edn/test_transparence.c

163 lines
5.7 KiB
C

// gcc test_transparence.c -o out `pkg-config --cflags --libs gtk+-3.0` -DUSE_GTK_VERSION_3_0
// gcc test_transparence.c -o out `pkg-config --cflags --libs gtk+-2.0` -DUSE_GTK_VERSION_2_0
// includes system, malloc, EXIT_SUCCESS
#include <stdlib.h>
// includes fopen, fwrite, fseek, ftell
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <assert.h>
#include <gdk/gdkkeysyms.h>
#include <gtk/gtk.h>
#include <cairo.h>
static void screen_changed(GtkWidget *widget, GdkScreen *old_screen, gpointer user_data);
static gboolean expose(GtkWidget *widget, GdkEventExpose *event, gpointer user_data);
static void clicked(GtkWindow *win, GdkEventButton *event, gpointer user_data);
#if USE_GTK_VERSION_3_0
const GdkRGBA color = { 1.0, 1.0, 0.0, 0.0};
#endif
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);
// Remove double-buffering ==> in the current case we can not get the previous display...
gtk_widget_set_double_buffered(window, FALSE);
# if USE_GTK_VERSION_3_0
g_signal_connect(G_OBJECT(window), "draw", G_CALLBACK(expose), NULL);
# elif USE_GTK_VERSION_2_0
g_signal_connect(G_OBJECT(window), "expose-event", G_CALLBACK(expose), NULL);
# endif
g_signal_connect(G_OBJECT(window), "screen-changed", G_CALLBACK(screen_changed), NULL);
# if USE_GTK_VERSION_3_0
GtkStyleContext *context;
GdkRGBA rgba;
context = gtk_widget_get_style_context(window);
gtk_style_context_get_background_color(context, GTK_STATE_FLAG_NORMAL,
&rgba);
gtk_widget_override_background_color(window,
GTK_STATE_FLAG_NORMAL, &rgba);
/*
gtk_widget_override_background_color(window,
GTK_STATE_FLAG_NORMAL,// | GTK_STATE_FLAG_ACTIVE | GTK_STATE_FLAG_PRELIGHT | GTK_STATE_FLAG_SELECTED | GTK_STATE_FLAG_INSENSITIVE | GTK_STATE_FLAG_INCONSISTENT | GTK_STATE_FLAG_FOCUSED,
&color);
gtk_widget_override_color(window,
GTK_STATE_FLAG_NORMAL,// | GTK_STATE_FLAG_ACTIVE | GTK_STATE_FLAG_PRELIGHT | GTK_STATE_FLAG_SELECTED | GTK_STATE_FLAG_INSENSITIVE | GTK_STATE_FLAG_INCONSISTENT | GTK_STATE_FLAG_FOCUSED,
&color);
*/
#endif
//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 colormap */
# ifdef USE_GTK_VERSION_2_0
GdkScreen *screen = gtk_widget_get_screen(widget);
GdkColormap *colormap = gdk_screen_get_rgba_colormap(screen);
if (!colormap)
{
printf("Your screen does not support alpha channels!\n");
colormap = gdk_screen_get_rgb_colormap(screen);
supports_alpha = FALSE;
}
else
{
printf("Your screen supports alpha channels!\n");
supports_alpha = TRUE;
}
gtk_widget_set_colormap(widget, colormap);
#endif
/*
gtk_widget_override_background_color(widget,
GTK_STATE_FLAG_NORMAL,// | GTK_STATE_FLAG_ACTIVE | GTK_STATE_FLAG_PRELIGHT | GTK_STATE_FLAG_SELECTED | GTK_STATE_FLAG_INSENSITIVE | GTK_STATE_FLAG_INCONSISTENT | GTK_STATE_FLAG_FOCUSED,
&color);
gtk_widget_override_color(widget,
GTK_STATE_FLAG_NORMAL,// | GTK_STATE_FLAG_ACTIVE | GTK_STATE_FLAG_PRELIGHT | GTK_STATE_FLAG_SELECTED | GTK_STATE_FLAG_INSENSITIVE | GTK_STATE_FLAG_INCONSISTENT | GTK_STATE_FLAG_FOCUSED,
&color);
*/
}
static gboolean expose(GtkWidget *widget, GdkEventExpose *event, gpointer userdata)
{
//return FALSE;
GdkWindow * m_windows = NULL;
# if USE_GTK_VERSION_3_0
m_windows = gtk_widget_get_window(widget);
# elif USE_GTK_VERSION_2_0
m_windows = widget->window;
# endif
gtk_widget_shape_combine_mask(widget, NULL, 0, 0);
cairo_t *cr = gdk_cairo_create(m_windows);
//if (TRUE == supports_alpha) {
cairo_set_source_rgba (cr, 0.0, 0.0, 1.0, 0.2); // transparent
/*} else {
cairo_set_source_rgb (cr, 1.0, 0.0, 0.0); // opaque white
}*/
/* draw the background */
cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
cairo_paint (cr);
/* draw a circle */
int width, height;
gtk_window_get_size(GTK_WINDOW(widget), &width, &height);
cairo_set_source_rgba(cr, 1, 0.2, 0.2, 0.6);
cairo_arc(cr, width / 2, height / 2, (width < height ? width : height) / 2 - 8 , 0, 2 * 3.14);
cairo_fill(cr);
cairo_stroke(cr);
cairo_destroy(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));
}