From ba4d70e7a495fcb68ebd9b0ff13bcf61ed309579 Mon Sep 17 00:00:00 2001
From: 0penBrain <48731257+0penBrain@users.noreply.github.com>
Date: Tue, 7 Apr 2020 21:20:23 +0200
Subject: [PATCH] [Expression] Default to current 'constant' value when editing
 if no expression set yet ; fixes #4298

 Move signals connecting before value initialization so it's not needed to call them manually
 Only spin boxes implemented (should be the major usage)
---
 src/Gui/DlgExpressionInput.cpp | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/Gui/DlgExpressionInput.cpp b/src/Gui/DlgExpressionInput.cpp
index 55426e0f80..40e3faa240 100644
--- a/src/Gui/DlgExpressionInput.cpp
+++ b/src/Gui/DlgExpressionInput.cpp
@@ -55,14 +55,20 @@ DlgExpressionInput::DlgExpressionInput(const App::ObjectIdentifier & _path,
     // Setup UI
     ui->setupUi(this);
 
-    if (expression) {
-        ui->expression->setText(Base::Tools::fromStdString(expression->toString()));
-        textChanged(Base::Tools::fromStdString(expression->toString()));
-    }
-
     // Connect signal(s)
     connect(ui->expression, SIGNAL(textChanged(QString)), this, SLOT(textChanged(QString)));
     connect(ui->discardBtn, SIGNAL(clicked()), this, SLOT(setDiscarded()));
+    
+    if (expression) {
+        ui->expression->setText(Base::Tools::fromStdString(expression->toString()));
+    }
+    else
+    {
+        QAbstractSpinBox *sb = dynamic_cast<QAbstractSpinBox*>(parent);
+        if (sb) {
+            ui->expression->setText(sb->text());
+        }
+    }
 
     // Set document object on line edit to create auto completer
     DocumentObject * docObj = path.getDocumentObject();