Way to obtain destination port of qan::Connector?

[petrmanek]

During implementation of my custom drag-to-connect logic I found that there is no easy way to obtain the destination port item of qan::Connector inside my requestEdgeCreation() signal handler.

The default implementation exposes getSourcePort() that allows me to determine from where the drag originated. In connectorReleased() the internals of qan::Connector also retrieve the destination port that is used to bind the default edge, if enabled. Unfortunately, if I want to create my custom edge using the requestEdgeCreation signal instead, the destination port is lost in the scope of that function and not accessible anywhere else. I could implement my custom connector for this, however I believe that would be an overkill, especially given that this is would be easy to remedy. Below I propose two alternative solutions to extend the current API.

Option 1: add destinationPort as a property of qan::Connector

class Connector : public qan::NodeItem
{
    // ...
public:
    Q_PROPERTY(qan::PortItem* destinationPort READ getDestinationPort NOTIFY destinationPortChanged FINAL)
    inline qan::PortItem*   getDestinationPort() const noexcept { return _destinationPort.data(); }
private:
    QPointer<qan::PortItem> _destinationPort;
signals:
    void                    destinationPortChanged();
private slots:
    //! Called when the current destination port is destroyed.
    void                    destinationPortDestroyed();
    // ...
};

This property can be set somewhere around here and later accessed by user code in requestEdgeCreation().

Option 2: pass destination port in the signal

class Connector : public qan::NodeItem
{
    // ...
    void    requestEdgeCreation(qan::Node* src, QObject* dst, qan::PortItem* dstPort);
    // ...
};

This is a little bit out of line with the current API but it is less work. When the signal is emitted, it can be passed dstPort from here.

[cneben]

Hi @petrmanek, looking at it !

[petrmanek]

@cneben How is it going? Is there any more information that I can provide?

[cneben]

@petrmanek Sorry for the delay, too much work !
I think I will have a test with option 2 which is much more simpler to implement and look more reusable.

Modifications are in f/#167-edge-selection

[cneben]

e6001b5#diff-d05196eed1993514958224acf1e5b040406a8cf3cabacc9bcb50a5af3ff4e521L77

[petrmanek]

@cneben Brilliant! I will give that a test but it looks good initially.

[petrmanek]

Just tested it, works beautifully. Thank you!