Hello, apologies for my English, I speak French, C++, then English.

I begin with Qt, currently using multiple views of a tree model.
I tried to add widgets (buttons) in a filtered view but the buttons are disapearing when I add a row to the model.

In the doc, it is said to use a delegate for dynamic data. It seems to me that delegates are fit for custom paint or data editors. Am I wrong ? setIndexWidget looked quite adequate ...

Shall I use a delegate ? If yes, is there somewhere a delegate example for the equivalent of setIndexWidget? The paint method doesn't look appropriate, is it possible to paint a button in it ?
On the other side, shall I re-add the buttons in the rows each time I change the model ?
I tried to re-add a button, but it seams impossible to reuse a disappeared button. Is it destroyed ?

Here is an example code, thanks in advance you for your answers, Derf.

Qt Code: 
  1. int main(int argc, char**argv)
  2. {
  3. //------ test  proxy and setIndexWidget
  4. QApplication application(argc,argv);
  5. //-- model
  7. QModelIndex parent;
  8. for (int i=0; i<4; ++i) {
  9.   parent = testModel.index(0,0,parent);
  10.   testModel.insertRows(0,1,parent);
  11.   testModel.insertColumns(0,1,parent);
  12.   QModelIndex index = testModel.index(0,0,parent);
  13.   testModel.setData(index,i);
  14. }
  15.  
  16. //-- tree and filtered tree
  17. QTreeView tree;
  18. tree.setModel(&testModel);
  19. tree.setWindowTitle("direct");
  20. tree.show();
  21.  
  23. filter.setSourceModel(&testModel);
  24.  
  25. QTreeView filteredTree;
  26. filteredTree.setModel(&filter);
  27. filteredTree.setWindowTitle("filtered");
  28. filteredTree.show();
  29.  
  30. //-- add buttons
  31. QModelIndex modelIndex = testModel.index(0,0,QModelIndex());
  32. QToolButton * button1 = new QToolButton(&tree);
  33. button1->setText("button1");
  34. tree.setIndexWidget(modelIndex,button1);
  35.  
  36. QModelIndex filterIndex = filter.mapFromSource(modelIndex);
  37. QToolButton * button2 = new QToolButton(&filteredTree);
  38. button2->setText("button2");
  39. filteredTree.setIndexWidget(filter.mapFromSource(modelIndex),button2);
  40.  
  41. //-- change model
  42. testModel.insertRows(0,1,QModelIndex());
  43. testModel.setData(testModel.index(0,0,QModelIndex()),42);
  44.  
  45. //-- add buttons
  46. modelIndex = testModel.index(0,0,QModelIndex());
  47. QToolButton * button3 =new QToolButton(&tree);
  48. button3->setText("button3");
  49. tree.setIndexWidget(modelIndex,button3);
  50.  
  51. filterIndex = filter.mapFromSource(modelIndex);
  52. QToolButton * button4 = new QToolButton(&filteredTree);
  53. button4->setText("button4");
  54. filteredTree.setIndexWidget(filterIndex,button4);
  55.  
  56. //-- add again button, normal ? 
  57. //-- doesn't work with the same (button2) ? is it destroyed when the model changes ?
  58. //modelIndex = testModel.index(1,0,QModelIndex());
  59. //filterIndex = filter.mapFromSource(modelIndex);
  60. //QToolButton * button5 = new QToolButton(&filteredTree);
  61. //button5->setText("button5");
  62. //filteredTree.setIndexWidget(filter.mapFromSource(modelIndex),button5);
  63.  
  64. //-- run
  65. application.exec();
  66. return 0;
  67. }
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