I have a basic question about the usage of QTable. Consider the following example. I would like to create a table with three columns - Name, Age and weight. An "add" button should be able to add a row in the table. The newly added row show be completely edited before leaving (i.e. all the three columns should be edited). Is there a signal which indicates that the complete row is left or the control is no more there in current row?
Such a signal will help me to put some error checking on the input values (e.g. checking if age is a positive no.) in all three columns (also to ensure that none of them is empty). Since this seems to be a very basic requirement, I think I am either missing the signal or the mechanism to support such working.
Instead of QTable you should use QTableWidget or QTableView.
See http://doc.qt.io/qt-4.8/porting4.html#qtable
Now, responding to your question.
Have you tried using the itemSelectionChanged() or itemEntered() signals?
Another way to do it would be to use the signal cellActivated() or the signal fired by your "Add" button - to indicate that the edit has started. Then you setup a connection to catch the next mouse button click or Return key pressed signals to detect the editing ended.
Edit:
I suppose that in your app you subclass QMainWindow or QWidget, if so, reimplement QWidget::mouseMoveEvent and/or QWidget::keyPressedEvent to detect when the left mouse button was clicked ( use keyPressedEvent to detect when the Return Key is pressed ).
You can read more about events in http://doc.qt.io/qt-5/eventsandfilters.html
Related
I want to know how to change the order of QTableView rows by dragging, and store the order changes to the model?
I use QTableView as view and QSqlTableModel as model. I am using Qt 5.15.
I set:
ui->table_view->setSelectionMode(QAbstractItemView::SingleSelection);
ui->table_view->setSelectionBehavior(QAbstractItemView::SelectRows);
ui->table_view->setEditTriggers(QAbstractItemView::NoEditTriggers);
Methods I tried:
1.
ui->table_view->setSectionsMovable(true);
ui->table_view->setDragEnabled(true);
ui->table_view->setDragDropMode(QAbstractItemView::InternalMove);
ui->table_view->setAcceptDrops(true);
It doesn't take effect. The row cannot be dragged.
2.
ui->table_view->verticalHeader()->setSectionsMovable(true);
ui->table_view->verticalHeader()->setDragEnabled(true);
ui->table_view->verticalHeader()->setDragDropMode(QAbstractItemView::InternalMove);
ui->table_view->verticalHeader()->setAcceptDrops(true);
The row can be dragged by vertical header. But the order of changes will not affect the model.
As far as I know the QTableView does not call moveRows method of the model by itself. Instead drag and drop actions call *mimeData methods.
So, one option would be the following:
In your model you need to implement mimeData and dropMimeData functions. When you drag and drop a row the view will ask for mimeData() of the given row. If you are sure that you need only internal moves you can encode the selected row indices to QMimeData. Then in the dropMimeData() you decode the indices that were selected and use them to call your moveRows() implementation. Return false from this function to prevent removing of the moved out rows.
Another option can be to override the QTableView methods such as dropEvent() in a way, that it calls the model moveRows() method directly.
I have custom QTableView class that shows content of custom model based on QAbstractItemModel. In the model I've implemented all needed methods to support changing rows order by DragAndDrop ( using dropMimeData()).
But I do not know how to update selection in the view after model (and view) changed.
For example:
user clicks on the row, it becomes 'selected';
user drags this row to other place;
rows are swaps in the model and view;
BUT selection stays on the first selected row.
How model can notify view to change selection?
NOTE: I cant to create additional signals and slots because don't use MOC.
The solution is:
In function dropMimeData() need to use beginMoveRows() and andMoveRows() around place where data changed.
Need to process signal QAbstractItemModel::rowsMoved of the model, where we can retrieve index of the target row.
I'm trying to implement multiple record selection feature on a grid.
It is very similar to http://www.tek-tips.com/faqs.cfm?fid=3831
It adds an extra column with check boxes. I want those check boxes!!
But it depends on a extra logical field in the underlying table. It need to create a class clscheck which inherits CHECKBOX. I'm not sure why this CLICK procedure is needed for the checkbox.
PROCEDURE CLICK
IF DODEFAULT()
KEYBOARD '{DNARROW}'
ENDIF
ENDPROC
When I removed it, row selection did not work correctly as expected. Why this?
Here is my requirement:
1) I don't want to add an extra logical field in the underlying table.
2) To work with controls in the grid, I think AllowCellSelection must be .T. I want AllowCellSelection = .F. because I don't need to work with any control in the grid except the check boxes. I need to work only with check boxes. The other columns will be read-only.
3) Can I have selected list without the logical field in the underlying table?
4) Can I remove the usage of KEYBOARD '{DNARROW}'?
In fact, I have a grid which is AllowCellSelection = .F., but it only provides single selection.
I need to enhance it with multiple selection, thus, I just want to add an extra column with check boxes so that user can know he can select multiple records.
No need Shift+Click or Ctrl+Click which is not familiar with idiot users.
I have found this - http://www.tek-tips.com/faqs.cfm?fid=433
It also depends on an extra logical field and it depends Shift+Click and Ctrl+Click.
What you are seeing is quite common for multi-select grids. I've used them SIMILAR to this in the past. However, you are afraid of the extra column in the underlying table. That may/not be true. You don't always have to update the ORIGINAL table, but a temporary CURSOR you are presenting to the user. Ex: If you want to display a list of employees in a table. No, you don't want to keep adding this column to the original employee table as then anyone else trying to do multi-select could falsely get your selection. However, if you pulled into your own local cursor and presented to the user, then no problem. Example...
Thisform.YourGrid.RecordSource = "Employees"
(bound directly to your employee table -- not necessarily the right thing)
vs
use in select( "C_MultiPickEmployees" )
select ;
.F. as IsChosen, ;
E.* ;
from ;
Employees E;
into ;
cursor C_MultiPickEmployees READWRITE
Thisform.YourGrid.RecordSource = "C_MultiPickEmployees"
NOW, you have your extra column without dealing with issues to the underlying table. If you wanted to further filter what you were showing -- such as employees for a certain division/department, then just add that to a WHERE clause, add an Order By if so needed and you are good to go.
As for the "Allow Cell Selection", I've never had to deal with that. I just add a "checkbox" to the first column and set
Thisform.YourGrid.Column[1].CurrentControl = "CheckBoxControl"
(based on the name it is added to the column).
Then, set the column 1's "ControlSource" = "C_MultiPickEmployees.IsChosen" and you should mostly be done.
As for the "CLICK" event trying to force the down arrow. This is more for automatically scrolling to the next record so you can just click, click, click for multiple entries.
Hope this helps clarify things for you.
I'm using PyQt to create a GUI application. In a view inherited from QTableView, need to detect the row the user has selected when they double click a row. The table has sorting, but no editing.
How do I do it?
Note - tried the doubleClicked(int) signal. It is emitted by mouse buttons, not by data cells, so it was never fired. :(
Ian
I dont understand.
The doubleClicked signal of the QTableView has the signature
void doubleClicked ( const QModelIndex & index )
If you connect that signal you should obtain the correct QModelIndex.
No need to use SIGNALs anymore:
self.your_table.doubleClicked.connect(your_function)
"doubleClicked" being inherited from QAbstractItemView.
Once you have the modelIndex, (from Frank's comment above) you can use it to find which cell was double clicked.
def slotDoubleClicked(self, mi):
row = mi.row()
column = mi.column()
You then can use these row and col values to access the table with table.setItem(row, column, newdata) or other table method
Like #regomodo said, you can simply connect your function to the double click via:
self.your_table.doubleClicked.connect(your_function)
Then, if you want to know on which row the user double clicked, you can use the following code:
for idx in self.your_table.selectionModel().selectedIndexes():
row_number = idx.row()
column_number = idx.column()
It will return an integer corresponding to the row or the column number.
There will always only be a single value as the double click remove the previous selection.
If you link your function to a push button or another signal, you can receive a list containing multiple elements selected by the user.
For example, you can easily retrieve a list of all selected rows using this code:
rows = []
for idx in self.your_table.selectionModel().selectedIndexes():
rows.append(idx.row())
rows = list(set(rows))
This will return a list of all selected rows (The set function will also remove any duplicates).
Cheers!
I'm working on my first ever AIR application with flashbuilder - just so you know.
I've bound a mx:DataGrid component to a DataProvider which is a mx:HTTPService fetching an xml file with items. To keep the data up to data I'm polling the webservice on a given interval.
My problem is that I loose the currently selected item in my DataGrid when the data is updated. I've tried to save the DataGrid.selectedIndex and set when the data is updated, but I'm not sure when to do it?! The closest I've come is to restore the index when the updateComplete event of DataGrid is fired. This works, but the selection first fades away and then fades in - not updated soon enough.
So what is the best way to keep the selection? (only one selected item at a time)
And as a side question: is there a convenient way to only update the data when it has actually changed?
Thankful for any suggestions!
I'll start from the bottom, the only way to only update the data when it has changed is to pass a check on the data on the server side to see if data has changed and make that a call before the actual update. So in short, you make two calls, one to see if the data has changed, which is a server side query, and the next only if that returns true, which updates the data.
Alternatively, you can also get the update, and compare it to your current data, and only update the UI if that data is different, but I have a feeling you mean the former answer of only doing the update CALL at all, if the data has changed.
As for the other solution, after you've saved the selectedIndex, do this inside your updateComplete:
private function yourDataGridUpdateComplete(event:FlexEvent):void{
yourDataGrid.selectedIndex = yourIndex;
yourDataGrid.validateNow();
yourDataGrid.scrollToIndex(yourIndex);
}
The DG uses the UUID of the data items to determine whether the item should be still selected after a refresh. If the data items don't implement IUID they basically get random values created each time they are added to the DG.
If your data items implement the IUID and you use a consistent value (DB sequence number for example) the DG will "know" that after a refresh, the data item is the same one as before.