~ubuntu-branches/ubuntu/utopic/glib2.0/utopic

<a class="link" href="glib-GVariant.html#GVariant" title="GVariant">GVariant</a> instances can be sent over D-Bus. See <a class="link" href="glib-GVariantType.html#GVariantType" title="GVariantType">GVariantType</a> for

1057

exceptions. (However, <a class="link" href="glib-GVariant.html#GVariant" title="GVariant">GVariant</a>'s serialisation format is not the same

1058

as the serialisation format of a D-Bus message body: use <a href="http://library.gnome.org/devel/gio/unstable/GDBusMessage.html">GDBusMessage</a>,

1058

as the serialisation format of a D-Bus message body: use <a href="../gio/GDBusMessage.html">GDBusMessage</a>,

1059

in the gio library, for those.)

1060

For space-efficiency, the <a class="link" href="glib-GVariant.html#GVariant" title="GVariant">GVariant</a> serialisation format does not

1061

automatically include the variant's type or endianness, which must

1062

either be implied from context (such as knowledge that a particular

1063

file format always contains a little-endian <a class="link" href="glib-GVariantType.html#G-VARIANT-TYPE-VARIANT:CAPS" title="G_VARIANT_TYPE_VARIANT"><code class="literal">G_VARIANT_TYPE_VARIANT</code></a>)

1064

or supplied out-of-band (for instance, a type and/or endianness

1061

automatically include the variant's length, type or endianness,

1062

which must either be implied from context (such as knowledge that a

1063

particular file format always contains a little-endian

1064

<a class="link" href="glib-GVariantType.html#G-VARIANT-TYPE-VARIANT:CAPS" title="G_VARIANT_TYPE_VARIANT"><code class="literal">G_VARIANT_TYPE_VARIANT</code></a> which occupies the whole length of the file)

1065

or supplied out-of-band (for instance, a length, type and/or endianness

1065

1066

indicator could be placed at the beginning of a file, network message

1066

1067

or network stream).

1067

1068

A <a class="link" href="glib-GVariant.html#GVariant" title="GVariant">GVariant</a>'s size is limited mainly by any lower level operating

1089

1090

<a name="id-1.6.19.6.13"></a><h4>Serialised Data Memory</h4>

1090

1091

This is the memory that is used for storing GVariant data in

1091

1092

serialised form. This is what would be sent over the network or

1092

what would end up on disk.

1093

what would end up on disk, not counting any indicator of the

1094

endianness, or of the length or type of the top-level variant.

1093

1095

The amount of memory required to store a boolean is 1 byte. 16,

1094

1096

32 and 64 bit integers and double precision floating point numbers

1095

1097

use their "natural" size. Strings (including object path and

1656

1658

check fails then a <a class="link" href="glib-Message-Logging.html#g-critical" title="g_critical()"><code class="function">g_critical()</code></a> is printed and <a class="link" href="glib-Standard-Macros.html#FALSE:CAPS" title="FALSE"><code class="literal">FALSE</code></a> is returned.

1657

1659

This function is meant to be used by functions that wish to provide

1658

1660

varargs accessors to <a class="link" href="glib-GVariant.html#GVariant" title="GVariant">GVariant</a> values of uncertain values (eg:

1659

<a class="link" href="glib-GVariant.html#g-variant-lookup" title="g_variant_lookup ()"><code class="function">g_variant_lookup()</code></a> or <a href="http://library.gnome.org/devel/gio/unstable/GMenuModel.html#g-menu-model-get-item-attribute"><code class="function">g_menu_model_get_item_attribute()</code></a>).

1661

<a class="link" href="glib-GVariant.html#g-variant-lookup" title="g_variant_lookup ()"><code class="function">g_variant_lookup()</code></a> or <a href="../gio/GMenuModel.html#g-menu-model-get-item-attribute"><code class="function">g_menu_model_get_item_attribute()</code></a>).

1660

1662

1661

1663

<a name="id-1.6.19.7.13.7"></a><h4>Parameters</h4>

1662

1664

1847

1849

1848

1850

1849

1851

8</pre></td>

1850

<td class="listing_code"><pre class="programlisting">MyFlags some_flags = FLAG_ONE | FLAG_TWO;

1851

const gchar *some_strings[] = { "a", "b", "c", <a href="glib-Standard-Macros.html#NULL:CAPS">NULL</a> };

1852

GVariant *new_variant;

1852

<td class="listing_code"><pre class="programlisting">MyFlags some_flags = FLAG_ONE | FLAG_TWO;

1853

const gchar *some_strings[] = { "a", "b", "c", NULL };

1854

GVariant *new_variant;

1853

1855

1854

new_variant = <a href="glib-GVariant.html#g-variant-new">g_variant_new</a> ("(t^as)",

1855

/* This cast is required. */

1856

(<a href="glib-Basic-Types.html#guint64">guint64</a>) some_flags,

1857

some_strings);</pre></td>

1856

new_variant = <a href="glib-GVariant.html#g-variant-new">g_variant_new</a> ("(t^as)",

1857

/* This cast is required. */

1858

(guint64) some_flags,

1859

some_strings);</pre></td>

1858

1860

</tr>

1859

1861

</tbody>

1860

1862

</table>

4911

4913

4912

4914

4913

4915

18</pre></td>

4914

<td class="listing_code"><pre class="programlisting">// recursively iterate a container

4915

void

4916

iterate_container_recursive (GVariant *container)

4917

{

4918

GVariantIter iter;

4919

GVariant *child;

4920

4921

<a href="glib-GVariant.html#g-variant-iter-init">g_variant_iter_init</a> (&iter, container);

4922

while ((child = <a href="glib-GVariant.html#g-variant-iter-next-value">g_variant_iter_next_value</a> (&iter)))

4923

{

4924

<a href="glib-Warnings-and-Assertions.html#g-print">g_print</a> ("type '%s'\n", <a href="glib-GVariant.html#g-variant-get-type-string">g_variant_get_type_string</a> (child));

4925

4926

4927

iterate_container_recursive (child);

4928

4929

<a href="glib-GVariant.html#g-variant-unref">g_variant_unref</a> (child);

4930

}

4931

}</pre></td>

4916

<td class="listing_code"><pre class="programlisting">// recursively iterate a container

4917

void

4918

iterate_container_recursive (GVariant *container)

4919

{

4920

GVariantIter iter;

4921

GVariant *child;

4922

4923

<a href="glib-GVariant.html#g-variant-iter-init">g_variant_iter_init</a> (&iter, container);

4924

while ((child = <a href="glib-GVariant.html#g-variant-iter-next-value">g_variant_iter_next_value</a> (&iter)))

4925

{

4926

<a href="glib-Warnings-and-Assertions.html#g-print">g_print</a> ("type '%s'\n", <a href="glib-GVariant.html#g-variant-get-type-string">g_variant_get_type_string</a> (child));

4927

4928

if (<a href="glib-GVariant.html#g-variant-is-container">g_variant_is_container</a> (child))

4929

iterate_container_recursive (child);

4930

4931

<a href="glib-GVariant.html#g-variant-unref">g_variant_unref</a> (child);

4932

}

4933

}</pre></td>

4932

4934

</tr>

4933

4935

</tbody>

4934

4936

</table>

4996

4998

4997

4999

4998

5000

19</pre></td>

4999

<td class="listing_code"><pre class="programlisting">// Iterates a dictionary of type 'a{sv}'

5000

void

5001

iterate_dictionary (GVariant *dictionary)

5002

{

5003

GVariantIter iter;

5004

GVariant *value;

5005

gchar *key;

5006

5007

5008

while (<a href="glib-GVariant.html#g-variant-iter-next">g_variant_iter_next</a> (&iter, "{sv}", &key, &value))

5009

{

5010

5011

<a href="glib-GVariant.html#g-variant-get-type-string">g_variant_get_type_string</a> (value));

5012

5013

// must free data for ourselves

5014

5015

<a href="glib-Memory-Allocation.html#g-free">g_free</a> (key);

5016

}

5017

}</pre></td>

5001

<td class="listing_code"><pre class="programlisting">// Iterates a dictionary of type 'a{sv}'

5002

void

5003

iterate_dictionary (GVariant *dictionary)

5004

{

5005

GVariantIter iter;

5006

GVariant *value;

5007

gchar *key;

5008

5009

5010

while (<a href="glib-GVariant.html#g-variant-iter-next">g_variant_iter_next</a> (&iter, "{sv}", &key, &value))

5011

{

5012

<a href="glib-Warnings-and-Assertions.html#g-print">g_print</a> ("Item '%s' has type '%s'\n", key,

5013

<a href="glib-GVariant.html#g-variant-get-type-string">g_variant_get_type_string</a> (value));

5014

5015

// must free data for ourselves

5016

<a href="glib-GVariant.html#g-variant-unref">g_variant_unref</a> (value);

5017

<a href="glib-Memory-Allocation.html#g-free">g_free</a> (key);

5018

}

5019

}</pre></td>

5018

5020

</tr>

5019

5021

</tbody>

5020

5022

</table>

5112

5114

5113

5115

5114

5116

18</pre></td>

5115

<td class="listing_code"><pre class="programlisting">// Iterates a dictionary of type 'a{sv}'

5116

void

5117

5118

{

5119

GVariantIter iter;

5120

GVariant *value;

5121

gchar *key;

5122

5123

5124

while (<a href="glib-GVariant.html#g-variant-iter-loop">g_variant_iter_loop</a> (&iter, "{sv}", &key, &value))

5125

{

5126

5127

5128

5129

// no need to free 'key' and 'value' here

5130

// unless breaking out of this loop

5131

}

5132

}</pre></td>

5117

<td class="listing_code"><pre class="programlisting">// Iterates a dictionary of type 'a{sv}'

5118

void

5119

iterate_dictionary (GVariant *dictionary)

5120

{

5121

GVariantIter iter;

5122

GVariant *value;

5123

gchar *key;

5124

5125

5126

while (<a href="glib-GVariant.html#g-variant-iter-loop">g_variant_iter_loop</a> (&iter, "{sv}", &key, &value))

5127

{

5128

5129

<a href="glib-GVariant.html#g-variant-get-type-string">g_variant_get_type_string</a> (value));

5130

5131

// no need to free 'key' and 'value' here

5132

// unless breaking out of this loop

5133

}

5134

}</pre></td>

5133

5135

</tr>

5134

5136

</tbody>

5135

5137

</table>

5447

5449

5448

5450

5449

5451

17</pre></td>

5450

<td class="listing_code"><pre class="programlisting"><a href="glib-GVariant.html#GVariant">GVariant</a> *

5451

make_pointless_dictionary (void)

5452

{

5453

GVariantBuilder builder;

5454

int i;

5455

5456

<a href="glib-GVariant.html#g-variant-builder-init">g_variant_builder_init</a> (&builder, <a href="glib-GVariantType.html#G-VARIANT-TYPE-ARRAY:CAPS">G_VARIANT_TYPE_ARRAY</a>);

5457

for (i = 0; i < 16; i++)

5458

{

5459

gchar buf[3];

5460

5461

sprintf (buf, "%d", i);

5462

<a href="glib-GVariant.html#g-variant-builder-add">g_variant_builder_add</a> (&builder, "{is}", i, buf);

5463

}

5464

5465

return <a href="glib-GVariant.html#g-variant-builder-end">g_variant_builder_end</a> (&builder);

5466

}</pre></td>

5452

<td class="listing_code"><pre class="programlisting">GVariant *

5453

make_pointless_dictionary (void)

5454

{

5455

GVariantBuilder builder;

5456

int i;

5457

5458

<a href="glib-GVariant.html#g-variant-builder-init">g_variant_builder_init</a> (&builder, G_VARIANT_TYPE_ARRAY);

5459

for (i = 0; i < 16; i++)

5460

{

5461

gchar buf[3];

5462

5463

sprintf (buf, "%d", i);

5464

<a href="glib-GVariant.html#g-variant-builder-add">g_variant_builder_add</a> (&builder, "{is}", i, buf);

5465

}

5466

5467

return <a href="glib-GVariant.html#g-variant-builder-end">g_variant_builder_end</a> (&builder);

5468

}</pre></td>

5467

5469

</tr>

5468

5470

</tbody>

5469

5471

</table>

5532

5534

5533

5535

5534

5536

12</pre></td>

5535

<td class="listing_code"><pre class="programlisting"><a href="glib-GVariant.html#GVariant">GVariant</a> *

5536

make_pointless_dictionary (void)

5537

{

5538

GVariantBuilder builder;

5539

int i;

5537

<td class="listing_code"><pre class="programlisting">GVariant *

5538

make_pointless_dictionary (void)

5539

{

5540

GVariantBuilder builder;

5541

int i;

5540

5542

5541

5542

<a href="glib-GVariant.html#g-variant-builder-add-parsed">g_variant_builder_add_parsed</a> (&builder, "{'width', <%i>}", 600);

5543

<a href="glib-GVariant.html#g-variant-builder-add-parsed">g_variant_builder_add_parsed</a> (&builder, "{'title', <%s>}", "foo");

5544

<a href="glib-GVariant.html#g-variant-builder-add-parsed">g_variant_builder_add_parsed</a> (&builder, "{'transparency', <0.5>}");

5545

5546

}</pre></td>

5543

5544

<a href="glib-GVariant.html#g-variant-builder-add-parsed">g_variant_builder_add_parsed</a> (&builder, "{'width', <%i>}", 600);

5545

<a href="glib-GVariant.html#g-variant-builder-add-parsed">g_variant_builder_add_parsed</a> (&builder, "{'title', <%s>}", "foo");

5546

<a href="glib-GVariant.html#g-variant-builder-add-parsed">g_variant_builder_add_parsed</a> (&builder, "{'transparency', <0.5>}");

5547

5548

}</pre></td>

5547

5549

</tr>

5548

5550

</tbody>

5549

5551

</table>

6340

6342

<tbody>

6341

6343

<tr>

6342

6344

6343

<td class="listing_code"><pre class="programlisting"><a href="glib-GVariant.html#g-variant-new-parsed">g_variant_new_parsed</a> ("[('one', 1), ('two', %i), (%s, 3)]", 2, "three");</pre></td>

6345

<td class="listing_code"><pre class="programlisting"><a href="glib-GVariant.html#g-variant-new-parsed">g_variant_new_parsed</a> ("[('one', 1), ('two', %i), (%s, 3)]", 2, "three");</pre></td>

6344

6346

</tr>

6345

6347

</tbody>

6346

6348

</table>

6355

6357

<tbody>

6356

6358

<tr>

6357

6359

6358

<td class="listing_code"><pre class="programlisting">[('one', 1), ('two', 2), ('three', 3)]</pre></td>

6360

<td class="listing_code"><pre class="programlisting">[('one', 1), ('two', 2), ('three', 3)]</pre></td>

6359

6361

</tr>

6360

6362

</tbody>

6361

6363

</table>

6418

6420

<td class="listing_lines" align="right"><pre>1

6419

6421

6420

6422

3</pre></td>

6421

<td class="listing_code"><pre class="programlisting">unterminated string constant:

6422

(1, 2, 3, 'abc

6423

<td class="listing_code"><pre class="programlisting">unterminated string constant:

6424

(1, 2, 3, 'abc

6423

6425

^^^^</pre></td>

6424

6426

</tr>

6425

6427

</tbody>

6435

6437

<td class="listing_lines" align="right"><pre>1

6436

6438

6437

6439

3</pre></td>

6438

<td class="listing_code"><pre class="programlisting">unable to find a common type:

6439

[1, 2, 3, 'str']

6440

^ ^^^^^</pre></td>

6440

<td class="listing_code"><pre class="programlisting">unable to find a common type:

6441

[1, 2, 3, 'str']

6442

^ ^^^^^</pre></td>

6441

6443

</tr>

6442

6444

</tbody>

6443

6445

</table>

6718

6720

6719

6721

6720

6722

19</pre></td>

6721

<td class="listing_code"><pre class="programlisting"><a href="glib-GVariant.html#GVariant">GVariant</a> *

6722

add_to_count (GVariant *orig,

6723

GError **error)

6724

{

6725

GVariantDict dict;

6726

guint32 count;

6727

6728

<a href="glib-GVariant.html#g-variant-dict-init">g_variant_dict_init</a> (&dict, orig);

6729

if (!<a href="glib-GVariant.html#g-variant-dict-lookup">g_variant_dict_lookup</a> (&dict, "count", "u", &count))

6730

{

6731

<a href="glib-Error-Reporting.html#g-set-error">g_set_error</a> (...);

6732

<a href="glib-GVariant.html#g-variant-dict-clear">g_variant_dict_clear</a> (&dict);

6733

return <a href="glib-Standard-Macros.html#NULL:CAPS">NULL</a>;

6734

}

6735

6736

<a href="glib-GVariant.html#g-variant-dict-insert">g_variant_dict_insert</a> (&dict, "count", "u", count + 1);

6737

6738

return <a href="glib-GVariant.html#g-variant-dict-end">g_variant_dict_end</a> (&dict);

6739

}</pre></td>

6723

<td class="listing_code"><pre class="programlisting">GVariant *

6724

add_to_count (GVariant *orig,

6725

GError **error)

6726

{

6727

GVariantDict dict;

6728

guint32 count;

6729

6730

<a href="glib-GVariant.html#g-variant-dict-init">g_variant_dict_init</a> (&dict, orig);

6731

if (!<a href="glib-GVariant.html#g-variant-dict-lookup">g_variant_dict_lookup</a> (&dict, "count", "u", &count))

6732

{

6733

<a href="glib-Error-Reporting.html#g-set-error">g_set_error</a> (...);

6734

<a href="glib-GVariant.html#g-variant-dict-clear">g_variant_dict_clear</a> (&dict);

6735

return NULL;

6736

}

6737

6738

<a href="glib-GVariant.html#g-variant-dict-insert">g_variant_dict_insert</a> (&dict, "count", "u", count + 1);

6739

6740

return <a href="glib-GVariant.html#g-variant-dict-end">g_variant_dict_end</a> (&dict);

6741

}</pre></td>

6740

6742

</tr>

6741

6743

</tbody>

6742

6744

</table>

6775

6777

6776

6778

6777

6779

25</pre></td>

6778

<td class="listing_code"><pre class="programlisting"><a href="glib-GVariant.html#GVariant">GVariant</a> *

6779

6780

GError **error)

6781

{

6782

GVariantDict *dict;

6783

GVariant *result;

6784

guint32 count;

6785

6786

dict = <a href="glib-GVariant.html#g-variant-dict-new">g_variant_dict_new</a> (orig);

6787

6788

if (<a href="glib-GVariant.html#g-variant-dict-lookup">g_variant_dict_lookup</a> (dict, "count", "u", &count))

6789

{

6790

<a href="glib-GVariant.html#g-variant-dict-insert">g_variant_dict_insert</a> (dict, "count", "u", count + 1);

6791

result = <a href="glib-GVariant.html#g-variant-dict-end">g_variant_dict_end</a> (dict);

6792

}

6793

else

6794

{

6795

<a href="glib-Error-Reporting.html#g-set-error">g_set_error</a> (...);

6796

result = <a href="glib-Standard-Macros.html#NULL:CAPS">NULL</a>;

6797

}

6798

6799

<a href="glib-GVariant.html#g-variant-dict-unref">g_variant_dict_unref</a> (dict);

6800

6801

return result;

6802

}</pre></td>

6780

<td class="listing_code"><pre class="programlisting">GVariant *

6781

add_to_count (GVariant *orig,

6782

GError **error)

6783

{

6784

GVariantDict *dict;

6785

GVariant *result;

6786

guint32 count;

6787

6788

dict = <a href="glib-GVariant.html#g-variant-dict-new">g_variant_dict_new</a> (orig);

6789

6790

if (<a href="glib-GVariant.html#g-variant-dict-lookup">g_variant_dict_lookup</a> (dict, "count", "u", &count))

6791

{

6792

<a href="glib-GVariant.html#g-variant-dict-insert">g_variant_dict_insert</a> (dict, "count", "u", count + 1);

6793

result = <a href="glib-GVariant.html#g-variant-dict-end">g_variant_dict_end</a> (dict);

6794

}

6795

else

6796

{

6797

<a href="glib-Error-Reporting.html#g-set-error">g_set_error</a> (...);

6798

result = NULL;

6799

}

6800

6801

<a href="glib-GVariant.html#g-variant-dict-unref">g_variant_dict_unref</a> (dict);

6802

6803

return result;

6804

}</pre></td>

6803

6805

</tr>

6804

6806

</tbody>

6805

6807

</table>

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