Package org.freedesktop.wayland.client

Class WlShmPoolProxy

java.lang.Object

org.freedesktop.wayland.client.Proxy<WlShmPoolEvents>

org.freedesktop.wayland.client.WlShmPoolProxy

All Implemented Interfaces:

WaylandObject

public class WlShmPoolProxy
extends Proxy<WlShmPoolEvents>

a shared memory pool

The wl_shm_pool object encapsulates a piece of memory shared between the compositor and client. Through the wl_shm_pool object, the client can allocate shared memory wl_buffer objects. All objects created through the same pool share the same underlying mapped memory. Reusing the mapped memory avoids the setup/teardown overhead and is useful when interactively resizing a surface or for many small buffers.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	INTERFACE_NAME

Fields inherited from class org.freedesktop.wayland.client.Proxy

pointer

Constructor Summary

Constructors

Constructor	Description
WlShmPoolProxy(MemorySegment pointer)
WlShmPoolProxy(MemorySegment pointer, WlShmPoolEvents implementation, int version)

Method Summary

Modifier and Type	Method	Description
WlBufferProxy	createBuffer(WlBufferEvents implementation, int offset, int width, int height, int stride, int format)	create a buffer from the pool
void	destroy()	destroy the pool
void	resize(int size)	change the size of the pool mapping

Methods inherited from class org.freedesktop.wayland.client.Proxy

equals, getId, getImplementation, getPointer, getVersion, hashCode, marshal, marshal, marshalConstructor, setQueue

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Details

INTERFACE_NAME

public static final String INTERFACE_NAME

See Also:

• Constant Field Values

Constructor Details

WlShmPoolProxy

public WlShmPoolProxy(MemorySegment pointer,
 WlShmPoolEvents implementation,
 int version)

WlShmPoolProxy

public WlShmPoolProxy(MemorySegment pointer)

Method Details

createBuffer

public WlBufferProxy createBuffer(WlBufferEvents implementation,
 int offset,
 int width,
 int height,
 int stride,
 int format)

create a buffer from the pool

Create a wl_buffer object from the pool.

The buffer is created offset bytes into the pool and has width and height as specified. The stride argument specifies the number of bytes from the beginning of one row to the beginning of the next. The format is the pixel format of the buffer and must be one of those advertised through the wl_shm.format event.

A buffer will keep a reference to the pool it was created from so it is valid to destroy the pool immediately after creating a buffer from it.

Parameters:

implementation - A protocol event listener for the newly created proxy.

offset - buffer byte offset within the pool

width - buffer width, in pixels

height - buffer height, in pixels

stride - number of bytes from the beginning of one row to the beginning of the next row

format - buffer pixel format

destroy

public void destroy()

destroy the pool

Destroy the shared memory pool.

The mmapped memory will be released when all buffers that have been created from this pool are gone.

Overrides:

destroy in class Proxy<WlShmPoolEvents>

resize

public void resize(int size)

change the size of the pool mapping

This request will cause the server to remap the backing memory for the pool from the file descriptor passed when the pool was created, but using the new size. This request can only be used to make the pool bigger.

This request only changes the amount of bytes that are mmapped by the server and does not touch the file corresponding to the file descriptor passed at creation time. It is the client's responsibility to ensure that the file is at least as big as the new pool size.

Parameters:

size - new size of the pool, in bytes