[SOLVED]GtkList syncronize scroolbar

perosoft · **Posted:** Tue Feb 28, 2012 7:38 am

thanks to @errol.

Hi,

I have created a GtkListStore.
Lots of elements.
After fill up the list i have selected the last row of the list.

Code:

for ( int i = 0; i<300;i++ ) {
     gtk_list_store_append( store, &iter );
     gtk_list_store_set(  store,  &iter, ......, -1 );
}
selection = gtk_tree_view_get_selection( GTK_TREE_VIEW( view ));
gtk_tree_selection_select_iter( selection, &iter );
// .......add solving code !!!!! ............
gtk_tree_selection_get_selected( selection, &model, &iter );
path = gtk_tree_model_get_path( model, &iter );
gtk_tree_view_scroll_to_cell( GTK_TREE_VIEW( view ),  path, NULL, FALSE, 0, 0 );
gtk_tree_path_free( path );
// .................................................

Row is selected but is not show in the window of list.
If i drag the vertical scrollbar i can see the row selected.
How can i syncronize the scrollbar to see directly the row selected ?

kepica · **Posted:** Tue Feb 28, 2012 11:34 am

interesting, it seems like gtk_tree_view_scroll_to_cell candidate, but couldn't get to work. only thing that does work

Code:

gtk_widget_grab_focus (GTK_WIDGET (view));
int i;
gboolean result;
for (i=0; i<10100; i++)
{
g_signal_emit_by_name (GTK_TREE_VIEW (view), "move-cursor", GTK_MOVEMENT_DISPLAY_LINES, 0, &result);
}

It is realy primitive hack. Put any number of record ( greater than 10100 ).
But it works !
Cheers !

perosoft · **Posted:** Tue Feb 28, 2012 12:28 pm

thanks, but not working for me !

kepica wrote:

interesting, it seems like gtk_tree_view_scroll_to_cell candidate, but couldn't get to work. only thing that does work

Code:

gtk_widget_grab_focus (GTK_WIDGET (view));
int i;
gboolean result;
for (i=0; i<10100; i++)
{
g_signal_emit_by_name (GTK_TREE_VIEW (view), "move-cursor", GTK_MOVEMENT_DISPLAY_LINES, 0, &result);
}

It is realy primitive hack. Put any number of record ( greater than 10100 ).
But it works !
Cheers !

errol · **Posted:** Wed Feb 29, 2012 9:49 am

Hi,

What has happened is you have updated the list store but this is not realised until control is returned back to the GTK main loop and the actual Tree View is updated. The code to realise and display the data is done a number of calls via Glib idle call backs. What you need to do is add your data, and add a Glib idle call back function that calls gtk_tree_view_scroll_to_cell ().

What should be happening is you :
- Update list store
- Create Glib Idle call back at normal priority and to be called only once, this call back to call gtk_tree_view_scroll_to_cell ()
- return control back to the GTK main loop

The main loop
- A Glib Idle call back at a high priority is called to update the GtkTreeView
- Your Glib Idle call back at normal priority is called to scroll to your cell.
- Any other call backs are done to update the display

The reason GTK updates GtkTreeView via an Idle call back is for efficiency. You could be adding or removing large amounts of data to the store, but if you also updated the display at the same time it would slow things down greatly.

perosoft · **Posted:** Thu Mar 01, 2012 6:43 am

thanks @errol, is working now !

errol wrote:

Hi,

What has happened is you have updated the list store but this is not realised until control is returned back to the GTK main loop and the actual Tree View is updated. The code to realise and display the data is done a number of calls via Glib idle call backs. What you need to do is add your data, and add a Glib idle call back function that calls gtk_tree_view_scroll_to_cell ().

What should be happening is you :
- Update list store
- Create Glib Idle call back at normal priority and to be called only once, this call back to call gtk_tree_view_scroll_to_cell ()
- return control back to the GTK main loop

The main loop
- A Glib Idle call back at a high priority is called to update the GtkTreeView
- Your Glib Idle call back at normal priority is called to scroll to your cell.
- Any other call backs are done to update the display

The reason GTK updates GtkTreeView via an Idle call back is for efficiency. You could be adding or removing large amounts of data to the store, but if you also updated the display at the same time it would slow things down greatly.

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[SOLVED]GtkList syncronize scroolbar

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