Commit c770fdd0 authored by Matthias Clasen's avatar Matthias Clasen

Move GtkDrawingArea docs inline

Based on a patch by Garrett Regier.

https://bugzilla.gnome.org/show_bug.cgi?id=617315
parent 72161a07
......@@ -17,6 +17,7 @@ gtkcombobox.sgml
gtkcomboboxentry.sgml
gtkcontainer.sgml
gtkdialog.sgml
gtkdrawingarea.sgml
gtkeditable.sgml
gtkentry.sgml
gtkentrybuffer.sgml
......
<!-- ##### SECTION Title ##### -->
GtkDrawingArea
<!-- ##### SECTION Short_Description ##### -->
A widget for custom user interface elements
<!-- ##### SECTION Long_Description ##### -->
<para>
The #GtkDrawingArea widget is used for creating custom user interface
elements. It's essentially a blank widget; you can draw on
<literal>widget-&gt;window</literal>. After creating a drawing area,
the application may want to connect to:
<itemizedlist>
<listitem>
<para>
Mouse and button press signals to respond to input from
the user. (Use gtk_widget_add_events() to enable events
you wish to receive.)
</para>
</listitem>
<listitem>
<para>
The "realize" signal to take any necessary actions
when the widget is instantiated on a particular display.
(Create GDK resources in response to this signal.)
</para>
</listitem>
<listitem>
<para>
The "configure_event" signal to take any necessary actions
when the widget changes size.
</para>
</listitem>
<listitem>
<para>
The "draw" signal to handle redrawing the contents of the
widget.
</para>
</listitem>
</itemizedlist>
</para>
<para>
The following code portion demonstrates using a drawing
area to display a circle in the normal widget foreground
color.
Note that GDK automatically clears the exposed area
to the background color before sending the expose event, and
that drawing is implicitly clipped to the exposed area.
</para>
<example>
<title>Simple <structname>GtkDrawingArea</structname> usage.</title>
<programlisting>
gboolean
draw_callback (GtkWidget *widget, cairo_t *cr, gpointer data)
{
guint width, height;
GdkRGBA color;
width = gtk_widget_get_allocated_width (widget);
height = gtk_widget_get_allocated_height (widget);
cairo_arc (cr,
width / 2.0, height / 2.0,
MIN (width, height) / 2.0,
0, 2 * G_PI);
gtk_style_context_get_color (gtk_widget_get_style_context (widget),
0,
&amp;color);
gdk_cairo_set_source_rgba (cr, &amp;color);
cairo_fill (cr);
return FALSE;
}
/* ... */
GtkWidget *drawing_area = gtk_drawing_area_new (<!-- -->);
gtk_widget_set_size_request (drawing_area, 100, 100);
g_signal_connect (G_OBJECT (drawing_area), "draw",
G_CALLBACK (draw_callback), NULL);
</programlisting>
</example>
<para>
Draw signals are normally delivered when a drawing area first comes
onscreen, or when it's covered by another window and then uncovered.
You can also force a redraw by adding to the "damage region" of the
drawing area's window; use gtk_widget_queue_draw_area() to do this.
You'll then get a draw event for the invalid region.
</para>
<para>
The available routines for drawing are documented on the <link
linkend="gdk3-Cairo-Interaction">GDK Drawing Primitives</link> page
and the cairo documentation.
</para>
<para>
To receive mouse events on a drawing area, you will need to enable
them with gtk_widget_add_events(). To receive keyboard events, you
will need to set the #GTK_CAN_FOCUS flag on the drawing area, and
should probably draw some user-visible indication that the drawing
area is focused. Use the GTK_HAS_FOCUS() macro in your expose event
handler to decide whether to draw the focus indicator. See
gtk_paint_focus() for one way to draw focus.
</para>
<!-- ##### SECTION See_Also ##### -->
<para>
Sometimes #GtkImage is a useful alternative to a drawing area.
You can put a #GdkPixmap in the #GtkImage and draw to the #GdkPixmap,
calling gtk_widget_queue_draw() on the #GtkImage when you want to
refresh to the screen.
</para>
<!-- ##### SECTION Stability_Level ##### -->
<!-- ##### SECTION Image ##### -->
<!-- ##### STRUCT GtkDrawingArea ##### -->
<para>
The #GtkDrawingArea struct contains private data only, and
should be accessed using the functions below.
</para>
<!-- ##### FUNCTION gtk_drawing_area_new ##### -->
<para>
Creates a new drawing area.
</para>
@void:
@Returns: a new #GtkDrawingArea
......@@ -21,7 +21,7 @@
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include "config.h"
......@@ -29,9 +29,109 @@
#include "gtkintl.h"
/**
* SECTION:gtkdrawingarea
* @Short_description: A widget for custom user interface elements
* @Title: GtkDrawingArea
* @See_also: #GtkImage
*
* The #GtkDrawingArea widget is used for creating custom user interface
* elements. It's essentially a blank widget; you can draw on it. After
* creating a drawing area, the application may want to connect to:
*
* <itemizedlist>
* <listitem>
* <para>
* Mouse and button press signals to respond to input from
* the user. (Use gtk_widget_add_events() to enable events
* you wish to receive.)
* </para>
* </listitem>
* <listitem>
* <para>
* The #GtkWidget::realize signal to take any necessary actions
* when the widget is instantiated on a particular display.
* (Create GDK resources in response to this signal.)
* </para>
* </listitem>
* <listitem>
* <para>
* The #GtkWidget::configure-event signal to take any necessary
* actions when the widget changes size.
* </para>
* </listitem>
* <listitem>
* <para>
* The #GtkWidget::draw signal to handle redrawing the
* contents of the widget.
* </para>
* </listitem>
* </itemizedlist>
*
* The following code portion demonstrates using a drawing
* area to display a circle in the normal widget foreground
* color.
*
* Note that GDK automatically clears the exposed area to the
* background color before sending the expose event, and that
* drawing is implicitly clipped to the exposed area.
*
* <example>
* <title>Simple GtkDrawingArea usage</title>
* <programlisting>
* gboolean
* draw_callback (GtkWidget *widget, cairo_t *cr, gpointer data)
* {
* guint width, height;
* GdkRGBA color;
*
* width = gtk_widget_get_allocated_width (widget);
* height = gtk_widget_get_allocated_height (widget);
* cairo_arc (cr,
* width / 2.0, height / 2.0,
* MIN (width, height) / 2.0,
* 0, 2 * G_PI);
*
* gtk_style_context_get_color (gtk_widget_get_style_context (widget),
* 0,
* &amp;color);
* gdk_cairo_set_source_rgba (cr, &amp;color);
*
* cairo_fill (cr);
*
* return FALSE;
* }
* [...]
* GtkWidget &ast;drawing_area = gtk_drawing_area_new (<!-- -->);
* gtk_widget_set_size_request (drawing_area, 100, 100);
* g_signal_connect (G_OBJECT (drawing_area), "draw",
* G_CALLBACK (draw_callback), NULL);
* </programlisting>
* </example>
*
* Draw signals are normally delivered when a drawing area first comes
* onscreen, or when it's covered by another window and then uncovered.
* You can also force an expose event by adding to the "damage region"
* of the drawing area's window; gtk_widget_queue_draw_area() and
* gdk_window_invalidate_rect() are equally good ways to do this.
* You'll then get a draw signal for the invalid region.
*
* The available routines for drawing are documented on the <link
* linkend="gdk3-Cairo-Interaction">GDK Drawing Primitives</link> page
* and the cairo documentation.
*
* To receive mouse events on a drawing area, you will need to enable
* them with gtk_widget_add_events(). To receive keyboard events, you
* will need to set the #GTK_CAN_FOCUS flag on the drawing area, and
* should probably draw some user-visible indication that the drawing
* area is focused. Use the GTK_HAS_FOCUS() macro in your expose event
* handler to decide whether to draw the focus indicator. See
* gtk_paint_focus() for one way to draw focus.
*/
static void gtk_drawing_area_realize (GtkWidget *widget);
static void gtk_drawing_area_size_allocate (GtkWidget *widget,
GtkAllocation *allocation);
GtkAllocation *allocation);
static void gtk_drawing_area_send_configure (GtkDrawingArea *darea);
G_DEFINE_TYPE (GtkDrawingArea, gtk_drawing_area, GTK_TYPE_WIDGET)
......@@ -50,7 +150,13 @@ gtk_drawing_area_init (GtkDrawingArea *darea)
{
}
/**
* gtk_drawing_area_new:
*
* Creates a new drawing area.
*
* Returns: a new #GtkDrawingArea
*/
GtkWidget*
gtk_drawing_area_new (void)
{
......@@ -101,7 +207,7 @@ gtk_drawing_area_realize (GtkWidget *widget)
static void
gtk_drawing_area_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
GtkAllocation *allocation)
{
g_return_if_fail (GTK_IS_DRAWING_AREA (widget));
g_return_if_fail (allocation != NULL);
......@@ -135,7 +241,7 @@ gtk_drawing_area_send_configure (GtkDrawingArea *darea)
event->configure.y = allocation.y;
event->configure.width = allocation.width;
event->configure.height = allocation.height;
gtk_widget_event (widget, event);
gdk_event_free (event);
}
......@@ -68,8 +68,8 @@ struct _GtkDrawingAreaClass
};
GType gtk_drawing_area_get_type (void) G_GNUC_CONST;
GtkWidget* gtk_drawing_area_new (void);
GType gtk_drawing_area_get_type (void) G_GNUC_CONST;
GtkWidget* gtk_drawing_area_new (void);
G_END_DECLS
......
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