Qt Database content view / manipulation as list view - qt

I have a database, which tables should viewed in a widget. Seems simple, but I can't decide what to du or use.
Each row of the table should be viewed as one list view item, for instance, imagine table with this fields: id, title, content, date, number.
I need to view it as a list view (not hard-coded, it may also be another thing, if it is possible or better), and the label of the list view item should be the title field. But when the user clicks or double clicks on that item it should open all the contents of the current row in a separate widget. The all of these can be implemented easily by me, but I can't understand what to use: QListView with its model, or QListWidget? Or maybe QSqlTableModel? The last one is unfamiliar to me, I can read about from documentation, but if you have heard or met some kind things/applications, please provide a better solution for described problem.
Hope I could explain my problem correctly,
Thanks in advance.

Have you read about model/view programming in Qt? Basically you should use some model (QSqlTableModel, QSqlQueryModel, QSqlRelationalTableModel or create your own) an then attach it to QListView or QListWidget.

Related

QML Nested List View with separators

I'm trying to implement a tree view that represent structure of buildings/floors/rooms. All rooms should be classified by floor and building ( thus header for each building and floor is required.
First I implemented it with Repeater, Row and Grid elements. However i need a selection behaviour so i need to use ListView and GridView. However I have problems displaying nested list views.
Here's my code so far: http://pastie.org/private/3seqntgvskbyxnmnuluaua
Expected Result( when using Grid and Repeater instead of GridView and List View ):
Haven't tried it myself, but here is how to implementation a tree view in QML.
http://www.codeproject.com/Articles/632795/QML-TreeModel-and-TreeView
There is still no official tree view component in Qt (as of version 5.2). However, see the solution provided by jens on this thread
http://qt-project.org/forums/viewthread/30521
This is by far the best tree view that I have come across. It should provide a good basis for what you are trying to do.
Looks like Qt Company is releasing a QML TreeView in Qt5.5. Alpha release should be coming out in February.
http://blog.qt.io/blog/2015/02/05/licensing-of-new-modules-in-qt-5-5/

How to display drop-down in column of QTableView and filter based on drop-down

I am newbie to Qt. I have to display a chunk of data in a QTableView and filter it column wise. For this I have used QSortFilterProxyModel, but as per requirement each column of the QTableView should have a drop-down list which shows unique values in that column. On selection of any of these values in the drop-down, only the rows having that particular value in the column should be displayed in the QTableView (Like you can do in Excel).
How would I implement this?
I had the same issue a week ago
I found a tutorial explaining how to do it. see link below
http://programmingexamples.net/wiki/Qt/Delegates/ComboBoxDelegate
Now my problem is how to retrieve the value of a specific combobox.
I think it is such a complex things to do in C++ and Qt display a combobox into a tableView.
For being a web developer at first I can tell that web language are better suited to do thoses kind of things.
But still some time performance matter and I tried to do it in C++ with Qt but it is not as easy as it seems to be in Web language.
This is very general question, and if I try to explain it all it will take pages, so it's better if you read the Qt model/view architecture documentation.
You can create your own class inherited from QTableView to create your customized table view. You have to use delegates for drop down functions and all. so read the QItemDelegate class documentation and documentation on subclassing delegates as well.
If you want to display it always and not just when editing, I would suggest setting a widget for the specific column like described in this thread: Qt - QTableView - Clickable button in table row

Flex DataGrid sequencial inserting

I come from the Delphi school. I was really used and pleased with Delphi grids with the plus features of InfoPower. Not just me, my users loves all features that include grids. Some motives for that are:
With grids they have the ability to insert detail information using only the keyboard. Input, Tab, Input, Tab, Input Tab (automatically insert new row), input, tab, etc.
They were able to simply click in a row and edit it´s data.
They could navigate between records using only arrow keys.
In my flex apps I´ve being working arround this quite often, sometimes using a popup to insert data, sometimes using repeater instead of grid. But now I really really need some intuitive, fast way for my users to insert this data.
I am trying to use DataGrid (or AdvancedDataGrid) with inline editors and I am living a real hell to do that. For the last 3 days I am struggling, tweaking and workarrounding in order to try to mimic the features that I had with Delphi.
Main problems are:
DateField simply don´t work as an inline editor. It gets focus but never looses, only with pressing ESC, wich makes me loose the inputed data.
AdvancedAutoComplete: I have a component descendant from AdvancedAutoComplete with a custom browser. The custom browser is a popup, when I try to PopupManager.remove flex raises an exception of a null pointer inside it´s focus managing engines.
I couldn´t get to insert a new line focused in it´s first column when TABing in the last column of last row.
Having all these problems and not getting substantial material to solve them makes me think the (now obvious) fact that it is just not the way grids are intended to work in flex. My question is: what are the patterns used in flex applications to make sequencial, intuitive, fast, keyboard only insertions in a detail?
To answer your question bluntly, there are no specific established patterns to make editing or inserting data in the DataGrid fast and easy. Not being able to Tab between fields is one of the things I really wish Adobe had added to the DataGrid by default.
In order to get the functionality you want, you'll have to do some custom coding and extend/override the DataGrid's default functionality. Switch On The Code has an example up on tabbing between fields, but you would have to build upon their sample a bit further to include features like adding a new row when pressing tab in the last field of the last row in the DataGrid.
You may also want to consider Flexicious. Based on the Flexicious Ultimate demo, it looks like they have the functionality you're looking for (and then some!).

Show Editors for All Cells in Row in QTableView

I would like to display editors for all cells in a row when a user begins editing any cell in a QTableView. I have made several attempts but I cannot obtain the correct behaviour.
The only way to open multiple editors is by QAbstractItemView::openPersistentEditor() - attempts to successively call QAbstractItemView::edit() results in only one editor.
I cannot use signals such as clicked() and doubleClicked() from QAbstractItemView to invoke editing, because then it would not respect the edit triggers of the view.
There appears to be no "editing complete" signal. I would like to connect this signal to a slot that calls closePersistentEditor() for cells in the editing row.
Any suggestions would be appreciated.
Thanks!
I hate to be the bearer of bad news, but I can't think of any easy way to do what you want. I can think of a couple of options, each more painful than the last:
You could create a delegate that always shows the editors, and when the user changes the selected row, set that delegate for the newly selected row, and the original delegate for the deselected row.
You could try inheriting from the table view, and overriding the behavior for drawing the appropriate items for everything in the given row. I have no idea how hard this would be, but I doubt it would be trivial.
You could create your own view to display the model. I've never done this, and I'd hate to think about all that would be required to "complete" support the models. However, to match with one specific model, you might be able to get away with it.

How do I tell Qt to always show an editor in a QTableView?

I've got a QTableView for which I want to display the last column always in edit mode. (It's a QComboBox where the user should be able to always change the value.)
I think I've seen the solution in the Qt documentation, but I can't find it anymore. Is there a simple way of doing it?
I think I could archive this effect by using openPersistentEditor() for every cell, but I'm looking for a better way. (Like specifying it only one time for the whole column.)
One way to get the automatic editing behaviour is to call the view's setEditTriggers() function with the QAbstractItemView::AllEditTriggers value.
To display the contents of a given column in a certain way, take a look at QAbstractItemView::setItemDelegateForColumn(). This will let you specify a custom delegate just for those items that need it. However, it won't automatically create an editor widget for each of them (there could in principle be thousands of them), but you could use the delegate to render each item in a way that makes it look like an editor widget.
There are two possibilities:
Using setIndexWidget, but Trolltech writes:
This function should only be used to
display static content within the
visible area corresponding to an item
of data. If you want to display custom
dynamic content or implement a custom
editor widget, subclass QItemDelegate
instead.
(And it breaks the Model/View pattern…)
Or using a delegate's paint method. But here you have to implement everything like enabled/disabled elements yourself.
The QAbstractItemModel::flags virtual function is called to test if an item is editable (see Qt::ItemIsEditable). Take a look at Making the Model Editable in the Model/View Programming documentation.
I can't see an easy way to do this, but you might be able to manage by using a delegate. I honestly don't know exactly how it would work, but you should be able to get something working if you try hard enough. If you get a proper delegate, you should be able to set it on a whole view, one cell of a view, or just a column or row.

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