#1526 get dpi from comtypes

and refactor comtypes query into a utility context manager

xpra/platform/gui.py

@@ -90,6 +90,11 @@ def get_ydpi():
     return -1
 
 
+def get_monitors_info(display, xscale=1, yscale=1):
+    from xpra.gtk_common import gtk_util
+    return gtk_util.get_monitors_info(display, xscale, yscale)
+
+
 def get_icon_size():
     xdpi = get_xdpi()
     ydpi = get_ydpi()
@@ -324,7 +329,7 @@ def fnames(l):
                 "get_session_type",
                 "get_vrefresh", "get_workarea", "get_workareas",
                 "get_number_of_desktops", "get_desktop_names",
-                "get_antialias_info", "get_icc_info", "get_display_icc_info", "get_xdpi", "get_ydpi",
+                "get_antialias_info", "get_icc_info", "get_display_icc_info", "get_xdpi", "get_ydpi", "get_monitors_info",
                 "get_icon_size",
                 "get_window_min_size", "get_window_max_size",
                 "get_mouse_config",

xpra/platform/win32/comtypes_util.py

@@ -25,6 +25,9 @@ def __enter__(self):
             logger.setLevel(logging.WARNING)
         self.verbose = None
         from comtypes import client                  #@UnresolvedImport
+        client.gen_dir = None
+        from comtypes import CoInitialize               #@UnresolvedImport
+        CoInitialize()
         gen = getattr(client, "_generate", None)
         if gen:
             self.verbose = getattr(gen, "__verbose__", None)
@@ -41,3 +44,17 @@ def __exit__(self, *_args):
                 gen.__verbose__ = self.verbose
         for i, logger in enumerate(self.loggers):
             logger.setLevel(self.saved_levels[i])
+
+
+class CIMV2_Query(QuietenLogging):
+
+    def __init__(self, query):
+        self.query = query
+        super().__init__()
+
+    def __enter__(self):
+        super().__enter__()
+        from comtypes.client import CreateObject        #@UnresolvedImport
+        o = CreateObject("WbemScripting.SWbemLocator")
+        s = o.ConnectServer(".", "root\\cimv2")
+        return s.ExecQuery(self.query)

xpra/platform/win32/gui.py

@@ -35,7 +35,6 @@
     GetIntSystemParametersInfo,
     GetUserObjectInformationA, OpenInputDesktop, CloseDesktop,
     GetMonitorInfo,
-    user32,
     )
 from xpra.common import KeyEvent
 from xpra.util import AdHocStruct, csv, envint, envbool, typedict
@@ -53,6 +52,7 @@
 REINIT_VISIBLE_WINDOWS = envbool("XPRA_WIN32_REINIT_VISIBLE_WINDOWS", True)
 SCREENSAVER_LISTENER_POLL_DELAY = envint("XPRA_SCREENSAVER_LISTENER_POLL_DELAY", 10)
 APP_ID = os.environ.get("XPRA_WIN32_APP_ID", "Xpra")
+MONITOR_DPI = envbool("XPRA_WIN32_MONITOR_DPI", True)
 
 
 PyCapsule_GetPointer = pythonapi.PyCapsule_GetPointer
@@ -902,6 +902,47 @@ def show_desktop(b):
         log.warn("failed to call show_desktop(%s): %s", b, e)
 
 
+
+def get_monitors_info(display, xscale=1, yscale=1):
+    from xpra.gtk_common import gtk_util
+    monitors_info = gtk_util.get_monitors_info(display, xscale, yscale)
+    if MONITOR_DPI:
+        #try to get more precise data by querying the DPI using comtypes:
+        from xpra.platform.win32.comtypes_util import CIMV2_Query
+        with CIMV2_Query("SELECT * FROM Win32_DesktopMonitor") as res:
+            index = 0
+            for monitor in res:
+                dminfo = dict((k, monitor.Properties_[k].Value) for k in (
+                    "DeviceID", "MonitorManufacturer", "MonitorType",
+                    "ScreenWidth", "ScreenHeight",
+                    "PixelsPerXLogicalInch", "PixelsPerYLogicalInch",
+                    ))
+                log(f"Win32_DesktopMonitor {index}: {dminfo}")
+                manufacturer = dminfo["MonitorManufacturer"]
+                model = dminfo["MonitorType"]
+                #find this monitor entry in the gtk info:
+                mmatch = None
+                for monitor_info in monitors_info.values():
+                    if monitor_info.get("manufacturer")==manufacturer and monitor_info.get("model")==model:
+                        mmatch = monitor_info
+                        break
+                if mmatch:
+                    dpix = dminfo["PixelsPerXLogicalInch"]
+                    dpiy = dminfo["PixelsPerYLogicalInch"]
+                    #get the screen size from gtk because Win32_DesktopMonitor can be None!
+                    width = dminfo["ScreenWidth"] or mmatch["geometry"][2]
+                    height = dminfo["ScreenHeight"] or mmatch["geometry"][3]
+                    if dpix>0 and dpiy>0 and width>0 and height>0:
+                        mmatch.update({
+                            "dpi-x" : dpix,
+                            "dpi-y" : dpiy,
+                            "width-mm"  : round(width*25.4/dpix),
+                            "height-mm" : round(height*25.4/dpiy),
+                            })
+                index += 1
+    return monitors_info
+
+
 WM_WTSSESSION_CHANGE = 0x02b1
 WTS_CONSOLE_CONNECT         = 0x1
 WTS_CONSOLE_DISCONNECT      = 0x2

xpra/platform/win32/netdev_query.py

@@ -8,18 +8,10 @@
 
 
 def get_interface_info(_fd, iface):
-    from xpra.platform.win32.comtypes_util import QuietenLogging
-    with QuietenLogging():
-        try:
-            import comtypes.client
-            comtypes.client.gen_dir = None
-            from comtypes import CoInitialize               #@UnresolvedImport
-            CoInitialize()
-            from comtypes.client import CreateObject        #@UnresolvedImport
-            o = CreateObject("WbemScripting.SWbemLocator")
-            s = o.ConnectServer(".", "root\\cimv2")
-            query = "SELECT * FROM Win32_NetworkAdapter WHERE GUID='%s'" % iface
-            res = s.ExecQuery(query)
+    from xpra.platform.win32.comtypes_util import CIMV2_Query
+    query = "SELECT * FROM Win32_NetworkAdapter WHERE GUID='%s'" % iface
+    try:
+        with CIMV2_Query(query) as res:
             log("ExecQuery(%s) returned %i rows", query, res.Count)
             if res.Count==1:
                 for r in res:
@@ -44,13 +36,14 @@ def get_interface_info(_fd, iface):
                             props[ik] = v
                     log("get_interface_info(%s)=%s" % (iface, props))
                     return props
-        except Exception as e:
-            log("get_interface_info(%s)", iface, exc_info=True)
-            from xpra.util import first_time
-            if first_time("win32-network-query"):
-                log.info("cannot query network interface:")
-                log.info(" %s", e)
-        return {}
+    except Exception as e:
+        log("get_interface_info(%s)", iface, exc_info=True)
+        from xpra.util import first_time
+        if first_time("win32-network-query"):
+            log.info("cannot query network interface:")
+            log.info(" %s", e)
+    return {}
+
 
 def get_tcp_info(sock):  #pylint: disable=unused-argument
     """