io.helins.linux.gpio.GpioBuffer Maven / Gradle / Ivy
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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
package io.helins.linux.gpio ;
import com.sun.jna.Memory ;
import com.sun.jna.Pointer ;
import io.helins.linux.gpio.GpioLine ;
/**
* Class representing a buffer for reading and/or writing the state of up to 64 GPIO lines.
*
* It does not do any IO on its own.
*/
public class GpioBuffer {
/**
* How many lines a buffer can drive.
*/
public static final int SIZE = 64 ;
// Pointer to the buffer's native memory.
//
private final Memory buffer ;
/**
* Basic constructor.
*/
public GpioBuffer() {
this.buffer = new Memory( SIZE ) ;
this.buffer.clear() ;
}
/**
* Retrieves the state of a given line.
*
* @param line
* The GPIO line
*
* @return A boolean representing the state.
*/
public boolean get( GpioLine line ) {
return this.buffer.getByte( line.index ) == 1 ;
}
/**
* Sets the new state of a given line.
*
* @param line
* The GPIO line.
*
* @param value
* The new state.
*
* @return This instance.
*/
public GpioBuffer set( GpioLine line ,
boolean value ) {
this.buffer.setByte( line.index ,
(byte)( value ? 1
: 0 ) ) ;
return this ;
}
/**
* Toggles the state of a given line.
*
* @param line
* The GPIO line.
*
* @return This instance.
*/
public GpioBuffer toggle( GpioLine line ) {
this.set( line ,
!( this.get( line ) ) ) ;
return this ;
}
/**
* Clears this buffer by setting every state to false.
*
* @return This instance.
*/
public GpioBuffer clear() {
this.buffer.clear() ;
return this ;
}
// Retrieves the pointer to the buffer's native memory.
//
Pointer getPointer() {
return (Pointer)( this.buffer ) ;
}
}