Added interface iButton

Signed-off-by: Stefan Andritoiu <stefan.andritoiu@gmail.com>
Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/button/button.cxx

@@ -59,6 +59,11 @@ int Button::value()
     return mraa_gpio_read(m_gpio);
 }
 
+bool Button::isPressed()
+{
+    return (bool) Button::value();
+}
+
 void Button::installISR(mraa::Edge level, void (*isr)(void *), void *arg)
 {
   if (m_isrInstalled)

src/button/button.hpp

@@ -28,6 +28,7 @@
 
 #include <string>
 #include <mraa/gpio.hpp>
+#include <interfaces/iButton.hpp>
 
 namespace upm {
 
@@ -54,7 +55,7 @@ namespace upm {
  * @image html button.jpg
  * @snippet button.cxx Interesting
  */
-class Button{
+class Button : virtual public iButton {
     public:
         /**
          * button constructor
@@ -79,6 +80,13 @@ class Button{
          */
         int value();
 
+        /**
+         * Gets the current button press state.
+         *
+         * @returns Button state
+         */
+         virtual bool isPressed();
+
         /**
          * Installs an interrupt service routine (ISR) to be called when
          * the button is activated or deactivated.

src/grove/grovebutton.cxx

@@ -58,6 +58,11 @@ int GroveButton::value()
     return mraa_gpio_read(m_gpio);
 }
 
+bool GroveButton::isPressed()
+{
+    return (bool) GroveButton::value();
+}
+
 void GroveButton::installISR(mraa::Edge level, void (*isr)(void *), void *arg)
 {
   if (m_isrInstalled)

src/grove/grovebutton.hpp

@@ -29,6 +29,7 @@
 #include <string>
 #include <mraa/gpio.hpp>
 #include "grovebase.hpp"
+#include <interfaces/iButton.hpp>
 
 namespace upm {
 
@@ -51,7 +52,7 @@ namespace upm {
  * @image html grovebutton.jpg
  * @snippet grove-grovebutton.cxx Interesting
  */
-class GroveButton: public Grove {
+class GroveButton: public Grove, virtual public iButton {
     public:
         /**
          * Grove button constructor
@@ -76,6 +77,13 @@ class GroveButton: public Grove {
          */
         int value();
 
+        /**
+         * Gets the current button press state.
+         *
+         * @returns Button state
+         */
+         virtual bool isPressed();
+
         /**
          * Installs an interrupt service routine (ISR) to be called when
          * the button is activated or deactivated.

src/ttp223/ttp223.hpp

@@ -25,6 +25,7 @@
 
 #include <string>
 #include <mraa/gpio.hpp>
+#include <interfaces/iButton.hpp>
 
 namespace upm {
 /**
@@ -52,7 +53,7 @@ namespace upm {
  * @image html ttp223.jpg
  * @snippet ttp223.cxx Interesting
  */
-class TTP223 {
+class TTP223 : virtual public iButton {
     public:
         /**
          * TTP223 constructor
@@ -85,7 +86,7 @@ class TTP223 {
          *
          * @return True if touched, false otherwise
          */
-        bool isPressed();
+        virtual bool isPressed();
 
         /**
          * Installs an interrupt service routine (ISR) to be called when