Package org.freedesktop.gstreamer.gst

Interface Preset

All Superinterfaces:

Proxy

All Known Implementing Classes:

AudioEncoder, AudioEncoder.AudioEncoder$Impl, Preset.Preset$Impl, VideoEncoder, VideoEncoder.VideoEncoder$Impl

@Generated("io.github.jwharm.JavaGI")
public interface Preset
extends Proxy

This interface offers methods to query and manipulate parameter preset sets. A preset is a bunch of property settings, together with meta data and a name. The name of a preset serves as key for subsequent method calls to manipulate single presets. All instances of one type will share the list of presets. The list is created on demand, if presets are not used, the list is not created.

The interface comes with a default implementation that serves most plugins. Wrapper plugins will override most methods to implement support for the native preset format of those wrapped plugins. One method that is useful to be overridden is gst_preset_get_property_names(). With that one can control which properties are saved and in which order. When implementing support for read-only presets, one should set the vmethods for gst_preset_save_preset() and gst_preset_delete_preset() to null. Applications can use gst_preset_is_editable() to check for that.

The default implementation supports presets located in a system directory, application specific directory and in the users home directory. When getting a list of presets individual presets are read and overlaid in 1) system, 2) application and 3) user order. Whenever an earlier entry is newer, the later entries will be updated. Since 1.8 you can also provide extra paths where to find presets through the GST_PRESET_PATH environment variable. Presets found in those paths will be considered as "app presets".

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Preset.Preset$Impl	The Preset$Impl type represents a native instance of the Preset interface.
static class	Preset.PresetInterface	GstPreset interface.

Method Summary

Modifier and Type	Method	Description
default boolean	deletePreset(String name)	Delete the given preset.
static @Nullable String	getAppDir()	Gets the directory for application specific presets if set by the application.
default boolean	getMeta(String name, String tag, Out<String> value)	Gets the value for an existing meta data tag. Meta data tag names can be something like e.g.
default String[]	getPresetNames()	Get a copy of preset names as a null terminated string array.
default String[]	getPropertyNames()	Get a the names of the GObject properties that can be used for presets.
static @Nullable Type	getType()	Get the GType of the Preset class
default boolean	isEditable()	Check if one can add new presets, change existing ones and remove presets.
default boolean	loadPreset(String name)	Load the given preset.
default boolean	renamePreset(String oldName, String newName)	Renames a preset.
default boolean	savePreset(String name)	Save the current object settings as a preset under the given name.
static boolean	setAppDir(String appDir)	Sets an extra directory as an absolute path that should be considered when looking for presets.
default boolean	setMeta(String name, String tag, @Nullable String value)	Sets a new value for an existing meta data item or adds a new item.

Methods inherited from interface org.javagi.base.Proxy

handle

Method Details

getType

static @Nullable Type getType()

Get the GType of the Preset class

Returns:

the GType

getAppDir

static @Nullable String getAppDir()

Gets the directory for application specific presets if set by the application.

Returns:

the directory or null, don't free or modify the string

setAppDir

static boolean setAppDir(String appDir)

Sets an extra directory as an absolute path that should be considered when looking for presets. Any presets in the application dir will shadow the system presets.

Parameters:

appDir - the application specific preset dir

Returns:

true for success, false if the dir already has been set

deletePreset

default boolean deletePreset(String name)

Delete the given preset.

Parameters:

name - preset name to remove

Returns:

true for success, false if e.g. there is no preset with that name

getMeta

default boolean getMeta(String name,
 String tag,
 Out<String> value)

Gets the value for an existing meta data tag. Meta data tag names can be something like e.g. "comment". Returned values need to be released when done.

Parameters:

name - preset name

tag - meta data item name

value - value

Returns:

true for success, false if e.g. there is no preset with that name or no value for the given tag

getPresetNames

default String[] getPresetNames()

Get a copy of preset names as a null terminated string array.

Returns:

list with names, use g_strfreev() after usage.

getPropertyNames

default String[] getPropertyNames()

Get a the names of the GObject properties that can be used for presets.

Returns:

an array of property names which should be freed with g_strfreev() after use.

isEditable

default boolean isEditable()

Check if one can add new presets, change existing ones and remove presets.

Returns:

true if presets are editable or false if they are static

Since:

1.6

loadPreset

default boolean loadPreset(String name)

Load the given preset.

Parameters:

name - preset name to load

Returns:

true for success, false if e.g. there is no preset with that name

renamePreset

default boolean renamePreset(String oldName,
 String newName)

Renames a preset. If there is already a preset by the newName it will be overwritten.

Parameters:

oldName - current preset name

newName - new preset name

Returns:

true for success, false if e.g. there is no preset with oldName

savePreset

default boolean savePreset(String name)

Save the current object settings as a preset under the given name. If there is already a preset by this name it will be overwritten.

Parameters:

name - preset name to save

Returns:

true for success, false

setMeta

default boolean setMeta(String name,
 String tag,
 @Nullable String value)

Sets a new value for an existing meta data item or adds a new item. Meta data tag names can be something like e.g. "comment". Supplying null for the value will unset an existing value.

Parameters:

name - preset name

tag - meta data item name

value - new value

Returns:

true for success, false if e.g. there is no preset with that name