Add a multi-screen compositor example

This example shows how shell surfaces can move across outputs in order to
create traditional multi-monitor desktop functionality.

Change-Id: Ie7c0aa1dc47c0c1a944dffcce5237dee92785396
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@hawaiios.org>

7 files changed, 367 insertions, 0 deletions

diff --git a/examples/wayland/multi-screen/main.cpp b/examples/wayland/multi-screen/main.cpp
new file mode 100644
index 00000000..81adbc13
--- /dev/null
+++ b/examples/wayland/multi-screen/main.cpp
@@ -0,0 +1,55 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/QUrl>
+#include <QtCore/QDebug>
+
+#include <QtGui/QGuiApplication>
+
+#include <QtQml/QQmlApplicationEngine>
+
+int main(int argc, char *argv[])
+{
+    QGuiApplication app(argc, argv);
+
+    QQmlApplicationEngine appEngine(QUrl("qrc:///qml/main.qml"));
+
+    return app.exec();
+}
diff --git a/examples/wayland/multi-screen/multi-screen.pro b/examples/wayland/multi-screen/multi-screen.pro
new file mode 100644
index 00000000..29e1479d
--- /dev/null
+++ b/examples/wayland/multi-screen/multi-screen.pro
@@ -0,0 +1,18 @@
+QT += gui qml
+
+SOURCES += \
+    main.cpp
+
+OTHER_FILES = \
+    qml/main.qml \
+
+RESOURCES += multi-screen.qrc
+
+target.path = $$[QT_INSTALL_EXAMPLES]/wayland/multi-screen
+sources.files = $$SOURCES $$HEADERS $$RESOURCES $$FORMS multi-screen.pro
+sources.path = $$[QT_INSTALL_EXAMPLES]/wayland/multi-screen
+INSTALLS += target sources
+
+DISTFILES += \
+    qml/Screen.qml \
+    qml/Chrome.qml
diff --git a/examples/wayland/multi-screen/multi-screen.qrc b/examples/wayland/multi-screen/multi-screen.qrc
new file mode 100644
index 00000000..57fcd3cf
--- /dev/null
+++ b/examples/wayland/multi-screen/multi-screen.qrc
@@ -0,0 +1,7 @@
+<RCC>
+    <qresource prefix="/">
+        <file>qml/main.qml</file>
+        <file>qml/Screen.qml</file>
+        <file>qml/Chrome.qml</file>
+    </qresource>
+</RCC>
diff --git a/examples/wayland/multi-screen/qml/Chrome.qml b/examples/wayland/multi-screen/qml/Chrome.qml
new file mode 100644
index 00000000..d91a9304
--- /dev/null
+++ b/examples/wayland/multi-screen/qml/Chrome.qml
@@ -0,0 +1,77 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2016 Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.0
+import QtWayland.Compositor 1.0
+
+Item {
+    id: chrome
+    property alias shellSurface: surfaceItem.shellSurface
+    property alias surfaceItem: surfaceItem
+    property alias moveItem: surfaceItem.moveItem
+
+    x: surfaceItem.moveItem.x - surfaceItem.output.geometry.x
+    y: surfaceItem.moveItem.y - surfaceItem.output.geometry.y
+
+    ShellSurfaceItem {
+        id: surfaceItem
+        onSurfaceDestroyed: chrome.destroy();
+    }
+
+    onXChanged: updatePrimary()
+    onYChanged: updatePrimary()
+    function updatePrimary() {
+        var w = surfaceItem.width
+        var h = surfaceItem.height
+        var area = w * h;
+        var screenW = surfaceItem.output.geometry.width;
+        var screenH = surfaceItem.output.geometry.height;
+        var x1 = Math.max(0, x);
+        var y1 = Math.max(0, y);
+        var x2 = Math.min(x + w, screenW);
+        var y2 = Math.min(y + h, screenH);
+        var w1 = Math.max(0, x2 - x1);
+        var h1 = Math.max(0, y2 - y1);
+        if (w1 * h1 * 2 > area) {
+            surfaceItem.setPrimary();
+        }
+    }
+}
diff --git a/examples/wayland/multi-screen/qml/Screen.qml b/examples/wayland/multi-screen/qml/Screen.qml
new file mode 100644
index 00000000..7e2eb01d
--- /dev/null
+++ b/examples/wayland/multi-screen/qml/Screen.qml
@@ -0,0 +1,82 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.0
+import QtWayland.Compositor 1.0
+import QtQuick.Window 2.2
+
+WaylandOutput {
+    id: screen
+    property variant viewsBySurface: ({})
+    property alias surfaceArea: background
+    property alias text: t.text
+    sizeFollowsWindow: true
+
+    window: Window {
+        width: 1024
+        height: 760
+        visible: true
+
+        WaylandMouseTracker {
+            id: mouseTracker
+            anchors.fill: parent
+            windowSystemCursorEnabled: false
+
+            Rectangle {
+                anchors.fill: parent
+                id: background
+
+                Text {
+                    id: t
+                    anchors.centerIn: parent
+                    font.pointSize: 72
+                }
+            }
+
+            WaylandCursorItem {
+                inputEventsEnabled: false
+                x: mouseTracker.mouseX
+                y: mouseTracker.mouseY
+                seat: comp.defaultSeat
+                visible: mouseTracker.containsMouse
+            }
+        }
+    }
+}
diff --git a/examples/wayland/multi-screen/qml/main.qml b/examples/wayland/multi-screen/qml/main.qml
new file mode 100644
index 00000000..37350289
--- /dev/null
+++ b/examples/wayland/multi-screen/qml/main.qml
@@ -0,0 +1,127 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2016 Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.0
+import QtWayland.Compositor 1.0
+
+WaylandCompositor {
+    id: comp
+    defaultOutput: middleScreen
+
+    Screen {
+        id: leftScreen
+        position.x: -leftScreen.surfaceArea.width
+        position.y: 0
+        surfaceArea.color: "#f00"
+        text: "Left"
+        compositor: comp
+    }
+
+    Screen {
+        id: middleScreen
+        position.x: leftScreen.position.x + leftScreen.surfaceArea.width
+        position.y: 0
+        text: "Middle"
+        surfaceArea.color: "#0f0"
+        compositor: comp
+    }
+
+    Screen {
+        id: rightScreen
+        position.x: middleScreen.position.x + middleScreen.surfaceArea.width
+        position.y: 0
+        surfaceArea.color: "#00f"
+        text: "Right"
+        compositor: comp
+    }
+
+    Component {
+        id: chromeComponent
+        Chrome {}
+    }
+
+    Component {
+        id: moveItemComponent
+        Item {}
+    }
+
+    Item {
+        id: rootItem
+        x: leftScreen.position.x
+        y: leftScreen.position.y
+        width: leftScreen.surfaceArea.width + middleScreen.surfaceArea.width + rightScreen.surfaceArea.width
+        height: Math.max(leftScreen.surfaceArea.height, middleScreen.surfaceArea.height, rightScreen.surfaceArea.height)
+    }
+
+    WlShell {
+        onWlShellSurfaceCreated: handleShellSurfaceCreated(shellSurface)
+    }
+
+    XdgShellV5 {
+        onXdgSurfaceCreated: handleShellSurfaceCreated(xdgSurface)
+        onXdgPopupCreated: handleShellSurfaceCreated(xdgPopup)
+    }
+
+    function createShellSurfaceItem(shellSurface, moveItem, output) {
+        var parentSurfaceItem = output.viewsBySurface[shellSurface.parentSurface];
+        var parent = parentSurfaceItem || output.surfaceArea;
+        var item = chromeComponent.createObject(parent, {
+            "shellSurface": shellSurface,
+            "moveItem": moveItem,
+            "output": output
+        });
+        if (parentSurfaceItem) {
+            item.x += output.position.x;
+            item.y += output.position.y;
+        }
+        output.viewsBySurface[shellSurface.surface] = item;
+    }
+
+    function handleShellSurfaceCreated(shellSurface) {
+        var moveItem = moveItemComponent.createObject(rootItem, {
+            "width": Qt.binding(function() { return shellSurface.surface.width; }),
+            "height": Qt.binding(function() { return shellSurface.surface.height; })
+        });
+        createShellSurfaceItem(shellSurface, moveItem, middleScreen);
+        createShellSurfaceItem(shellSurface, moveItem, leftScreen);
+        createShellSurfaceItem(shellSurface, moveItem, rightScreen);
+    }
+}
diff --git a/examples/wayland/wayland.pro b/examples/wayland/wayland.pro
index f36bf69e..2a539500 100644
--- a/examples/wayland/wayland.pro
+++ b/examples/wayland/wayland.pro
@@ -10,6 +10,7 @@ contains(QT_CONFIG, opengl):qtHaveModule(quick) {
     SUBDIRS += spanning-screens
     SUBDIRS += pure-qml
     SUBDIRS += multi-output
+    SUBDIRS += multi-screen
     SUBDIRS += custom-extension
     SUBDIRS += server-buffer
     SUBDIRS += ivi-compositor