Putting dynamic data in QT and can selection it - qt

I want to do the next.
I have a program that must search and show some files. Before, I will do it with a QTextEdit, searching in the system and appending it when I found one.
Now I want to to the next: I want to show the name of the files but I want to select it in the GUI and, in anohter text edit, show the first line in the document.
So, I want to transform any file in something that I can select it (like a Radio Button, a check button or something like this).
I search info in the web but I dont found anything.
Anyone knows what I can do?


Usually you use something like a list view (list of selectable items) to do this. Fortunatley Qt has one! called QListView :)
See this link: QListView
You add one entry to the listview per file (for exampe). And then when you click/select an entry this triggers an event which you can make display the contents of the file in a nearby text box.

Related

Kivy, shade/shadow under widget

I want to know how can I achieve a button (in kivy) like the image that I have attached below. I want to know how to create a shade/shadow like this. I just need a hint to know where to start and what are the essentials.
Thanks
kivy button

The look of a Button is determined by its properties background_normal, background_down, background_disabled_normal, and background_disabled_down. Those are just strings naming the images that are used to represent the different states of the Button. So you can create new image files containing your desired look and just set those properties to those new files.
You can see the default Button images and how they are handled in the kivy style.kv and the defaulttheme.atlas.

How to do a context dependant layout in Qt Designer and PyQt5?

I have a group box or the like containing a combobox and some more widgets that shall not all be visible at the same time. Depending on the selection I want at the same place to be displayed a button or a line edit or a (second) combobox. So if combobox entry one is selected it shows the button, if entry two is selected it shows the line edit, if entry three is selected it shows the second combobox, while not showing the other two.
I know that I can do it all dynamically but this results in a lot of code lines. I want to use QT Designer and a grid layout and I can't see how to put two widgets at the same place and then make only one visible programmatically.
I hope I could explain properly.
I played with Qt Designer but could not place two widgets over one another in a grid layout.
Thanks for any help.

Thank you G.M.
Yes, I was looking for QStackedWidget. I wasn't aware of this at all. I tried it and it works easily out of the box.

QListView and QAbstractListModel: how to manually set an item under editing, with cursor flashing?

I have a QAbstractListModel and QListView (for example, a list of input ports of an electronic device).
I've just added a row into the model, gave it a temp name (something like "RENAME_ME_PLZ_ASAP"). I want user to rename it, and I want to set the editing focus to this cell to make it possible to start typing the new port name without aiming the mouse to the cell added and double-clicking on it.
The editing of the item should begin, and its temp text contents should be selected (to be deleted by user when the typing will start).
How can it be done?

As you said you should should be able to edit, without aiming the mouse to the cell added and double-clicking on it.
Probably you can use QAbstractItemView::CurrentChanged edit trigger.
QListView *pListView = new QListView(<<Your parent widget>>); //rough
pListView->setEditTriggers(QAbstractItemView::CurrentChanged);
You have many edit triggers in below link, but I guess the above one suits you best.
http://doc.qt.io/qt-5/qabstractitemview.html#EditTrigger-enum
And if you are on embedded LINUX you can also use.
pListView->setEditFocus(true);

Well, I've just called QAbstractItemModel::edit(...) method.
^__^

PyQt5 - Signals&Slots - How to enable a button through content change of lineEdit?

since there isn't any useful How-To for beginners of PyQt5, I'm stuck with a little problem about signals & slots.
I do have a lineEdit which will get a directory path by a dialog (which works fine).
If one starts the program this lineEdit is empty by default and that's ok. A button, which shall generate a file list and show it in a list view, exists. It's functionality is implemented already and working fine. This button by default is disabled when the program is started for the first time.
What I want to do now is, enabling the button when something is entered at the lineEdit and disabling it when the content is removed.
I gave it a shot with this:
self.lineEdit_SelectedDirectory.editingFinished.connect(self.pushButton_CreateFileList.setEnabled)
but I get the error that it has not enough arguments, which might be clear because there aren't any provided in this code line.
Again, this was just a guess. How would one do this?
I would love something which takes the content into account like that, that it decides whether the content is empty or not and than sets the appropriate value to the button.
thx in advance for the help.
Christian

Looks like you want the textChanged signal, since that sends the current text:
self.lineEdit_SelectedDirectory.textChanged.connect(
lambda text: self.pushButton_CreateFileList.setEnabled(bool(text)))

How can I tell a QTableWidget to end editing a cell?

I'm showing a popup menu to select some values in a QTableWidget. The lowest item is a "Modify list" entry, when I select it a new window should automatically appear and the QComboBox should vanish and the cell return to a Qt::DisplayRole state.
Now Qt has all those nice API-calls like QTableWidget.edit() and QTableWidget.editItem(), what I'm really looking for is a QTableWidget.endEditing(), preferably without specifying the index of the cell, though I could get that using this call:
table.currentIndex()
… but I don't know if I can guarantee that the current cell is the cell being edited at all times.
Is there an API to close those kind of editors?

QTableWidget inherits 19 public slots from QWidget. One of those is setDisabled(), which should disable input events for that widget and all of its children.
I would try:
table.setDisabled( true );
table.setDisabled( false );
Although you said it does not work for you, there is an alternative method:
If you don't like that (the table loses focus, I believe), you can try using EditTriggers. For example:
table.setEditTriggers( QAbstractItemView::NoEditTriggers );

table.setCurrentItem(None) is what worked for me. (Don’t forget to block signals if you use some cellChanged/itemChanged slot function.)
This is with PyQt. For C++ I think replace None with NULL.

You may be able to use QTableWidget.closePersistentEditor() to close the editor. However, QAbstractItemView.closeEditor() may be closer to what you want, especially since you seem to be comfortable with the QModelIndex-based API and are already using a custom editor widget.

In my case, none of the options worked properly. So, I figured: I need to send the key press event to the line edit itself. The following works with QTreeView but probably does work with any other view or widget that opens a line edit to edit cells.
QWidget* editingWidget = treeView->findChild<QLineEdit*>();
if(editingWidget)
{
QKeyEvent keyPressEvent(QEvent::KeyPress, Qt::Key_Return, Qt::NoModifier);
QApplication::sendEvent(editingWidget, &keyPressEvent);
QApplication::processEvents(); // see note below
}
In my case, I wanted to start editing another field directly when having finished editing one item. That is why I put processEvents there, in most cases you can probably remove that line.
PS: yeah, it's C++, but should be easily adaptable to Python. I found this thread when I searched for the C++ solution, so maybe it helps anyone else, too.

I can't speak for list widgets. But, I got here trying to do something similar.
I was double-clicking a cell, and based on the column, bringing up a sub-form with a list, then when that was closed move to the next appropriate column based on the value selected.
My problem was I could get the value in the cell and "select" the next appropriate cell, but the original cell stayed selected in edit mode!
It finally dawned on me that my double-click was selecting the cell, ie. editing.
A single-click selects the cell but doesn't open an edit mode.
Side note: Never could get that sub-form to act truly modal, so I created a loop in the calling form: while the sub form was visible, with the only code being app.processEvents()

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