QComboBox , tabviews, C++ - c++

I am developing an application with tabviews.
I want that tabView to change the widget depending on the ComboBox choice.
ex: if the first index chosen I want tabView1 to appear
if the second index chosen I want tabView2 to appear
I tired few methods, if(str == "a") layout->tabview1; else layout->tabView2.
I also tried the connect(combobox,SIGNAL(currentTextChanged()),this,SIGNAL(swithcall()))
one of the main problems I can't do much instructions in swticahll function because in that case I will have to identify the tabviews as global variables which is not the best choice.
Any recommendations?

You can use lambdas inside a connect line,
ex:
connect(combobox,&QComboBox::currentIndexChanged,this,[tabView](int index) mutable{
// change tabView as wanted
});
If you want to change by text and index (not just index like here), you can use (inside the lambda):
QString currText = combobox->currentText();

You can just connect QComboBox's signal currentIndexChanged to QTabWidget's setCurrentIndex slot like connect(combobox, &QComboBox::cutrentIndexChanged, tabview, &QTabWidget::setCurrentIndex), and add widgets to your tabview in the required order that corresponds to items order in your combobox.

Related

QTreeWidgetItem setting not selectable clears the selection

I have a QTreeWidget and I want certain rows to be non select-able, which can be achieved by QTreeWidgetItem::setFlags(treeWidgetItem->flags() & ~Qt::ItemIsSelectable).
The problem is that I have an existing row that is already selected and later I click on the non select-able row, selectedItems() returns an empty list. I want the selected row to keep its selection if the user tries to select a non select-able row.
Should I keep track of the selection and handle this scenario in the code, or this can be achieved somehow else. I'd rather not reinvent the wheel.
Thank you.
Cause
Calling QTreeView::mousePressEvent(event) clears the selection when clicked on a non-selectable item if the selection mode is set to QAbstractItemView::SingleSelection.
Solution
My solution would be to either:
Set the selection mode to QAbstractItemView::MultiSelection,
or (in case this is not desired):
Reimplement the mouse events in a subclass of QTreeWidget in order to bypass the default behavior.
Note: In either case, use the QItemSelectionModel::selectionChanged signal to get the list of the selected items.
Example
Here is an example re-implementation of the mouse events in MyTreeWidget preventing the selection of being cleared by clicking a non-selectable item. The top item is expanded/collapsed on a double click:
void MyTreeWidget::mousePressEvent(QMouseEvent *event)
{
if (indexAt(event->pos())->flags() & Qt::ItemIsSelectable)
QTreeWidget::mousePressEvent(event);
}
void MyTreeWidget::mouseDoubleClickEvent(QMouseEvent *event)
{
QTreeWidget::mouseDoubleClickEvent(event);
QTreeWidgetItem *item = itemAt(event->pos());
if (item && item->childCount())
item->setExpanded(!item->isExpanded());
}
The modified in the described manner version of the provided example is available on GitHub.
Improvements
Special thanks to #eyllanesc for making this example more waterproof by:
adding a check if item is not NULL
replacing itemAt with indexAt

Finding a wxMenu's Selected Radio Item

Let's say that I have a group of radio items in a wxMenu. I know that exactly one of these will be checked at any given time.
Does the wxMenu or some other construct hold onto the index of the checked item, or do I need to call the isChecked on each radio item till I find the checked element to find it's index?
I've asked this question about how to do that, but I'd much prefer wxWidgets saved me from doing that everywhere.
No, saving the index of the last selected item (as shown in ravenspoint's answer) or using wxMenuBarBase::IsChecked() until you find the selected radio button is the only way to do it.
For wxWidgets to provide access to the currently selected button it would need not only to store it (which means not forgetting to update not only when the selected changes, but also when items are inserted into/deleted from the menu, so it's already not completely trivial), but to somehow provide access to the radio items group you're interested in, which would require being able to identify it and currently there is no way to do it and adding it isn't going to be particularly simple.
What could be done easily, however, is writing a reusable function int GetIndexOfSelectedRadioItem(int firstItem) that would start at the given item and call IsChecked() on subsequent items until it returns true and return the offset of the item. You should be able to do it in your own code, but if you'd like to include such function in wxWidgets itself (as a static wxMenuBar method, probably), please don't hesitate to send patches/pull requests doing it!
It is easy enough to roll your own.
Bind an event handler to wxEVT_COMMAND_RADIOBUTTON_SELECTED for every button. In the handler, extract the ID of the selected radio button and store it somewhere.
Like this:
ResolMenu = new wxMenu();
ResolMenu->AppendRadioItem(idRcvLoRez,"Low Resolution");
ResolMenu->AppendRadioItem(idRcvMeRez,"Medium Resolution");
ResolMenu->AppendRadioItem(idRcvHiRez,"High Resolution");
ResolMenu->Check( idRcvLoRez, true );
Bind(wxEVT_MENU,&cFrame::onRcvRez,this,idRcvLoRez);
Bind(wxEVT_MENU,&cFrame::onRcvRez,this,idRcvMeRez);
Bind(wxEVT_MENU,&cFrame::onRcvRez,this,idRcvHiRez);
void onRcvRez( wxCommandEvent& event )
{
myRezID = event.GetId();

Select item from one ComboBox and remove that item from other ComboBoxes

Im writing an QT application, where I have 3 QComboBoxes, with a list of values. I'm trying to do so, when I select one item in a QComboBox, I will remove it from the other QComboBoxes, and when I select another or nothing, it will reappear in the other QComboBoxes again.
Do you have any ideas for this?
Edit:
I have tried to use QStringList, where I had a slot, which removed it from the other QComboBoxes, but it was very bugged and often inserted 2 whitespaces and the same drink twice.
If all comboboxes contain the same items, then you can use the current index of one combobox to disable and hide that index of other comboboxes.
You can just subclass QComboBox and create a slot like this:
void MyComboBox::disableItem(int index)
{
QListView *list_view = qobject_cast<QListView*>(view());
if(list_view)
{
QStandardItemModel *model = qobject_cast<QStandardItemModel*>(list_view->model());
list_view->setRowHidden(index, true);
if(model)
{
model->item(index, 0)->setEnabled(false);
}
}
}
Then you just connect the QComboBox::currentIndexChanged(int index) signal from other comboboxes to this slot. Do this for all 3 comboboxes.
You should also create a logic for enabling and showing the items again when they shouldn't be disabled. It's almost the same function as the one above. You could just create a list of indexes that should be hidden for that combobox and use that to show all the other indexes.

Is there a Dojo list container that sorts child widgets automatically?

I'd like a graphical container that I can add and remove my custom widgets to where I can set a sort function that is automatically applied when these operations take place.
Is there a suitable object in Dojo already that I've missed? Or maybe I'm not thinking about the problem correctly?
If not, are there any examples etc. of a minimal working custom container widget out there?
Dont think there is really - how would a standard component's sort functionality know, with which parameters it should weight the order, when containers can contain any widget type?
Using a layout widget extension would be your best option imho. They each have a function to add children, following this prototype:
addChild(/*Object*/ dijit, /*Integer?*/ insertIndex)
The dijit.layout.StackContainer is a good starting point, it inherits from dijit._Container (and dijit.layout._LayoutWidget). So you choose when to call the extension functionality of your override.
dojo.declare("my.Container", [dijit._Container], {
getSortOrder : function(newDijit) {
var newIndex = -1; ??
// something to work with
var currentChildren = this.getChildren();
var currentDescendants = this.getDescendants();
return newIndex;
},
addChild: function(dijit, index) {
// figure out index
arguments[1] = this.getSortOrder(dijit);
this.inherited(arguments);
}
});
But be aware, that layoutwidgets has more to it then choosing order, also positioning like with bordercontainer's region parameter.
Use SitePen's dgrid, then define a List widget with a column of type Editor. Send your custom widget to the Editor's parameter. dgrid's List widget should be able to sort as if it were a grid based on your data, and the Editor column should be able to display anything you want as part of a List's item's content.
If you need anything I'll be around. Luck,

Is it possible to inherit QVBoxLayout and set it as layout in QWidget?

What I'm trying to accomplish:
Create 2 classes that inherit QVBoxLayout simply to set up each class with a series of different objects.
e.g.:
Class 1 (inherits QVBoxLayout), has QLabels to show an appointment and those labels set up with this->addWidget(labels);
Class 2 (inherits QVBoxLayout), has QLineEdits (and so on) to edit an appointment and those objects are also set up with this->addWidget(lineedits);
Is it possible to have a QWidget class then switch between these 2 layouts by calling this->setLayout(class1_object); and this->setLayout(class2_object);?
Or how would you suggest the swapping of the active objects on the widget (when clicking the edit button on the view-part or the save button on the edit-part)?
Simply use object->setShown(false);?
IMO, it's easier to use QTabWidget here.
Make a QTabWidget with 2 tabs. On Tab1, put your labels. On Tab2, put your edits. Call Tab2 something like "Edit the appointment". Now, use the currentChanged() slot for catching the tab switching.
If saving edits should be simple, all you will need to do is just to copy the edited data from edits to labels, and vice-versa.
If saving requires more than that, e.g. you want a confirmation dialog, you can permit the user to change back to Tab1 until some condition is met:
void MainWindow::on_tabWidget_currentChanged(int index)
{
//if the user is trying to go back to Tab1 (where the labels are)...
if(index == 0)
{
//...and if user didn't accept something, we just return him to the current tab
//It's probably a good idea to tell him what went wrong, too :P
if(!userAcceptedSaveDialog())
ui.tabWidget.setCurrentIndex(1);
}
}