Add support for QML debugging/profiling

meshroom/env.py

@@ -0,0 +1,70 @@
+"""
+Meshroom environment variable management.
+"""
+
+__all__ = [
+    "EnvVar",
+    "EnvVarHelpAction",
+]
+
+import argparse
+import os
+from dataclasses import dataclass
+from enum import Enum
+import sys
+from typing import Any, Type
+
+
+@dataclass
+class VarDefinition:
+    """Environment variable definition."""
+
+    # The type to cast the value to.
+    valueType: Type
+    # Default value if the variable is not set in the environment.
+    default: str
+    # Description of the purpose of the variable.
+    description: str = ""
+
+    def __str__(self) -> str:
+        return f"{self.description} ({self.valueType.__name__}, default: '{self.default}')"
+
+
+class EnvVar(Enum):
+    """Meshroom environment variables catalog."""
+
+    # UI - Debug
+    MESHROOM_QML_DEBUG = VarDefinition(bool, "False", "Enable QML debugging")
+    MESHROOM_QML_DEBUG_PARAMS = VarDefinition(
+        str, "port:3768", "QML debugging params as expected by -qmljsdebugger"
+    )
+
+    @staticmethod
+    def get(envVar: "EnvVar") -> Any:
+        """Get the value of `envVar`, cast to the variable type."""
+        value = os.environ.get(envVar.name, envVar.value.default)
+        return EnvVar._cast(value, envVar.value.valueType)
+
+    @staticmethod
+    def _cast(value: str, valueType: Type) -> Any:
+        if valueType is str:
+            return value
+        elif valueType is bool:
+            return value.lower() in {"true", "1", "on"}
+        return valueType(value)
+
+    @classmethod
+    def help(cls) -> str:
+        """Return a formatted string with the details of each environment variables."""
+        return "\n".join([f"{var.name}: {var.value}" for var in cls])
+
+
+class EnvVarHelpAction(argparse.Action):
+    """Argparse action for printing Meshroom environment variables help and exit."""
+
+    DEFAULT_HELP = "Print Meshroom environment variables help and exit."
+
+    def __call__(self, parser, namespace, value, option_string=None):
+        print("Meshroom environment variables:")
+        print(EnvVar.help())
+        sys.exit(0)

meshroom/ui/app.py

@@ -8,13 +8,17 @@
 from PySide6 import QtCore
 from PySide6.QtCore import Qt, QUrl, QJsonValue, qInstallMessageHandler, QtMsgType, QSettings
 from PySide6.QtGui import QIcon
+from PySide6.QtQml import QQmlDebuggingEnabler
+from PySide6.QtQuickControls2 import QQuickStyle
 from PySide6.QtWidgets import QApplication
 
 import meshroom
 from meshroom.core import nodesDesc
 from meshroom.core.taskManager import TaskManager
 from meshroom.common import Property, Variant, Signal, Slot
 
+from meshroom.env import EnvVar, EnvVarHelpAction
+
 from meshroom.ui import components
 from meshroom.ui.components.clipboard import ClipboardHelper
 from meshroom.ui.components.filepath import FilepathHelper
@@ -181,17 +185,29 @@ def createMeshroomParser(args):
         + '\n'.join(['    - ' + p for p in meshroom.core.pipelineTemplates]),
     )
 
+    advanced_group = parser.add_argument_group("Advanced Options")
+    advanced_group.add_argument(
+        "--env-help",
+        action=EnvVarHelpAction,
+        nargs=0,
+        help=EnvVarHelpAction.DEFAULT_HELP,
+    )
+
     return parser.parse_args(args[1:])
 
 
 class MeshroomApp(QApplication):
     """ Meshroom UI Application. """
-    def __init__(self, args):
+    def __init__(self, inputArgs):
         meshroom.core.initPipelines()
 
-        QtArgs = [args[0], '-style', 'Fusion'] + args[1:]  # force Fusion style by default
-
-        args = createMeshroomParser(args)
+        args = createMeshroomParser(inputArgs)
+        qtArgs = []
+
+        if EnvVar.get(EnvVar.MESHROOM_QML_DEBUG):
+            debuggerParams = EnvVar.get(EnvVar.MESHROOM_QML_DEBUG_PARAMS)
+            self.debugger = QQmlDebuggingEnabler(printWarning=True)
+            qtArgs = [f"-qmljsdebugger={debuggerParams}"]
 
         logStringToPython = {
             'fatal': logging.FATAL,
@@ -203,7 +219,7 @@ def __init__(self, args):
         }
         logging.getLogger().setLevel(logStringToPython[args.verbose])
 
-        super(MeshroomApp, self).__init__(QtArgs)
+        super(MeshroomApp, self).__init__(inputArgs[:1] + qtArgs)
 
         self.setOrganizationName('AliceVision')
         self.setApplicationName('Meshroom')
@@ -213,6 +229,9 @@ def __init__(self, args):
         font.setPointSize(9)
         self.setFont(font)
 
+        # Use Fusion style by default.
+        QQuickStyle.setStyle("Fusion")
+
         pwd = os.path.dirname(__file__)
         self.setWindowIcon(QIcon(os.path.join(pwd, "img/meshroom.svg")))