c++ - Reuse a widget using g_object_ref() -



c++ - Reuse a widget using g_object_ref() -

i have gtkgrid , want show within 1 cell widget or according choices of user. wrote code according this, says:

removes widget container . widget must within container . note that container own reference widget , , may be the lastly reference held; removing widget container can destroy widget. if want utilize widget again, need add a reference while it’s not within container, using g_object_ref(). if don’t want utilize widget 1 time again it’s more efficient destroy straight using gtk_widget_destroy() since remove container , help break circular reference count cycles.

here fragment of code:

// definitions gtkwidget *mylist1, *mylist2; // creation mylist1 = gtk_tree_view_new(); mylist2 = gtk_tree_view_new(); gtk_grid_attach(gtk_grid(gridlist), mylist1, 0, 1, 2, 1); // attach mylist1 // switching in runtime if (x) { g_object_ref(mylist1); gtk_container_remove(gtk_container(gridlist), mylist1); gtk_grid_attach(gtk_grid(gridlist), mylist2, 0, 1, 2, 1); } else { g_object_ref(mylist2); gtk_container_remove(gtk_container(gridlist), mylist2); gtk_grid_attach(gtk_grid(gridlist), mylist1, 0, 1, 2, 1); }

when perform switching (i want remove mylist1 , insert mylist2), empty cell in grid. anyway, when repeat switching, object mylist1 reappears in grid want.

i don't gtk warning on terminal during operations. x set true or false correctly according selection of 2 radio buttons.

what's going on? missing passages?

you need gtk_widget_show_all(mylist2) show up. gtk_widget_show_all() shows gtkwindow gtkgrid kid of shows children at time of call.

your code has latent bug: reference counts increment 2 decrement 1 because gtk_grid_attach() (actually gtk_widget_set_parent()) own g_object_ref() (actually g_object_ref_sink()).

c++ c widget gtk

Comments

Post a Comment

Popular posts from this blog

Delphi change the assembly code of a running process -

Delphi change the assembly code of a running process - i'm trying alter address 00741fa5 has push test.009e721c . alter push test.009e71c8 . procedure callback; asm force $9e71c8 end; procedure tform2.btn1click(sender: tobject); var ppid :dword; pprocess : cardinal; begin getwindowthreadprocessid(findwindow(nil,pchar('test')), @ppid); pprocess := openprocess(process_all_access, false, ppid); injectasm(pprocess, $741fa5, 10, integer(@callback), 0); end; here injectasm function (with error checking) function injectasm(process: longword; injectaddress, injectsize, codeaddress, codesize : integer): pointer; var csize, rsize : integer; replaced : array of byte; jmp : array [0..4] of byte; jmpaddress : integer; nopv : byte; : integer; nbr: ulong_ptr; begin //injectsize must equal or greater 5, because need space our //(far) jmp wwxxyyzz instruction //if there's no space, inject in place of few instructions if injectsize ...
Read more

json - Hibernate and Jackson (java.lang.IllegalStateException: Cannot call sendError() after the response has been committed) -

json - Hibernate and Jackson (java.lang.IllegalStateException: Cannot call sendError() after the response has been committed) - hello have problem hibernate , jackson. have 2 pojos @entity @table(name = "users") public class user implements serializable { static final long serialversionuid = 4235637833262722256l; @id @generatedvalue private int id; @column(name = "creation_date") private date creationdate; @column(name = "first_name") private string firstname; @column(name = "last_name") private string lastname; @version @column(name = "version") private int version; @column(name = "e_mail") private string email; @column(name = "enabled") private boolean enabled; @column(name = "login") private string login; @column(name = "password") private string password; @jsonmanagedreference("role") @onetomany(mappedby = "user", cascade = cascadetype.all,fetch = fetchtyp...
Read more

C++ 11 "class" keyword -

C++ 11 "class" keyword - i've started using c++ 11 little bit more , have few questions on special uses of class keyword. know it's used declare class, there's 2 instances have seen don't understand: method<class t>(); and class class_name *var; why precede typename keyword class in first example, , keyword pointer in sec example? that known elaborated type specifier , necessary when class name "shadowed" or "hidden" , need explicit. class t { }; // love of god don't t t; t t2; if compiler smart, give these warnings: main.cpp:15:5: error: must utilize 'class' tag refer type 't' in scope t t2; ^ class main.cpp:14:7: note: class 't' hidden non-type declaration of 't' here t t; ^ if class not defined, deed forwards declaration. for example: template <typename t> void method() { using type = typename t::value_type; } method...
Read more