GTK Glade C - pass variables to function including treeview - c

Question

It's only possible to pass one variable in a callback function. So we have to built structures. I'm okay with this but how to do with Treeview and Treemodel/Liststore ?
I want to avoid global variables. This test program should get the content of the selected row displayed in the EntryBoxes. I don't know if i'm wrong making the struct including the Treeview or if there's something wrong inside the function. I get segfault.
What would be the correct way to deal with that ?
#include <gtk/gtk.h>
typedef struct {
GtkWidget *ent_date;
GtkWidget *ent_lib;
GtkWidget *ent_mont;
GtkTreeView *treeview;
} app_widgets;
enum
{
DATE_COLUMN,
LIBELLE_COLUMN,
MONTANT_COLUMN,
N_COLUMN
};
void on_window_main_destroy()
{
gtk_main_quit();
}
void on_treeview_selection1_changed (GtkTreeSelection *treeselection, app_widgets *app_wid) {
gchar value[3];
GtkTreeIter iter;
GtkTreePath *path;
//GtkTreeView *treeview = (GtkTreeView *)app_wid->treeview;
GtkListStore *store = GTK_LIST_STORE(gtk_tree_view_get_model(GTK_TREE_VIEW(app_wid->treeview)));
gtk_tree_view_get_cursor (app_wid->treeview, &path, NULL);
gtk_tree_model_get_iter (GTK_TREE_MODEL(store), &iter, path);
gtk_tree_path_free (path);
if (gtk_tree_selection_get_selected(treeselection, &store, &iter))
{
gtk_tree_model_get(GTK_TREE_MODEL(store), &iter, DATE_COLUMN, &value[0], LIBELLE_COLUMN, &value[1],MONTANT_COLUMN, &value[2], -1);
}
gtk_entry_set_text(GTK_ENTRY(app_wid->ent_date), value[0]);
gtk_entry_set_text(GTK_ENTRY(app_wid->ent_lib), value[1]);
gtk_entry_set_text(GTK_ENTRY(app_wid->ent_mont), value[2]);
g_free(value);
}
int main(int argc, char *argv[])
{
GtkBuilder *builder;
app_widgets *widgets = g_slice_new(app_widgets);
gtk_init(&argc, &argv);
builder = gtk_builder_new();
gtk_builder_add_from_file (builder, "test.glade", NULL);
widgets->ent_date = GTK_WIDGET(gtk_builder_get_object(builder, "entry_date"));
widgets->ent_lib = GTK_WIDGET(gtk_builder_get_object(builder, "entry_lib"));
widgets->ent_mont = GTK_WIDGET(gtk_builder_get_object(builder, "entry_mont"));
widgets->treeview = GTK_TREE_VIEW(gtk_builder_get_object(builder, "treeview1"));
gtk_builder_connect_signals(builder, NULL);
gtk_widget_show(GTK_WIDGET(gtk_builder_get_object(builder, "window1")));
g_object_unref(builder);
gtk_main();
g_slice_free(app_widgets, widgets);
return 0;
}
Here's the glade file:
<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.18.3 -->
<interface>
<requires lib="gtk+" version="3.12"/>
<object class="GtkListStore" id="liststore1">
<columns>
<!-- column-name Date -->
<column type="gchararray"/>
<!-- column-name Libellé -->
<column type="gchararray"/>
<!-- column-name Montant -->
<column type="gchararray"/>
</columns>
<data>
<row>
<col id="0" translatable="yes">20.05.2017</col>
<col id="1" translatable="yes">Something - here</col>
<col id="2" translatable="yes">30.20</col>
</row>
<row>
<col id="0" translatable="yes">25.06.2017</col>
<col id="1" translatable="yes">Something else - overthere</col>
<col id="2" translatable="yes">24.90</col>
</row>
<row>
<col id="0" translatable="yes">11.08.2017</col>
<col id="1" translatable="yes">Third thing - lala</col>
<col id="2" translatable="yes">5.15</col>
</row>
</data>
</object>
<object class="GtkWindow" id="window1">
<property name="can_focus">False</property>
<property name="margin_left">5</property>
<property name="margin_right">5</property>
<property name="margin_top">5</property>
<property name="margin_bottom">5</property>
<property name="window_position">center</property>
<child>
<object class="GtkBox" id="box1">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="orientation">vertical</property>
<child>
<object class="GtkScrolledWindow" id="scrolledwindow1">
<property name="visible">True</property>
<property name="can_focus">True</property>
<property name="shadow_type">in</property>
<child>
<object class="GtkTreeView" id="treeview1">
<property name="visible">True</property>
<property name="can_focus">True</property>
<property name="model">liststore1</property>
<child internal-child="selection">
<object class="GtkTreeSelection" id="treeview-selection1">
<signal name="changed" handler="on_treeview_selection1_changed" swapped="no"/>
</object>
</child>
<child>
<object class="GtkTreeViewColumn" id="treeviewcolumn1">
<property name="resizable">True</property>
<property name="fixed_width">70</property>
<property name="title" translatable="yes">Date</property>
<child>
<object class="GtkCellRendererText" id="cellrenderertext1"/>
<attributes>
<attribute name="text">0</attribute>
</attributes>
</child>
</object>
</child>
<child>
<object class="GtkTreeViewColumn" id="treeviewcolumn2">
<property name="resizable">True</property>
<property name="title" translatable="yes">Libellé</property>
<child>
<object class="GtkCellRendererText" id="cellrenderertext2"/>
<attributes>
<attribute name="text">1</attribute>
</attributes>
</child>
</object>
</child>
<child>
<object class="GtkTreeViewColumn" id="treeviewcolumn3">
<property name="resizable">True</property>
<property name="title" translatable="yes">Montant</property>
<child>
<object class="GtkCellRendererText" id="cellrenderertext3"/>
<attributes>
<attribute name="text">2</attribute>
</attributes>
</child>
</object>
</child>
</object>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">1</property>
</packing>
</child>
<child>
<object class="GtkBox" id="box2">
<property name="visible">True</property>
<property name="can_focus">False</property>
<child>
<object class="GtkBox" id="box_date">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="orientation">vertical</property>
<child>
<object class="GtkLabel" id="label1">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="label" translatable="yes">Date</property>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">0</property>
</packing>
</child>
<child>
<object class="GtkEntry" id="entry_date">
<property name="visible">True</property>
<property name="can_focus">True</property>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">1</property>
</packing>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">0</property>
</packing>
</child>
<child>
<object class="GtkBox" id="box_lib">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="orientation">vertical</property>
<child>
<object class="GtkLabel" id="label2">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="label" translatable="yes">Lib</property>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">0</property>
</packing>
</child>
<child>
<object class="GtkEntry" id="entry_lib">
<property name="visible">True</property>
<property name="can_focus">True</property>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">1</property>
</packing>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">1</property>
</packing>
</child>
<child>
<object class="GtkBox" id="box_mont">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="orientation">vertical</property>
<child>
<object class="GtkLabel" id="label3">
<property name="visible">True</property>
<property name="can_focus">False</property>
<property name="label" translatable="yes">Montant</property>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">0</property>
</packing>
</child>
<child>
<object class="GtkEntry" id="entry_mont">
<property name="visible">True</property>
<property name="can_focus">True</property>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">1</property>
</packing>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">2</property>
</packing>
</child>
</object>
<packing>
<property name="expand">False</property>
<property name="fill">True</property>
<property name="position">2</property>
</packing>
</child>
</object>
</child>
</object>
</interface>

Answer 1

First thing, you cannot use gtk_builder_connect_signals(builder, NULL); and then expect the callback handlers to receive user data.
You should have passed the widgets structure:
gtk_builder_connect_signals(builder, widgets);
Second thing, you over complicated the selection callback. The GtkTreeSelection instance will give you the model when you call gtk_tree_selection_get_selected. Then you must understand that this last function will "not work if you use selection GTK_SELECTION_MULTIPLE".
Also notice that gtk_tree_model_get should take pointers to char/gchar which will then point to newly allocated copies of the model content (means they must be freed afterwards).
So, your code should be something like this:
#include <gtk/gtk.h>
typedef struct {
GtkWidget *ent_date;
GtkWidget *ent_lib;
GtkWidget *ent_mont;
GtkTreeView *treeview;
} app_widgets;
enum
{
DATE_COLUMN,
LIBELLE_COLUMN,
MONTANT_COLUMN,
N_COLUMN
};
void on_window_main_destroy()
{
gtk_main_quit();
}
void on_treeview_selection1_changed (GtkTreeSelection *treeselection, app_widgets *app_wid) {
gchar *a,*b,*c;
GtkTreeIter iter;
GtkTreeModel *model;
if (gtk_tree_selection_get_selected(treeselection, &model, &iter))
{
gtk_tree_model_get(model, &iter, DATE_COLUMN, &a, LIBELLE_COLUMN, &b,MONTANT_COLUMN, &c, -1);
}
gtk_entry_set_text(GTK_ENTRY(app_wid->ent_date), a);
gtk_entry_set_text(GTK_ENTRY(app_wid->ent_lib), b);
gtk_entry_set_text(GTK_ENTRY(app_wid->ent_mont), c);
g_free(a);
g_free(b);
g_free(c);
}
int main(int argc, char *argv[])
{
GtkBuilder *builder;
app_widgets *widgets = g_slice_new(app_widgets);
gtk_init(&argc, &argv);
builder = gtk_builder_new();
gtk_builder_add_from_file (builder, "test.glade", NULL);
widgets->ent_date = GTK_WIDGET(gtk_builder_get_object(builder, "entry_date"));
widgets->ent_lib = GTK_WIDGET(gtk_builder_get_object(builder, "entry_lib"));
widgets->ent_mont = GTK_WIDGET(gtk_builder_get_object(builder, "entry_mont"));
widgets->treeview = GTK_TREE_VIEW(gtk_builder_get_object(builder, "treeview1"));
gtk_builder_connect_signals(builder, widgets);
gtk_widget_show(GTK_WIDGET(gtk_builder_get_object(builder, "window1")));
g_object_unref(builder);
gtk_main();
g_slice_free(app_widgets, widgets);
return 0;
}