external plugins: add methods to read image files

electrum/gui/qt/util.py

@@ -1237,6 +1237,10 @@ def icon_path(icon_basename: str):
 def read_QIcon(icon_basename: str) -> QIcon:
     return QIcon(icon_path(icon_basename))
 
+def read_QIcon_from_bytes(b: bytes) -> QIcon:
+    qp = QPixmap()
+    qp.loadFromData(b)
+    return QIcon(qp)
 
 class IconLabel(QWidget):
     HorizontalSpacing = 2

electrum/plugin.py

@@ -422,6 +422,14 @@ class BasePlugin(Logger):
     def settings_dialog(self, window):
         raise NotImplementedError()
 
+    def read_file(self, filename: str) -> bytes:
+        """ note: only for external plugins """
+        import zipfile
+        plugin_file_path = os.path.join(self.parent.get_external_plugin_dir(), self.name + '.zip')
+        with zipfile.ZipFile(plugin_file_path) as myzip:
+            with myzip.open(os.path.join(self.name, filename)) as myfile:
+                s = myfile.read()
+                return s
 
 class DeviceUnpairableError(UserFacingException): pass
 class HardwarePluginLibraryUnavailable(Exception): pass