Merge pull request #11 from pnnl/CODEVERIFY-21

GUI: empty png bug fix

constrain/app/app.py

@@ -23,6 +23,7 @@
 from .workflow_diagram import WorkflowDiagram
 from .rect_connect import CustomItem
 from .submit import Worker, SubmitPopup
+from . import utils
 
 from constrain.api.workflow import Workflow
 
@@ -148,6 +149,14 @@ def advancedPopupSetting(self):
 
     def exportFile(self):
         """Exports current state as a .json to local storage"""
+
+        scene = self.states_form.scene
+        if not scene.items():
+            utils.send_error(
+                "Export Error", "Workflow is empty. Add a workflow to export"
+            )
+            return
+
         fp, _ = QFileDialog.getSaveFileName(
             self, "Save JSON File", "", "JSON Files (*.json);;All Files (*)"
         )
@@ -162,11 +171,17 @@ def exportFile(self):
 
     def exportAsPng(self):
         """Exports current state as a .png to local storage"""
+
+        scene = self.states_form.scene
+        if not scene.items():
+            utils.send_error(
+                "Export Error", "Workflow is empty. Add a workflow to export"
+            )
+            return
+
         fp, _ = QFileDialog.getSaveFileName(self, "Save Image", "", "PNG Files (*.png)")
 
         if fp:
-            scene = self.states_form.scene
-            scene.sceneRect().size()
             pixmap = QPixmap(scene.sceneRect().size().toSize())
             pixmap.fill(QColor(255, 255, 255))
             painter = QPainter(pixmap)

constrain/app/rect_connect.py

@@ -9,6 +9,8 @@
 
 from PyQt6 import QtCore, QtGui, QtWidgets
 
+from . import utils
+
 
 class Path(QtWidgets.QGraphicsPathItem):
     def __init__(self, start, p2, end=None):
@@ -241,23 +243,16 @@ def newLineErrorCheck(self, pathItem):
             if existing.controlPoints() == pathItem.controlPoints():
                 return False
 
-        # define error message
-        def send_error(text):
-            error_msg = QtWidgets.QMessageBox()
-            error_msg.setIcon(QtWidgets.QMessageBox.Icon.Critical)
-            error_msg.setWindowTitle("Error in Path")
-            error_msg.setText(text)
-            error_msg.exec()
-
         # only consider sending error message if self is the start of the path
         if pathItem.start == self:
             # determine if parent will have too many children states
             rect_children_amt = len(self.parent.children)
             if rect_children_amt >= 1:
                 if self.parent.state["Type"] != "Choice":
                     # MethodCall type CustomItem can only connect to 1 CustomItem
-                    error_msg = "This type cannot connect to more than 1 state"
-                    send_error(error_msg)
+                    utils.send_error(
+                        "Error in Path", "This type cannot connect to more than 1 state"
+                    )
                     return False
                 elif self.parent.state["Type"] == "Choice":
                     # Choice type CustomItem can connect to more than 1 CustomItem, but need to see how many are defined in the state
@@ -267,7 +262,7 @@ def send_error(text):
 
                     if rect_children_amt >= choices_amt:
                         error_msg = f"This type cannot connect to more than {choices_amt} states"
-                        send_error(error_msg)
+                        utils.send_error("Error in Path", error_msg)
                         return False
             # add new child node to parent.children since path is viable
             self.parent.children.append(pathItem.end.parent)

constrain/app/utils.py

@@ -0,0 +1,14 @@
+from PyQt6.QtWidgets import QMessageBox
+
+
+def send_error(window_title, text):
+    """Displays an error message with given text
+
+    Args:
+        text (str): text to be displayed
+    """
+    error_msg = QMessageBox()
+    error_msg.setIcon(QMessageBox.Icon.Critical)
+    error_msg.setWindowTitle(window_title)
+    error_msg.setText(text)
+    error_msg.exec()