Commit 49621678 authored by Alexander Larsson's avatar Alexander Larsson

gtk-demo: Add test of transparent GdkWindows

This shows a semi-transparent shadow from a GtkOverlay window
parent d978ed85
......@@ -43,6 +43,7 @@ demos = \
textview.c \
textscroll.c \
toolpalette.c \
transparent.c \
tree_store.c \
ui_manager.c
......
/* Transparent
*
* Use transparent background on GdkWindows to create a shadow effect on a GtkOverlay widget.
*/
#include <gtk/gtk.h>
#define SHADOW_OFFSET_X 7
#define SHADOW_OFFSET_Y 7
#define SHADOW_RADIUS 5
static void
draw_shadow_box (cairo_t *cr,
GdkRectangle rect,
double radius,
double transparency)
{
cairo_pattern_t *pattern;
double x0, x1, x2, x3;
double y0, y1, y2, y3;
x0 = rect.x;
x1 = rect.x + radius;
x2 = rect.x + rect.width - radius;
x3 = rect.x + rect.width;
y0 = rect.y;
y1 = rect.y + radius;
y2 = rect.y + rect.height - radius;
y3 = rect.y + rect.height;
/* Fill non-border part */
cairo_set_source_rgba (cr, 0, 0, 0, transparency);
cairo_rectangle (cr,
x1, y1, x2 - x1, y2 - y1);
cairo_fill (cr);
/* Upper border */
pattern = cairo_pattern_create_linear (0, y0, 0, y1);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, 0.0);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, transparency);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x1, y0,
x2 - x1, y1 - y0);
cairo_fill (cr);
/* Bottom border */
pattern = cairo_pattern_create_linear (0, y2, 0, y3);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, transparency);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, 0.0);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x1, y2,
x2 - x1, y3 - y2);
cairo_fill (cr);
/* Left border */
pattern = cairo_pattern_create_linear (x0, 0, x1, 0);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, 0.0);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, transparency);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x0, y1,
x1 - x0, y2 - y1);
cairo_fill (cr);
/* Right border */
pattern = cairo_pattern_create_linear (x2, 0, x3, 0);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, transparency);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, 0.0);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x2, y1,
x3 - x2, y2 - y1);
cairo_fill (cr);
/* NW corner */
pattern = cairo_pattern_create_radial (x1, y1, 0,
x1, y1, radius);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, transparency);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, 0.0);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x0, y0,
x1 - x0, y1 - y0);
cairo_fill (cr);
/* NE corner */
pattern = cairo_pattern_create_radial (x2, y1, 0,
x2, y1, radius);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, transparency);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, 0.0);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x2, y0,
x3 - x2, y1 - y0);
cairo_fill (cr);
/* SW corner */
pattern = cairo_pattern_create_radial (x1, y2, 0,
x1, y2, radius);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, transparency);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, 0.0);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x0, y2,
x1 - x0, y3 - y2);
cairo_fill (cr);
/* SE corner */
pattern = cairo_pattern_create_radial (x2, y2, 0,
x2, y2, radius);
cairo_pattern_add_color_stop_rgba (pattern, 0.0, 0.0, 0, 0, transparency);
cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0, 0, 0.0);
cairo_set_source (cr, pattern);
cairo_pattern_destroy (pattern);
cairo_rectangle (cr,
x2, y2,
x3 - x2, y3 - y2);
cairo_fill (cr);
}
static gboolean
draw_callback (GtkWidget *widget,
cairo_t *cr,
gpointer data)
{
GdkRectangle rect;
gtk_widget_get_allocation (widget, &rect);
rect.x += SHADOW_OFFSET_X;
rect.y += SHADOW_OFFSET_Y;
rect.width -= SHADOW_OFFSET_X;
rect.height -= SHADOW_OFFSET_Y;
draw_shadow_box (cr,
rect, SHADOW_RADIUS, 0.4);
return FALSE;
}
GtkWidget *
do_transparent (GtkWidget *do_widget)
{
static GtkWidget *window = NULL;
if (!window)
{
GtkWidget *view;
GtkWidget *sw;
GtkWidget *overlay;
GtkWidget *align;
GtkWidget *entry;
GdkRGBA transparent = {0.1, 0, 0, 0};
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_screen (GTK_WINDOW (window),
gtk_widget_get_screen (do_widget));
gtk_window_set_default_size (GTK_WINDOW (window),
450, 450);
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_widget_destroyed), &window);
gtk_window_set_title (GTK_WINDOW (window), "Transparent");
gtk_container_set_border_width (GTK_CONTAINER (window), 0);
view = gtk_text_view_new ();
sw = gtk_scrolled_window_new (NULL, NULL);
gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
GTK_POLICY_AUTOMATIC,
GTK_POLICY_AUTOMATIC);
gtk_container_add (GTK_CONTAINER (sw), view);
overlay = gtk_overlay_new ();
gtk_container_add (GTK_CONTAINER (overlay), sw);
gtk_container_add (GTK_CONTAINER (window), overlay);
gtk_widget_override_background_color (overlay, 0, &transparent);
align = gtk_alignment_new (0.0, 0.0, 0.0, 0.0);
gtk_alignment_set_padding (GTK_ALIGNMENT (align),
0, SHADOW_OFFSET_Y, 0, SHADOW_OFFSET_X);
g_signal_connect (align, "draw", G_CALLBACK (draw_callback), NULL);
entry = gtk_entry_new ();
gtk_container_add (GTK_CONTAINER (align), entry);
gtk_overlay_add_overlay (GTK_OVERLAY (overlay), align);
gtk_widget_set_halign (align, GTK_ALIGN_CENTER);
gtk_widget_set_valign (align, GTK_ALIGN_START);
gtk_widget_show_all (overlay);
}
if (!gtk_widget_get_visible (window))
{
gtk_widget_show (window);
}
else
{
gtk_widget_destroy (window);
window = NULL;
}
return window;
}
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