Revising SD library API.

Open now returns a file object (which has a close() method); exists() no longer accepts a parent directory.

libraries/SD/File.cpp

@@ -0,0 +1,39 @@
+/*
+
+ SD - a slightly more friendly wrapper for sdfatlib
+
+ This library aims to expose a subset of SD card functionality
+ in the form of a higher level "wrapper" object.
+
+ License: GNU General Public License V3
+          (Because sdfatlib is licensed with this.)
+
+ (C) Copyright 2010 SparkFun Electronics
+
+ */
+
+#include <SD.h>
+
+void File::write(uint8_t val) {
+  SD.file.write(val);
+}
+
+void File::write(const char *str) {
+  SD.file.write(str);
+}
+
+void File::write(const uint8_t *buf, size_t size) {
+  SD.file.write(buf, size);
+}
+
+int File::read() {
+  return SD.file.read();
+}
+
+void File::close() {
+  SD.file.close();
+}
+
+File::operator bool() {
+  return SD.file.isOpen();
+}

libraries/SD/SD.cpp

@@ -327,7 +327,7 @@ void SDClass::begin(uint8_t csPin) {
 }
 
 
-boolean SDClass::open(char *filepath,
+File SDClass::open(char *filepath,
 			       boolean write, boolean append) {
   /*
 
@@ -368,19 +368,19 @@ boolean SDClass::open(char *filepath,
   fileOpenMode = oflag;
   walkPath(filepath, root, callback_openPath, this);
 
-  // TODO: Actually return something useful.
+  return File();
 
 }
 
 
-boolean SDClass::close() {
+//boolean SDClass::close() {
-  /*
+//  /*
-
+//
-    Closes the file opened by the `open` method.
+//    Closes the file opened by the `open` method.
-
+//
-   */
+//   */
-  file.close();
+//  file.close();
-}
+//}
 
 
 boolean SDClass::exists(char *filepath) {
@@ -389,19 +389,19 @@ boolean SDClass::exists(char *filepath) {
      Returns true if the supplied file path exists.
 
    */
-  return exists(filepath, root);
+  return walkPath(filepath, root, callback_pathExists);
 }
 
 
-boolean SDClass::exists(char *filepath, SdFile& parentDir) {
+//boolean SDClass::exists(char *filepath, SdFile& parentDir) {
-  /*
+//  /*
-
+//
-     Returns true if the supplied file path rooted at `parentDir`
+//     Returns true if the supplied file path rooted at `parentDir`
-     exists.
+//     exists.
-
+//
-   */
+//   */
-  return walkPath(filepath, parentDir, callback_pathExists);
+//  return walkPath(filepath, parentDir, callback_pathExists);
-}
+//}
 
 
 boolean SDClass::makeDir(char *filepath) {

libraries/SD/SD.h

@@ -23,6 +23,16 @@
 // Use this to configure the chip select pin of the SD card.
 #define SD_CARD_CHIP_SELECT_PIN 4 // For use with Arduino Ethernet Shield
 
+class File : public Print {
+  public:
+    virtual void write(uint8_t);
+    virtual void write(const char *str);
+    virtual void write(const uint8_t *buf, size_t size);
+    int read();
+    void close();
+    operator bool();
+};
+
 class SDClass {
 
  private:
@@ -40,14 +50,14 @@ class SDClass {
   // Open the specified file/directory with the supplied mode (e.g. read or
   // write, etc). Once opened the file can be accessed via the
   // `MemoryCard.file` field which is a standard `sdfatlib` file object.
-  boolean open(char *filename, boolean write = false, boolean append = true);
+  File open(char *filename, boolean write = false, boolean append = true);
 
   // Close an opened file object.
-  boolean close();
+  //boolean close();
 
   // Methods to determine if the requested file path exists.
   boolean exists(char *filepath);
-  boolean exists(char *filepath, SdFile& parentDir);
+  //boolean exists(char *filepath, SdFile& parentDir);
 
   // Create the requested directory heirarchy--if intermediate directories
   // do not exist they will be created.