Re: "draw" icon with string

[<c buhtz posteo jp>]

Thanks Chris for your example code.

But I am not able to map your C code to Pycairo.
Even the doc of Pycairo is not helpfull. No examples, no class trees.
I still don't know how to draw text to a cairo surface. It is also
unclear to me which surface I should use.


On 2018-09-09 18:22 Chris Moller <moller mollerware com> wrote:
> Here's a sample I came across some time ago.. Basically, you need to
> do all the drawing using cairo primitives.
>
>
> /*
>      Test drawing on a toggle button.
>
>      gcc -Wall cairobutton.c -o cairobutton `pkg-config --cflags
> --libs gtk+-3.0`
>
>      C. Eric Cashon
> */
>
> #include <gtk/gtk.h>
>
> gboolean
> draw_button1 (GtkWidget *widget, cairo_t *cr, gpointer user_data)
> {
>    guint width = gtk_widget_get_allocated_width(GTK_WIDGET(widget));
>    guint height = gtk_widget_get_allocated_height(GTK_WIDGET(widget));
>
>    if (gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(widget))) {
>      cairo_set_source_rgb (cr, 1.0, 0.0, 0.0);
>      cairo_paint (cr);
>    }
>    else {
>      cairo_set_source_rgb (cr, 0.1, 0.1, 0.1);
>      cairo_paint (cr);
>    }
>
>    //Draw rectangle around the button.
>    cairo_set_line_width (cr, 10.0);
>    cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
>    cairo_rectangle (cr, 0, 0, width, height);
>    cairo_stroke (cr);
>
>    //Add the text.
>    cairo_set_source_rgb (cr, 1.0, 1.0, 0.0);
>    cairo_text_extents_t extents;
>    cairo_select_font_face (cr, "Courier", CAIRO_FONT_SLANT_NORMAL,
>                CAIRO_FONT_WEIGHT_BOLD);
>    cairo_set_font_size (cr, 20);
>    cairo_text_extents (cr, "Cairo Toggle!", &extents);
>    cairo_move_to (cr, width/2 - extents.width/2, height/2 + 
> extents.height/2);
>    cairo_show_text (cr, "Cairo Toggle!");
>
>    return TRUE;
> }
>
> 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), 200, 100);
>    gtk_window_set_title (GTK_WINDOW (window), "Toggle Button");
>    g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit),
> NULL);
>
>    GtkWidget *button1 = gtk_toggle_button_new ();
>    gtk_widget_set_app_paintable (button1, TRUE);
>    gtk_widget_set_hexpand (button1, TRUE);
>    gtk_widget_set_vexpand (button1, TRUE);
>    g_signal_connect (button1, "draw", G_CALLBACK (draw_button1),
> NULL);
>
>    GtkWidget *grid = gtk_grid_new ();
>    gtk_container_set_border_width (GTK_CONTAINER (grid), 10);
>    gtk_grid_attach (GTK_GRID (grid), button1, 0, 0, 1, 1);
>
>    gtk_container_add (GTK_CONTAINER (window), grid);
>
>    gtk_widget_show_all (window);
>    gtk_main ();
>    return 0;
> }
>
>
> On 09/09/18 17:14, c.buhtz--- via gtk-app-devel-list wrote:
> > On 2018-09-09 23:01 "c.buhtz--- via gtk-app-devel-list"
> > <gtk-app-devel-list gnome org> wrote:  
> > > It is unclear to me how to create a cairo.Surface instance.
> > > <https://pycairo.readthedocs.io/en/latest/reference/surfaces.html#cairo.Surface>  
> > And I can not see any text/string drawing methods in the surface
> > class. _______________________________________________
> > gtk-app-devel-list mailing list
> > gtk-app-devel-list gnome org
> > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
> >
> >  
>
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