Qt Designer; difficulty placing widgets in the right parent

qtqt-designer

Using the Qt Designer I've made a couple of QFrames in each other, each having a horizontal layout. Their stylesheet predicates that they should have no margin nor a padding. This means that in the Qt Designers view as well as in the final result, no space is seen between the QFrames.

Using drag-and-drop I can place widgets into the window, it shows a blue line where it will be placed (in a layout). However, it's impossible to add another QFrame to a QFrame parent I can't see (and thus drop on). There is also a tree in the right panel, but dropping on the parent makes it automatically go in one of the childs…

Example, I have this setup:

QMainWindow
- QWidget
  - QFrame (parent)
    - QFrame (child)
    - QFrame (child)

Adding a new frame, whatever I try, gives me:

QMainWindow
- QWidget
  - QFrame (parent)
    - QFrame (child)
    - QFrame (child)
    - QFrame (new child)

But I really want:

QMainWindow
- QWidget
  - QFrame (parent)
    - QFrame (child)
    - QFrame (child)
  - QFrame (new parent)

Is there any feature I haven't discovered to accurately place new widgets?

Best Answer

You can use the Object Inspector window, but you don't seem to be able to paste into a QFrame that has a locked layout.

So given your layout:

QMainWindow
- QWidget
  - QFrame (A)
    - QFrame (B)
    - QFrame (C)
    - QFrame (D)

Select QFrame D in the Object Inspector window and Cut it, right click QWidget and Break the layout (ctrl-0), then paste. Then re-apply the layout.

Related Solutions

R – Drag & drop with .ui files

First off, if you haven't read Qt's Drag and Drop documentation you really want to start there. What I'm going to tell you is a summary of what's there. You also should definitely look at the drag and drop examples once you've read the description of the process.

Secondly, and I apologize if I'm misreading this, your question makes it sound like you aren't quite familiar with C++. You want to declare methods in the .h file, and define them in the .cpp file. You can use the Designer to do some of that declaration of events, but you will need to define the implementation of those events in the .cpp. If that's not clear you will need to go read more about basic C++ first.

If you're ok with those basics, here's a short summary of how drag and drop works:

Dragging is done by:
- Creating a QDrag. You want to do this in the event that triggers the drag, which is, in all cases I can think of a mouse-click (mousePressEvent or mouseMoveEvent -- which one depends on the exact behavior you want to see).
- Encoding the data you want to be dragged. You do this using MIME-encoding, a standard way of marking what type of document is being dragged. (Examples include text, images, and most other media formats). Assume text for the simple case.
  - Create a QMimeData
  - Set data for the appropriate type (e.g. for text use QMimeData::setText)\
  - Add the mime data to the drag object with QDrag::setMimeData.
  - Call QDrag::exec on your drag object.
Dropping is done by:
- Enabling the acceptDrops property on the given widget using QWidget::setAcceptDrops(true).
- Define dropEvent on your widget to handle the drop. The data you set in the drag using setMimeData is available as a method of the drop event QDropEvent::mimeData. You need to extract the data out of it using the appropriate document type (e.g. text()).

Obviously this isn't complete, but drag and drop has enough steps that you really should read about them in detail once and look at some examples. This summary is meant to give you an idea of what you need to do.

Qt4: Placing QMainWindow instance inside other QWidget/QMainWindow

Having the same problem, I found the solution here.

QMainWindow sets its window type to Qt::Window so that it will be in an independent window even if it has a parent (you can confirm this by calling show() on your QMainWindow, and you will see it in its own window). Try adding the line

window->setWindowFlags(Qt::Widget);

after you construct the QMainWindow.

Best Answer

Related Solutions

R – Drag & drop with .ui files

Qt4: Placing QMainWindow instance inside other QWidget/QMainWindow

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