[gtk+] Update some outdated content in the question index
- From: Matthias Clasen <matthiasc src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk+] Update some outdated content in the question index
- Date: Fri, 14 Jan 2011 04:11:03 +0000 (UTC)
commit 04248fbd396527661d1d6f2faa46be65155c4df1
Author: Matthias Clasen <mclasen redhat com>
Date: Thu Jan 13 23:10:25 2011 -0500
Update some outdated content in the question index
Based on a patch by Jasper St. Pierre
https://bugzilla.gnome.org/show_bug.cgi?id=639494
docs/reference/gtk/question_index.sgml | 369 ++++++++++++++------------------
1 files changed, 166 insertions(+), 203 deletions(-)
---
diff --git a/docs/reference/gtk/question_index.sgml b/docs/reference/gtk/question_index.sgml
index 2f3b6d3..f807bdd 100644
--- a/docs/reference/gtk/question_index.sgml
+++ b/docs/reference/gtk/question_index.sgml
@@ -35,8 +35,8 @@ How do I get started with GTK+?
</para></question>
<answer><para>
-The GTK+ <ulink url="http://www.gtk.org";>website</ulink> offers a
-<ulink url="http://www.gtk.org/tutorial";>tutorial</ulink> and a
+The GTK+ <ulink url="http://www.gtk.org";>website</ulink> offers a
+<ulink url="http://www.gtk.org/tutorial";>tutorial</ulink> and a
<ulink url="http://www.gtk.org/faq";>FAQ</ulink>. More documentation ranging
from whitepapers to online books can be found at the
<ulink url="http://library.gnome.org/devel/";>GNOME developer's site</ulink>.
@@ -47,7 +47,7 @@ this reference manual for details.
<qandaentry>
<question><para>
-Where can I get help with GTK+, submit a bug report, or make a feature
+Where can I get help with GTK+, submit a bug report, or make a feature
request?
</para></question>
@@ -102,11 +102,11 @@ state (explained in its documentation).
</para>
<para>
-For strings returned from functions, they will be declared "const" (using
-#G_CONST_RETURN) if they should not be freed. Non-const strings should be
-freed with g_free(). Arrays follow the same rule. (If you find an exception
-to the rules, please report a bug to <ulink
-url="http://bugzilla.gnome.org";>http://bugzilla.gnome.org</ulink>.)
+For strings returned from functions, they will be declared "const" (using
+#G_CONST_RETURN) if they should not be freed. Non-const strings should be
+freed with g_free(). Arrays follow the same rule. If you find an
+undocumented exception to the rules, please report a bug to <ulink
+url="http://bugzilla.gnome.org";>http://bugzilla.gnome.org</ulink>.
</para>
</answer>
@@ -164,8 +164,8 @@ How do I use GTK+ with threads?
<answer>
<para>
-This is covered in the <link linkend="gdk-Threads">GDK threads
-documentation</link>. See also the <link linkend="glib-Threads">GThread</link>
+This is covered in the <link linkend="gdk-Threads">GDK threads
+documentation</link>. See also the <link linkend="glib-Threads">GThread</link>
documentation for portable threading primitives.
</para>
@@ -182,33 +182,37 @@ How do I internationalize a GTK+ program?
<para>
Most people use <ulink url="http://www.gnu.org/software/gettext/";>GNU
gettext</ulink>, already required in order to install GLib. On a UNIX
-or Linux system with gettext installed, type <literal>info gettext</literal>
+or Linux system with gettext installed, type <literal>info gettext</literal>
to read the documentation.
</para>
<para>
-The short checklist on how to use gettext is: call bindtextdomain() so gettext
-can find the files containing your translations, call textdomain() to set the
-default translation domain, call bind_textdomain_codeset() to request that
-all translated strings are returned in UTF-8, then call gettext() to look up
-each string to be translated in the default domain.
+The short checklist on how to use gettext is: call bindtextdomain() so
+gettext can find the files containing your translations, call textdomain()
+to set the default translation domain, call bind_textdomain_codeset() to
+request that all translated strings are returned in UTF-8, then call
+gettext() to look up each string to be translated in the default domain.
+</para>
+<para>
+<filename>gi18n.h</filename> provides the following shorthand macros for
+convenience.
Conventionally, people define macros as follows for convenience:
<informalexample>
<programlisting>
- #define _(x) gettext (x)
- #define N_(x) x
+ #define _(x) gettext (x)
+ #define N_(x) x
+ #define C_(ctx,x) pgettext (ctx, x)
</programlisting>
</informalexample>
-You use N_() (N stands for no-op) to mark a string for translation in a
-context where a function call to gettext() is not allowed, such as in an
-array initializer.
-You eventually have to call gettext() on the string to actually fetch the
-translation. _() both marks the string for translation and actually
+You use N_() (N stands for no-op) to mark a string for translation in
+a location where a function call to gettext() is not allowed, such as
+in an array initializer.
+You eventually have to call gettext() on the string to actually fetch
+the translation. _() both marks the string for translation and actually
translates it.
-</para>
-<para>
-Nowadays, GLib provides the common shorthand macros in the header file
-<filename>gi18n.h</filename>, so you don't have to define them yourself,
-just include that header.
+The C_() macro (C stands for context) adds an additional context to
+the string that is marked for translation, which can help to disambiguate
+short strings that might need different translations in different
+parts of your program.
</para>
<para>
Code using these macros ends up looking like this:
@@ -231,22 +235,22 @@ Code using these macros ends up looking like this:
</informalexample>
</para>
<para>
-Libraries using gettext should use dgettext() instead of gettext(), which
-allows them to specify the translation domain each time they ask for a
-translation. Libraries should also avoid calling textdomain(), since they
-will be specifying the domain instead of using the default. For dgettext()
-the _() macro can be defined as:
+Libraries using gettext should use dgettext() instead of gettext(), which
+allows them to specify the translation domain each time they ask for a
+translation. Libraries should also avoid calling textdomain(), since
+they will be specifying the domain instead of using the default.
+</para>
+<para>
+With the convention that the macro <literal>GETTEXT_PACKAGE</literal> is
+defined to hold your libraries translation domain,
+<filename>gi18n-lib.h</filename> can be included to provide
+the following convenience:
<informalexample>
<programlisting>
- #define _(x) dgettext ("MyDomain", x)
+ #define _(x) dgettext (GETTEXT_PACKAGE, x)
</programlisting>
</informalexample>
</para>
-<para>
-Again, GLib comes with the <filename>gi18n-lib.h</filename>, saving you the
-trouble of defining the macros by hand. The macros in that header expect the
-translation domain to be specified by the %GETTEXT_PACKAGE macro.
-</para>
</answer>
</qandaentry>
@@ -259,9 +263,9 @@ How do I use non-ASCII characters in GTK+ programs ?
<answer>
<para>
-GTK+ uses <ulink url="http://www.unicode.org";>Unicode</ulink> (more exactly
-UTF-8) for all text. UTF-8 encodes each Unicode codepoint as a sequence of
-one to six bytes and has a number of nice properties which make it a good
+GTK+ uses <ulink url="http://www.unicode.org";>Unicode</ulink> (more exactly
+UTF-8) for all text. UTF-8 encodes each Unicode codepoint as a sequence of
+one to six bytes and has a number of nice properties which make it a good
choice for working with Unicode text in C programs:
<itemizedlist>
<listitem><para>
@@ -271,30 +275,30 @@ ASCII characters are encoded by their familiar ASCII codepoints.
ASCII characters never appear as part of any other character.
</para></listitem>
<listitem><para>
-The zero byte doesn't occur as part of a character, so that UTF-8 strings
-can be manipulated with the usual C library functions for handling
+The zero byte doesn't occur as part of a character, so that UTF-8 strings
+can be manipulated with the usual C library functions for handling
zero-terminated strings.
</para></listitem>
</itemizedlist>
-More information about Unicode and UTF-8 can be found in the
-<ulink url="http://www.cl.cam.ac.uk/~mgk25/unicode.html";>UTF-8 and Unicode i
+More information about Unicode and UTF-8 can be found in the
+<ulink url="http://www.cl.cam.ac.uk/~mgk25/unicode.html";>UTF-8 and Unicode
FAQ for Unix/Linux</ulink>.
GLib provides functions for converting strings between UTF-8 and other
encodings, see g_locale_to_utf8() and g_convert().
</para>
<para>
Text coming from external sources (e.g. files or user input), has to be
-converted to UTF-8 before being handed over to GTK+. The following example
-writes the content of a IS0-8859-1 encoded text file to
+converted to UTF-8 before being handed over to GTK+. The following example
+writes the content of a IS0-8859-1 encoded text file to
<literal>stdout</literal>:
<informalexample><programlisting>
gchar *text, *utf8_text;
gsize length;
GError *error = NULL;
-if (g_file_get_contents (filename, &text, &length, NULL))
+if (g_file_get_contents (filename, &text, &length, NULL))
{
- utf8_text = g_convert (text, length, "UTF-8", "ISO-8859-1",
+ utf8_text = g_convert (text, length, "UTF-8", "ISO-8859-1",
NULL, NULL, &error);
if (error != NULL)
{
@@ -304,7 +308,7 @@ if (g_file_get_contents (filename, &text, &length, NULL))
else
g_print (utf8_text);
}
-else
+else
fprintf (stderr, "Unable to read file %s\n", filename);
</programlisting></informalexample>
</para>
@@ -315,36 +319,37 @@ handling non-ASCII content:
<varlistentry><term>direct UTF-8</term>
<listitem><para>
If your editor and compiler are capable of handling UTF-8 encoded sources,
-it is very convenient to simply use UTF-8 for string literals, since it allows
-you to edit the strings in "wysiwyg". Note that choosing this option may
-reduce the portability of your code.
+it is very convenient to simply use UTF-8 for string literals, since it
+allows you to edit the strings in "wysiwyg". Note that choosing this option
+may reduce the portability of your code.
</para></listitem>
</varlistentry>
<varlistentry><term>escaped UTF-8</term>
<listitem><para>
-Even if your toolchain can't handle UTF-8 directly, you can still encode string
-literals in UTF-8 by using octal or hexadecimal escapes like
-<literal>\212</literal> or <literal>\xa8</literal> to
-encode each byte. This is portable, but modifying the escaped strings is not
-very convenient. Be careful when mixing hexadecimal escapes with ordinary text;
+Even if your toolchain can't handle UTF-8 directly, you can still encode
+string literals in UTF-8 by using octal or hexadecimal escapes like
+<literal>\212</literal> or <literal>\xa8</literal> to encode each byte.
+This is portable, but modifying the escaped strings is not very convenient.
+Be careful when mixing hexadecimal escapes with ordinary text;
<literal>"\xa8abcd"</literal> is a string of length 1 !
</para></listitem>
</varlistentry>
<varlistentry><term>runtime conversion</term>
<listitem><para>
-If the string literals can be represented in an encoding which your toolchain
-can handle (e.g. IS0-8859-1), you can write your source files in that encoding
-and use g_convert() to convert the strings to UTF-8 at runtime. Note that this
-has some runtime overhead, so you may want to move the conversion out of inner
-loops.
+If the string literals can be represented in an encoding which your
+toolchain can handle (e.g. IS0-8859-1), you can write your source files
+in that encoding and use g_convert() to convert the strings to UTF-8 at
+runtime. Note that this has some runtime overhead, so you may want to move
+the conversion out of inner loops.
</para></listitem>
</varlistentry>
</variablelist>
-Here is an example showing the three approaches using the copyright sign
-© which has Unicode and ISO-8859-1 codepoint 169 and is represented in
-UTF-8 by the two bytes 194, 169:
+Here is an example showing the three approaches using the copyright sign
+© which has Unicode and ISO-8859-1 codepoint 169 and is represented
+in UTF-8 by the two bytes 194, 169, or <literal>"\302\251"</literal> as
+a string literal:
<informalexample><programlisting>
g_print ("direct UTF-8: ©");
g_print ("escaped UTF-8: \302\251");
@@ -368,9 +373,9 @@ How do I use GTK+ with C++?
<answer>
<para>
-There are two ways to approach this. The GTK+ header files use the subset
-of C that's also valid C++, so you can simply use the normal GTK+ API
-in a C++ program. Alternatively, you can use a "C++ binding"
+There are two ways to approach this. The GTK+ header files use the subset
+of C that's also valid C++, so you can simply use the normal GTK+ API
+in a C++ program. Alternatively, you can use a "C++ binding"
such as <ulink url="http://gtkmm.sourceforge.net/";>gtkmm</ulink>
which provides a native C++ API.
</para>
@@ -380,20 +385,20 @@ connected to signals, not methods. So you will need to use global
functions or "static" class functions for signal connections.
</para>
<para>
-Another common issue when using GTK+ directly is that
-C++ will not implicitly convert an integer to an enumeration.
+Another common issue when using GTK+ directly is that
+C++ will not implicitly convert an integer to an enumeration.
This comes up when using bitfields; in C you can write the following
code:
<informalexample>
<programlisting>
- gdk_window_set_events (gdk_window,
+ gdk_window_set_events (gdk_window,
GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
</programlisting>
</informalexample>
while in C++ you must write:
<informalexample>
<programlisting>
- gdk_window_set_events (gdk_window,
+ gdk_window_set_events (gdk_window,
(GdkEventMask) GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
</programlisting>
</informalexample>
@@ -427,19 +432,19 @@ How do I load an image or animation from a file?
<answer>
<para>
-To load an image file straight into a display widget, use
-gtk_image_new_from_file() <footnote><para> If the file load fails,
-gtk_image_new_from_file() will display no image graphic — to detect
-a failed load yourself, use gdk_pixbuf_new_from_file() directly, then
-gtk_image_new_from_pixbuf().</para></footnote>.
+To load an image file straight into a display widget, use
+gtk_image_new_from_file() <footnote><para> If the file load fails,
+gtk_image_new_from_file() will display no image graphic — to detect
+a failed load yourself, use gdk_pixbuf_new_from_file() directly, then
+gtk_image_new_from_pixbuf().</para></footnote>.
To load an image for another purpose, use gdk_pixbuf_new_from_file(). To i
load an animation, use gdk_pixbuf_animation_new_from_file().
-gdk_pixbuf_animation_new_from_file() can also load non-animated images, so
-use it in combination with gdk_pixbuf_animation_is_static_image() to load a
-file of unknown type.
+gdk_pixbuf_animation_new_from_file() can also load non-animated images, so
+use it in combination with gdk_pixbuf_animation_is_static_image() to load a
+file of unknown type.
</para>
<para>
-To load an image or animation file asynchronously (without blocking), use
+To load an image or animation file asynchronously (without blocking), use
#GdkPixbufLoader.
</para>
</answer>
@@ -453,14 +458,13 @@ How do I draw text ?
<answer>
<para>
-To draw a piece of text, use a Pango layout and gdk_draw_layout(),
-using code like the following:
+To draw a piece of text, use a Pango layout and gdk_draw_layout().
<informalexample>
<programlisting>
layout = gtk_widget_create_pango_layout (widget, text);
fontdesc = pango_font_description_from_string ("Luxi Mono 12");
- pango_layout_set_font_description (layout, fontdesc);
- gdk_draw_layout (..., layout);
+ pango_layout_set_font_description (layout, fontdesc);
+ pango_cairo_show_layout (cr, layout);
pango_font_description_free (fontdesc);
g_object_unref (layout);
</programlisting>
@@ -485,13 +489,13 @@ How do I measure the size of a piece of text ?
<answer>
<para>
-To obtain the size of a piece of text, use a Pango layout and
+To obtain the size of a piece of text, use a Pango layout and
pango_layout_get_pixel_size(), using code like the following:
<informalexample>
<programlisting>
layout = gtk_widget_create_pango_layout (widget, text);
fontdesc = pango_font_description_from_string ("Luxi Mono 12");
- pango_layout_set_font_description (layout, fontdesc);
+ pango_layout_set_font_description (layout, fontdesc);
pango_layout_get_pixel_size (layout, &width, &height);
pango_font_description_free (fontdesc);
g_object_unref (layout);
@@ -510,21 +514,21 @@ section of <ulink url="http://library.gnome.org/devel/pango/stable/";>Pango manua
<qandaentry>
<question>
<para>
-Why are types not registered if I use their <literal>GTK_TYPE_BLAH</literal>
+Why are types not registered if I use their <literal>GTK_TYPE_BLAH</literal>
macro ?
</para>
</question>
<answer>
<para>
-The <literal>GTK_TYPE_BLAH</literal> macros are defined as calls to
+The <literal>GTK_TYPE_BLAH</literal> macros are defined as calls to
<literal>gtk_blah_get_type()</literal>, and the <literal>_get_type()</literal> i
functions are declared as %G_GNUC_CONST which allows the compiler to optimize
the call away if it appears that the value is not being used.
</para>
<para>
-A common workaround for this problem is to store the result in a volatile
+A common workaround for this problem is to store the result in a volatile
variable, which keeps the compiler from optimizing the call away.
<informalexample><programlisting>
volatile GType dummy = GTK_TYPE_BLAH;
@@ -543,7 +547,7 @@ How do I create a transparent toplevel window ?
<answer>
<para>
To make a window transparent, it needs to use a visual which supports that.
-This is done by getting the RGBA colormap of the screen with
+This is done by getting the RGBA colormap of the screen with
gdk_screen_get_rgba_colormap() and setting it on the window. Note that
gdk_screen_get_rgba_colormap() will return %NULL if transparent windows
are not supported on the screen; also note that this may change from
@@ -563,8 +567,8 @@ gdk_draw_rgb_32_image().
</para>
<para>
Note that the presence of an RGBA visual is no guarantee that the
-window will actually appear transparent on screen. On X11, this
-requires a compositing manager to be running. See
+window will actually appear transparent on screen. On X11, this
+requires a compositing manager to be running. See
gtk_widget_is_composited() for a way to find out if the alpha
channel will be respected.
</para>
@@ -583,7 +587,7 @@ channel will be respected.
<answer>
<para>
See <link linkend="TreeWidget">tree widget overview</link> — you
-should use the #GtkTreeView widget. (A list is just a tree with no branches,
+should use the #GtkTreeView widget. (A list is just a tree with no branches,
so the tree widget is used for lists as well).
</para>
</answer>
@@ -600,8 +604,8 @@ See <link linkend="TextWidget">text widget overview</link> — you
should use the #GtkTextView widget.
</para>
<para>
-If you only have a small amount of text, #GtkLabel may also be appropriate
-of course. It can be made selectable with gtk_label_set_selectable(). For a
+If you only have a small amount of text, #GtkLabel may also be appropriate
+of course. It can be made selectable with gtk_label_set_selectable(). For a
single-line text entry, see #GtkEntry.
</para>
</answer>
@@ -615,8 +619,8 @@ single-line text entry, see #GtkEntry.
<answer>
<para>
-#GtkImage can display images in just about any format GTK+ understands.
-You can also use #GtkDrawingArea if you need to do something more complex,
+#GtkImage can display images in just about any format GTK+ understands.
+You can also use #GtkDrawingArea if you need to do something more complex,
such as draw text or graphics over the top of the image.
</para>
</answer>
@@ -648,17 +652,14 @@ How do I change the color of a widget?
</para></question>
<answer><para>
-See gtk_widget_modify_fg(), gtk_widget_modify_bg(), gtk_widget_modify_base(),
-and gtk_widget_modify_text(). See <link linkend="gtk-Resource-Files">GTK+
-resource files</link> for more discussion. You can also change widget color
-by installing a resource file and parsing it with gtk_rc_add_default_file().
-The advantage of a resource file is that users can then override the
-color you've chosen.
+See gtk_widget_override_color() and gtk_widget_override_background_color().
+You can also change the appearance of a widget by installing a
+custom style provider, see gtk_style_context_add_provider().
</para>
-<para>To change the background color for widgets such as #GtkLabel that have
-no background, place them in a #GtkEventBox and set the background of the
-event box.
+<para>To change the background color for widgets such as #GtkLabel that
+have no background, place them in a #GtkEventBox and set the background
+of the event box.
</para></answer>
</qandaentry>
@@ -668,35 +669,38 @@ How do I change the font of a widget?
</para></question>
<answer><para>
-This has several possible answers, depending on what exactly you want to
-achieve. One option is gtk_widget_modify_font(). Note that this function
-can be used to change only the font size, as in the following example:
+This has several possible answers, depending on what exactly you want to
+achieve. One option is gtk_widget_override_font().
<informalexample><programlisting>
PangoFontDesc *font_desc = pango_font_description_new (<!-- -->);
pango_font_description_set_size (font_desc, 40);
- gtk_widget_modify_font (widget, font);
+ gtk_widget_override_font (widget, font);
pango_font_description_free (font_desc);
</programlisting></informalexample>
</para>
<para>
-If you want to make the text of a label larger, you can use
+If you want to make the text of a label larger, you can use
gtk_label_set_markup():
<informalexample><programlisting>
gtk_label_set_markup (label, "<big>big text</big>");
</programlisting></informalexample>
-This is preferred for many apps because it's a relative size to the
-user's chosen font size. See g_markup_escape_text() if you are
+This is preferred for many apps because it's a relative size to the
+user's chosen font size. See g_markup_escape_text() if you are
constructing such strings on the fly.
</para>
<para>
You can also change the font of a widget by putting
<programlisting>
- gtk-font-name = "Sans 30"
+ .my-widget-class {
+ font: Sans 30;
+ }
</programlisting>
-in a resource file and parsing it with gtk_rc_add_default_file().
-The advantage of a resource file is that users can then override the font you
-have chosen. See <link linkend="gtk-Resource-Files">GTK+ resource files</link>
-for more discussion.
+in a CSS file, loading it with gtk_css_provider_load_from_file(), and
+adding the provider with gtk_style_context_add_provider_for_screen().
+To associate this style information with your widget, set a style class
+on its #GtkStyleContext using gtk_style_context_add_class().
+The advantage of this approach is that users can then override the font
+you have chosen. See the #GtkStyleContext documentation for more discussion.
</para>
</answer>
</qandaentry>
@@ -706,8 +710,9 @@ for more discussion.
How do I disable/ghost/desensitize a widget?
</para></question>
-<answer><para> In GTK+ a disabled widget is termed "insensitive." See
-gtk_widget_set_sensitive().
+<answer><para>
+In GTK+ a disabled widget is termed "insensitive."
+See gtk_widget_set_sensitive().
</para></answer>
</qandaentry>
@@ -746,14 +751,14 @@ How do I make a text widget display its complete contents in a specific font?
</para></question>
<answer><para>
-If you use gtk_text_buffer_insert_with_tags() with appropriate tags to select
-the font, the inserted text will have the desired appearance, but text typed
-in by the user before or after the tagged block will appear in the default
-style.
+If you use gtk_text_buffer_insert_with_tags() with appropriate tags to
+select the font, the inserted text will have the desired appearance, but
+text typed in by the user before or after the tagged block will appear in
+the default style.
</para>
<para>
-To ensure that all text has the desired appearance, use gtk_widget_modify_font()
-to change the default font for the widget.
+To ensure that all text has the desired appearance, use
+gtk_widget_override_font() to change the default font for the widget.
</para></answer>
</qandaentry>
@@ -770,17 +775,17 @@ A good way to keep a text buffer scrolled to the end is to place a
<link linkend="GtkTextMark">mark</link> at the end of the buffer, and
give it right gravity. The gravity has the effect that text inserted
at the mark gets inserted <emphasis>before</emphasis>, keeping the mark
-at the end.
+at the end.
</para>
-<para>
+<para>
To ensure that the end of the buffer remains visible, use
gtk_text_view_scroll_to_mark() to scroll to the mark after
inserting new text.
</para>
<para>
-The gtk-demo application contains an example of this technique.
+The gtk-demo application contains an example of this technique.
</para>
</answer>
</qandaentry>
@@ -797,25 +802,10 @@ How do I associate some data with a row in the tree?
<answer>
<para>
-Remember that the #GtkTreeModel columns don't necessarily have to be displayed.
-So you can put non-user-visible data in your model just like any other data,
-and retrieve it with gtk_tree_model_get(). See the
-<link linkend="TreeWidget">tree widget overview</link>.
-</para>
-</answer>
-</qandaentry>
-
-<qandaentry>
-<question><para>
-What's the #GtkTreeView equivalent of gtk_clist_find_row_from_data()?
-</para></question>
-
-<answer>
-<para>
-As there is no separate data column in the #GtkTreeModel, there's no
-built in function to find the iter from data. You can write a custom
-searching function to walk the tree and find the data, or use
-gtk_tree_model_foreach().
+Remember that the #GtkTreeModel columns don't necessarily have to be
+displayed. So you can put non-user-visible data in your model just
+like any other data, and retrieve it with gtk_tree_model_get().
+See the <link linkend="TreeWidget">tree widget overview</link>.
</para>
</answer>
</qandaentry>
@@ -827,9 +817,9 @@ How do I put an image and some text in the same column?
<answer>
<para>
-You can pack more than one #GtkCellRenderer into a single #GtkTreeViewColumn
-using gtk_tree_view_column_pack_start() or gtk_tree_view_column_pack_end().
-So pack both a #GtkCellRendererPixbuf and a #GtkCellRendererText into the
+You can pack more than one #GtkCellRenderer into a single #GtkTreeViewColumn
+using gtk_tree_view_column_pack_start() or gtk_tree_view_column_pack_end().
+So pack both a #GtkCellRendererPixbuf and a #GtkCellRendererText into the
column.
</para>
</answer>
@@ -837,15 +827,15 @@ column.
<qandaentry>
<question><para>
-I can set data easily on my #GtkTreeStore/#GtkListStore models using
+I can set data easily on my #GtkTreeStore/#GtkListStore models using
gtk_list_store_set() and gtk_tree_store_set(), but can't read it back?
</para></question>
<answer>
<para>
Both the #GtkTreeStore and the #GtkListStore implement the #GtkTreeModel
-interface. Consequentially, the can use any function this interface
-implements. The easiest way to read a set of data back is to use
+interface. Consequentially, you can use any function this interface
+implements. The easiest way to read a set of data back is to use
gtk_tree_model_get().
</para>
</answer>
@@ -857,14 +847,14 @@ How do I change the way that numbers are formatted by #GtkTreeView?
</para></question>
<answer><para>
Use gtk_tree_view_insert_column_with_data_func()
-or gtk_tree_view_column_set_cell_data_func() and do the conversion from i
-number to string yourself (with, say, g_strdup_printf()).
+or gtk_tree_view_column_set_cell_data_func() and do the conversion
+from number to string yourself (with, say, g_strdup_printf()).
</para>
<para>
The following example demonstrates this:
<informalexample><programlisting>
-enum
+enum
{
DOUBLE_COLUMN,
N_COLUMNS
@@ -873,11 +863,11 @@ enum
GtkListStore *mycolumns;
GtkTreeView *treeview;
-void
+void
my_cell_double_to_text (GtkTreeViewColumn *tree_column,
- GtkCellRenderer *cell,
+ GtkCellRenderer *cell,
GtkTreeModel *tree_model,
- GtkTreeIter *iter,
+ GtkTreeIter *iter,
gpointer data)
{
GtkCellRendererText *cell_text = (GtkCellRendererText *)cell;
@@ -892,7 +882,7 @@ my_cell_double_to_text (GtkTreeViewColumn *tree_column,
g_free (text);
}
-void
+void
set_up_new_columns (GtkTreeView *myview)
{
GtkCellRendererText *renderer;
@@ -908,7 +898,7 @@ set_up_new_columns (GtkTreeView *myview)
/* Create a new column that has a title ("Example column"),
* uses the above created renderer that will render the double
- * value into text from the associated model's rows.
+ * value into text from the associated model's rows.
*/
column = gtk_tree_view_column_new (<!-- -->);
gtk_tree_view_column_set_title (column, "Example column");
@@ -922,10 +912,10 @@ set_up_new_columns (GtkTreeView *myview)
*/
/* Set up a custom function that will be called when the column content
* is rendered. We use the func_data pointer as an index into our
- * model. This is convenient when using multi column lists.
+ * model. This is convenient when using multi column lists.
*/
gtk_tree_view_column_set_cell_data_func (column, renderer,
- my_cell_double_to_text,
+ my_cell_double_to_text,
(gpointer)DOUBLE_COLUMN, NULL);
}
</programlisting></informalexample>
@@ -953,42 +943,15 @@ How do I use cairo to draw in GTK+ applications ?
</para></question>
<answer><para>
-Use gdk_cairo_create() to obtain a cairo context for drawing
-on a GDK window or pixmap. See <link linkend="gdk-Cairo-Interaction">Cairo
-Interaction</link> for some more useful functions.
-</para></answer>
-</qandaentry>
-
-<qandaentry>
-<question><para>
-I have created a cairo context with gdk_cairo_create(), but when I
-later use it, my drawing does not show up. Why is that ?
-</para></question>
-
-<answer>
-<para>
-All drawing in GTK+ is normally done in an expose handler, and GTK+
-creates a temporary pixmap for double-buffering the drawing. If you
-create a cairo context outside the expose handler, it is backed
-by the GDK window itself, not the double-buffering pixmap. Consequently,
-any drawing you do with that cairo context gets overwritten at the
-end of the expose handler, when the double-buffering pixmap is copied
-back.
+The #GtkWidget::draw signal gets a ready-to-use cairo context
+as parameter that you should use.
</para>
<para>
-Possible solutions to this problem are:
-<itemizedlist>
-<listitem><para>
-Turn off double-buffering, with gtk_widget_set_double_buffered().
-This is not ideal, since it can cause some flickering.
-</para></listitem>
-<listitem><para>
-Create the cairo context inside the expose handler. If you do this,
-gdk_cairo_create() arranges for it to be backed by the double-buffering
-pixmap. This is the preferred solution, and is used throughout GTK+
-itself.
-</para></listitem>
-</itemizedlist>
+All drawing in GTK+ is normally done in a draw handler, and GTK+
+creates a temporary pixmap for double-buffering the drawing.
+It is possible to turn off double-buffering, with
+gtk_widget_set_double_buffered(), but this is not ideal,
+since it can cause some flickering.
</para>
</answer>
</qandaentry>
@@ -996,7 +959,7 @@ itself.
<qandaentry>
<question><para>
Can I improve the performance of my application by using the
-Glitz backend of cairo ?
+Glitz or GL backend of cairo ?
</para></question>
<answer><para>
@@ -1016,7 +979,7 @@ Can I use cairo to draw on a #GdkPixbuf ?
<answer><para>
No, at least not yet. The cairo image surface does not support the
-pixel format used by GdkPixbuf.
+pixel format used by GdkPixbuf.
</para></answer>
</qandaentry>
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