Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. [SOLVED] Extending widgets
Forum Updated to NodeBB v4.3 + New Features

[SOLVED] Extending widgets

Scheduled Pinned Locked Moved General and Desktop
widgetcustom
14 Posts 3 Posters 8.5k Views 3 Watching
  • 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.
  • mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by
    #2

    Hi

    The promote feature is an easy way to use a custom widget in Designer.

    The full plugin road is for widgets where you want to be able to alter
    properties design time.

    N 1 Reply Last reply
    1
    • mrjjM mrjj

      Hi

      The promote feature is an easy way to use a custom widget in Designer.

      The full plugin road is for widgets where you want to be able to alter
      properties design time.

      N Offline
      N Offline
      nitzan
      wrote on last edited by
      #3

      Ok, then promoting sounds like the option for me.
      What do I need to provide for that? cpp and h files?

      mrjjM 1 Reply Last reply
      0
      • N nitzan

        Ok, then promoting sounds like the option for me.
        What do I need to provide for that? cpp and h files?

        mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by
        #4

        @nitzan
        Yes, just a normal cpp and h file.
        Just make sure you type ClassName (of your widget) correctly as it don't validate it :)

        N 1 Reply Last reply
        1
        • mrjjM mrjj

          @nitzan
          Yes, just a normal cpp and h file.
          Just make sure you type ClassName (of your widget) correctly as it don't validate it :)

          N Offline
          N Offline
          nitzan
          wrote on last edited by
          #5

          @mrjj

          thanks!
          that worked well, except for one problem.
          calling the setTest method seems to have no effect at all..
          I'm doing this:

          MyWidget::MyWidget(QWidget* parent) : QLabel(parent) {
          	qDebug() << "MyWidget ctor";
          	this->setText("hey there");
          	this->setAttribute(Qt::WA_Hover);
          }
          
          bool MyWidget::event(QEvent* event) {
          	switch (event->type()) {
          		case QEvent::HoverEnter:
          			this->setStyleSheet("color: rgb(255, 0, 0)");
          			break;
          
          		case QEvent::HoverLeave:
          			this->setStyleSheet("color: rgb(0, 0, 0)");
          			break;
          
          		default:
          			return QLabel::event(event);
          	}
          
          	return true;
          }
          

          And the label has no text in it.
          Any idea why?

          1 Reply Last reply
          0
          • mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #6

            @nitzan said:

            this->setText(..)

            Have you tried SetText from outside, like via a button ?
            Sometimes I get fooled by stuff overwritten by the ui->setup which is run after
            your constructor.

            N 1 Reply Last reply
            0
            • mrjjM mrjj

              @nitzan said:

              this->setText(..)

              Have you tried SetText from outside, like via a button ?
              Sometimes I get fooled by stuff overwritten by the ui->setup which is run after
              your constructor.

              N Offline
              N Offline
              nitzan
              wrote on last edited by
              #7

              @mrjj
              but that creates coupling i would prefer to avoid..
              is there anyway to have that in the same class in a way that will be called after the ui->setup?

              mrjjM 1 Reply Last reply
              0
              • N nitzan

                @mrjj
                but that creates coupling i would prefer to avoid..
                is there anyway to have that in the same class in a way that will be called after the ui->setup?

                mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #8

                @nitzan
                It was just for testing.

                Have you tried to set it on the label you promote. ?
                And not call SetText at all in constructor.

                I get the text here. (from designer)

                N 1 Reply Last reply
                0
                • mrjjM mrjj

                  @nitzan
                  It was just for testing.

                  Have you tried to set it on the label you promote. ?
                  And not call SetText at all in constructor.

                  I get the text here. (from designer)

                  N Offline
                  N Offline
                  nitzan
                  wrote on last edited by
                  #9

                  @mrjj
                  calling setText from outside the class works well, even if I do it from the event method it works, but not in the ctor.

                  I can't set the text from the designer as the actual text I'm trying to put there is from font awesome (using QtAwesome), and so the actual code is:

                  UserWidget::UserWidget(QWidget* parent) : QLabel(parent) {
                  	qDebug() << "UserWidget ctor";
                  	this->setText(QString(QChar(fa::user)).append(" login"));
                  	this->setAttribute(Qt::WA_Hover);
                  }
                  
                  1 Reply Last reply
                  0
                  • Chris KawaC Offline
                    Chris KawaC Offline
                    Chris Kawa
                    Lifetime Qt Champion
                    wrote on last edited by Chris Kawa
                    #10

                    If you don't want the text overwritten by the text from designer then instead of promoting QLabel to your class promote a plain QWidget. It won't have the Text property in the editor so the generated setupUi code won't call setText and the value set in your constructor will be preserved.

                    N 1 Reply Last reply
                    1
                    • Chris KawaC Chris Kawa

                      If you don't want the text overwritten by the text from designer then instead of promoting QLabel to your class promote a plain QWidget. It won't have the Text property in the editor so the generated setupUi code won't call setText and the value set in your constructor will be preserved.

                      N Offline
                      N Offline
                      nitzan
                      wrote on last edited by
                      #11

                      @Chris-Kawa
                      Sounds like a workaround, but I would like to understand why it's needed.

                      As the ctor of QLabel is called before the code in my widget is executed, then the setupUi code should be executed before my code as well.
                      Unless I'm missing something?

                      1 Reply Last reply
                      0
                      • mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #12

                        Well its the setupui for the mainform/dialog.
                        It creates the Qlabel and set its text.
                        So calls setText after the constructor.

                        1 Reply Last reply
                        1
                        • Chris KawaC Offline
                          Chris KawaC Offline
                          Chris Kawa
                          Lifetime Qt Champion
                          wrote on last edited by Chris Kawa
                          #13

                          It's not a workaround. You should always promote from the "lowest" widget of which functionality you want to preserve. In this case you don't want to have the label's ability to edit text in the designer so you promote from a widget, not label.

                          As the ctor of QLabel is called before the code in my widget is executed, then the setupUi code should be executed before my code as well. Unless I'm missing something?

                          The code of the window widget's constructor usually looks something like this:

                          Foo::Foo(QWidget* parent) : QWidget(parent) {
                              ui->setupUi(this);
                          }
                          

                          which "expands" to something like this:

                          Foo::Foo(QWidget* parent) : QWidget(parent) {
                              ...
                              ui->someLabel = new YourLabel(this);
                              ui->someLabel->setText(whateverWasSetinTheDesigner);
                              ...
                          }
                          

                          so as you can see whatever you set in the constructor is immediately overwritten by what was set in the designer.
                          If you promote from a QWidget the designer doesn't "know" it's a label and it won't generate the setText() call.

                          N 1 Reply Last reply
                          1
                          • Chris KawaC Chris Kawa

                            It's not a workaround. You should always promote from the "lowest" widget of which functionality you want to preserve. In this case you don't want to have the label's ability to edit text in the designer so you promote from a widget, not label.

                            As the ctor of QLabel is called before the code in my widget is executed, then the setupUi code should be executed before my code as well. Unless I'm missing something?

                            The code of the window widget's constructor usually looks something like this:

                            Foo::Foo(QWidget* parent) : QWidget(parent) {
                                ui->setupUi(this);
                            }
                            

                            which "expands" to something like this:

                            Foo::Foo(QWidget* parent) : QWidget(parent) {
                                ...
                                ui->someLabel = new YourLabel(this);
                                ui->someLabel->setText(whateverWasSetinTheDesigner);
                                ...
                            }
                            

                            so as you can see whatever you set in the constructor is immediately overwritten by what was set in the designer.
                            If you promote from a QWidget the designer doesn't "know" it's a label and it won't generate the setText() call.

                            N Offline
                            N Offline
                            nitzan
                            wrote on last edited by
                            #14

                            Alright, promoting from QWidget indeed did the job and now it works well!
                            Thanks for the both of you.

                            1 Reply Last reply
                            0

                            • Login

                            • Login or register to search.
                            • First post
                              Last post
                            0
                            • Categories
                            • Recent
                            • Tags
                            • Popular
                            • Users
                            • Groups
                            • Search
                            • Get Qt Extensions
                            • Unsolved