GTK Main blocking Others threads.How to solve - gtk

I have 2 threads
1)Holds the GTK main and gtk screen display codes (code is explained below) 2)generates key events according to user rquirement
if() block i ported into my code. but result is same. Once the signal is generated .after that its not coming to 2nd thread(signal generation thread). Have put debug prints ,but its not happening Seems its waiting on gtk_main on first thread.
What my code is :
void S1(void)
{
GtkWidget *Win_1;
GtkBuilder *builder;
builder = gtk_builder_new ();
gtk_builder_add_from_file (builder, "/home/glade/glade1.glade", NULL);
window = GTK_WIDGET (gtk_builder_get_object (builder, "Win_1"));
g_signal_connect_swapped(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), G_OBJECT(window));
g_signal_connect (G_OBJECT (window), "key_press_event", G_CALLBACK(kp_event), NULL);
gtk_widget_show_all(window);
gtk_main();
}
kp_event()
{
gtk_widget_destroy (window);
S2();
}
S2 is same as S1,only screen item difference.Am calling S2() from keypress handler of S1 & vice versa. Since i have no keyboards attached,need to change two screens base on some user input via sockets or something.

You may need to call gtk_main() just one time, and use gtk_widget_hide() and gtk_window_present(), instead of gtk_widget_destroy(), declaring window1 and window2 as global variables, and creating the two windows at startup. A sample code:
GtkWidget * window1;
GtkWidget * window2;
void S1() {
// create the window
window1 = GTK_WIDGET (gtk_builder_get_object (builder, "Win_1"));
// do not call gtk_main()
}
void S2() {
// create the window
window2 = GTK_WIDGET (gtk_builder_get_object (builder, "Win_2"));
// do not call gtk_main()
}
kp_event_S1() {
gtk_widget_hide(window1);
gtk_window_present(GTK_WINDOW(window2));
}
kp_event_S2() {
gtk_widget_hide(window2);
gtk_window_present(GTK_WINDOW(window1));
}
int main() {
gtk_init();
S1();
S2();
gtk_widget_hide(window2);
gtk_main();
}
If you don't want to use global variables, you can do:
GtkWidget * S1() {
// create the window
GtkWidget * window1 = GTK_WIDGET (gtk_builder_get_object (builder, "Win_1"));
return window1;
}
GtkWidget * S2() {
// create the window
GtkWidget * window2 = GTK_WIDGET (gtk_builder_get_object (builder, "Win_2"));
return window2;
}
gboolean kp_event_S1(GtkWidget * window, GdkEvent e, gpointer user_data) {
gtk_widget_hide(window);
gtk_window_present(GTK_WINDOW(user_data));
}
gboolean kp_event_S2(GtkWidget * window, GdkEvent e, gpointer user_data) {
gtk_widget_hide(window);
gtk_window_present(GTK_WINDOW(user_data));
}
int main() {
gtk_init();
GtkWidget * w1 = S1();
GtkWidget * w2 = S2();
gtk_widget_hide(w2);
g_signal_connect (G_OBJECT (w1), "key-press-event", G_CALLBACK(kp_event_S1), (gpointer)w2);
g_signal_connect (G_OBJECT (w2), "key-press-event", G_CALLBACK(kp_event_S2), (gpointer)w1);
gtk_main();
}

Related

Trying to create a gsocket server with GUI program

I am trying to set up server that also has a gui using GTK on a Raspberry Pi. The program is just a proof-of-concept demo.
I create a socket and the client can connect and send data, I see it in wireshark. But the read does not complete until the client disconnects. My code uses g_data_input_stream_read_line_async and g_data_input_stream_read_line_finish. The program displays the data the client sent after the client disconnects.
Here is the output of the program (that is the correct data that was sent by the client).
g_socket_listener_add_inet_port status: 1
g_signal_connect status: 2 (waits here until client connects)
socket connection established!
after g_data_input_stream_new
after g_data_input_stream_set_newline_type
after g_data_input_stream_read_line_async (waits here after client connects, and after client sends data)
before g_data_input_stream_read_line_finish (displays remaining output lines after client disconnects)
after g_data_input_stream_read_line_finish
length: 14
0 5 0 4 0 1 0 1 0 6 0 0 0 7
I suspect I am missing something simple since the data is received, but I've spent quite a few hours unsuccessfully trying to figure out what is missing.
// compiles with:
// gcc `pkg-config --cflags gtk+-3.0` gtk3serv.c -o gtk3serv `pkg-config --libs gtk+-3.0`
#include <gtk/gtk.h>
#include <gio/gio.h>
static void
print_hello (GtkWidget *widget,
gpointer data)
{
g_print ("Hello World\n");
}
static void
activate (GtkApplication *app,
gpointer user_data)
{
GtkWidget *window;
GtkWidget *button;
GtkWidget *button_box;
window = gtk_application_window_new (app);
gtk_window_set_title (GTK_WINDOW (window), "Window");
gtk_window_set_default_size (GTK_WINDOW (window), 200, 200);
button_box = gtk_button_box_new (GTK_ORIENTATION_HORIZONTAL);
gtk_container_add (GTK_CONTAINER (window), button_box);
button = gtk_button_new_with_label ("Hello World");
g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_widget_destroy), window);
gtk_container_add (GTK_CONTAINER (button_box), button);
gtk_widget_show_all (window);
}
// v<>v<>v<>v<>v<>v<>v<>v<>v<>v<>v
static void on_input_read_finish(GObject *object,
GAsyncResult *result,
gpointer user_data)
{
gchar *clientdata;
gsize length = -1;
gsize i;
g_print("before g_data_input_stream_read_line_finish\n"); // only for debug
clientdata = g_data_input_stream_read_line_finish(G_DATA_INPUT_STREAM(object),
result,
&length,
NULL);
g_print("after g_data_input_stream_read_line_finish\n"); // only for debug
g_print("length: %d\n", length); // only for debug
for(i=0; i<length; i++)
{
g_print("%x ", clientdata[i]);
}
g_print("\n");
}
gboolean sockconnectionestablished(GSocketService *sockservice,
GSocketConnection *connection,
GObject *source_object,
gpointer user_Data)
{
char *clientdata;
gsize length = -1;
gsize i;
g_print("socket connection established!\n"); // only for debug
GDataInputStream *gis = g_data_input_stream_new(g_io_stream_get_input_stream(G_IO_STREAM(connection)));
g_print("after g_data_input_stream_new\n"); // only for debug
g_data_input_stream_set_newline_type(G_DATA_INPUT_STREAM(gis), G_DATA_STREAM_NEWLINE_TYPE_ANY);
g_print("after g_data_input_stream_set_newline_type\n"); // only for debug
g_data_input_stream_read_line_async(G_DATA_INPUT_STREAM(gis),
G_PRIORITY_DEFAULT,
NULL,
on_input_read_finish,
NULL);
g_print("after g_data_input_stream_read_line_async\n"); // only for debug
return 1;
}
// ^<>^<>^<>^<>^<>^<>^<>^<>^<>^<>^
int
main (int argc,
char **argv)
{
GtkApplication *app;
int status;
// v<>v<>v<>v<>v<>v<>v<>v<>v<>v<>v
GError *sockerror = NULL;
GSocketService *sockservice;
gboolean sockstatus;
sockservice = g_socket_service_new();
sockstatus = g_socket_listener_add_inet_port(G_SOCKET_LISTENER(sockservice),
8888,
NULL,
NULL);
g_print("g_socket_listener_add_inet_port status: %d\n", sockstatus); // only for debug
status = g_signal_connect(sockservice,
"incoming",
G_CALLBACK(sockconnectionestablished),
NULL);
g_print("g_signal_connect status: %d\n", status); // only for debug
// ^<>^<>^<>^<>^<>^<>^<>^<>^<>^<>^
app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}

making a vending machine out of GTK

#include "UI.h"
GtkWidget* create_main_frame(gint wid, gint hgt)
{
GtkWidget* main_frame = gtk_window_new(GTK_WINDOW_TOPLEVEL);
/* window attributes */
gtk_window_set_title( GTK_WINDOW(main_frame), "Welcome!!" );
gtk_window_set_default_size( GTK_WINDOW(main_frame), wid, hgt );
/* signals */
g_signal_connect(main_frame, "destroy", G_CALLBACK(gtk_main_quit), NULL);
return main_frame;
}
GtkWidget* create_scrolled_window(void)
{
GtkWidget* scrolled_window = gtk_scrolled_window_new(NULL, NULL);
gtk_scrolled_window_set_policy( GTK_SCROLLED_WINDOW(scrolled_window), GTK_POLICY_AUTOMATIC, GTK_POLICY_ALWAYS );
gtk_container_set_border_width( GTK_CONTAINER(scrolled_window), 10 );
return scrolled_window;
}
GtkWidget* create_box(GtkOrientation orn, gint spc)
{
GtkWidget* box = gtk_box_new(orn, spc);
//gtk_container_set_border_width( GTK_CONTAINER(box), 5 );
return box;
}
GtkWidget* create_layout(guint wid, guint hgt)
{
GtkWidget* layout = gtk_layout_new(NULL, NULL);
gtk_layout_set_size( GTK_LAYOUT(layout), wid, hgt );
return layout;
}
GtkWidget* create_grid(guint rsp, guint csp)
{
GtkWidget* grid = gtk_grid_new();
gtk_grid_set_row_spacing( GTK_GRID(grid), rsp );
gtk_grid_set_column_spacing( GTK_GRID(grid), csp );
return grid;
}
/*
GtkWidget* create_token_button(Token* tkn)
{
char parsed_value[11];
char* string = parse_to_string(tkn -> value, parsed_value);
GtkWidget* button = gtk_button_new_with_label(value);
//gtk_signal_connect(button, "clicked", G_CALLBACK, );
return button;
}
*/
GtkWidget* create_commodity_button(Commodity* com)
{
GtkWidget* button = gtk_button_new_with_label(com -> name);
//gtk_signal_connect(button, "clicked", G_CALLBACK, );
return button;
}
#include "UI.h"
int main(int argc, char* argv[])
{
int i, j;
/* vending machine */
VendingMachine* vending_machine;
/* frames */
GtkWidget* main_frame;
GtkWidget* scrolled_window;
GtkWidget* commodity_box, * commodity_layout, * commodity_grid, * commodity_button;
/* initialize */
gtk_init(&argc, &argv);
make_new_vending_machine_memory(&vending_machine, sizeof(VendingMachine) );
boot_vending_machine(vending_machine, 13, 13);
/* setting main frame */
main_frame = create_main_frame(1000, 750);
/* setting commodty frames and button table */
commodity_box = create_box(GTK_ORIENTATION_HORIZONTAL, 10);
scrolled_window = create_scrolled_window();
commodity_layout = create_layout(500, 700);
commodity_grid = create_grid(10, 10);
for (i = 0; i < 13; i++)
for (j = 0; j < 13; j++) {
commodity_button = create_commodity_button(&vending_machine -> commodity[i][j]);
gtk_grid_attach( GTK_GRID(commodity_grid), commodity_button, i * 300, j * 300, 5, 7 );
}
/* start adding and packing */
gtk_layout_put( GTK_LAYOUT(commodity_layout), commodity_grid, 10, 10 );
gtk_container_add( GTK_CONTAINER(scrolled_window), commodity_layout );
gtk_box_pack_start( GTK_BOX(commodity_box), scrolled_window, TRUE, TRUE, 10 );
gtk_container_add( GTK_CONTAINER(main_frame), commodity_box );
/* show all */
gtk_widget_show_all(main_frame);
gtk_main();
return 0;
}
I'm done writing the basic functions that are needed in my small vending machine project.
Now, I'm trying to make an UI out of the functions with GTK+. And I'm very confused since
this is the first time I'm actually using GTK.
I want a grid of commodity buttons that should be displayed on the left side, but I got
pretty much stuck on this part. What I'm trying to do is, since I "malloc"ed the commodities
for the purpose of adding and remove comms, I want a scroll bar attached to the comm window.
what I did as you can see in the source code
I made a grid of comm buttons and added on a layout widget.
I added the layout on a scrollbar widget
I added that scrollbar on a box and packed it.
I added that box to the main window.
the result is well "not satisfing"
I'm struggling through the GNOME official APIs
can somebody help me with this??
If you don't see how to create your user interface, give Glade a try. You'll be able to quickly try and see how the widgets fit together.

How do I make a gtkwindow background transparent on Linux?

I would like to make the background transparent, and only the widgets are visible.
Here is my code:
#include <gtk/gtk.h>
int main (int argc, char *argv[])
{
gtk_init (&argc, &argv);
GtkWidget *window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
// Title
gtk_window_set_title(GTK_WINDOW (window), "Transparency");
//gtk_window_set_opacity(GTK_WINDOW(window), 0.5);
// CSS
GtkCssProvider *provider = gtk_css_provider_new();
GdkDisplay *display = gdk_display_get_default();
GdkScreen *screen = gdk_display_get_default_screen(display);
gtk_style_context_add_provider_for_screen(screen, GTK_STYLE_PROVIDER (provider), GTK_STYLE_PROVIDER_PRIORITY_USER);
gtk_css_provider_load_from_data(GTK_CSS_PROVIDER (provider),
"GtkWindow {\n"
" background-color: rgba(0,0,0,0);\n"
"}\n",
-1, NULL);
g_object_unref (provider);
// Window
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_window_resize(GTK_WINDOW(window), 400, 300);
gtk_widget_show_all(window);
gtk_main();
return 0;
}
I use gtk3. When the program execute, it just shows black. The CSS (or rgba) function does not work.
I try to use gtk_window_set_opacity(), but it also just shows black.
How do I fix my code?
I followed the link suggested by the comment, but unfortunately it was written for Gtk 2. I have re-worked it for Gtk 3. (I am using Gtk 3.8, but as far as I know it does not use anything deprecated in Gtk 3.10). The program produces a green semi-transparent square with button in it. Of course, you could make the square completely transparent by changing the last argument for the function cairo_set_source_rgba to 0.
Note: I compiled this with the following command (assuming you call the file transparent.c):
gcc -o transparent transparent.c `pkg-config gtk+-3.0 --libs --cflags`
Here is the code:
Version for C
/**
* Original code by: Mike - http://plan99.net/~mike/blog (now a dead link--unable to find it).
* Modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtk 3 by Louis Melahn, L.C., January 30, 2014.
*/
#include <gtk/gtk.h>
static void screen_changed(GtkWidget *widget, GdkScreen *old_screen, gpointer user_data);
static gboolean draw(GtkWidget *widget, cairo_t *new_cr, gpointer user_data);
static void clicked(GtkWindow *win, GdkEventButton *event, gpointer user_data);
int main(int argc, char **argv)
{
gtk_init(&argc, &argv);
GtkWidget *window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_window_set_default_size(GTK_WINDOW(window), 400, 400);
gtk_window_set_title(GTK_WINDOW(window), "Alpha Demo");
g_signal_connect(G_OBJECT(window), "delete-event", gtk_main_quit, NULL);
gtk_widget_set_app_paintable(window, TRUE);
g_signal_connect(G_OBJECT(window), "draw", G_CALLBACK(draw), NULL);
g_signal_connect(G_OBJECT(window), "screen-changed", G_CALLBACK(screen_changed), NULL);
gtk_window_set_decorated(GTK_WINDOW(window), FALSE);
gtk_widget_add_events(window, GDK_BUTTON_PRESS_MASK);
g_signal_connect(G_OBJECT(window), "button-press-event", G_CALLBACK(clicked), NULL);
GtkWidget* fixed_container = gtk_fixed_new();
gtk_container_add(GTK_CONTAINER(window), fixed_container);
GtkWidget* button = gtk_button_new_with_label("button1");
gtk_widget_set_size_request(button, 100, 100);
gtk_container_add(GTK_CONTAINER(fixed_container), button);
screen_changed(window, NULL, NULL);
gtk_widget_show_all(window);
gtk_main();
return 0;
}
gboolean supports_alpha = FALSE;
static void screen_changed(GtkWidget *widget, GdkScreen *old_screen, gpointer userdata)
{
/* To check if the display supports alpha channels, get the visual */
GdkScreen *screen = gtk_widget_get_screen(widget);
GdkVisual *visual = gdk_screen_get_rgba_visual(screen);
if (!visual)
{
printf("Your screen does not support alpha channels!\n");
visual = gdk_screen_get_system_visual(screen);
supports_alpha = FALSE;
}
else
{
printf("Your screen supports alpha channels!\n");
supports_alpha = TRUE;
}
gtk_widget_set_visual(widget, visual);
}
static gboolean draw(GtkWidget *widget, cairo_t *cr, gpointer userdata)
{
cairo_save (cr);
if (supports_alpha)
{
cairo_set_source_rgba (cr, 0.5, 1.0, 0.50, 0.5); /* transparent */
}
else
{
cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* opaque white */
}
/* draw the background */
cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
cairo_paint (cr);
cairo_restore (cr);
return FALSE;
}
static void clicked(GtkWindow *win, GdkEventButton *event, gpointer user_data)
{
/* toggle window manager frames */
gtk_window_set_decorated(win, !gtk_window_get_decorated(win));
}
Version for C++
I include a very similar program, this time written for gtkmm in C++. It can be compiled with the following command:
g++ -otransparent main.cpp transparent.cpp `pkg-config gtkmm-3.0 --cflags --libs` -std=c++11
Note that I used some of the features in the new C++-11 standard, so you will need a compiler that supports them. (If you don't have one, you just have to replace the auto keyword when it appears with the appropriate type, which you can figure out from the definition of the function.) There are three files: main.cpp, transparent.h, and transparent.cpp.
main.cpp
/**
* main.cpp
*
* Code adapted from 'alphademo.c' by Mike
* (http://plan99.net/~mike/blog--now a dead link--unable to find it.)
* as modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtkmm 3.0 by Louis Melahn, L.C. January 31, 2014.
*/
#include "transparent.h"
#include
int main (int argc, char *argv[])
{
Glib::RefPtr app = Gtk::Application::create(argc, argv, "org.gtkmm.example.transparent");
Transparent transparent;
//Shows the window and returns when it is closed.
return app->run(transparent);
}
transparent.h
/**
* transparent.h
*
* Code adapted from 'alphademo.c' by Mike
* (http://plan99.net/~mike/blog--now a dead link--unable to find it.)
* as modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtkmm 3.0 by Louis Melahn, L.C. January 31, 2014.
*/
#ifndef TRANSPARENT_H_
#define TRANSPARENT_H_
#include <iostream>
#include <gtk/gtk.h>
#include <gtkmm/window.h>
#include <gtkmm/button.h>
#include <gtkmm/alignment.h>
class Transparent : public Gtk::Window
{
private:
std::string _buttonLabel;
public:
Transparent();
void set_visual(Glib::RefPtr<Gdk::Visual> visual);
virtual ~Transparent();
protected:
// Signal handlers:
// Note that on_draw is actually overriding a virtual function
// from the Gtk::Window class. I set it as virtual here in case
// someone wants to override it again in a derived class.
void on_button_clicked();
virtual bool on_draw(const ::Cairo::RefPtr< ::Cairo::Context>& cr);
void on_screen_changed(const Glib::RefPtr<Gdk::Screen>& previous_screen);
bool on_window_clicked(GdkEventButton* event);
// Member widgets:
Gtk::Alignment _alignment;
Gtk::Button _button;
bool _SUPPORTS_ALPHA = false;
};
#endif /* TRANSPARENT_H_ */
transparent.cpp
/**
* transparent.cpp
*
* Code adapted from 'alphademo.c' by Mike
* (http://plan99.net/~mike/blog--now a dead link--unable to find it.)
* as modified by karlphillip for StackExchange:
* (https://stackoverflow.com/questions/3908565/how-to-make-gtk-window-background-transparent)
* Re-worked for Gtkmm 3.0 by Louis Melahn, L.C. January 31, 2014.
*/
#include "transparent.h"
Transparent::Transparent() :
_buttonLabel("Button1"),
_alignment(Gtk::ALIGN_START, Gtk::ALIGN_START, 0.0, 0.0), // Aligns the button.
_button(_buttonLabel) // Creates a new button with label '_buttonLabel'.
{
// Set up the top-level window.
set_title("Transparency test");
set_default_size(400,400);
set_decorated(false);
add_events(Gdk::BUTTON_PRESS_MASK);
set_position(Gtk::WIN_POS_CENTER);
set_app_paintable(true);
// Signal handlers
signal_draw().connect(sigc::mem_fun(*this, &Transparent::on_draw));
signal_screen_changed().connect(sigc::mem_fun(*this, &Transparent::on_screen_changed));
signal_button_press_event().connect(sigc::mem_fun(*this, &Transparent::on_window_clicked));
_button.signal_clicked().connect(sigc::mem_fun(*this, &Transparent::on_button_clicked));
// Widgets
on_screen_changed(get_screen());
// This will add the aligner.
add(_alignment);
// Now pack the button into the aligner.
_alignment.add(_button);
// Set up the button
_button.set_size_request(100, 100);
// Show the window and all its children.
show_all();
}
Transparent::~Transparent()
{
}
void Transparent::on_button_clicked()
{
std::cout << "The button '" << _buttonLabel << "' was pressed." << std::endl;
}
bool Transparent::on_draw(const Cairo::RefPtr<Cairo::Context>& cr)
{
cr->save();
if (_SUPPORTS_ALPHA) {
cr->set_source_rgba(0.5, 1.0, 0.5, 0.5); // transparent
} else {
cr->set_source_rgb(0.5, 1.0, 0.5); // opaque
}
cr->set_operator(Cairo::OPERATOR_SOURCE);
cr->paint();
cr->restore();
return Gtk::Window::on_draw(cr);
}
/**
* Checks to see if the display supports alpha channels
*/
void Transparent::on_screen_changed(const Glib::RefPtr<Gdk::Screen>& previous_screen) {
auto screen = get_screen();
auto visual = screen->get_rgba_visual();
if (!visual) {
std::cout << "Your screen does not support alpha channels!" << std::endl;
} else {
std::cout << "Your screen supports alpha channels!" << std::endl;
_SUPPORTS_ALPHA = TRUE;
}
set_visual(visual);
}
/**
* This simply adds a method which seems to be missing in Gtk::Widget,
* so I had to use Gtk+ manually.
*
* Sets the visual for 'this' (the current widget).
*/
void Transparent::set_visual(Glib::RefPtr<Gdk::Visual> visual) {
gtk_widget_set_visual(GTK_WIDGET(gobj()), visual->gobj());
}
/**
* If I click somewhere other than the button, this toggles
* between having window decorations and not having them.
*/
bool Transparent::on_window_clicked(GdkEventButton* event) {
set_decorated(!get_decorated());
return false;
}
Hope this helps!
While struggling with the same issue, I have noticed that if I call gtk_window_set_opacity() on the toplevel window after the show_all function, making the whole window (partial) transparent works for me. Give this a try:
gtk_widget_show_all ( window );
gtk_widget_set_opacity (GTK_WIDGET (window), 0.5);
Does that work for you too?

gtkbin seems to not get event from my gtkwindow toplevel widget

I have some questions, in this moment I try to make a custom widget in gtk with gtkbin so I want to know if it is possible to subclass gtkbin and how to do that...
Thanks for your help.
I have finally managed to implement this myself. Here's how for people who want to derive gtkbin widget.
1) It is important to understand the hierarchy of widgets.
>Hierarchy of widgets:
GtkWidget <- GtkContainer <- GtkBin
If Gtkcontainer and GtkBin don't rewrite a contumize function for GtkWidgetClass->draw, for example, the custom widget class which derives directly from GtkBin will use the default draw function of the GtkWidgetClass.
2) Info about gtkbin:
Download the source code of gtk and open gtkwidget.c, gtkcontainer.c, gtkwindow.c and look at the class_init function in all this files.
In the GtkWidgetClass:
1) We have to see that, widget class doesn't implement the "draw" function:
GtkWidgetClass->draw
2) We have to see that, the implementation of GtkWidgetClass->get_preferred_width and GtkWidgetClass_preferred_width_height always returns "0" which is not correct.
We also see that GtkWidgetClass->size_allocate only allocates size for the widget you want to derive, it doesn't take in count the children of the customize widget.
You have to rewrite these four functions to everything to work properly.
Since GtkWindow is a widget which derives directly from GtkBin, we can implement our functions by viewing the corresponding implementation in GtkWindow.c file and make some changes.
Here is my implementation:
widget_class->get_preferred_width = item_list_get_preferred_width;
widget_class->get_preferred_height = item_list_get_preferred_height;
widget_class->draw = dsn_itemlist_draw;
widget_class->size_allocate = item_list_size_allocate;
void item_list_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
{
GtkAllocation child_allocation;
GtkWidget *child;
guint border_width;
gtk_widget_set_allocation (widget, allocation);
child = gtk_bin_get_child (GTK_BIN(widget));
if (child && gtk_widget_get_visible (child))
{
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
child_allocation.x = border_width;
child_allocation.y = border_width;
child_allocation.width = MAX (1, allocation->width - border_width * 2);
child_allocation.height = MAX (1, allocation->height - border_width * 2);
gtk_widget_size_allocate (child, &child_allocation);
}
}
gboolean dsn_itemlist_draw( GtkWidget *widget, cairo_t *cr)
{
GtkWidget *child;
GtkBin *bin = GTK_BIN(widget);
GtkContainer *container = GTK_CONTAINER(widget);
child = gtk_bin_get_child(bin);
gtk_container_propagate_draw(container, child, cr);
printf("bonnnnnnn\n");
return TRUE;
}
void item_list_get_preferred_width(GtkWidget *widget,
gint *minimum_size,
gint *natural_size)
{
//GtkWindow *window;
GtkWidget *child;
guint border_width;
//window = GTK_WINDOW (widget);
child = gtk_bin_get_child (GTK_BIN (widget)/*(window)*/);
border_width = 0;//gtk_container_get_border_width (GTK_CONTAINER (window));
*minimum_size = border_width * 2;
*natural_size = border_width * 2;
if (child && gtk_widget_get_visible (child))
{
gint child_min, child_nat;
gtk_widget_get_preferred_width (child, &child_min, &child_nat);
*minimum_size += child_min;
*natural_size += child_nat;
}
}
void item_list_get_preferred_height(GtkWidget *widget,
gint *minimum_size,
gint *natural_size)
{
//GtkWindow *window;
GtkWidget *child;
guint border_width;
//window = GTK_WINDOW (widget);
child = gtk_bin_get_child (GTK_BIN (widget)/*(window)*/);
border_width = 0;//gtk_container_get_border_width (GTK_CONTAINER (window));
*minimum_size = border_width * 2;
*natural_size = border_width * 2;
if (child && gtk_widget_get_visible (child))
{
gint child_min, child_nat;
gtk_widget_get_preferred_height (child, &child_min, &child_nat);
*minimum_size += child_min;
*natural_size += child_nat;
}
}
Note: In the init function, we have to tell gtk that our widget doesn't own a window (gdkwindow) but that it inherits one from its parent widget by calling
gtk_widget_set_has_window (GTK_WIDGET (this_instance), FALSE);
That concludes...

Gtk, runtime menu

I have runtime-created menu based on words in selected gtkTreeView row.
gboolean
menu_RELEASE(GtkObject *object, GdkEvent *event, gpointer user_data)
{
if (strlen(user_data) > 0)
{
gtk_entry_set_text(GTK_ENTRY(entry1), user_data);
gtk_widget_grab_focus(entry1);
}
else
main_art(get_sifra());
return TRUE;
}
gboolean
treeview1_BUTTONRELEASE(GtkWidget *widget, GdkEventButton *event, gpointer *user_data)
{
if (event->type == GDK_BUTTON_RELEASE && event->button == 3)
{
char *ntext;
treesel = gtk_tree_view_get_selection(GTK_TREE_VIEW(view));
if (gtk_tree_selection_get_selected(treesel, &model ,&iter))
{
gtk_tree_model_get(model, &iter, cNaziv, &ntext, -1);
GtkWidget *menu, *menu_item;
menu = gtk_menu_new();
char *sresult = NULL;
sresult = strtok(ntext, " ");
while(sresult != NULL)
{
if (strlen(sresult)>1)
{
menu_item = gtk_menu_item_new_with_label(sresult);
gtk_menu_shell_append(GTK_MENU_SHELL(menu), menu_item);
g_signal_connect(G_OBJECT(menu_item), "button-release-event", G_CALLBACK(menu_RELEASE), (gpointer)sresult);
}
sresult = strtok(NULL, " ");
}
menu_item = gtk_separator_menu_item_new();
gtk_menu_shell_append(GTK_MENU_SHELL(menu), menu_item);
//
menu_item = gtk_image_menu_item_new_with_label("Uredi...");
gtk_image_menu_item_set_image(GTK_IMAGE_MENU_ITEM(menu_item), GTK_WIDGET(gtk_image_new_from_stock(GTK_STOCK_EDIT, GTK_ICON_SIZE_MENU)));
gtk_menu_shell_append(GTK_MENU_SHELL(menu), menu_item);
g_signal_connect(G_OBJECT(menu_item), "button-release-event", G_CALLBACK(menu_RELEASE), (gpointer)"");
//
gtk_widget_show_all(menu);
gtk_menu_popup(GTK_MENU(menu), NULL, NULL, NULL, NULL, 0, gtk_get_current_event_time());
return TRUE;
}
}
return FALSE;
}
When menu item was released action from "menu_RELEASE" should appear.
But what happened?
Menu don't dissappear, stay's visible and active.
What is wrong with my code?
You're not supposed to connect to mouse-button signals of the items, that's being too low-level. Your handler is "swallowing" the mouse button signal, preventing GTK+ from handling it.
Use the activate signal.