdf4b..263b9fbdd 100644
--- a/examples/wayland/custom-extension/compositor/compositor.pro
+++ b/examples/wayland/custom-extension/compositor/compositor.pro
@@ -2,6 +2,10 @@ QT += core gui qml
 
 QT += waylandcompositor
 
+CONFIG += qmltypes
+QML_IMPORT_NAME = io.qt.examples.customextension
+QML_IMPORT_MAJOR_VERSION = 1
+
 CONFIG += wayland-scanner
 CONFIG += c++11
 SOURCES += \
diff --git a/examples/wayland/custom-extension/compositor/customextension.cpp b/examples/wayland/custom-extension/compositor/customextension.cpp
index e6968adc6..0d19a62e2 100644
--- a/examples/wayland/custom-extension/compositor/customextension.cpp
+++ b/examples/wayland/custom-extension/compositor/customextension.cpp
@@ -8,7 +8,7 @@
 #include <QDebug>
 
 CustomExtension::CustomExtension(QWaylandCompositor *compositor)
-    :QWaylandCompositorExtensionTemplate(compositor)
+    : QWaylandCompositorExtensionTemplate(compositor)
 {
 }
 
@@ -19,6 +19,7 @@ void CustomExtension::initialize()
     init(compositor->display(), 1);
 }
 
+//! [setFontSize]
 void CustomExtension::setFontSize(QWaylandSurface *surface, uint pixelSize)
 {
     if (surface) {
@@ -29,6 +30,7 @@ void CustomExtension::setFontSize(QWaylandSurface *surface, uint pixelSize)
         }
     }
 }
+//! [setFontSize]
 
 void CustomExtension::showDecorations(QWaylandClient *client, bool shown)
 {
@@ -39,7 +41,6 @@ void CustomExtension::showDecorations(QWaylandClient *client, bool shown)
             send_set_window_decoration(target->handle, shown);
         }
     }
-
 }
 
 void CustomExtension::close(QWaylandSurface *surface)
@@ -53,6 +54,7 @@ void CustomExtension::close(QWaylandSurface *surface)
     }
 }
 
+//! [example_extension_bounce]
 void CustomExtension::example_extension_bounce(QtWaylandServer::qt_example_extension::Resource *resource, wl_resource *wl_surface, uint32_t duration)
 {
     Q_UNUSED(resource);
@@ -60,6 +62,7 @@ void CustomExtension::example_extension_bounce(QtWaylandServer::qt_example_exten
     qDebug() << "server received bounce" << surface << duration;
     emit bounce(surface, duration);
 }
+//! [example_extension_bounce]
 
 void CustomExtension::example_extension_spin(QtWaylandServer::qt_example_extension::Resource *resource, wl_resource *wl_surface, uint32_t duration)
 {
@@ -90,7 +93,6 @@ CustomExtensionObject::CustomExtensionObject(const QString &color, const QString
     , m_color(color)
     , m_text(text)
 {
-
 }
 
 void CustomExtensionObject::sendClicked()
diff --git a/examples/wayland/custom-extension/compositor/customextension.h b/examples/wayland/custom-extension/compositor/customextension.h
index 330199697..e377d5f57 100644
--- a/examples/wayland/custom-extension/compositor/customextension.h
+++ b/examples/wayland/custom-extension/compositor/customextension.h
@@ -9,14 +9,18 @@
 #include <QtWaylandCompositor/QWaylandCompositorExtensionTemplate>
 #include <QtWaylandCompositor/QWaylandQuickExtension>
 #include <QtWaylandCompositor/QWaylandCompositor>
+#include <QtWaylandCompositor/QWaylandSurface>
 #include "qwayland-server-custom.h"
 
 class CustomExtensionObject;
 
+//! [CustomExtension]
 class CustomExtension  : public QWaylandCompositorExtensionTemplate<CustomExtension>
         , public QtWaylandServer::qt_example_extension
 {
     Q_OBJECT
+    QML_ELEMENT
+//! [CustomExtension]
 public:
     CustomExtension(QWaylandCompositor *compositor = nullptr);
     void initialize() override;
@@ -25,7 +29,6 @@ signals:
     void surfaceAdded(QWaylandSurface *surface);
     void bounce(QWaylandSurface *surface, uint ms);
     void spin(QWaylandSurface *surface, uint ms);
-
     void customObjectCreated(CustomExtensionObject *obj);
 
 public slots:
@@ -33,11 +36,12 @@ public slots:
     void showDecorations(QWaylandClient *client, bool);
     void close(QWaylandSurface *surface);
 
+//! [example_extension_bounce]
 protected:
     void example_extension_bounce(Resource *resource, wl_resource *surface, uint32_t duration) override;
+//! [example_extension_bounce]
     void example_extension_spin(Resource *resource, wl_resource *surface, uint32_t duration) override;
     void example_extension_register_surface(Resource *resource, wl_resource *surface) override;
-
     void example_extension_create_local_object(Resource *resource, uint32_t id, const QString &color, const QString &text) override;
 };
 
diff --git a/examples/wayland/custom-extension/compositor/main.cpp b/examples/wayland/custom-extension/compositor/main.cpp
index a44027229..458f5b9a3 100644
--- a/examples/wayland/custom-extension/compositor/main.cpp
+++ b/examples/wayland/custom-extension/compositor/main.cpp
@@ -11,15 +11,9 @@
 
 #include "customextension.h"
 
-static void registerTypes()
-{
-    qmlRegisterType<CustomExtensionQuickExtension>("io.qt.examples.customextension", 1, 0, "CustomExtension");
-}
-
 int main(int argc, char *argv[])
 {
     QGuiApplication app(argc, argv);
-    registerTypes();
     QQmlApplicationEngine appEngine(QUrl("qrc:///qml/main.qml"));
 
     return app.exec();
diff --git a/examples/wayland/custom-extension/compositor/qml/CompositorScreen.qml b/examples/wayland/custom-extension/compositor/qml/CompositorScreen.qml
index ec70a4373..ea2cb9b16 100644
--- a/examples/wayland/custom-extension/compositor/qml/CompositorScreen.qml
+++ b/examples/wayland/custom-extension/compositor/qml/CompositorScreen.qml
@@ -9,6 +9,7 @@ WaylandOutput {
     id: output
     property alias surfaceArea: background
     sizeFollowsWindow: true
+
     window: Window {
         id: screen
 
diff --git a/examples/wayland/custom-extension/compositor/qml/main.qml b/examples/wayland/custom-extension/compositor/qml/main.qml
index 7005af841..9907263da 100644
--- a/examples/wayland/custom-extension/compositor/qml/main.qml
+++ b/examples/wayland/custom-extension/compositor/qml/main.qml
@@ -91,13 +91,14 @@ WaylandCompositor {
                 bounceAnimation.start()
             }
 
+//! [setFontSize]
             onFontSizeChanged: {
                 custom.setFontSize(surface, fontSize)
             }
+//! [setFontSize]
         }
     }
 
-
     Component {
         id: customObjectComponent
         Rectangle {
@@ -107,7 +108,7 @@ WaylandCompositor {
 
             width: 100
             height: 100
-            radius: width/2
+            radius: width / 2
             x: Math.random() * (defaultOutput.surfaceArea.width - 100)
             y: Math.random() * (defaultOutput.surfaceArea.height - 100)
 
@@ -138,12 +139,13 @@ WaylandCompositor {
             var h = defaultOutput.surfaceArea.height / 2
             item.x = Math.random() * w
             item.y = Math.random() * h
-            var listCopy = itemList; // List properties cannot be modified through Javascript operations
+            var listCopy = itemList // List properties cannot be modified through Javascript operations
             listCopy.push(item)
             itemList = listCopy
         }
     }
 
+//! [CustomExtension]
     CustomExtension {
         id: custom
 
@@ -151,26 +153,31 @@ WaylandCompositor {
             var item = itemForSurface(surface)
             item.isCustom = true
         }
+
         onBounce: (surface, ms) => {
             var item = itemForSurface(surface)
             item.doBounce(ms)
         }
+
         onSpin: (surface, ms) => {
             var item = itemForSurface(surface)
             item.doSpin(ms)
         }
+
         onCustomObjectCreated: (obj) => {
             var item = customObjectComponent.createObject(defaultOutput.surfaceArea,
-                                                          { "color": obj.color, "text": obj.text, "obj": obj } )
+                                                          { "color": obj.color,
+                                                            "text": obj.text,
+                                                            "obj": obj } )
         }
     }
 
     function setDecorations(shown) {
         var n = itemList.length
         for (var i = 0; i < n; i++) {
-            // TODO: we only need to do it once for each client
             if (itemList[i].isCustom)
                 custom.showDecorations(itemList[i].surface.client, shown)
         }
     }
+//! [CustomExtension]
 }