Quote Originally Posted by linoprit View Post
So, I have nothing to do with setting the color in the application code. All that must be done is to set the active row.

Qt Code: 
  1. void MyModel::setActiveRow(int row) // called from slot doubleClick
  2. {
  3.   active_row = row;
  4. }
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This method changes the model's data, i.e. MyModel::data() returns different values after that call changed active_row.
So naturally it is the place to emit change signals.

Qt Code: 
  1. void MyModel::setActiveRow(int row)
  2. {
  3.     if (active_row == row)
  4.         return; // no change
  5.  
  6.     int oldRow = active_row;
  7.     active_row = row;
  8.  
  9.     // de-highlight previously active row
  10.     if (oldRow > -1) {
  11.         QModelIndex rowBegin = index(oldRow, 0);
  12.         QModelIndex rowEnd = index(oldRow, columnCount() - 1);
  13.         emit dataChanged(rowBegin, rowEnd);
  14.     }
  15.  
  16.     // highlight newly active row
  17.     if (row > -1) {
  18.         QModelIndex rowBegin = index(row, 0);
  19.         QModelIndex rowEnd = index(row, columnCount() - 1);
  20.         emit dataChanged(rowBegin, rowEnd);
  21.     }
  22. }
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Cheers,
_