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cgtkglade

GTK Glade C - pass variables to function including treeview


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>

Solution

  • 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;
    }