Carl Ding wrote:
> The problem is when I delete a row, I use Fl::delete_widget to remove
> all the embedded widgets in that row. The program crashed when doing
> fl_draw(). Is there anything else should be done to remove a row from
> Fl_Table?
Tell Fl_Table there's one less row by setting Fl_Table::rows(val),
e.g.:
if ( table.rows() > 0 )
table.rows(table.rows() - 1);
Fl_Table doesn't have a 'delete row' function because it doesn't
maintain any data of its own, so there's nothing to 'delete'.
It's just a space managing template that uses the rows() and
cols() values you tell it, and it just calls your draw method
once for each of the cells in all the rows and columns it knows
about.
When you delete a row of your data, you have to tell Fl_Table
there's one less row to draw, otherwise your draw function will
crash when Fl_Table calls it to draw data for that last row that
no longer exists.
Fl_Table is analogous to the 'for()' loop in the following:
for ( int row=0; row<rows; row++ )
printf("%d) %f\n", row, data[row]);
..where the 'for' loop is Fl_Table, and the printf() is your draw
routine, and data[] is your own data; Fl_Table is just the loop,
it knows nothing about the printf() or your array of data.. it just
knows to call your printf() once for all of the 'rows'.
So if you decide to realloc() the data[] array to be smaller,
but don't decrement 'rows', your printf() will crash printing
the last element because the data is no longer there. Decrementing
'rows' when you resize the array would be the same as decrementing
the Fl_Table::rows() value.
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