QmlDesigner: Add transition item label

* Add label to transition item
* Change signature of drawArrow()

Task-number: QDS-2085
Change-Id: Ia719958ead404ea083a15fdee440a8e6a306ee62
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmldesigner/components/formeditor/formeditoritem.cpp

@@ -26,6 +26,7 @@
 #include "formeditoritem.h"
 #include "formeditorscene.h"
 
+#include <variantproperty.h>
 #include <bindingproperty.h>
 
 #include <modelnode.h>
@@ -814,8 +815,46 @@ static bool horizontalOverlap(const QRectF &from, const QRectF &to)
     return false;
 }
 
+static void drawLabel(QPainter *painter,
+                      const QPainterPath &path,
+                      const QString &text,
+                      const qreal percent,
+                      const qreal offset,
+                      bool flipSide)
+{
+    if (text.isEmpty())
+        return;
+
+    const int flags = Qt::AlignHCenter | Qt::AlignVCenter | Qt::TextDontClip;
+
+    QPointF pos = path.pointAtPercent(percent);
+    qreal angle = path.angleAtPercent(percent);
+
+    QLineF tmp(pos, QPointF(10, 10));
+    tmp.setLength(offset);
+    tmp.setAngle(angle + (flipSide ? 270 : 90));
+
+    QRectF textRect(0, 0, 100, 50);
+    textRect.moveCenter(tmp.p2());
+
+    auto normalizeAngle = [](int angle) {
+        int newAngle = angle;
+        while (newAngle <= -90) newAngle += 180;
+        while (newAngle > 90) newAngle -= 180;
+        return newAngle;
+    };
+
+    painter->save();
+    painter->translate(textRect.center());
+    painter->rotate(-normalizeAngle(angle));
+    painter->translate(-textRect.center());
+    painter->drawText(textRect, flags, text);
+    painter->restore();
+}
+
 static void drawArrow(QPainter *painter,
-                      const QLineF &line,
+                      const QPointF &point,
+                      const qreal &angle,
                       int arrowLength,
                       int arrowWidth)
 {
@@ -825,8 +864,8 @@ static void drawArrow(QPainter *painter,
 
     painter->save();
 
-    painter->translate(line.p2());
+    painter->translate(point);
-    painter->rotate(-line.angle());
+    painter->rotate(-angle);
     painter->drawLine(leftP, peakP);
     painter->drawLine(rightP, peakP);
 
@@ -1029,7 +1068,8 @@ static QPainterPath sShapedConnection(const QPointF &start,
 static void paintConnection(QPainter *painter,
                             const QRectF &from,
                             const QRectF &to,
-                            const ConnectionStyle &style)
+                            const ConnectionStyle &style,
+                            const QString &label)
 {
     painter->save();
     painter->setRenderHint(QPainter::Antialiasing);
@@ -1126,11 +1166,18 @@ static void paintConnection(QPainter *painter,
     pen.setStyle(Qt::SolidLine);
     painter->setPen(pen);
 
-    drawArrow(painter, QLineF(path.pointAtPercent(0.9), endP), arrowLength, arrowWidth);
+    qreal anglePercent = 1.0;
+
+    if (extraLine && style.bezier < 80)
+        anglePercent = 1.0 - qMin(1.0, (80 - style.bezier) / 10.0) * 0.05;
+
+    drawArrow(painter, endP, path.angleAtPercent(anglePercent), arrowLength, arrowWidth);
 
     painter->setBrush(Qt::white);
     painter->drawEllipse(startP, arrowLength / 3, arrowLength / 3);
 
+    drawLabel(painter, path, label, style.labelPosition / 100.0, style.labelOffset, style.labelFlipSide);
+
     painter->restore();
 }
 
@@ -1260,10 +1307,35 @@ void FormEditorTransitionItem::paint(QPainter *painter, const QStyleOptionGraphi
     if (qmlItemNode().modelNode().hasAuxiliaryData("type"))
         style.type = static_cast<ConnectionType>(qmlItemNode().modelNode().auxiliaryData("type").toInt());
 
+
+    QFont font = painter->font();
+    font.setPixelSize(16 / scaleFactor);
+    painter->setFont(font);
+
+    QString label;
+
+    if (qmlItemNode().modelNode().hasBindingProperty("condition"))
+        label = qmlItemNode().modelNode().bindingProperty("condition").expression();
+
+    if (qmlItemNode().modelNode().hasVariantProperty("question"))
+        label = qmlItemNode().modelNode().variantProperty("question").value().toString();
+
+    style.labelOffset = 14 / scaleFactor;
+
+    style.labelPosition = 50.0;
+
+    if (qmlItemNode().modelNode().hasAuxiliaryData("labelPosition"))
+        style.labelPosition = qmlItemNode().modelNode().auxiliaryData("labelPosition").toReal();
+
+    style.labelFlipSide = false;
+
+    if (qmlItemNode().modelNode().hasAuxiliaryData("labelFlipSide"))
+        style.labelFlipSide = qmlItemNode().modelNode().auxiliaryData("labelFlipSide").toBool();
+
     if (resolved.isStartLine)
         fromRect.translate(0, style.outOffset);
 
-    paintConnection(painter, fromRect, toRect, style);
+    paintConnection(painter, fromRect, toRect, style, label);
 
     if (resolved.isStartLine) {
 

src/plugins/qmldesigner/components/formeditor/formeditoritem.h

@@ -66,6 +66,9 @@ public:
     int radius;
     int bezier;
     ConnectionType type;
+    qreal labelOffset;
+    qreal labelPosition;
+    bool labelFlipSide;
 };
 
 class QMLDESIGNERCORE_EXPORT FormEditorItem : public QGraphicsItem

src/plugins/qmldesigner/components/propertyeditor/propertyeditorqmlbackend.cpp

@@ -179,6 +179,10 @@ QVariant properDefaultAuxiliaryProperties(const QmlObjectNode &qmlObjectNode,
         return 50;
     else if (propertyName == "bezier")
         return 50;
+    else if (propertyName == "labelPosition")
+        return 50.0;
+    else if (propertyName == "labelFlipSide")
+        return false;
     else if (propertyName == "customId")
         return QString();
     else if (propertyName == "joinConnection")
@@ -248,7 +252,7 @@ void PropertyEditorQmlBackend::setupAuxiliaryProperties(const QmlObjectNode &qml
     propertyNames.append("customId");
 
     if (itemNode.isFlowTransition()) {
-        propertyNames.append({"color", "width", "inOffset", "outOffset", "dash", "breakPoint", "type", "radius", "bezier"});
+        propertyNames.append({"color", "width", "inOffset", "outOffset", "dash", "breakPoint", "type", "radius", "bezier", "labelPosition", "labelFlipSide"});
     } else if (itemNode.isFlowItem()) {
         propertyNames.append({"color", "width", "inOffset", "outOffset", "joinConnection"});
     } else if (itemNode.isFlowActionArea()) {