TTkTable alignment

[lucaminifreelance-art]

Hi,
I don't found a way to to align text inside columns and to set the column size. In the older table there was these two methods:

[...]
    table1.setColumnSize((5,10,-1,10,20))
    table1.setAlignment((
            ttk.TTkK.LEFT_ALIGN,
            ttk.TTkK.RIGHT_ALIGN,
            ttk.TTkK.LEFT_ALIGN,
            ttk.TTkK.LEFT_ALIGN,
            ttk.TTkK.CENTER_ALIGN
        ))
[...]

the first one I'm not sure that there's no other way to do the same thing... but for the second, the alignment is the most important to me...could you implement these in the newer TkTable as well?
Thanks in advance,
Luca

[ceccopierangiolieugenio]

Yes, I can implement the alignment but it is going to take few days.
Thanks for trying it, I need to sort out all the features are still missing.

[lucaminifreelance-art]

I understand!
I'm trying (and using...) this library because I believe this is one of the best and potentially full of features TUI library I know.
I hope you can keep it going for a long time.

[ceccopierangiolieugenio]

hi, about the alignment, I can think of different solution.
the most qt-like version
where you extend the model returning the text alignment required.
is to implement something like:

from PySide6.QtWidgets import QApplication, QTableView
from PySide6.QtCore import Qt, QAbstractTableModel

class MyTableModel(QAbstractTableModel):
    def __init__(self, data):
        super().__init__()
        self._data = data

    def rowCount(self, parent=None):
        return len(self._data)

    def columnCount(self, parent=None):
        return len(self._data[0])

    def data(self, index, role=Qt.DisplayRole):
        if not index.isValid():
            return None

        value = self._data[index.row()][index.column()]

        if role == Qt.DisplayRole:
            return value


        if role == Qt.TextAlignmentRole:
            if index.column() == 0:
                return Qt.AlignLeft | Qt.AlignTop
            elif index.column() == 1:
                return Qt.AlignCenter
            elif index.column() == 2:
                return Qt.AlignRight | Qt.AlignVCenter

        return None

app = QApplication([])

data = [
    ["Left", "Center\npippo", "Right"],
    ["Apple", "Banana\npippo", "Cherry"],
    ["Dog", "Elephant\npippo", "Fox"]
]

model = MyTableModel(data)
view = QTableView()
view.setModel(model)
view.show()

app.exec()

in pyTermTk could be somethinglike:

class ModelWithAlignment(ttk.TTkTableModelList):
    def data(self, row, col, role=ttk.TTkK.DisplayRole):
        if role == ttk.TTkK.TextAlignmentRole:
            if col == 0:
                return ttk.TTkK.AlignLeft | ttk.TTkK.AlignTop
            elif col == 1:
                return ttk.TTkK.AlignCenter
            elif col == 2:
                return ttk.TTkK.AlignRight | ttk.TTkK.AlignVCenter
        return supet().data(row,col,role)

tableModel = ModelWithAlignment(data=dataList)

Another solution is to have a displayModel that you can use in the tableModel and that you can customize to return a different alignment per cell and I can provide a set of predefined models, where you for example can specify the alignment per column, row or cell or area.

I prefer to avoid to overspecialize the TableWidget,
If you may think of a better approach or API let me know.
I haven't used many other table widgets and normally most of them require you to define a callback that return the style you need for each cell.

[lucaminifreelance-art]

Hi, the second proposed approach (displaymodel) is very good for my mindset.

I don't believe to have a better approach in mind but, I have in mind what PrettyTable do, where simply every column have its own alignment, but in pyTermTk library you can do something better. What do you think about an alignment "per cell" with a method? I believe the success of a library is its usage simplicity and its versatility. So, creating a method to align table data per cell, for you, means overspecialize the TableWidget? the same method can be implemented in other widgets like list, tree, combobox...
Another way: in a my application, I extended prettytable with a parameter where I used to pass 'auto' for auto alignment (for example: strings at left, numbers at right) or a dictionary with {"col_name": "alignment"}.
Tables are good for data representation, and your table widget is really gorgeous: it is simple, editable and the graphical quality is very high. I think it's worth equipping it with the best features :)

[ceccopierangiolieugenio]

PrettyTable was the first table experiment inspired by the bpytop task table, It was too simple and didn't allow customisation and it was becoming overspecialised (what if I need to have a different alignemt or color on a specific row or cell?).

About overspecializing means avoid to add a function to define the alignment per column, another for the cells or rows or areas or a function that accept a long list of parameters to allow any possible align permutations.

A model is a better approach,
For example the model can have a callback that return the alignment or the text transformation based on the content, i.e. you can have a different representiation if you are displaying numbers/time/currencies and so on.
I need to think about.
The QT approach is the one explained before but I don't want to overload the table model with stuff that are not related to the model itself but the visual representation.

[lucaminifreelance-art]

If you don't want overspecialize, I agree with you that the model approach is a good way to implement it.

[ceccopierangiolieugenio]

WIP:

Screen.Recording.2025-10-18.at.22.47.56.002.mov

I opted to extend the tableModel with the displayData method that can be used to customize the alignment.
Any other solution would have required similar trickery in order to be properly implemented.

class MyTableModel(ttk.TTkTableModelList):
    def displayData(self:ttk.TTkTableModelList, row:int, col:int) -> Tuple[ttk.TTkString, ttk.TTkK.Alignment]:
        data, legacy_align = super().displayData(row,col)
        if 0 == col%4:
            return data, ttk.TTkK.Alignment.LEFT_ALIGN
        if 1 == col%4:
            return data, ttk.TTkK.Alignment.CENTER_ALIGN
        if 2 == col%4:
            return data, ttk.TTkK.Alignment.RIGHT_ALIGN
        if 3 == col%4:
            return data, ttk.TTkK.Alignment.JUSTIFY
        return data, legacy_align

[ceccopierangiolieugenio]

Actually I was thinking, considering that excel and google docs, by default align numbers to right, I can use this as default behavior, so you don't need to customize the alignment unless you need it.
What do you think?

[lucaminifreelance-art]

I think it's a really good idea. So, if you do so, there are fewer cases where one needs to customize the model. Anyway It will be good to have an example how to do if one will needs.

[ceccopierangiolieugenio]

the change has been deployed, it will be ready to the next release