gtk2/gtk/gtkcsscustomgadget.c

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/*
* Copyright © 2015 Red Hat Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Authors: Benjamin Otte <otte@gnome.org>
*/
#include "config.h"
#include "gtkcsscustomgadgetprivate.h"
#include "gtkcssnodeprivate.h"
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/*
* GtkCssCustomGadget is a subclass that lets widgets customize size
* requests, size allocation and drawing of gadgets. The gadget is passed
* to the callbacks as the first argument, and you can use gtk_css_gadget_get_owner()
* to obtain the widget. Note that the widgets style context is not saved,
* so if you want to query style properties or call gtk_render functions which
* take the style context as an argument, you should use
* gtk_style_context_save_to_node to make the gadget's CSS node take effect.
*
* The callbacks are
*
* GtkCssPreferredSizeFunc:
* @gadget: the #GtkCssCustomGadget
* @orientation: whether a width (ie horizontal) or height (ie vertical) is requested
* @for_size: the available size in the opposite direction, or -1
* @minimum: return location for the minimum size
* @natural: return location for the natural size
* @minimum_baseline: (nullable): return location for the baseline at minimum size
* @natural_baseline: (nullable): return location for the baseline at natural size
* @data: data provided when registering the callback
*
* The GtkCssPreferredSizeFunc is called to determine the content size in
* gtk_css_gadget_get_preferred_size(). @for_size is a content size (ie excluding
* CSS padding, border and margin) and the returned @minimum, @natural,
* @minimum_baseline, @natural_baseline should be content sizes excluding CSS
* padding, border and margin as well.
*
* Typically, GtkCssPreferredSizeFunc will query the size of sub-gadgets and
* child widgets that are placed relative to the gadget and determine its own
* needed size from the results. If the gadget has no sub-gadgets or child
* widgets that it needs to place, then a GtkCssPreferredSizeFunc is only
* needed if you want to enforce a minimum size independent of CSS min-width
* and min-height (e.g. if size-related style properties need to be supported
* for compatibility).
*
* GtkCssAllocateFunc:
* @gadget: the #GtkCssCustomGadget
* @allocation: the allocation
* @baseline: the baseline
* @out_clip: (out): return location for the content clip
* @data: data provided when registering the callback
*
* The GtkCssAllocateFunc is called to allocate the gadgets content in
* gtk_css_gadget_allocate(). @allocation and @baseline are content sizes
* (ie excluding CSS padding, border and margin).
*
* Typically, GtkCssAllocateFunc will allocate sub-gadgets and child widgets
* that are placed relative to the gadget, and merge their clips into the
* value returned as @out_clip. For clip handling in the main gadget of
* containers, gtk_container_get_children_clip() can be useful. Gadgets that
* don't have sub-gadgets of child widgets don't need a GtkCssAllocateFunc
* (although it is still required to call gtk_css_gadget_allocate() on them).
*
* Note that @out_clip *must* be set to meaningful values. If in doubt,
* just set it to the allocation.
*
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* GtkCssDrawFunc:
* @gadget: the #GtkCssCustomGadget
* @cr: the cairo context to draw on
* @x: the x origin of the content area
* @y: the y origin of the content area
* @width: the width of the content area
* @height: the height of the content area
* @data: data provided when registering the callback
*
* The GtkCssDrawFunc is called to draw the gadgets content in
* gtk_css_gadget_draw(). It gets passed an untransformed cairo context
* and the coordinates of the area to draw the content in.
*
* Typically, GtkCssDrawFunc will draw sub-gadgets and child widgets
* that are placed relative to the gadget, as well as custom content
* such as icons, checkmarks, arrows or text.
*/
typedef struct _GtkCssCustomGadgetPrivate GtkCssCustomGadgetPrivate;
struct _GtkCssCustomGadgetPrivate {
GtkCssPreferredSizeFunc preferred_size_func;
GtkCssAllocateFunc allocate_func;
GtkCssDrawFunc draw_func;
gpointer data;
GDestroyNotify destroy_func;
};
G_DEFINE_TYPE_WITH_CODE (GtkCssCustomGadget, gtk_css_custom_gadget, GTK_TYPE_CSS_GADGET,
G_ADD_PRIVATE (GtkCssCustomGadget))
static void
gtk_css_custom_gadget_get_preferred_size (GtkCssGadget *gadget,
GtkOrientation orientation,
gint for_size,
gint *minimum,
gint *natural,
gint *minimum_baseline,
gint *natural_baseline)
{
GtkCssCustomGadgetPrivate *priv = gtk_css_custom_gadget_get_instance_private (GTK_CSS_CUSTOM_GADGET (gadget));
if (priv->preferred_size_func)
return priv->preferred_size_func (gadget, orientation, for_size,
minimum, natural,
minimum_baseline, natural_baseline,
priv->data);
else
return GTK_CSS_GADGET_CLASS (gtk_css_custom_gadget_parent_class)->get_preferred_size (gadget, orientation, for_size,
minimum, natural,
minimum_baseline, natural_baseline);
}
static void
gtk_css_custom_gadget_allocate (GtkCssGadget *gadget,
const GtkAllocation *allocation,
int baseline,
GtkAllocation *out_clip)
{
GtkCssCustomGadgetPrivate *priv = gtk_css_custom_gadget_get_instance_private (GTK_CSS_CUSTOM_GADGET (gadget));
if (priv->allocate_func)
return priv->allocate_func (gadget, allocation, baseline, out_clip, priv->data);
else
return GTK_CSS_GADGET_CLASS (gtk_css_custom_gadget_parent_class)->allocate (gadget, allocation, baseline, out_clip);
}
static gboolean
gtk_css_custom_gadget_draw (GtkCssGadget *gadget,
cairo_t *cr,
int x,
int y,
int width,
int height)
{
GtkCssCustomGadgetPrivate *priv = gtk_css_custom_gadget_get_instance_private (GTK_CSS_CUSTOM_GADGET (gadget));
if (priv->draw_func)
return priv->draw_func (gadget, cr, x, y, width, height, priv->data);
else
return GTK_CSS_GADGET_CLASS (gtk_css_custom_gadget_parent_class)->draw (gadget, cr, x, y, width, height);
}
static void
gtk_css_custom_gadget_finalize (GObject *object)
{
GtkCssCustomGadgetPrivate *priv = gtk_css_custom_gadget_get_instance_private (GTK_CSS_CUSTOM_GADGET (object));
if (priv->destroy_func)
priv->destroy_func (priv->data);
G_OBJECT_CLASS (gtk_css_custom_gadget_parent_class)->finalize (object);
}
static void
gtk_css_custom_gadget_class_init (GtkCssCustomGadgetClass *klass)
{
GtkCssGadgetClass *gadget_class = GTK_CSS_GADGET_CLASS (klass);
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = gtk_css_custom_gadget_finalize;
gadget_class->get_preferred_size = gtk_css_custom_gadget_get_preferred_size;
gadget_class->allocate = gtk_css_custom_gadget_allocate;
gadget_class->draw = gtk_css_custom_gadget_draw;
}
static void
gtk_css_custom_gadget_init (GtkCssCustomGadget *custom_gadget)
{
}
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/**
* gtk_css_custom_gadget_new_for_node:
* @node: the #GtkCssNode to use for the gadget
* @owner: the widget that the gadget belongs to
* @preferred_size_func: (nullable): the GtkCssPreferredSizeFunc to use
* @allocate_func: (nullable): the GtkCssAllocateFunc to use
* @draw_func: (nullable): the GtkCssDrawFunc to use
* @data: (nullable): user data to pass to the callbacks
* @destroy_func: (nullable): destroy notify for @data
*
* Creates a #GtkCssCustomGadget for an existing CSS node.
* This function is typically used in the widgets init function
* to create the main gadget for the widgets main CSS node (which
* is obtained with gtk_widget_get_css_node()), as well as other
* permanent sub-gadgets. Sub-gadgets that only exist sometimes
* (e.g. depending on widget properties) should be created and
* destroyed as needed. All gadgets should be destroyed in the
* finalize (or dispose) vfunc.
*
* Returns: (transfer full): the new gadget
*/
GtkCssGadget *
gtk_css_custom_gadget_new_for_node (GtkCssNode *node,
GtkWidget *owner,
GtkCssPreferredSizeFunc preferred_size_func,
GtkCssAllocateFunc allocate_func,
GtkCssDrawFunc draw_func,
gpointer data,
GDestroyNotify destroy_func)
{
GtkCssCustomGadgetPrivate *priv;
GtkCssGadget *result;
result = g_object_new (GTK_TYPE_CSS_CUSTOM_GADGET,
"node", node,
"owner", owner,
NULL);
priv = gtk_css_custom_gadget_get_instance_private (GTK_CSS_CUSTOM_GADGET (result));
priv->preferred_size_func = preferred_size_func;
priv->allocate_func = allocate_func;
priv->draw_func = draw_func;
priv->data = data;
priv->destroy_func = destroy_func;
return result;
}
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/**
* gtk_css_custom_gadget_new:
* @name: the name for the CSS node
* @owner: the widget that the gadget belongs to
* @parent: the gadget that has the parent CSS node
* @next_sibling: the gadget that has the sibling CSS node
* @preferred_size_func: (nullable): the GtkCssPreferredSizeFunc to use
* @allocate_func: (nullable): the GtkCssAllocateFunc to use
* @draw_func: (nullable): the GtkCssDrawFunc to use
* @data: (nullable): user data to pass to the callbacks
* @destroy_func: (nullable): destroy notify for @data
*
* Creates a #GtkCssCustomGadget with a new CSS node which gets
* placed below the @parent's and before the @next_sibling's CSS node.
*
* Returns: (transfer full): the new gadget
*/
GtkCssGadget *
gtk_css_custom_gadget_new (const char *name,
GtkWidget *owner,
GtkCssGadget *parent,
GtkCssGadget *next_sibling,
GtkCssPreferredSizeFunc preferred_size_func,
GtkCssAllocateFunc allocate_func,
GtkCssDrawFunc draw_func,
gpointer data,
GDestroyNotify destroy_func)
{
GtkCssNode *node;
GtkCssGadget *result;
node = gtk_css_node_new ();
gtk_css_node_set_name (node, g_intern_string (name));
if (parent)
gtk_css_node_insert_before (gtk_css_gadget_get_node (parent),
node,
next_sibling ? gtk_css_gadget_get_node (next_sibling) : NULL);
result = gtk_css_custom_gadget_new_for_node (node,
owner,
preferred_size_func,
allocate_func,
draw_func,
data,
destroy_func);
g_object_unref (node);
return result;
}