Add live cursor-coordinate readout to the element editor status bar (#580)

Displays the cursor's scene position (same grid units as the parts'
X/Y property spinboxes) in a permanent status bar label, updated on
every mouse move. Addresses the overlapping-node mis-click case from
the originating forum report: with a live readout, precise pointing
no longer requires guessing against nearby z-ordered points.

ElementScene::mouseMoveEvent already computed the (optionally
grid-snapped) scene position on every move; it now also emits it via
a new mouseMoved(QPointF) signal, which QETElementEditor's status bar
label subscribes to.

sources/editor/elementscene.cpp

@@ -124,6 +124,7 @@ void ElementScene::mouseMoveEvent(QGraphicsSceneMouseEvent *e)
 {
 	if (m_event_interface) {
 		if (m_event_interface -> mouseMoveEvent(e)) {
+			emit mouseMoved(e -> scenePos());
 			if (m_event_interface->isFinish()) {
 				delete m_event_interface;
 				m_event_interface = nullptr;
@@ -136,6 +137,8 @@ void ElementScene::mouseMoveEvent(QGraphicsSceneMouseEvent *e)
 	if (!(e -> modifiers() & Qt::ControlModifier))
 		event_pos = snapToGrid(event_pos);
 
+	emit mouseMoved(event_pos);
+
 	if (m_behavior == PasteArea) {
 		QRectF current_rect(m_paste_area -> rect());
 		current_rect.moveCenter(event_pos);

sources/editor/elementscene.h

@@ -179,6 +179,8 @@ class ElementScene : public QGraphicsScene
 		void elementInfoChanged();
 		/// Signal emitted when the element type changes
 		void elementTypeChanged();
+		/// Signal emitted with the current cursor position (scene coordinates) on every mouse move
+		void mouseMoved(const QPointF &pos);
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(ElementScene::ItemOptions)

sources/editor/ui/qetelementeditor.cpp

@@ -1194,6 +1194,16 @@ void QETElementEditor::initGui()
 		if (te) te->refreshMasterLabelVisibility();
 	});
 
+		//Live cursor position readout, in the same scene coordinates as the parts' X/Y properties
+	m_position_label = new QLabel(this);
+	m_position_label->setMinimumWidth(120);
+	statusBar()->addPermanentWidget(m_position_label);
+	connect(m_elmt_scene, &ElementScene::mouseMoved, this, [this](const QPointF &pos) {
+		m_position_label->setText(tr("X: %1  Y: %2")
+			.arg(pos.x(), 0, 'f', 1)
+			.arg(pos.y(), 0, 'f', 1));
+	});
+
 	statusBar()->showMessage(tr("Éditeur d'éléments", "status bar message"));
 }
 

sources/editor/ui/qetelementeditor.h

@@ -161,6 +161,8 @@ class QETElementEditor : public QMainWindow
 
 		QLabel *m_default_informations = nullptr;
 
+		QLabel *m_position_label = nullptr;
+
 };
 
 #endif // QETELEMENTEDITOR_H