I'm using Qt 5.12. I want to remove all items from combo Box at a time. is there any procedure to remove all items at a time without removing one by one index.
If you take a look at https://doc.qt.io/qt-5/qcombobox.html you will see the function clear().
Function description:
“Clears the combobox, removing all items.
Note: If you have set an external model on the combobox this model will still be cleared when calling this function.”
Related
I have a wxListbook that has some items, the following it is just a preview picture:
I want to get all item titles but before that, I want to get all items first then creating a for loop which in turn getting each item's title.
I found a method called GetListView() but it doesn't return array-like.
Is there a method to get all the items of that wxListbook?
wxListbook inherits from wxBookCtrlBase which defines GetPageCount() and GetPageText() methods that you can use to iterate over the pages and retrieve their labels, respectively.
Currently I want to implement a widget to allow user to enable/disbale all provided options of a QSet. So i took a combobox and added selectable items. So far so good, but how I can change text displayed in combobox? Currently all my items have just ItemIsUserCheckable and ItemIsEnabled as enabled flags (ItemIsSelectable is not enabled), so text of ComboBox is always text of first item. Instead I want as text "Flag1, Flag 3, Flag6" if there multiple flags and user enabled Flag 1, 3 and 6. But setCurrentText and setEditText requiring setEditable(true) or an custom lineEdit. But using an lineEdit is changing appearance. So is there another way?
I had a similar problem a while back, I ended up 'solving' it by adding an extra item to my model that was first in the list and always set as the current item. I then updated it's text to say 'Select items...' or 'X item(s) selected' as appropriate.
upon construction of QTreeWidgetItem you can pass a list of strings, so when you insert it in a table(QTreeWidget), you get the strings listed on a row. However, from the methods of the table you can also call setItemWidget and set a text widget or any sort of widget to be in that row, but it seems incompatible with having a string list, since the widget is drawn over the strings. There is also a setData method for the QTreeWidgetItem, which sets some data that can be retreived, but isn't visible to the user. Is there a cookie-cutter way of properly using all three data storage methods? Are they even compatible or must I stick to only one?
The Constructor of QTreeWidgetItem is convenient to immediately list the desired content.
When inserting a custom widget in a cell, you need to change its autoFillBackgroundproperty to true, so that it is not transparent. See the QTreewidget::setItemWidget description:
The given widget's autoFillBackground property must be set to true,
otherwise the widget's background will be transparent, showing both
the model data and the tree widget item.
QTreeWidgetItem::setData can be used when already having an item and you want to change one of its contents.
Of course you can combine any of these methods, but it is hard to say, which approach is best without knowing your use case. Just one more hint: If you just need a plain stupid representation of data that does not change, using QTreeWidget is fine. But if your displayed data can change, e.g. objects get deleted, added, changed in various locations of your code, a QTreeView with a custom data model might be a better choice.
Aloha
I have a QTableWidget with two columns that are currently using a ComboboxDelegate (my subclass of QItemDelegate) to present options to the user. I'd like the choice in the first column to effect the options available in the second, for the current row only.
E.g have a list of cars in the first column, and in the second a list of colours which are available for that car. Other rows to have different cars selected and thus different colour choices available.
From what I can see, I can only set an item delegate per row or column, so I can't see how to change the options in the second column's delegate without affecting all the other rows.
Is this possible? I'd really like to avoid going to a full view/model separation as I have quite a bit of code looking at this QTableWidget already (and I'm under time pressure)
Well for those interested; I went back to my pre-delegate approach, which was to use QTableWidget::setItemWidget() to provide a combobox widget for each cell.
I subclassed qcombobox to take a reference to the table, and connected the combobox CurrentIndexChanged with a slot to update the table data.
(setting a widget in a cell does not affect the tablewidget data unless you do this).
Using a full combobox like this is more expensive than an itemdelegate, but my tables are very small so I can get away with it. The rendering of the combobox is not as nice as the delegate (the combobox is visible all the time instead of only during editing in the delegate's case), but with time I'm sure I can improve on this.
I want to delete a selected row from the table when I click on the delete button.
But I can't find anything regarding deleting rows in the Qt documentation. Any ideas?
You can use the bool QAbstractItemModel::removeRow(int row, const QModelIndex & parent = QModelIndex()) functionality for this.
Here you can find an example for all this.
Also, here is an inline quote from that documentation:
removeRows()
Used to remove rows and the items of data they contain
from all types of model. Implementations must call beginRemoveRows()
before inserting new columns into any underlying data structures, and
call endRemoveRows() immediately afterwards.
The second part of the task would be to connect the button's clicked signal to the slot executing the removal for you.
If you are removing multiple rows you can run into some complications using the removeRow() call. This operates on the row index, so you need to remove rows from the bottom up to keep the row indices from shifting as you remove them. This is how I did it in PyQt, don't know C++ but I imagine it is quite similar:
rows = set()
for index in self.table.selectedIndexes():
rows.add(index.row())
for row in sorted(rows, reverse=True):
self.table.removeRow(row)
Works perfectly for me! However one thing to know, in my case this function gets called when a user clicks on a specific cell (which has a pushbutton with an 'X'). Unfortunately when they click on that pushbutton it deselects the row, which then prevents it from getting removed. To fix this I just captured the row of the sender and appended it to the "remove_list" at the very beginning, before the "for loops". That looks like this:
rows.add(self.table.indexAt(self.sender().pos()).row())
You can use another way by deleting the row from database, then clear the model and fill it again, this solution is also safe when you are removing multiple rows.