I add a layout in a dialog and sometimes I want it and all its containing widgets to hide. How to implement it? I try layout->setEnable(false), but it doesn't seem to work in my tests.
You can't do that. You should add a widget in your form, put children inside the widget and assign desired layout to the widget. The behavior will be generally the same, but you can use setVisible or hide methods of the widget.
Transform QLayout to QWidget first, then you can use QWidget->hide().
Related
So I currently have got a custom widget, and I want to add them to the main window after clicking a button. I would like to add them all to one fixed position first and then I will be able to drag them wherever I like. I am able to create and display these custom widgets with help of QHBoxLayout or QVBoxLayout, but in this case they will not be in the same position after I create them. Any help will be appreciated!
As the names suggest, the QLayout classes manage the position and geometry of the items added to them. You cannot move (eg. drag) an item out of a layout w/out first removing it from the layout (QLayout::removeItem() and derivatives). For example when you drag a toolbar or dock widget out of a QMainWindow it goes through all sorts of machinations to remove it from the MW layout, change the widget's window flags, remember the old position in the layout, and so on. And the reverse to dock it again.
To do what you describe (drag widgets arbitrarily around a window) you would need to not use a QLayout and position the widgets manually by specifying a QWidget::setGeometry() for example. After initial position, and assuming the user has some way to grab the widget (title bar or drag handle you made, etc), you'll probably still need to manage their positions, for example if the main window is resized (if you care about keeping them contained). Essentially you'd have a bunch of separate widgets acting as individual windows and probably need some way to keep track of them.
I don't know what kind of widgets you're talking about, but one option may be a QMdiArea which lets the user drag windowed widgets around, tabify them, save/restore state, and so on.
For more flexibility you could also look into the Qt Graphics Framework. The graphics scene has a lot of features for user-movable items/widgets, keeping track of them, and so on. It is probably the most flexible method overall, and you can also use regular QWidgets inside a graphics scene.
A couple other Q/A about arbitrarily positioning widgets (I'm sure there are more to be found):
QPushButton alignment on top another widget
How to keep Push Buttons constant in relative to change of Label Size in PyQt4
In Qt: I create a widget-ui class, and I want to make the widget appear in two different layouts in two separate base widget(or window). So I want to:
widget_based_class* inside = new widget_based_class(base_widget1);
QHBoxLayout *lay1=new QHBoxLayout(base_widget1);
base_widget->setLayout(lay1);
lay1->addWidget(inside);
base_widget1.show();
-------------------------------
base_widget1.hide();
QHBoxLayout *lay2=new QHBoxLayout(base_widget2);
base_widget->setLayout(lay2);
lay2->addWidget(inside);
base_widget2.show();
How cound I achieve this? (My program is more complicated, and I didn't see the code work.)
Tank you.
A QWidget has only one parent widget and only one geometry (position and size) in that parent. Every call of QLayout::addWidget() will reparent that widget to the widget, the layout is installed on.
Your second call of setLayout won't work as expected, because you have to delete the the existing layout manager before setting the new one:
delete base_widget->layout();
base_widget->setLayout(lay2);
If base_widget hasn't already got a layout manager, the layout manager lay2 would simply be reparented.
If the widget will never be displayed twice on the screen, I don't see why you can't reparent it by addWidget/removeWidget.
In the OP, the parent widget/window is always hidden before the other one is shown. addWidget is called on the fly. We should also call removeWidget on the fly. It should be possible to move the widget around.
widget_based_class* inside = new widget_based_class(base_widget1);
QHBoxLayout *lay1=new QHBoxLayout(base_widget1);
base_widget->setLayout(lay1);
lay2->removeWidget(inside); // remove widget from other layout
lay1->addWidget(inside); // add widget to this layout
base_widget1.show();
-------------------------------
base_widget1.hide();
QHBoxLayout *lay2=new QHBoxLayout(base_widget2);
base_widget->setLayout(lay2);
lay1->removeWidget(inside); //remove widget from other layout
lay2->addWidget(inside); // add widget to this layout
base_widget2.show();
Make one widget and use a pointer in each layout?
I have a Rectangle widget, and a resize box widget, and a text edit widget. How can I compose them without using layouts ? I want all of them as a single widget.
The documentation for how to do a manual layout is in Qt Layout Management here.
Are you sure you can't use one of the standard layouts? You can make a custom widget with three children positioned inside using a layout (or layouts) and your new custom widget will still be just a single widget.
Is it possible to have individual indentation of items in a QTreeWidget?
In specific, I have have a column containing both text, icon and for some of them a CheckBox. The items without a CheckBox gets shifted to the left so the indentation of the icon and the text is not inline with the others. Could maybe be fixed with a hidden CheckBox if that is possible?
Maybe the use of Delegates will give you a nice and proper implementation. You'll have the opportunity to re-implement the paint() and sizeHint() methods, and therefore, choose the way your QTreeWidgetItem are being drawn...
More documentation here : http://doc.trolltech.com/4.6/model-view-delegate.html
An example : http://doc.trolltech.com/4.6/itemviews-pixelator.html
Hope it helps a bit !
You can try using the QWidget::setContentMargins() on the widget returned by QTreeWidget::itemWidget().
Several examples on trolltech use QWidget rather than a QMainWindow as the main window for simple Qt applications.
Now I need just a simple window with a single content widget (QGlWidget) that covers the entire client area.
However, when I show a QWidget window with a single content window it automatically resizes itself to be tiny.
If I create the QWidget parent window without a child It is a nice large default size.
I don't want to resort to using Layouts for a single child window :/
What I understand is that you use a QWidget to display your QGIWidget. Try calling the show method of your QGIWidget directly (if your QGIWidget class inherits QWidget), Qt will create the window decoration for you.
Otherwise if you really need your widget to be inside one another, and fit its size, you'll have to use a layout.
Either follow gregseth's advice or you can simply resize the widget yourself.
(though this way you'll loose nice auto-resizing which is provided by Qt when you use layouts)
In your case you can basically do something like:
QGlWidget* myWidget = new QGlWidget;
myWidget->resize(QApplication::desktopWidget()->availableGeometry().size());
// or maybe instead of resizing show it in fullscreen:
myWidget->showFullScreen();
(actually I don't remember if showFullScreen() will do resizing for you, maybe you'll need both resize+showFullScreen :))
Cheers :)
P.S. Using layout is actually an option. It's not expensive and it's flexible. All it gets: "layout = new QVBoxLayout(myWidget); layout->addWidget(myWidget);" and you're done :)
Not always.
I've found that a QMainWindow will not work as the parent widget when using the QVBoxLayout and QHBoxLayout to arrange child widgets.
If you create a QWidget and use that in place of the QMainWindow then the layouts will work correctly.
QWidget* centralWidget = new QWidget( MainWindow );
MainWindow->setCentralWidget( centralWidget );
If you use QtCreator and look at the code it creates you can see it creating a 'hidden' widget if you try to use the layouts directly at the top level.
It's not obvious, intuitive, or documented anywhere that I've found.