QX11Info: add nextStartupId/setNextStartupId - for startup-notification

This controls what the next window to be shown will send as startup-notification
message.
http://standards.freedesktop.org/startup-notification-spec/startup-notification-latest.txt

Change-Id: Ia1b5e6ba004d61ca6fdfd6683d2e22dfcd0c42fb
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Reviewed-by: Richard J. Moore <rich@kde.org>

3 files changed, 79 insertions, 0 deletions

diff --git a/src/x11extras/qx11info_x11.cpp b/src/x11extras/qx11info_x11.cpp
index 2a7e495..fb70ba8 100644
--- a/src/x11extras/qx11info_x11.cpp
+++ b/src/x11extras/qx11info_x11.cpp
@@ -287,6 +287,53 @@ unsigned long QX11Info::getTimestamp()
 }
 
 /*!
+    Returns the startup ID that will be used for the next window to be shown by this process.
+
+    After the next window is shown, the next startup ID will be empty.
+
+    http://standards.freedesktop.org/startup-notification-spec/startup-notification-latest.txt
+
+    \since 5.4
+    \sa setNextStartupId()
+*/
+QByteArray QX11Info::nextStartupId()
+{
+    if (!qApp)
+        return 0;
+    QPlatformNativeInterface *native = qApp->platformNativeInterface();
+    if (!native)
+        return 0;
+    return static_cast<char *>(native->nativeResourceForIntegration("startupid"));
+}
+
+/*!
+    Sets the next startup ID to \a id.
+
+    This is the startup ID that will be used for the next window to be shown by this process.
+
+    The startup ID of the first window comes from the environment variable DESKTOP_STARTUP_ID.
+    This method is useful for subsequent windows, when the request comes from another process
+    (e.g. via DBus).
+
+    \since 5.4
+    \sa nextStartupId()
+*/
+void QX11Info::setNextStartupId(const QByteArray &id)
+{
+    if (!qApp)
+        return;
+    QPlatformNativeInterface *native = qApp->platformNativeInterface();
+    if (!native)
+        return;
+    typedef void (*SetStartupIdFunc)(const char*);
+    SetStartupIdFunc func = reinterpret_cast<SetStartupIdFunc>(native->nativeResourceFunctionForIntegration("setstartupid"));
+    if (func)
+        func(id.constData());
+    else
+        qWarning("Internal error: QPA plugin doesn't implement setStartupId");
+}
+
+/*!
     Returns the default display for the application.
 
     \sa appScreen()
diff --git a/src/x11extras/qx11info_x11.h b/src/x11extras/qx11info_x11.h
index d5d00f3..6e07ba7 100644
--- a/src/x11extras/qx11info_x11.h
+++ b/src/x11extras/qx11info_x11.h
@@ -69,6 +69,9 @@ public:
 
     static unsigned long getTimestamp();
 
+    static QByteArray nextStartupId();
+    static void setNextStartupId(const QByteArray &id);
+
     static Display *display();
     static xcb_connection_t *connection();
 
diff --git a/tests/auto/qx11info/tst_qx11info.cpp b/tests/auto/qx11info/tst_qx11info.cpp
index 602de1d..8334690 100644
--- a/tests/auto/qx11info/tst_qx11info.cpp
+++ b/tests/auto/qx11info/tst_qx11info.cpp
@@ -52,6 +52,7 @@ class tst_QX11Info : public QObject
 
 private slots:
     void staticFunctionsBeforeQApplication();
+    void startupId();
     void isPlatformX11();
     void appTime();
 };
@@ -110,6 +111,34 @@ void tst_QX11Info::staticFunctionsBeforeQApplication()
     QCOMPARE(appTime, 0ul);
 }
 
+static const char idFromEnv[] = "startupid_TIME123456";
+void initialize()
+{
+    qputenv("DESKTOP_STARTUP_ID", idFromEnv);
+}
+Q_CONSTRUCTOR_FUNCTION(initialize)
+
+void tst_QX11Info::startupId()
+{
+    int argc = 0;
+    QApplication app(argc, 0);
+
+    // This relies on the fact that no widget was shown yet,
+    // so please make sure this method is always the first test.
+    QCOMPARE(QString(QX11Info::nextStartupId()), QString(idFromEnv));
+    QWidget w;
+    w.show();
+    QVERIFY(QX11Info::nextStartupId().isEmpty());
+
+    QByteArray idSecondWindow = "startupid2_TIME234567";
+    QX11Info::setNextStartupId(idSecondWindow);
+    QCOMPARE(QX11Info::nextStartupId(), idSecondWindow);
+
+    QWidget w2;
+    w2.show();
+    QVERIFY(QX11Info::nextStartupId().isEmpty());
+}
+
 void tst_QX11Info::isPlatformX11()
 {
     int argc = 0;