Offscreen: add configuration update API

Add support for updating the platform configuration at runtime,
which  enables use cases such as changing the screen configuration
from an auto test.

Provide functions for getting and setting the complete
configuration as a QJsonObject:

    QJsonObject configuration()
    void setConfiguration(QJsonObject)

User code can then either set a completely new configuration,
or make a smaller update by using a get-modify-set sequence:

    // Set the logical DPI for screen 0 to 192:
    auto config = configuration();
    config[“screens”][0][“logicalDpi] = 192
    setConfiguration(config);

This approach means we can expose a minimal but complete
API, at the cost of doing more work in the offscreen plugin
in order to figure out what changed.

Note that this change does not export thew API from the
platform plugin.

Change-Id: If776c36d5ae6d72dca715cc8e89e42768ed32c60
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h
index 7e26b76759..afd30d7b4b 100644
--- a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h
+++ b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h
@@ -56,6 +56,7 @@ class QOffscreenX11Info;
 class QOffscreenX11PlatformNativeInterface : public QOffscreenPlatformNativeInterface
 {
 public:
+    QOffscreenX11PlatformNativeInterface(QOffscreenIntegration *integration);
     ~QOffscreenX11PlatformNativeInterface();
 
     void *nativeResourceForScreen(const QByteArray &resource, QScreen *screen) override;
@@ -69,6 +70,7 @@ public:
 class QOffscreenX11Integration : public QOffscreenIntegration
 {
 public:
+    QOffscreenX11Integration(const QStringList& paramList);
     ~QOffscreenX11Integration();
     bool hasCapability(QPlatformIntegration::Capability cap) const override;