Sketcher: Change enter behavior on OVP to put OVP in lock state only

This patch adds/changes a couple of things:
* if you press enter on a label now, it moves you to another label and
  adds the label and lock on the previous label, instead of previous behavior
  where it was accepting whole dimension
* if you press enter and have lock state on both labels then you move to
  next stage
* if you press ctrl+enter it's as is if you'd press enter on both labels
  (the object becomes constrained with whatever dimensions that were in
  both labels)
* tab still works the same way
* you can remove "Lock" state from the label by typing something
  additional or removing the dimension at all

src/Gui/EditableDatumLabel.cpp

@@ -33,8 +33,13 @@
 
 #include <QEvent>
 #include <QKeyEvent>
+#include <QPixmap>
+#include <QLabel>
+#include <QHBoxLayout>
+#include <QString>
 
 #include <Gui/Application.h>
+#include <Gui/BitmapFactory.h>
 #include <Gui/View3DInventor.h>
 #include <Gui/View3DInventorViewer.h>
 
@@ -62,6 +67,7 @@ EditableDatumLabel::EditableDatumLabel(View3DInventorViewer* view,
     , value(0.0)
     , viewer(view)
     , spinBox(nullptr)
+    , lockIconLabel(nullptr)
     , cameraSensor(nullptr)
     , function(Function::Positioning)
 {
@@ -151,6 +157,9 @@ void EditableDatumLabel::startEdit(double val, QObject* eventFilteringObj, bool
         return;
     }
 
+    // Reset locked state when starting to edit
+    this->resetLockedState();
+
     QWidget* mdi = viewer->parentWidget();
 
     label->string = " ";
@@ -209,11 +218,30 @@ bool EditableDatumLabel::eventFilter(QObject* watched, QEvent* event)
         if (keyEvent->key() == Qt::Key_Return || keyEvent->key() == Qt::Key_Enter) {
 
             if (auto* spinBox = qobject_cast<QAbstractSpinBox*>(watched)) {
-                this->hasFinishedEditing = true;
-                Q_EMIT this->valueChanged(this->value);
-                return false;
+                // for ctrl + enter we accept values as they are
+                if (keyEvent->modifiers() & Qt::ControlModifier) {
+                    Q_EMIT this->finishEditingOnAllOVPs();
+                    return true;
+                }
+                else {
+                    // regular enter
+                    this->hasFinishedEditing = true;
+                    Q_EMIT this->spinBox->valueChanged(this->value);
+
+                    // only set lock state if it passed validation
+                    // (validation can unset isSet if value didn't pass
+                    // confusion point for example)
+                    if (this->isSet)
+                        this->setLockedAppearance(true);
+                    return true;
+                }
             }
         }
+        else if (this->hasFinishedEditing && keyEvent->key() != Qt::Key_Tab)
+        {
+            this->setLockedAppearance(false);
+            return false;
+        }
     }
 
     return QObject::eventFilter(watched, event);
@@ -233,6 +261,9 @@ void EditableDatumLabel::stopEdit()
 
         spinBox->deleteLater();
         spinBox = nullptr;
+        
+        // Lock icon will be automatically destroyed as it's a child of spinbox
+        lockIconLabel = nullptr;
     }
 }
 
@@ -311,6 +342,19 @@ void EditableDatumLabel::positionSpinbox()
     pxCoord.setX(posX);
     pxCoord.setY(posY);
     spinBox->move(pxCoord);
+    
+    // Update lock icon position inside the spinbox if it exists and is visible
+    if (lockIconLabel && lockIconLabel->isVisible()) {
+        int iconSize = 14;
+        int padding = 4;
+        QSize spinboxSize = spinBox->size();
+        lockIconLabel->setGeometry(
+            spinboxSize.width() - iconSize - padding,
+            (spinboxSize.height() - iconSize) / 2,
+            iconSize,
+            iconSize
+        );
+    }
 }
 
 SbVec3f EditableDatumLabel::getTextCenterPoint() const
@@ -441,6 +485,70 @@ void EditableDatumLabel::setSpinboxVisibleToMouse(bool val)
     spinBox->setAttribute(Qt::WA_TransparentForMouseEvents, !val);
 }
 
+void EditableDatumLabel::setLockedAppearance(bool locked)
+{
+    if (locked) {
+        if (spinBox) {
+            QWidget* mdi = viewer->parentWidget();
+            
+            // create lock icon label it it doesn't exist, if it does - show it
+            if (!lockIconLabel) {
+                lockIconLabel = new QLabel(spinBox);
+                lockIconLabel->setAttribute(Qt::WA_TransparentForMouseEvents, true);
+                lockIconLabel->setAlignment(Qt::AlignRight | Qt::AlignVCenter);
+            }
+            else
+            {
+                lockIconLabel->show();
+            }
+            
+            // load icon and scale it to fit in spinbox
+            QPixmap lockIcon = Gui::BitmapFactory().pixmap("Constraint_Lock");
+            QPixmap scaledIcon = lockIcon.scaled(14, 14, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+            lockIconLabel->setPixmap(scaledIcon);
+            
+            // position lock icon inside the spinbox
+            int iconSize = 14;
+            int padding = 4;
+            QSize spinboxSize = spinBox->size();
+            lockIconLabel->setGeometry(
+                spinboxSize.width() - iconSize - padding,
+                (spinboxSize.height() - iconSize) / 2,
+                iconSize,
+                iconSize
+            );
+            lockIconLabel->show();
+            
+            // style spinbox and add padding for lock
+            QString styleSheet = QString::fromLatin1(
+                "QSpinBox { "
+                "padding-right: %1px; "
+                "}"
+            ).arg(iconSize + padding + 2);
+            
+            spinBox->setStyleSheet(styleSheet);
+        }
+    } else {
+        this->hasFinishedEditing = false;
+
+        // if spinbox exists, reset its appearance
+        if (spinBox) {
+            spinBox->setStyleSheet(QString());
+            
+            // hide lock icon if it exists for later reuse
+            if (lockIconLabel) {
+                lockIconLabel->hide();
+            }
+        }
+    }
+}
+
+void EditableDatumLabel::resetLockedState()
+{
+    hasFinishedEditing = false;
+    setLockedAppearance(false);
+}
+
 EditableDatumLabel::Function EditableDatumLabel::getFunction()
 {
     return function;