xcb: support xrandr(1.5) monitor setup

More information about monitor in xrandr 1.5, see
https://keithp.com/blogs/MST-monitors/

Since this change, screen is logical instead of physical.

If xrandr 1.5 and later is installed, Qt screen info will get
from xrandr monitor object instead of xrandr output if only have
1.2 to 1.4.

Users can manipulate monitor as they want, for example, a
combination for two physical screens, half of one screen and etc.

Didn't have chance to access MST monitors, but it should work
if xrandr monitor object was created automatically.

[ChangeLog][xcb] Qt screen info will get from xrandr monitor
object if 1.5 is installed.

Fixes: QTBUG-65457
Change-Id: Iad339cc0d4293b2403b4ef6bf6eb770feb3e685f
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 10 insertions, 1 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index a7db3eda89..b0b26085d7 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -261,7 +261,16 @@ private:
                              const xcb_randr_output_change_t &outputChange,
                              xcb_randr_get_output_info_reply_t *outputInfo);
     void destroyScreen(QXcbScreen *screen);
-    void initializeScreens();
+    void initializeScreens(bool initialized);
+    void initializeScreensFromOutput(xcb_screen_iterator_t *it, int screenNumber, QXcbScreen *primaryScreen);
+
+    void updateScreen_monitor(QXcbScreen *screen, xcb_randr_monitor_info_t *monitorInfo, xcb_timestamp_t timestamp = XCB_NONE);
+    QXcbScreen *createScreen_monitor(QXcbVirtualDesktop *virtualDesktop,
+                                     xcb_randr_monitor_info_t *monitorInfo, xcb_timestamp_t timestamp = XCB_NONE);
+    QXcbVirtualDesktop* virtualDesktopForNumber(int n) const;
+    QXcbScreen* findScreenForMonitorInfo(const QList<QPlatformScreen *> &screens, xcb_randr_monitor_info_t *monitorInfo);
+    void initializeScreensFromMonitor(xcb_screen_iterator_t *it, int screenNumber, QXcbScreen *primaryScreen, bool initialized);
+
     bool compressEvent(xcb_generic_event_t *event) const;
     inline bool timeGreaterThan(xcb_timestamp_t a, xcb_timestamp_t b) const
     { return static_cast<int32_t>(a - b) > 0 || b == XCB_CURRENT_TIME; }