Re: Custom GtkHeaderBar

[Takao Fujiwara <tfujiwar redhat com>]

Thanks for the example.
But I'd pull the CSS color of GtkHeaderBar to follow the theme colors instead of the hardcoded draw_box().
As I attached in the previous mail, calling gtk_widget_class_set_css_name(class, "headerbar") can set the themed background-color but the behavior is 
different between GtkBox and inherited GtkBox as my test program.

Fujiwara

On 04/14/17 06:44, cecashon aol com-san wrote:
> Hi Fujiwara,
>
> The GtkBox is going to use the background window for it's color. The box just does the layout. If you create 
> a header bar from a box you will have to
> draw on the background where your header bar is going to be. This can get a little tricky to get the 
> measurements that you need. A simple case
> shouldn't be too difficult though. If you pass the box to the main window "draw" callback you can get 
> something going. You can draw with cairo or get
> your CSS color. I don't have a C# setup to test with so I hope C will do.
>
> By the way, I was just programming something similar looking at cairo meshes. Don't know if you like mesh 
> drawing but there is a little program at the
> following that changes some background windows from the UI.
>
> https://github.com/cecashon/OrderedSetVelociRaptor/blob/master/Misc/cairo_drawings/draw_mesh1.c
>
> Eric
>
> /*
>    gcc -Wall box1.c -o box1 `pkg-config --cflags --libs gtk+-3.0`
>    Tested with GTK3.18 on Ubuntu16.04
> */
> #include<gtk/gtk.h>
>
> static gboolean draw_box(GtkWidget *widget, cairo_t *cr, gpointer data);
>
> int main(int argc, char *argv[])
>   {
>     gtk_init (&argc, &argv);
>
>     GtkWidget *window=gtk_window_new (GTK_WINDOW_TOPLEVEL);
>     gtk_window_set_title(GTK_WINDOW(window), "Title Bar");
>     gtk_window_set_default_size(GTK_WINDOW(window), 200, 200);
>     gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
>     gtk_widget_set_app_paintable(window, TRUE);
>     g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
>
>     GtkWidget *label1=gtk_label_new("Header");
>     GtkWidget *label2=gtk_label_new("Bar");
>
>     GtkWidget *box=gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
>     gtk_container_set_border_width(GTK_CONTAINER(box), 10);
>     gtk_widget_set_hexpand(box, TRUE);
>     gtk_box_pack_start(GTK_BOX(box), label1, TRUE, TRUE, 0);
>     gtk_box_pack_start(GTK_BOX(box), label2, TRUE, TRUE, 0);
>     g_signal_connect(window, "draw", G_CALLBACK(draw_box), box);
>
>     GtkWidget *label3=gtk_label_new("Main");
>     gtk_widget_set_vexpand(label3, TRUE);
>     gtk_widget_set_hexpand(label3, TRUE);
>     GtkWidget *label4=gtk_label_new("Window");
>     gtk_widget_set_vexpand(label4, TRUE);
>     gtk_widget_set_hexpand(label4, TRUE);
>
>     GtkWidget *grid=gtk_grid_new();
>     gtk_grid_attach(GTK_GRID(grid), box, 0, 0, 1, 1);
>     gtk_grid_attach(GTK_GRID(grid), label3, 0, 1, 1, 1);
>     gtk_grid_attach(GTK_GRID(grid), label4, 0, 2, 1, 1);
>
>     gtk_container_add(GTK_CONTAINER(window), grid);
>
>     gtk_widget_show_all(window);
>
>     gtk_main();
>
>     return 0;
>   }
> static gboolean draw_box(GtkWidget *widget, cairo_t *cr, gpointer data)
>   {
>     //Paint the main window.
>     cairo_set_source_rgb(cr, 0.0, 1.0, 0.0);
>     cairo_paint(cr);
>     //Get the dimensions to draw header bar.
>     gint width=gtk_widget_get_allocated_width(GTK_WIDGET(widget));
>     gint height=gtk_widget_get_allocated_height(GTK_WIDGET(data));
>     cairo_set_source_rgb(cr, 1.0, 0.0, 1.0);
>     //Add 20 to height for 2 time contain width.
>     cairo_rectangle(cr, 0.0, 0.0, width, height+20);
>     cairo_fill(cr);
>     return FALSE;
>   }