/* Offscreen windows/Rotated button
*
* Offscreen windows can be used to transform parts of a widget
* hierarchy. Note that the rotated button is fully functional.
*/
#include <math.h>
#include <gtk/gtk.h>
#define GTK_TYPE_ROTATED_BIN (gtk_rotated_bin_get_type ())
#define GTK_ROTATED_BIN(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GTK_TYPE_ROTATED_BIN, GtkRotatedBin))
#define GTK_ROTATED_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GTK_TYPE_ROTATED_BIN, GtkRotatedBinClass))
#define GTK_IS_ROTATED_BIN(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GTK_TYPE_ROTATED_BIN))
#define GTK_IS_ROTATED_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GTK_TYPE_ROTATED_BIN))
#define GTK_ROTATED_BIN_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GTK_TYPE_ROTATED_BIN, GtkRotatedBinClass))
typedef struct _GtkRotatedBin GtkRotatedBin;
typedef struct _GtkRotatedBinClass GtkRotatedBinClass;
struct _GtkRotatedBin
{
GtkContainer container;
GtkWidget *child;
GdkWindow *offscreen_window;
gdouble angle;
};
struct _GtkRotatedBinClass
{
GtkContainerClass parent_class;
};
GType gtk_rotated_bin_get_type (void) G_GNUC_CONST;
GtkWidget* gtk_rotated_bin_new (void);
void gtk_rotated_bin_set_angle (GtkRotatedBin *bin,
gdouble angle);
/*** implementation ***/
static void gtk_rotated_bin_realize (GtkWidget *widget);
static void gtk_rotated_bin_unrealize (GtkWidget *widget);
static void gtk_rotated_bin_size_request (GtkWidget *widget,
GtkRequisition *requisition);
static void gtk_rotated_bin_size_allocate (GtkWidget *widget,
GtkAllocation *allocation);
static gboolean gtk_rotated_bin_damage (GtkWidget *widget,
GdkEventExpose *event);
static gboolean gtk_rotated_bin_expose (GtkWidget *widget,
GdkEventExpose *offscreen);
static void gtk_rotated_bin_add (GtkContainer *container,
GtkWidget *child);
static void gtk_rotated_bin_remove (GtkContainer *container,
GtkWidget *widget);
static void gtk_rotated_bin_forall (GtkContainer *container,
gboolean include_internals,
GtkCallback callback,
gpointer callback_data);
static GType gtk_rotated_bin_child_type (GtkContainer *container);
G_DEFINE_TYPE (GtkRotatedBin, gtk_rotated_bin, GTK_TYPE_CONTAINER);
static void
to_child (GtkRotatedBin *bin,
double widget_x,
double widget_y,
double *x_out,
double *y_out)
{
GtkAllocation child_area;
double x, y, xr, yr;
double c, s;
double w, h;
s = sin (bin->angle);
c = cos (bin->angle);
gtk_widget_get_allocation (bin->child, &child_area);
w = c * child_area.width + s * child_area.height;
h = s * child_area.width + c * child_area.height;
x = widget_x;
y = widget_y;
x -= (w - child_area.width) / 2;
y -= (h - child_area.height) / 2;
x -= child_area.width / 2;
y -= child_area.height / 2;
xr = x * c + y * s;
yr = y * c - x * s;
x = xr;
y = yr;
x += child_area.width / 2;
y += child_area.height / 2;
*x_out = x;
*y_out = y;
}
static void
to_parent (GtkRotatedBin *bin,
double offscreen_x,
double offscreen_y,
double *x_out,
double *y_out)
{
GtkAllocation child_area;
double x, y, xr, yr;
double c, s;
double w, h;
s = sin (bin->angle);
c = cos (bin->angle);
gtk_widget_get_allocation (bin->child, &child_area);
w = c * child_area.width + s * child_area.height;
h = s * child_area.width + c * child_area.height;
x = offscreen_x;
y = offscreen_y;
x -= child_area.width / 2;
y -= child_area.height / 2;
xr = x * c - y * s;
yr = x * s + y * c;
x = xr;
y = yr;
x += child_area.width / 2;
y += child_area.height / 2;
x -= (w - child_area.width) / 2;
y -= (h - child_area.height) / 2;
*x_out = x;
*y_out = y;
}
static void
gtk_rotated_bin_class_init (GtkRotatedBinClass *klass)
{
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
widget_class->realize = gtk_rotated_bin_realize;
widget_class->unrealize = gtk_rotated_bin_unrealize;
widget_class->size_request = gtk_rotated_bin_size_request;
widget_class->size_allocate = gtk_rotated_bin_size_allocate;
widget_class->expose_event = gtk_rotated_bin_expose;
g_signal_override_class_closure (g_signal_lookup ("damage-event", GTK_TYPE_WIDGET),
GTK_TYPE_ROTATED_BIN,
g_cclosure_new (G_CALLBACK (gtk_rotated_bin_damage),
NULL, NULL));
container_class->add = gtk_rotated_bin_add;
container_class->remove = gtk_rotated_bin_remove;
container_class->forall = gtk_rotated_bin_forall;
container_class->child_type = gtk_rotated_bin_child_type;
}
static void
gtk_rotated_bin_init (GtkRotatedBin *bin)
{
gtk_widget_set_has_window (GTK_WIDGET (bin), TRUE);
}
GtkWidget *
gtk_rotated_bin_new (void)
{
return g_object_new (GTK_TYPE_ROTATED_BIN, NULL);
}
static GdkWindow *
pick_offscreen_child (GdkWindow *offscreen_window,
double widget_x,
double widget_y,
GtkRotatedBin *bin)
{
GtkAllocation child_area;
double x, y;
if (bin->child && gtk_widget_get_visible (bin->child))
{
to_child (bin, widget_x, widget_y, &x, &y);
gtk_widget_get_allocation (bin->child, &child_area);
if (x >= 0 && x < child_area.width &&
y >= 0 && y < child_area.height)
return bin->offscreen_window;
}
return NULL;
}
static void
offscreen_window_to_parent (GdkWindow *offscreen_window,
double offscreen_x,
double offscreen_y,
double *parent_x,
double *parent_y,
GtkRotatedBin *bin)
{
to_parent (bin, offscreen_x, offscreen_y, parent_x, parent_y);
}
static void
offscreen_window_from_parent (GdkWindow *window,
double parent_x,
double parent_y,
double *offscreen_x,
double *offscreen_y,
GtkRotatedBin *bin)
{
to_child (bin, parent_x, parent_y, offscreen_x, offscreen_y);
}
static void
gtk_rotated_bin_realize (GtkWidget *widget)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (widget);
GdkWindow *gdk_window;
GdkWindowAttr attributes;
gint attributes_mask;
gint border_width;
GtkRequisition child_requisition;
GtkAllocation widget_allocation, bin_child_allocation;
GtkStyle *style;
gtk_widget_set_realized (widget, TRUE);
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
gtk_widget_get_allocation (widget, &widget_allocation);
attributes.x = widget_allocation.x + border_width;
attributes.y = widget_allocation.y + border_width;
attributes.width = widget_allocation.width - 2 * border_width;
attributes.height = widget_allocation.height - 2 * border_width;
attributes.window_type = GDK_WINDOW_CHILD;
attributes.event_mask = gtk_widget_get_events (widget)
| GDK_EXPOSURE_MASK
| GDK_POINTER_MOTION_MASK
| GDK_BUTTON_PRESS_MASK
| GDK_BUTTON_RELEASE_MASK
| GDK_SCROLL_MASK
| GDK_ENTER_NOTIFY_MASK
| GDK_LEAVE_NOTIFY_MASK;
attributes.visual = gtk_widget_get_visual (widget);
attributes.colormap = gtk_widget_get_colormap (widget);
attributes.wclass = GDK_INPUT_OUTPUT;
attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
gdk_window = gdk_window_new (gtk_widget_get_parent_window (widget), &attributes, attributes_mask);
gtk_widget_set_window (widget, gdk_window);
gdk_window_set_user_data (gdk_window, widget);
g_signal_connect (gdk_window, "pick-embedded-child",
G_CALLBACK (pick_offscreen_child), bin);
attributes.window_type = GDK_WINDOW_OFFSCREEN;
child_requisition.width = child_requisition.height = 0;
if (bin->child && gtk_widget_get_visible (bin->child))
{
gtk_widget_get_allocation (bin->child, &bin_child_allocation);
attributes.width = bin_child_allocation.width;
attributes.height = bin_child_allocation.height;
}
bin->offscreen_window = gdk_window_new (gtk_widget_get_root_window (widget),
&attributes, attributes_mask);
gdk_window_set_user_data (bin->offscreen_window, widget);
if (bin->child)
gtk_widget_set_parent_window (bin->child, bin->offscreen_window);
gdk_offscreen_window_set_embedder (bin->offscreen_window, gtk_widget_get_window (widget));
g_signal_connect (bin->offscreen_window, "to-embedder",
G_CALLBACK (offscreen_window_to_parent), bin);
g_signal_connect (bin->offscreen_window, "from-embedder",
G_CALLBACK (offscreen_window_from_parent), bin);
gtk_widget_style_attach (widget);
style = gtk_widget_get_style (widget);
gtk_style_set_background (style, gdk_window, GTK_STATE_NORMAL);
gtk_style_set_background (style, bin->offscreen_window, GTK_STATE_NORMAL);
gdk_window_show (bin->offscreen_window);
}
static void
gtk_rotated_bin_unrealize (GtkWidget *widget)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (widget);
gdk_window_set_user_data (bin->offscreen_window, NULL);
gdk_window_destroy (bin->offscreen_window);
bin->offscreen_window = NULL;
GTK_WIDGET_CLASS (gtk_rotated_bin_parent_class)->unrealize (widget);
}
static GType
gtk_rotated_bin_child_type (GtkContainer *container)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (container);
if (bin->child)
return G_TYPE_NONE;
return GTK_TYPE_WIDGET;
}
static void
gtk_rotated_bin_add (GtkContainer *container,
GtkWidget *widget)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (container);
if (!bin->child)
{
gtk_widget_set_parent_window (widget, bin->offscreen_window);
gtk_widget_set_parent (widget, GTK_WIDGET (bin));
bin->child = widget;
}
else
g_warning ("GtkRotatedBin cannot have more than one child\n");
}
static void
gtk_rotated_bin_remove (GtkContainer *container,
GtkWidget *widget)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (container);
gboolean was_visible;
was_visible = gtk_widget_get_visible (widget);
if (bin->child == widget)
{
gtk_widget_unparent (widget);
bin->child = NULL;
if (was_visible && gtk_widget_get_visible (GTK_WIDGET (container)))
gtk_widget_queue_resize (GTK_WIDGET (container));
}
}
static void
gtk_rotated_bin_forall (GtkContainer *container,
gboolean include_internals,
GtkCallback callback,
gpointer callback_data)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (container);
g_return_if_fail (callback != NULL);
if (bin->child)
(*callback) (bin->child, callback_data);
}
void
gtk_rotated_bin_set_angle (GtkRotatedBin *bin,
gdouble angle)
{
g_return_if_fail (GTK_IS_ROTATED_BIN (bin));
bin->angle = angle;
gtk_widget_queue_resize (GTK_WIDGET (bin));
gdk_window_geometry_changed (bin->offscreen_window);
}
static void
gtk_rotated_bin_size_request (GtkWidget *widget,
GtkRequisition *requisition)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (widget);
GtkRequisition child_requisition;
gint border_width;
double s, c;
double w, h;
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
child_requisition.width = 0;
child_requisition.height = 0;
if (bin->child && gtk_widget_get_visible (bin->child))
gtk_widget_size_request (bin->child, &child_requisition);
s = sin (bin->angle);
c = cos (bin->angle);
w = c * child_requisition.width + s * child_requisition.height;
h = s * child_requisition.width + c * child_requisition.height;
requisition->width = border_width * 2 + w;
requisition->height = border_width * 2 + h;
}
static void
gtk_rotated_bin_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (widget);
gint border_width;
gint w, h;
gdouble s, c;
gtk_widget_set_allocation (widget, allocation);
border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
w = allocation->width - border_width * 2;
h = allocation->height - border_width * 2;
if (gtk_widget_get_realized (widget))
gdk_window_move_resize (gtk_widget_get_window (widget),
allocation->x + border_width,
allocation->y + border_width,
w, h);
if (bin->child && gtk_widget_get_visible (bin->child))
{
GtkRequisition child_requisition;
GtkAllocation child_allocation;
s = sin (bin->angle);
c = cos (bin->angle);
gtk_widget_get_child_requisition (bin->child, &child_requisition);
child_allocation.x = 0;
child_allocation.y = 0;
child_allocation.height = child_requisition.height;
if (c == 0.0)
child_allocation.width = h / s;
else if (s == 0.0)
child_allocation.width = w / c;
else
child_allocation.width = MIN ((w - s * child_allocation.height) / c,
(h - c * child_allocation.height) / s);
if (gtk_widget_get_realized (widget))
gdk_window_move_resize (bin->offscreen_window,
child_allocation.x,
child_allocation.y,
child_allocation.width,
child_allocation.height);
child_allocation.x = child_allocation.y = 0;
gtk_widget_size_allocate (bin->child, &child_allocation);
}
}
static gboolean
gtk_rotated_bin_damage (GtkWidget *widget,
GdkEventExpose *event)
{
gdk_window_invalidate_rect (gtk_widget_get_window (widget), NULL, FALSE);
return TRUE;
}
static gboolean
gtk_rotated_bin_expose (GtkWidget *widget,
GdkEventExpose *event)
{
GtkRotatedBin *bin = GTK_ROTATED_BIN (widget);
gint width, height;
gdouble s, c;
gdouble w, h;
if (gtk_widget_is_drawable (widget))
{
if (event->window == gtk_widget_get_window (widget))
{
GdkPixmap *pixmap;
GtkAllocation child_area;
cairo_t *cr;
if (bin->child && gtk_widget_get_visible (bin->child))
{
pixmap = gdk_offscreen_window_get_pixmap (bin->offscreen_window);
gtk_widget_get_allocation (bin->child, &child_area);
cr = gdk_cairo_create (gtk_widget_get_window (widget));
/* transform */
s = sin (bin->angle);
c = cos (bin->angle);
w = c * child_area.width + s * child_area.height;
h = s * child_area.width + c * child_area.height;
cairo_translate (cr, (w - child_area.width) / 2, (h - child_area.height) / 2);
cairo_translate (cr, child_area.width / 2, child_area.height / 2);
cairo_rotate (cr, bin->angle);
cairo_translate (cr, -child_area.width / 2, -child_area.height / 2);
/* clip */
gdk_pixmap_get_size (pixmap, &width, &height);
cairo_rectangle (cr, 0, 0, width, height);
cairo_clip (cr);
/* paint */
gdk_cairo_set_source_pixmap (cr, pixmap, 0, 0);
cairo_paint (cr);
cairo_destroy (cr);
}
}
else if (event->window == bin->offscreen_window)
{
gtk_paint_flat_box (gtk_widget_get_style (widget), event->window,
GTK_STATE_NORMAL, GTK_SHADOW_NONE,
&event->area, widget, "blah",
0, 0, -1, -1);
if (bin->child)
gtk_container_propagate_expose (GTK_CONTAINER (widget),
bin->child,
event);
}
}
return FALSE;
}
/*** ***/
static void
scale_changed (GtkRange *range,
GtkRotatedBin *bin)
{
gtk_rotated_bin_set_angle (bin, gtk_range_get_value (range));
}
static GtkWidget *window = NULL;
GtkWidget *
do_offscreen_window (GtkWidget *do_widget)
{
if (!window)
{
GtkWidget *bin, *vbox, *scale, *button;
GdkColor black;
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_screen (GTK_WINDOW (window),
gtk_widget_get_screen (do_widget));
gtk_window_set_title (GTK_WINDOW (window), "Rotated widget");
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_widget_destroyed), &window);
gdk_color_parse ("black", &black);
gtk_widget_modify_bg (window, GTK_STATE_NORMAL, &black);
gtk_container_set_border_width (GTK_CONTAINER (window), 10);
vbox = gtk_vbox_new (0, FALSE);
scale = gtk_hscale_new_with_range (0, G_PI/2, 0.01);
gtk_scale_set_draw_value (GTK_SCALE (scale), FALSE);
button = gtk_button_new_with_label ("A Button");
bin = gtk_rotated_bin_new ();
g_signal_connect (scale, "value-changed", G_CALLBACK (scale_changed), bin);
gtk_container_add (GTK_CONTAINER (window), vbox);
gtk_box_pack_start (GTK_BOX (vbox), scale, FALSE, FALSE, 0);
gtk_box_pack_start (GTK_BOX (vbox), bin, TRUE, TRUE, 0);
gtk_container_add (GTK_CONTAINER (bin), button);
}
if (!gtk_widget_get_visible (window))
gtk_widget_show_all (window);
else
{
gtk_widget_destroy (window);
window = NULL;
}
return window;
}