Qt Forum

    • Login
    • Search
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups
    • Search
    • Unsolved

    Not able to use QList<Class> ComponentA (solved)

    General and Desktop
    3
    16
    3073
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • A
      alvinNew last edited by p3c0

      I am able to read XML element into variable.
      I need to read XML element into a container QList, thus created the 2 class.
      and append the read element into the object.

      class CComponent{
      public:
          QString ComponentID;
          QString ComponentType;
          int ComponentX;
          int ComponentY;
          int ComponentWidth;
          int ComponentHeight;
          int ComponentZOrder;
          int ComponentAspectRatio;
      
      };
      class CBackground{
      public:
          int Transparent;
          int Red;
          int Green;
          int Blue;
      };
      
          QList<CComponent> ComponentA;
          QList<CBackground> BackgroundA;
      
          while (xmlGet.findNextAndDescend("Component"))
          {
              QString ComponentID = xmlGet.getAttributeString("ID","unknown");
              QString ComponentType = xmlGet.getAttributeString("Type","unknown");
              int ComponentX = xmlGet.getAttributeInt("X");
              int ComponentY = xmlGet.getAttributeInt("Y");
              int ComponentWidth = xmlGet.getAttributeInt("Width");
              int ComponentHeight = xmlGet.getAttributeInt("Height");
              int ComponentZOrder = xmlGet.getAttributeInt("ZOrder");
              int ComponentAspectRatio = xmlGet.getAttributeInt("AspectRatio");
      
              ComponentA.append(ComponentID);
              ComponentA.append(ComponentType);
              ComponentA.append(ComponentX);
              ComponentA.append(ComponentY);
              ComponentA.append(ComponentWidth);
              ComponentA.append(ComponentHeight);
              ComponentA.append(ComponentZOrder);
              ComponentA.append(ComponentAspectRatio);
      
      p3c0 1 Reply Last reply Reply Quote 0
      • p3c0
        p3c0 Moderators @alvinNew last edited by

        @alvinNew The List ComponentA is QList of CComponent and you are adding everything other than that. That won't work.
        Store those values you extract from XML in an object of class CComponent and then append that object to ComponentA.

        157

        1 Reply Last reply Reply Quote 0
        • A
          alvinNew last edited by alvinNew

          I understand and realize that.
          But i do not want to hard-code the variable into ComponentA.
          How to make Component a QList.

          It's ok, i create a Component Template and move the contain variable into list before grabbing new data

          p3c0 1 Reply Last reply Reply Quote 0
          • p3c0
            p3c0 Moderators @alvinNew last edited by p3c0

            @alvinNew No need to hard code. You just need to store those values in an object of CComponent and add it to list. Define some setter methods in CComponent for storing values.

            class CComponent{
                public:
                QString ComponentID;
                QString ComponentType;
                ...
            
                void setComponentId(QString id) {
                ComponentID = id;
                }
            
                void setComponentType(QString type) {
                ComponentType = type;
                }
            };
            
            //Then during appending
            
            QList<CComponent> ComponentA;
            while (xmlGet.findNextAndDescend("Component"))
            {
                  QString ComponentID = xmlGet.getAttributeString("ID","unknown");
                  QString ComponentType = xmlGet.getAttributeString("Type","unknown");
            
                   CComponent comp;
                   comp.setComponentId(ComponentID); //store values
                   comp.setComponentType(ComponentType); //store values
            
                   //add that object to QList
                   ComponentA.append(comp);
            }
            

            157

            A 1 Reply Last reply Reply Quote 0
            • A
              alvinNew @p3c0 last edited by

              @p3c0

              Many thanks, i can learn alot from your simple coding.

              p3c0 1 Reply Last reply Reply Quote 0
              • p3c0
                p3c0 Moderators @alvinNew last edited by p3c0

                @alvinNew You're Welcome :) Happy Coding ...
                Also use ``` (3 backticks), key just above the tab button on keyboard for posting code blocks.

                157

                1 Reply Last reply Reply Quote 0
                • H
                  houmingc last edited by

                  My code is in pastebin, http://pastebin.com/JwKjfW0b
                  Like to ask how to read out the data in the class ( CComponent )

                  p3c0 1 Reply Last reply Reply Quote 0
                  • p3c0
                    p3c0 Moderators @houmingc last edited by

                    @houmingc You will need to write getter methods as well which will return the values stored in those variables.

                    157

                    1 Reply Last reply Reply Quote 0
                    • H
                      houmingc last edited by houmingc

                      Code below is not working although no compiler error

                      QList<CComponent> list;
                      
                         QListIterator<CComponent> i(list);
                         while(i.hasNext()){
                             qDebug()<<"xxxx is "<<ComponentTemplate.ComponentX;
                         }
                      p3c0 2 Replies Last reply Reply Quote 0
                      • p3c0
                        p3c0 Moderators @houmingc last edited by

                        @houmingc You are doing it wrong. First create some getter methods as said earlier. Then you need to cast the item to CComponent in the loop and access the getter methods to get the values stored in it.

                        157

                        1 Reply Last reply Reply Quote 0
                        • p3c0
                          p3c0 Moderators @houmingc last edited by p3c0

                          @houmingc Something like this

                          //CComponent class
                          
                          void CComponent::setId(QString id)
                          {
                              m_id = id;
                          }
                          
                          QString CComponent::getId()
                          {
                              return m_id;
                          }
                          
                          QString m_id, m_type;
                          

                          then to access after appending to list

                          QList<CComponent *> m_list;
                          ...
                          
                          CComponent *ca = new CComponent;
                          ca->setId("one");
                          ca->setType("big");
                          ...
                          
                          m_list.append(ca);
                          
                          ...
                          
                          QListIterator<CComponent*> i(m_list);
                          while (i.hasNext()) {
                              CComponent *comp = qobject_cast<CComponent*>(i.next()); //qobject_cast - if uses QObject
                              qDebug() << comp->getId() << comp->getType();
                          }
                          
                          

                          157

                          1 Reply Last reply Reply Quote 0
                          • H
                            houmingc last edited by houmingc

                            i have an error at cast object
                            error: no matching function for call to 'qobject_cast(CComponent* const&)'
                            CComponent comp = qobject_cast<CComponent>(i.next());

                            p3c0 1 Reply Last reply Reply Quote 0
                            • H
                              houmingc last edited by

                              qDebug() << ComponentList[0].GetComponentHeight(); // why accessing ComponentList array return error?

                              1 Reply Last reply Reply Quote 0
                              • p3c0
                                p3c0 Moderators @houmingc last edited by

                                @houmingc said:

                                i have an error at cast object
                                error: no matching function for call to 'qobject_cast(CComponent* const&)'
                                CComponent comp = qobject_cast<CComponent>(i.next());

                                Try it exactly how I have posted earlier in the example.

                                qDebug() << ComponentList[0].GetComponentHeight(); // why accessing ComponentList array return error?

                                What error ? ComponentList is a QList, right ?

                                157

                                1 Reply Last reply Reply Quote 0
                                • H
                                  houmingc last edited by houmingc

                                  I got the each component display. Thanks.
                                  No Casting needed.
                                  How to get 3rd item of the class? i am now wondering if QList should be used instead of QLinkedList

                                     QLinkedList<CComponent>::iterator iterator;
                                      for(iterator=ComponentList.begin();iterator != ComponentList.end(); iterator ++)
                                      {
                                          qDebug()<<iterator->GetComponentAspectRatio()<<endl;
                                      }
                                  p3c0 1 Reply Last reply Reply Quote 0
                                  • p3c0
                                    p3c0 Moderators @houmingc last edited by p3c0

                                    @houmingc Casting will be needed if you use QListIterator.

                                    QList<CComponent*> m_list;
                                    
                                    CComponent *ca = new CComponent;
                                    ca->setId("one");
                                    ca->setType("big");
                                    
                                    m_list.append(ca);
                                    
                                    QListIterator<CComponent*> i(m_list);
                                    while (i.hasNext()) {
                                        CComponent *comp = qobject_cast<CComponent*>(i.next()); //qobject_cast - if uses QObject
                                        qDebug() << comp->getId() << comp->getType(); //access using QListIterator
                                    }
                                    
                                    /*-------------------------------------------------------------*/
                                    
                                    qDebug() << m_list[0]->getType() << m_list[0]->getId(); //no need to cast
                                    

                                    157

                                    1 Reply Last reply Reply Quote 0
                                    • First post
                                      Last post