Proposed Multiline Grid Widget

gistfile1.py

#!/usr/bin/python3

import npyscreen, curses

class DividedMultiLine(npyscreen.wgwidget.Widget):

    _subwidget = npyscreen.Textfield

    def __init__(self, screen, values = None, **keywords):
        super(DividedMultiLine, self).__init__(screen, **keywords)
        self.values = values
        
        column_width = int(self.width / len(self.values[0]))

        self.rows = []

        y_offset = self.rely
        for row in self.values:
            x_offset = self.relx
            cells = []
            for item in row:
                cell = self._subwidget(self.parent, relx=x_offset, rely=y_offset, height=1, width=column_width + 1, value=self.display_value(item, column_width))
                cells.append(cell)

                x_offset += column_width

            self.rows.append(cells)

            y_offset += 1

            self.highlighted_row = 0
            self.highlight_row(0)            

    def update(self, clear=True):
        if clear:
            self.clear()
    
        for row in self.rows:
            for cell in row:
                cell.update()

    def highlight_row(self, idx, highlight=True):
        for cell in self.rows[idx]:
            if highlight == True:
                cell.highlight = 1
            else:
                cell.highlight = 0

            cell.update()

    ''' This returns a zero-padded string to mimic a highlight of the entire line '''
    def display_value(self, value, column_width):

        val_string = str(value)
        pad = column_width - len(val_string)

        # This is a bit lazy, I know
        if pad < 0:
            raise ValueError("Padding is negative, time for fixing it now!")

        return val_string + (" " * pad)

    def set_up_handlers(self):
        self.handlers = {
            curses.KEY_UP:      self.h_move_line_up,
            curses.KEY_DOWN:    self.h_move_line_down,
        }

    def h_move_line_up(self, ch):
        if self.highlighted_row == 0:
            return        

        self.highlight_row(self.highlighted_row, False)
        self.highlighted_row -= 1
        self.highlight_row(self.highlighted_row, True)

    def h_move_line_down(self, ch):
        if self.highlighted_row == len(self.values) - 1:
            return        

        self.highlight_row(self.highlighted_row, False)
        self.highlighted_row += 1
        self.highlight_row(self.highlighted_row, True)


class MyTestApp(npyscreen.NPSAppManaged):
    def onStart(self):
        self.registerForm("MAIN", MainForm())
    
class MainForm(npyscreen.FormBaseNew):
    def create(self):
        self.add(npyscreen.TitleText, name = "Text:", value= "Press Escape to quit application")
        self.how_exited_handers[npyscreen.wgwidget.EXITED_ESCAPE]  = self.exit_application

        self.nextrely += 1

        self.add(DividedMultiLine, values = [[1,2,3],[4,5,6],[7,8,9]])

    def exit_application(self):
        self.parentApp.setNextForm(None)
        self.editing = False

def main():
    TA = MyTestApp()
    TA.run()


if __name__ == '__main__':
    main()