/**
* adg_gtk_area_get_extents:
* @area: an #AdgGtkArea
*
* Gets the extents of the canvas bound to @area. The returned
* struct is owned by @area and should not modified or freed.
*
* The extents of an #AdgGtkArea instance are the extents of
* its canvas (as returned by adg_entity_get_extents()) with
* the margins added to it and the #AdgGtkArea:render-map
* transformation applied.
*
* If @area does not have any canvas associated to it or the
* canvas is invalid or empty, an undefined #CpmlExtents
* struct will be returned.
*
* The canvas will be updated, meaning adg_entity_arrange()
* is called before the extents computation.
*
* Returns: the extents of the @area canvas or <constant>NULL</constant> on errors.
*
* Since: 1.0
**/
const CpmlExtents *
adg_gtk_area_get_extents(AdgGtkArea *area)
{
g_return_val_if_fail(ADG_GTK_IS_AREA(area), NULL);
return _adg_get_extents(area);
}
/**
* adg_gtk_area_reset:
* @area: an #AdgGtkArea
*
* Forcibly resets the zoom ratio and position of the canvas bound
* to @area. This means the canvas will be scaled and centered on
* the current available space.
**/
void
adg_gtk_area_reset(AdgGtkArea *area)
{
AdgGtkAreaPrivate *data;
GtkWidget *parent;
const CpmlExtents *sheet;
GtkAllocation allocation;
CpmlPair size;
gdouble zoom;
g_return_if_fail(ADG_GTK_IS_AREA(area));
data = adg_gtk_area_get_instance_private(area);
cairo_matrix_init_identity(&data->render_map);
sheet = _adg_get_extents(area);
if (!sheet->is_defined || sheet->size.x <= 0 || sheet->size.y <= 0)
return;
parent = gtk_widget_get_parent((GtkWidget *) area);
gtk_widget_get_allocation(parent, &allocation);
size.x = allocation.width;
size.y = allocation.height;
zoom = MIN(size.x / sheet->size.x, size.y / sheet->size.y);
cairo_matrix_scale(&data->render_map, zoom, zoom);
cairo_matrix_translate(&data->render_map,
(size.x / zoom - sheet->size.x) / 2 - sheet->org.x,
(size.y / zoom - sheet->size.y) / 2 - sheet->org.y);
/* Trigger a resize trying to hide the scrollbars on the parent */
gtk_widget_queue_resize(parent);
}
static void
_adg_size_request(GtkWidget *widget, GtkRequisition *requisition)
{
AdgGtkArea *area = (AdgGtkArea *) widget;
const CpmlExtents *extents = _adg_get_extents(area);
if (extents->is_defined) {
requisition->width = extents->size.x;
requisition->height = extents->size.y;
}
}
static void
_adg_get_preferred_width_for_height(GtkWidget *widget, gint height,
gint *minimum_width, gint *natural_width)
{
AdgGtkArea *area;
const CpmlExtents *extents;
area = (AdgGtkArea *) widget;
extents = _adg_get_extents(area);
if (extents->is_defined && extents->size.y > 0) {
*minimum_width = extents->size.x;
*natural_width = *minimum_width * height / extents->size.y;
}
}
static void
_adg_get_preferred_height_for_width(GtkWidget *widget, gint width,
gint *minimum_height, gint *natural_height)
{
AdgGtkArea *area;
const CpmlExtents *extents;
area = (AdgGtkArea *) widget;
extents = _adg_get_extents(area);
if (extents->is_defined && extents->size.x > 0) {
*minimum_height = extents->size.y;
*natural_height = *minimum_height * width / extents->size.x;
}
}
/**
* _adg_size_allocate:
* @widget: an #AdgGtkArea widget
* @allocation: the new allocation struct
*
* Scales the drawing according to the new allocation if
* #AdgGtkArea:autozoom is <constant>TRUE</constant>.
*
* TODO: the current implementation initially centers the canvas
* on the allocation space. Further allocations (due to a
* window resizing, for example) use the top/left corner of the
* canvas as reference point. Plan different policies for either
* those situations.
*
* Since: 1.0
**/
static void
_adg_size_allocate(GtkWidget *widget, GtkAllocation *allocation)
{
AdgGtkArea *area;
AdgGtkAreaPrivate *data;
const CpmlExtents *sheet;
CpmlVector size;
gdouble factor;
if (_ADG_OLD_WIDGET_CLASS->size_allocate)
_ADG_OLD_WIDGET_CLASS->size_allocate(widget, allocation);
area = (AdgGtkArea *) widget;
data = area->data;
sheet = _adg_get_extents(area);
if (!sheet->is_defined || sheet->size.x <= 0 || sheet->size.y <= 0)
return;
size.x = allocation->width;
size.y = allocation->height;
if (data->autozoom) {
/* Adjust the zoom according to the allocation and sheet size */
factor = MIN(size.x / sheet->size.x, size.y / sheet->size.y);
} else if (!data->initialized) {
/* First allocation with autozoom off: keep the current zoom */
factor = 1;
} else {
/* Not the first allocation and autozoom off: keep the old map */
return;
}
if (!data->initialized) {
/* TODO: plan different attachment policies other than centering */
cairo_matrix_init_translate(&data->render_map,
(size.x - sheet->size.x) / 2 - sheet->org.x,
(size.y - sheet->size.y) / 2 - sheet->org.y);
data->initialized = TRUE;
}
/* TODO: plan other reference points other than left/top (x0, y0) */
data->render_map.x0 *= factor;
data->render_map.y0 *= factor;
data->render_map.xx *= factor;
data->render_map.yy *= factor;
}
static void
_adg_set_map(GtkWidget *widget,
gboolean local_space,
const cairo_matrix_t *map)
{
AdgGtkAreaPrivate *data = adg_gtk_area_get_instance_private((AdgGtkArea *) widget);
AdgEntity *entity = (AdgEntity *) data->canvas;
if (entity == NULL)
return;
if (local_space) {
/* TODO: this forcibly overwrites any local transformation */
adg_entity_set_local_map(entity, map);
} else {
adg_matrix_transform(&data->render_map, map, ADG_TRANSFORM_BEFORE);
}
/* This will emit the extents-changed signal when applicable */
_adg_get_extents((AdgGtkArea *) widget);
}
