wt5001: Added functions that throw exceptions when failing to read from sensors. Added java exception handling, and modified examples.

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

examples/java/WT5001Sample.java

@@ -1,3 +1,5 @@
+import java.io.IOException;
+
 /*
  * Author: Stefan Andritoiu <stefan.andritoiu@intel.com>
  * Copyright (c) 2015 Intel Corporation.
@@ -44,7 +46,7 @@ public class WT5001Sample {
 		System.out.println("4  - previous track");
 	}
 
-	public static void main(String[] args) throws InterruptedException {
+	public static void main(String[] args) {
 		// ! [Interesting]
 		// Instantiate a WT5001 serial MP3 player on uart 0
 		upm_wt5001.WT5001 mp3 = new upm_wt5001.WT5001(0);
@@ -87,21 +89,37 @@ public class WT5001Sample {
 		}
 
 		// print out some information
-		short vol[] = new short[1];
-		if (mp3.getVolume(vol))
-			System.out.println("The current volume is: " + vol[0]);
+		try {
+			short vol;
+			vol = mp3.getVolume();
+			System.out.println("The current volume is: " + vol);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
 
-		short ps[] = new short[1];
-		if (mp3.getPlayState(ps))
-			System.out.println("The current play state is: " + ps[0]);
+		try {
+			short ps;
+			ps = mp3.getPlayState();
+			System.out.println("The current play state is: " + ps);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
 
-		int numf[] = new int[1];
-		if (mp3.getNumFiles(upm_wt5001.WT5001.WT5001_PLAYSOURCE_T.SD, numf))
-			System.out.println("The number of files on the SD card is: " + numf[0]);
+		try {
+			int numf;
+			numf = mp3.getNumFiles(upm_wt5001.WT5001.WT5001_PLAYSOURCE_T.SD);
+			System.out.println("The number of files on the SD card is: " + numf);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
 
-		int curf[] = new int[1];
-		if (mp3.getCurrentFile(curf))
-			System.out.println("The current file is: " + curf[0]);
+		try {
+			int curf;
+			curf = mp3.getCurrentFile();
+			System.out.println("The current file is: " + curf);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
 
 		int year[] = new int[1];
 		short month[] = new short[1];

src/java_exceptions.i

@@ -0,0 +1,21 @@
+/* -----------------------------------------------------------------------------
+ * java_exceptions.i
+ *
+ * SWIG library file providing java-specific exception handling in the upm library
+ * ----------------------------------------------------------------------------- */
+
+/*
+ * Use this macro for functions that read data from a sensor and throw a 
+ * std::runtime_error in case of a read failure
+*/
+%define READDATA_EXCEPTION(function)
+%javaexception("java.io.IOException") function {
+  try {
+     $action
+  } catch (std::runtime_error &e) {
+    jclass clazz = jenv->FindClass("java/io/IOException");
+    jenv->ThrowNew(clazz, e.what());
+    return $null;
+   }
+}
+%enddef

src/upm.i

@@ -2,11 +2,9 @@
 %include "stdint.i"
 %include "upm_exception.i"
 
-    /* %include "arrays_java.i"; */
-    /* %apply unsigned char[] {uint8_t *mama}; */
-    %apply int { speed_t };
-    %apply int { mraa_result_t };
-    %apply int { mraa::Result };
+%apply int { speed_t };
+%apply int { mraa_result_t };
+%apply int { mraa::Result };
 
 #if (SWIG_JAVASCRIPT_V8)
 %{

src/wt5001/javaupm_wt5001.i

@@ -3,6 +3,7 @@
 %include "stdint.i"
 %include "typemaps.i"
 %include "../java_buffer.i"
+%include "../java_exceptions.i"
 
 %apply uint8_t *OUTPUT { uint8_t *vol };
 %apply uint8_t *OUTPUT { uint8_t *ps };
@@ -17,5 +18,17 @@
     speed_t int_B9600 = B9600;
 %}
 
+%ignore getVolume(uint8_t *vol);
+READDATA_EXCEPTION(getVolume())
+
+%ignore getPlayState(uint8_t *ps);
+READDATA_EXCEPTION(getPlayState())
+
+%ignore getNumFiles(WT5001_PLAYSOURCE_T psrc, uint16_t *numf);
+READDATA_EXCEPTION(getNumFiles(WT5001_PLAYSOURCE_T psrc))
+
+%ignore getCurrentFile(uint16_t *curf);
+READDATA_EXCEPTION(getCurrentFile())
+
 %include "wt5001.h"
 speed_t int_B9600 = B9600;

src/wt5001/wt5001.cxx

@@ -450,6 +450,15 @@ bool WT5001::getVolume(uint8_t *vol)
   return true;
 }
 
+uint8_t WT5001::getVolume()
+{
+  uint8_t vol = 0;
+  if (!getVolume(&vol))
+    throw std::runtime_error(std::string(__PRETTY_FUNCTION__) +
+                                ": readData() failed");
+  return vol;
+}
+
 bool WT5001::getPlayState(uint8_t *ps)
 {
   char pkt[4];
@@ -473,6 +482,15 @@ bool WT5001::getPlayState(uint8_t *ps)
   return true;
 }
 
+uint8_t WT5001::getPlayState()
+{
+  uint8_t ps = 0;
+  if (!getPlayState(&ps))
+    throw std::runtime_error(std::string(__PRETTY_FUNCTION__) +
+                                ": readData() failed");
+  return ps;
+}
+
 bool WT5001::getNumFiles(WT5001_PLAYSOURCE_T psrc, uint16_t *numf)
 {
   char pkt[4];
@@ -515,6 +533,15 @@ bool WT5001::getNumFiles(WT5001_PLAYSOURCE_T psrc, uint16_t *numf)
   return true;
 }
 
+uint16_t WT5001::getNumFiles(WT5001_PLAYSOURCE_T psrc)
+{
+  uint16_t numf = 0;
+  if (!getNumFiles(psrc, &numf))
+    throw std::runtime_error(std::string(__PRETTY_FUNCTION__) +
+                                ": readData() failed");
+  return numf;
+}
+
 bool WT5001::getCurrentFile(uint16_t *curf)
 {
   char pkt[4];
@@ -541,6 +568,15 @@ bool WT5001::getCurrentFile(uint16_t *curf)
   return true;
 }
 
+uint16_t WT5001::getCurrentFile()
+{
+  uint16_t curf = 0;
+  if (!getCurrentFile(&curf))
+    throw std::runtime_error(std::string(__PRETTY_FUNCTION__) +
+                                ": readData() failed");
+  return curf;
+}
+
 bool WT5001::getDate(uint16_t *year, uint8_t *month, uint8_t *day)
 {
   char pkt[4];

src/wt5001/wt5001.h

@@ -292,6 +292,14 @@ namespace upm {
      */
     bool getVolume(uint8_t *vol);
 
+    /**
+     * Gets the current volume
+     *
+     * @return Volume
+     * @throws std::runtime_error if reading from the sensor failed
+     */
+    uint8_t getVolume();
+
     /**
      * Gets the current play state: 1 = playing, 2 = stopped, 3 = paused
      *
@@ -300,6 +308,14 @@ namespace upm {
      */
     bool getPlayState(uint8_t *ps);
 
+    /**
+     * Gets the current play state: 1 = playing, 2 = stopped, 3 = paused
+     *
+     * @return Play state
+     * @throws std::runtime_error if reading from the sensor failed
+     */
+    uint8_t getPlayState();
+
     /**
      * Gets the number of files present on the source device
      *
@@ -309,6 +325,15 @@ namespace upm {
      */
     bool getNumFiles(WT5001_PLAYSOURCE_T psrc, uint16_t *numf);
 
+    /**
+     * Gets the number of files present on the source device
+     *
+     * @param psrc Storage source
+     * @return Number of files
+     * @throws std::runtime_error if reading from the sensor failed
+     */
+    uint16_t getNumFiles(WT5001_PLAYSOURCE_T psrc);
+
     /**
      * Gets the index of the current file
      *
@@ -317,6 +342,14 @@ namespace upm {
      */
     bool getCurrentFile(uint16_t *curf);
 
+    /**
+     * Gets the index of the current file
+     *
+     * @return Index of the curretn file
+     * @throws std::runtime_error if reading from the sensor failed
+     */
+    uint16_t getCurrentFile();
+    
     /**
      * Gets the device date
      *