#185 Add snapToGrid and snapToGridSize to qan::Graph.

Modify groups sample for snap to grid support. Nice. Signed-off-by: cneben <benoit@destrat.io>
cneben · Dec 25, 2022 · b0351e6 · b0351e6
1 parent 381eaeb
commit b0351e6
Show file tree

Hide file tree

Showing 5 changed files with 95 additions and 31 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # CHANGELOG
 
+## 20221225 prev2.3.0:
+- #185: Add support for "snap to grid" when moving node or groups.
+- Add |qan::Graph`, `snapToGrid` and `snapToGridSize` properties.
+
+## 20221225 v2.2.0:
+- Release v2.2.0
+
 ## 20221215 v2.2.0:
 - #183: Add a `multipleSelectionEnabled` property to `qan::Graph` to enable or disable multiple selection.
 
@@ -16,7 +23,7 @@
 - #167: Add partial edge selection support.
 - #164: Change signature of qan::Graph::connectorRequestEdgeCreation().
 
-## 20220824 v2.1.1:
+## 20220824 v2*$.1.1:
 - Change signature of two public API methods (public but presumably mainly used internally):
   - Rename qan::Graph::collectInerEdges() to qan::Graph::collectInnerEdges().
   - Rename qan::Graph::collectAncestorsDfs() to qan::Graph::collectAncestors().

diff --git a/samples/groups/groups.qml b/samples/groups/groups.qml
@@ -193,7 +193,7 @@ ApplicationWindow {
         RowLayout {
             anchors.top: parent.top; anchors.topMargin: 15
             anchors.horizontalCenter: parent.horizontalCenter
-            width: 200
+            width: 550
             ToolButton {
                 text: "Add Group"
                 onClicked: {
@@ -221,7 +221,6 @@ ApplicationWindow {
                 property var node: undefined
                 enabled: node !== undefined
                 onClicked: {
-                    console.info("node.group=" + node.group)
                     if (node && node.group )
                         topology.ungroupNode(node)
                 }
@@ -236,6 +235,21 @@ ApplicationWindow {
                     ;
                 }
             }
+
+            Switch {
+                text: "Snap to Grid"
+                checked: topology.snapToGrid
+                onClicked: topology.snapToGrid = checked
+            }
+            Label { text: "Grid size:" }
+            SpinBox {
+                enabled: topology.snapToGrid
+                from: 1
+                to: 100
+                stepSize: 5
+                value: topology.snapToGridSize.width
+                onValueModified: { topology.snapToGridSize = Qt.size(value, value) }
+            }
         }
         Pane {
             id: groupEditor

diff --git a/src/qanDraggableCtrl.cpp b/src/qanDraggableCtrl.cpp
@@ -242,28 +242,32 @@ void    DraggableCtrl::dragMove(const QPointF& sceneDragPos, bool dragSelection)
     // 2.2. If target position is "centered" on grid
     //    or mouse delta > grid
     //   2.2.1 Compute snapped position, apply it
-    const auto gridSize = QSizeF{10., 10.};
-    bool applyX = std::fabs(delta.x()) > (gridSize.width() / 2.001);
-    bool applyY = std::fabs(delta.y()) > (gridSize.height() / 2.001);
-
-    //qWarning() << "--------";
-    //qWarning() << "targetUnsnapPos=" << targetUnsnapPos;
-    if (!applyX) {
-        const auto posModGridX = fmod(targetUnsnapPos.x(), gridSize.width());
-        //qWarning() << "posModGridX=" << posModGridX;
-        applyX = qFuzzyIsNull(posModGridX);
-    }
-    if (!applyY) {
-        const auto posModGridY = fmod(targetUnsnapPos.y(), gridSize.height());
-        //qWarning() << "posModGridY=" << posModGridY;
-        applyY = qFuzzyIsNull(posModGridY);
-    }
-    //qWarning() << "applyX=" << applyX << "   applyY=" << applyY;
-    if (applyX || applyY) {
-        const auto targetSnapPosX = gridSize.width() * std::round(targetUnsnapPos.x() / gridSize.width());
-        const auto targetSnapPosY = gridSize.height() * std::round(targetUnsnapPos.y() / gridSize.height());
-        _targetItem->setPosition(QPointF{targetSnapPosX,
-                                         targetSnapPosY});
+    if (getGraph()->getSnapToGrid()) {
+        const auto& gridSize = getGraph()->getSnapToGridSize();
+        bool applyX = std::fabs(delta.x()) > (gridSize.width() / 2.001);
+        bool applyY = std::fabs(delta.y()) > (gridSize.height() / 2.001);
+
+        //qWarning() << "--------";
+        //qWarning() << "targetUnsnapPos=" << targetUnsnapPos;
+        if (!applyX) {
+            const auto posModGridX = fmod(targetUnsnapPos.x(), gridSize.width());
+            //qWarning() << "posModGridX=" << posModGridX;
+            applyX = qFuzzyIsNull(posModGridX);
+        }
+        if (!applyY) {
+            const auto posModGridY = fmod(targetUnsnapPos.y(), gridSize.height());
+            //qWarning() << "posModGridY=" << posModGridY;
+            applyY = qFuzzyIsNull(posModGridY);
+        }
+        //qWarning() << "applyX=" << applyX << "   applyY=" << applyY;
+        if (applyX || applyY) {
+            const auto targetSnapPosX = gridSize.width() * std::round(targetUnsnapPos.x() / gridSize.width());
+            const auto targetSnapPosY = gridSize.height() * std::round(targetUnsnapPos.y() / gridSize.height());
+            _targetItem->setPosition(QPointF{targetSnapPosX,
+                                             targetSnapPosY});
+        }
+    } else { // Do not snap to grid
+        _targetItem->setPosition(targetUnsnapPos);
     }
     // FIXME #185 Selection move does not works...
     if (dragSelection) {

diff --git a/src/qanGraph.cpp b/src/qanGraph.cpp
@@ -1363,6 +1363,25 @@ std::vector<QQuickItem*>    Graph::getSelectedItems() const
 
 
 /* Alignment Management *///---------------------------------------------------
+bool    Graph::setSnapToGrid(bool snapToGrid) noexcept
+{
+    if (snapToGrid != _snapToGrid) {
+        _snapToGrid = snapToGrid;
+        emit snapToGridChanged();
+        return true;
+    }
+    return false;
+}
+bool    Graph::setSnapToGridSize(QSizeF snapToGridSize) noexcept
+{
+    if (snapToGridSize != _snapToGridSize) {
+        _snapToGridSize = snapToGridSize;
+        emit snapToGridSizeChanged();
+        return true;
+    }
+    return false;
+}
+
 void    Graph::alignSelectionHorizontalCenter() { alignHorizontalCenter(getSelectedItems()); }
 
 void    Graph::alignSelectionRight() { alignRight(getSelectedItems()); }

diff --git a/src/qanGraph.h b/src/qanGraph.h
@@ -780,8 +780,28 @@ class Graph : public gtpo::graph<QQuickItem, qan::Node, qan::Group, qan::Edge>
     //@}
     //-------------------------------------------------------------------------
 
-    /*! \name Alignment Management *///----------------------------------------
+    /*! \name Grid and Alignment Management *///-------------------------------
     //@{
+public:
+    //! Snap dragged objects (both groups and nodes) to grid based on \c snapGridSize (default to false is no snap).
+    Q_PROPERTY(bool snapToGrid READ getSnapToGrid WRITE setSnapToGrid NOTIFY snapToGridChanged FINAL)
+    bool            setSnapToGrid(bool snapToGrid) noexcept;
+    bool            getSnapToGrid() const noexcept { return _snapToGrid; }
+private:
+    bool            _snapToGrid = false;
+signals:
+    void            snapToGridChanged();
+
+public:
+    //! Snap to grid size (default to 10x10), active only when \c snapToGrid is true.
+    Q_PROPERTY(QSizeF snapToGridSize READ getSnapToGridSize WRITE setSnapToGridSize NOTIFY snapToGridSizeChanged FINAL)
+    bool            setSnapToGridSize(QSizeF snapToGridSize) noexcept;
+    QSizeF          getSnapToGridSize() const noexcept { return _snapToGridSize; }
+private:
+    QSizeF          _snapToGridSize{10., 10.};
+signals:
+    void            snapToGridSizeChanged();
+
 public:
     //! \brief Align selected nodes/groups items horizontal center.
     Q_INVOKABLE void    alignSelectionHorizontalCenter();
@@ -812,11 +832,11 @@ class Graph : public gtpo::graph<QQuickItem, qan::Node, qan::Group, qan::Edge>
 public:
     /*! \brief Graph style manager (ie list of style applicable to graph primitive).
      */
-    Q_PROPERTY( qan::StyleManager* styleManager READ getStyleManager CONSTANT FINAL )
-    inline qan::StyleManager*       getStyleManager() noexcept { return &_styleManager; }
-    inline const qan::StyleManager* getStyleManager() const noexcept { return &_styleManager; }
+    Q_PROPERTY(qan::StyleManager* styleManager READ getStyleManager CONSTANT FINAL)
+    qan::StyleManager*       getStyleManager() noexcept { return &_styleManager; }
+    const qan::StyleManager* getStyleManager() const noexcept { return &_styleManager; }
 private:
-    qan::StyleManager   _styleManager;
+    qan::StyleManager       _styleManager;
     //@}
     //-------------------------------------------------------------------------
 
@@ -851,7 +871,7 @@ class Graph : public gtpo::graph<QQuickItem, qan::Node, qan::Group, qan::Edge>
 
 public:
     //! Default delegate for node in/out port.
-    Q_PROPERTY( QQmlComponent* portDelegate READ getPortDelegate WRITE qmlSetPortDelegate NOTIFY portDelegateChanged FINAL )
+    Q_PROPERTY(QQmlComponent* portDelegate READ getPortDelegate WRITE qmlSetPortDelegate NOTIFY portDelegateChanged FINAL)
     //! \copydoc portDelegate
     inline QQmlComponent*   getPortDelegate() noexcept { return _portDelegate.get(); }
 protected: