#812 add PoC image overlay and image stamp to png transfers

git-svn-id: https://xpra.org/svn/Xpra/trunk@22826 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/x11/gtk_x11/clipboard.py

@@ -5,6 +5,7 @@
 
 import os
 import struct
+from io import BytesIO
 
 from xpra.gtk_common.error import xsync, xswallow
 from xpra.gtk_common.gobject_util import one_arg_signal, n_arg_signal
@@ -27,7 +28,7 @@
     X11WindowBindings,                          #@UnresolvedImport
     )
 from xpra.os_util import bytestostr
-from xpra.util import csv, repr_ellipsized, first_time
+from xpra.util import csv, repr_ellipsized, first_time, envbool
 from xpra.log import Logger
 
 gdk = import_gdk()
@@ -584,8 +585,8 @@ def do_property_notify(self, event):
                         return
                     self.cancel_incr_data_timer()
                     data = b"".join(self.incr_data_chunks)
-                    self.reset_incr_data()
                     log("got incremental data termination, total size=%i bytes", len(data))
+                    self.reset_incr_data()
                     self.got_local_contents(target, dtype, dformat, data)
                     return
         except PropertyError:
@@ -597,6 +598,7 @@ def do_property_notify(self, event):
         self.got_local_contents(target, dtype, dformat, data)
 
     def got_local_contents(self, target, dtype=None, dformat=None, data=None):
+        data = self.filter_data(target, dtype, dformat, data)
         target_requests = self.local_requests.pop(target, {})
         for timer, got_contents, time in target_requests.values():
             if log.is_debug_enabled():
@@ -605,6 +607,44 @@ def got_local_contents(self, target, dtype=None, dformat=None, data=None):
             glib.source_remove(timer)
             got_contents(dtype, dformat, data)
 
+    def filter_data(self, target, dtype=None, dformat=None, data=None):
+        log("filter_data(%s, %s, %s, ..)", target, dtype, dformat)
+        IMAGE_OVERLAY = os.environ.get("XPRA_CLIPBOARD_IMAGE_OVERLAY", None)
+        if IMAGE_OVERLAY and not os.path.exists(IMAGE_OVERLAY):
+            IMAGE_OVERLAY = None
+        IMAGE_STAMP = envbool("XPRA_CLIPBOARD_IMAGE_STAMP", True)
+        if dtype in ("image/png", ) and (IMAGE_STAMP or IMAGE_OVERLAY):
+            from xpra.codecs.pillow.decoder import open_only
+            img = open_only(data, ("png", ))
+            has_alpha = img.mode=="RGBA"
+            if not has_alpha and IMAGE_OVERLAY:
+                img = img.convert("RGBA")
+            w, h = img.size
+            from PIL import Image   #@UnresolvedImport
+            overlay = Image.open(IMAGE_OVERLAY)
+            if overlay.mode!="RGBA":
+                log.warn("Warning: cannot use overlay image '%s'", IMAGE_OVERLAY)
+                log.warn(" invalid mode '%s'", overlay.mode)
+            else:
+                log("adding clipboard image overlay to %s", dtype)
+                overlay_resized = overlay.resize((w, h), Image.ANTIALIAS)
+                composite = Image.alpha_composite(img, overlay_resized)
+                if not has_alpha and img.mode=="RGBA":
+                    composite = composite.convert("RGB")
+                img = composite
+            if IMAGE_STAMP:
+                log("adding clipboard image stamp to %s", dtype)
+                from datetime import datetime
+                from PIL import ImageDraw
+                img_draw = ImageDraw.Draw(img)
+                w, h = img.size
+                img_draw.text((10, max(0, h//2-16)), 'via Xpra, %s' % datetime.now().isoformat(), fill='black')
+            buf = BytesIO()
+            img.save(buf, "PNG")
+            data = buf.getvalue()
+            buf.close()
+        return data
+
 
     def reschedule_incr_data_timer(self):
         self.cancel_incr_data_timer()