/*
 * This file is part of gtkD.
 *
 * gtkD 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 3
 * of the License, or (at your option) any later version, with
 * some exceptions, please read the COPYING file.
 *
 * gtkD 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 gtkD; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
 */

// generated automatically - do not change
// find conversion definition on APILookup.txt
// implement new conversion functionalities on the wrap.utils pakage


module gio.Resource;

private import gio.InputStream;
private import gio.c.functions;
public  import gio.c.types;
private import glib.Bytes;
private import glib.ConstructionException;
private import glib.ErrorG;
private import glib.GException;
private import glib.Str;
private import gobject.ObjectG;
public  import gtkc.giotypes;
private import gtkd.Loader;


/**
 * Applications and libraries often contain binary or textual data that is
 * really part of the application, rather than user data. For instance
 * #GtkBuilder .ui files, splashscreen images, GMenu markup XML, CSS files,
 * icons, etc. These are often shipped as files in `$datadir/appname`, or
 * manually included as literal strings in the code.
 * 
 * The #GResource API and the [glib-compile-resources][glib-compile-resources] program
 * provide a convenient and efficient alternative to this which has some nice properties. You
 * maintain the files as normal files, so its easy to edit them, but during the build the files
 * are combined into a binary bundle that is linked into the executable. This means that loading
 * the resource files are efficient (as they are already in memory, shared with other instances) and
 * simple (no need to check for things like I/O errors or locate the files in the filesystem). It
 * also makes it easier to create relocatable applications.
 * 
 * Resource files can also be marked as compressed. Such files will be included in the resource bundle
 * in a compressed form, but will be automatically uncompressed when the resource is used. This
 * is very useful e.g. for larger text files that are parsed once (or rarely) and then thrown away.
 * 
 * Resource files can also be marked to be preprocessed, by setting the value of the
 * `preprocess` attribute to a comma-separated list of preprocessing options.
 * The only options currently supported are:
 * 
 * `xml-stripblanks` which will use the xmllint command
 * to strip ignorable whitespace from the XML file. For this to work,
 * the `XMLLINT` environment variable must be set to the full path to
 * the xmllint executable, or xmllint must be in the `PATH`; otherwise
 * the preprocessing step is skipped.
 * 
 * `to-pixdata` which will use the gdk-pixbuf-pixdata command to convert
 * images to the GdkPixdata format, which allows you to create pixbufs directly using the data inside
 * the resource file, rather than an (uncompressed) copy if it. For this, the gdk-pixbuf-pixdata
 * program must be in the PATH, or the `GDK_PIXBUF_PIXDATA` environment variable must be
 * set to the full path to the gdk-pixbuf-pixdata executable; otherwise the resource compiler will
 * abort.
 * 
 * Resource files will be exported in the GResource namespace using the
 * combination of the given `prefix` and the filename from the `file` element.
 * The `alias` attribute can be used to alter the filename to expose them at a
 * different location in the resource namespace. Typically, this is used to
 * include files from a different source directory without exposing the source
 * directory in the resource namespace, as in the example below.
 * 
 * Resource bundles are created by the [glib-compile-resources][glib-compile-resources] program
 * which takes an XML file that describes the bundle, and a set of files that the XML references. These
 * are combined into a binary resource bundle.
 * 
 * An example resource description:
 * |[
 * <?xml version="1.0" encoding="UTF-8"?>
 * <gresources>
 * <gresource prefix="/org/gtk/Example">
 * <file>data/splashscreen.png</file>
 * <file compressed="true">dialog.ui</file>
 * <file preprocess="xml-stripblanks">menumarkup.xml</file>
 * <file alias="example.css">data/example.css</file>
 * </gresource>
 * </gresources>
 * ]|
 * 
 * This will create a resource bundle with the following files:
 * |[
 * /org/gtk/Example/data/splashscreen.png
 * /org/gtk/Example/dialog.ui
 * /org/gtk/Example/menumarkup.xml
 * /org/gtk/Example/example.css
 * ]|
 * 
 * Note that all resources in the process share the same namespace, so use Java-style
 * path prefixes (like in the above example) to avoid conflicts.
 * 
 * You can then use [glib-compile-resources][glib-compile-resources] to compile the XML to a
 * binary bundle that you can load with g_resource_load(). However, its more common to use the --generate-source and
 * --generate-header arguments to create a source file and header to link directly into your application.
 * This will generate `get_resource()`, `register_resource()` and
 * `unregister_resource()` functions, prefixed by the `--c-name` argument passed
 * to [glib-compile-resources][glib-compile-resources]. `get_resource()` returns
 * the generated #GResource object. The register and unregister functions
 * register the resource so its files can be accessed using
 * g_resources_lookup_data().
 * 
 * Once a #GResource has been created and registered all the data in it can be accessed globally in the process by
 * using API calls like g_resources_open_stream() to stream the data or g_resources_lookup_data() to get a direct pointer
 * to the data. You can also use URIs like "resource:///org/gtk/Example/data/splashscreen.png" with #GFile to access
 * the resource data.
 * 
 * Some higher-level APIs, such as #GtkApplication, will automatically load
 * resources from certain well-known paths in the resource namespace as a
 * convenience. See the documentation for those APIs for details.
 * 
 * There are two forms of the generated source, the default version uses the compiler support for constructor
 * and destructor functions (where available) to automatically create and register the #GResource on startup
 * or library load time. If you pass `--manual-register`, two functions to register/unregister the resource are created
 * instead. This requires an explicit initialization call in your application/library, but it works on all platforms,
 * even on the minor ones where constructors are not supported. (Constructor support is available for at least Win32, Mac OS and Linux.)
 * 
 * Note that resource data can point directly into the data segment of e.g. a library, so if you are unloading libraries
 * during runtime you need to be very careful with keeping around pointers to data from a resource, as this goes away
 * when the library is unloaded. However, in practice this is not generally a problem, since most resource accesses
 * are for your own resources, and resource data is often used once, during parsing, and then released.
 * 
 * When debugging a program or testing a change to an installed version, it is often useful to be able to
 * replace resources in the program or library, without recompiling, for debugging or quick hacking and testing
 * purposes. Since GLib 2.50, it is possible to use the `G_RESOURCE_OVERLAYS` environment variable to selectively overlay
 * resources with replacements from the filesystem.  It is a colon-separated list of substitutions to perform
 * during resource lookups.
 * 
 * A substitution has the form
 * 
 * |[
 * /org/gtk/libgtk=/home/desrt/gtk-overlay
 * ]|
 * 
 * The part before the `=` is the resource subpath for which the overlay applies.  The part after is a
 * filesystem path which contains files and subdirectories as you would like to be loaded as resources with the
 * equivalent names.
 * 
 * In the example above, if an application tried to load a resource with the resource path
 * `/org/gtk/libgtk/ui/gtkdialog.ui` then GResource would check the filesystem path
 * `/home/desrt/gtk-overlay/ui/gtkdialog.ui`.  If a file was found there, it would be used instead.  This is an
 * overlay, not an outright replacement, which means that if a file is not found at that path, the built-in
 * version will be used instead.  Whiteouts are not currently supported.
 * 
 * Substitutions must start with a slash, and must not contain a trailing slash before the '='.  The path after
 * the slash should ideally be absolute, but this is not strictly required.  It is possible to overlay the
 * location of a single resource with an individual file.
 *
 * Since: 2.32
 */
public class Resource
{
	/** the main Gtk struct */
	protected GResource* gResource;
	protected bool ownedRef;

	/** Get the main Gtk struct */
	public GResource* getResourceStruct(bool transferOwnership = false)
	{
		if (transferOwnership)
			ownedRef = false;
		return gResource;
	}

	/** the main Gtk struct as a void* */
	protected void* getStruct()
	{
		return cast(void*)gResource;
	}

	/**
	 * Sets our main struct and passes it to the parent class.
	 */
	public this (GResource* gResource, bool ownedRef = false)
	{
		this.gResource = gResource;
		this.ownedRef = ownedRef;
	}

	~this ()
	{
		if ( Linker.isLoaded(LIBRARY_GIO) && ownedRef )
			g_resource_unref(gResource);
	}


	/** */
	public static GType getType()
	{
		return g_resource_get_type();
	}

	/**
	 * Creates a GResource from a reference to the binary resource bundle.
	 * This will keep a reference to @data while the resource lives, so
	 * the data should not be modified or freed.
	 *
	 * If you want to use this resource in the global resource namespace you need
	 * to register it with g_resources_register().
	 *
	 * Note: @data must be backed by memory that is at least pointer aligned.
	 * Otherwise this function will internally create a copy of the memory since
	 * GLib 2.56, or in older versions fail and exit the process.
	 *
	 * Params:
	 *     data = A #GBytes
	 *
	 * Returns: a new #GResource, or %NULL on error
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 * Throws: ConstructionException GTK+ fails to create the object.
	 */
	public this(Bytes data)
	{
		GError* err = null;

		auto p = g_resource_new_from_data((data is null) ? null : data.getBytesStruct(), &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		if(p is null)
		{
			throw new ConstructionException("null returned by new_from_data");
		}

		this(cast(GResource*) p);
	}

	/**
	 * Registers the resource with the process-global set of resources.
	 * Once a resource is registered the files in it can be accessed
	 * with the global resource lookup functions like g_resources_lookup_data().
	 *
	 * Params:
	 *     resource = A #GResource
	 *
	 * Since: 2.32
	 */
	public static void register(Resource resource)
	{
		g_resources_register((resource is null) ? null : resource.getResourceStruct());
	}

	/**
	 * Unregisters the resource from the process-global set of resources.
	 *
	 * Params:
	 *     resource = A #GResource
	 *
	 * Since: 2.32
	 */
	public static void unregister(Resource resource)
	{
		g_resources_unregister((resource is null) ? null : resource.getResourceStruct());
	}

	/**
	 * Returns all the names of children at the specified @path in the resource.
	 * The return result is a %NULL terminated list of strings which should
	 * be released with g_strfreev().
	 *
	 * If @path is invalid or does not exist in the #GResource,
	 * %G_RESOURCE_ERROR_NOT_FOUND will be returned.
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *
	 * Returns: an array of constant strings
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public string[] enumerateChildren(string path, GResourceLookupFlags lookupFlags)
	{
		GError* err = null;

		auto retStr = g_resource_enumerate_children(gResource, Str.toStringz(path), lookupFlags, &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		scope(exit) Str.freeStringArray(retStr);
		return Str.toStringArray(retStr);
	}

	/**
	 * Looks for a file at the specified @path in the resource and
	 * if found returns information about it.
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *     size = a location to place the length of the contents of the file,
	 *         or %NULL if the length is not needed
	 *     flags = a location to place the flags about the file,
	 *         or %NULL if the length is not needed
	 *
	 * Returns: %TRUE if the file was found. %FALSE if there were errors
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public bool getInfo(string path, GResourceLookupFlags lookupFlags, out size_t size, out uint flags)
	{
		GError* err = null;

		auto p = g_resource_get_info(gResource, Str.toStringz(path), lookupFlags, &size, &flags, &err) != 0;

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		return p;
	}

	/**
	 * Looks for a file at the specified @path in the resource and
	 * returns a #GBytes that lets you directly access the data in
	 * memory.
	 *
	 * The data is always followed by a zero byte, so you
	 * can safely use the data as a C string. However, that byte
	 * is not included in the size of the GBytes.
	 *
	 * For uncompressed resource files this is a pointer directly into
	 * the resource bundle, which is typically in some readonly data section
	 * in the program binary. For compressed files we allocate memory on
	 * the heap and automatically uncompress the data.
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *
	 * Returns: #GBytes or %NULL on error.
	 *     Free the returned object with g_bytes_unref()
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public Bytes lookupData(string path, GResourceLookupFlags lookupFlags)
	{
		GError* err = null;

		auto p = g_resource_lookup_data(gResource, Str.toStringz(path), lookupFlags, &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		if(p is null)
		{
			return null;
		}

		return new Bytes(cast(GBytes*) p, true);
	}

	/**
	 * Looks for a file at the specified @path in the resource and
	 * returns a #GInputStream that lets you read the data.
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *
	 * Returns: #GInputStream or %NULL on error.
	 *     Free the returned object with g_object_unref()
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public InputStream openStream(string path, GResourceLookupFlags lookupFlags)
	{
		GError* err = null;

		auto p = g_resource_open_stream(gResource, Str.toStringz(path), lookupFlags, &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		if(p is null)
		{
			return null;
		}

		return ObjectG.getDObject!(InputStream)(cast(GInputStream*) p, true);
	}

	/**
	 * Atomically increments the reference count of @resource by one. This
	 * function is MT-safe and may be called from any thread.
	 *
	 * Returns: The passed in #GResource
	 *
	 * Since: 2.32
	 */
	public Resource doref()
	{
		auto p = g_resource_ref(gResource);

		if(p is null)
		{
			return null;
		}

		return ObjectG.getDObject!(Resource)(cast(GResource*) p, true);
	}

	/**
	 * Atomically decrements the reference count of @resource by one. If the
	 * reference count drops to 0, all memory allocated by the resource is
	 * released. This function is MT-safe and may be called from any
	 * thread.
	 *
	 * Since: 2.32
	 */
	public void unref()
	{
		g_resource_unref(gResource);
	}

	/**
	 * Loads a binary resource bundle and creates a #GResource representation of it, allowing
	 * you to query it for data.
	 *
	 * If you want to use this resource in the global resource namespace you need
	 * to register it with g_resources_register().
	 *
	 * Params:
	 *     filename = the path of a filename to load, in the GLib filename encoding
	 *
	 * Returns: a new #GResource, or %NULL on error
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public static Resource load(string filename)
	{
		GError* err = null;

		auto p = g_resource_load(Str.toStringz(filename), &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		if(p is null)
		{
			return null;
		}

		return ObjectG.getDObject!(Resource)(cast(GResource*) p, true);
	}

	/**
	 * Returns all the names of children at the specified @path in the set of
	 * globally registered resources.
	 * The return result is a %NULL terminated list of strings which should
	 * be released with g_strfreev().
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *
	 * Returns: an array of constant strings
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public static string[] resourcesEnumerateChildren(string path, GResourceLookupFlags lookupFlags)
	{
		GError* err = null;

		auto retStr = g_resources_enumerate_children(Str.toStringz(path), lookupFlags, &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		scope(exit) Str.freeStringArray(retStr);
		return Str.toStringArray(retStr);
	}

	/**
	 * Looks for a file at the specified @path in the set of
	 * globally registered resources and if found returns information about it.
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *     size = a location to place the length of the contents of the file,
	 *         or %NULL if the length is not needed
	 *     flags = a location to place the #GResourceFlags about the file,
	 *         or %NULL if the flags are not needed
	 *
	 * Returns: %TRUE if the file was found. %FALSE if there were errors
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public static bool resourcesGetInfo(string path, GResourceLookupFlags lookupFlags, out size_t size, out uint flags)
	{
		GError* err = null;

		auto p = g_resources_get_info(Str.toStringz(path), lookupFlags, &size, &flags, &err) != 0;

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		return p;
	}

	/**
	 * Looks for a file at the specified @path in the set of
	 * globally registered resources and returns a #GBytes that
	 * lets you directly access the data in memory.
	 *
	 * The data is always followed by a zero byte, so you
	 * can safely use the data as a C string. However, that byte
	 * is not included in the size of the GBytes.
	 *
	 * For uncompressed resource files this is a pointer directly into
	 * the resource bundle, which is typically in some readonly data section
	 * in the program binary. For compressed files we allocate memory on
	 * the heap and automatically uncompress the data.
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *
	 * Returns: #GBytes or %NULL on error.
	 *     Free the returned object with g_bytes_unref()
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public static Bytes resourcesLookupData(string path, GResourceLookupFlags lookupFlags)
	{
		GError* err = null;

		auto p = g_resources_lookup_data(Str.toStringz(path), lookupFlags, &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		if(p is null)
		{
			return null;
		}

		return new Bytes(cast(GBytes*) p, true);
	}

	/**
	 * Looks for a file at the specified @path in the set of
	 * globally registered resources and returns a #GInputStream
	 * that lets you read the data.
	 *
	 * @lookup_flags controls the behaviour of the lookup.
	 *
	 * Params:
	 *     path = A pathname inside the resource
	 *     lookupFlags = A #GResourceLookupFlags
	 *
	 * Returns: #GInputStream or %NULL on error.
	 *     Free the returned object with g_object_unref()
	 *
	 * Since: 2.32
	 *
	 * Throws: GException on failure.
	 */
	public static InputStream resourcesOpenStream(string path, GResourceLookupFlags lookupFlags)
	{
		GError* err = null;

		auto p = g_resources_open_stream(Str.toStringz(path), lookupFlags, &err);

		if (err !is null)
		{
			throw new GException( new ErrorG(err) );
		}

		if(p is null)
		{
			return null;
		}

		return ObjectG.getDObject!(InputStream)(cast(GInputStream*) p, true);
	}
}