Animated GIF example added

1 files changed, 169 insertions, 0 deletions

diff --git a/examples/AnimatedGIF/FilenameFunctions.cpp b/examples/AnimatedGIF/FilenameFunctions.cpp
new file mode 100644
index 0000000..e8a8f04
--- /dev/null
+++ b/examples/AnimatedGIF/FilenameFunctions.cpp
@@ -0,0 +1,169 @@
+/*
+ * Animated GIFs Display Code for SmartMatrix and 32x32 RGB LED Panels
+ *
+ * This file contains code to enumerate and select animated GIF files by name
+ *
+ * Written by: Craig A. Lindley
+ * 
+ * Other references: https://github.com/espressif/arduino-esp32/blob/master/libraries/WebServer/examples/FSBrowser/FSBrowser.ino
+ *
+ */
+
+#include "FilenameFunctions.h"
+
+File file;
+
+int numberOfFiles;
+
+bool fileSeekCallback(unsigned long position) {
+    return file.seek(position);
+}
+
+unsigned long filePositionCallback(void) {
+    return file.position();
+}
+
+int fileReadCallback(void) {
+    return file.read();
+}
+
+int fileReadBlockCallback(void * buffer, int numberOfBytes) {
+    return file.read((uint8_t*)buffer, numberOfBytes);
+}
+
+bool isAnimationFile(const char filename []) {
+    String filenameString(filename);
+
+#if defined(ESP32)
+    // ESP32 filename includes the full path, so need to remove the path before looking at the filename
+    int pathindex = filenameString.lastIndexOf("/");
+    if(pathindex >= 0)
+        filenameString.remove(0, pathindex + 1);
+#endif
+
+    DBG_OUTPUT_PORT.print(filenameString);
+
+    if ((filenameString[0] == '_') || (filenameString[0] == '~') || (filenameString[0] == '.')) {
+        DBG_OUTPUT_PORT.println(" ignoring: leading _/~/. character");
+        return false;
+    }
+
+    filenameString.toUpperCase();
+    if (filenameString.endsWith(".GIF") != 1) {
+        DBG_OUTPUT_PORT.println(" ignoring: doesn't end of .GIF");
+        return false;
+    }
+
+    DBG_OUTPUT_PORT.println();
+
+    return true;
+}
+
+// Enumerate and possibly display the animated GIF filenames in GIFS directory
+int enumerateGIFFiles(const char *directoryName, boolean displayFilenames) {
+
+    numberOfFiles = 0;
+
+    File directory = FILESYSTEM.open(directoryName);
+    if (!directory) {
+        return -1;
+    }
+
+    File file = directory.openNextFile();
+    while (file) {
+        if (isAnimationFile(file.name())) {
+            numberOfFiles++;
+            if (displayFilenames) {
+                DBG_OUTPUT_PORT.println(file.name());
+            }
+        }
+        file.close();
+        file = directory.openNextFile();
+    }
+
+    file.close();
+    directory.close();
+
+    return numberOfFiles;
+}
+
+// Get the full path/filename of the GIF file with specified index
+void getGIFFilenameByIndex(const char *directoryName, int index, char *pnBuffer) {
+
+    char* filename;
+
+    // Make sure index is in range
+    if ((index < 0) || (index >= numberOfFiles))
+        return;
+
+    File directory = FILESYSTEM.open(directoryName);
+    if (!directory)
+        return;
+
+    File file = directory.openNextFile();
+    while (file && (index >= 0)) {
+        filename = (char*)file.name();
+
+        if (isAnimationFile(file.name())) {
+            index--;
+
+#if !defined(ESP32)
+            // Copy the directory name into the pathname buffer - ESP32 SD Library includes the full path name in the filename, so no need to add the directory name
+            strcpy(pnBuffer, directoryName);
+            // Append the filename to the pathname
+            strcat(pnBuffer, filename);
+#else
+            strcpy(pnBuffer, filename);
+#endif
+        }
+
+        file.close();
+        file = directory.openNextFile();
+    }
+
+    file.close();
+    directory.close();
+}
+
+int openGifFilenameByIndex(const char *directoryName, int index) {
+    char pathname[30]; // long filename will break this... Smash the stack! i.e:
+    /*
+     * Stack smashing protect failure!
+     * 
+     * abort() was called at PC 0x400d9a90 on core 1
+     * 
+     * Backtrace: 0x40088578:0x3ffb1ec0 0x4008877b:0x3ffb1ee0 0x400d9a90:0x3ffb1f00 0x400d1d62:0x3ffb1f20 0x400d182f:0x3ffb1f80 0x400ef86e:0x3ffb1fa0
+     * 
+     * Rebooting...
+
+     */
+
+    getGIFFilenameByIndex(directoryName, index, pathname);
+    
+    DBG_OUTPUT_PORT.print("Pathname: ");
+    DBG_OUTPUT_PORT.println(pathname);
+
+    if(file)
+    {
+        file.close();
+        DBG_OUTPUT_PORT.print("Closing old file...");
+    }
+
+    // Attempt to open the file for reading
+        DBG_OUTPUT_PORT.print("Opening new file...");    
+    file = FILESYSTEM.open(pathname);
+    if (!file) {
+        DBG_OUTPUT_PORT.println("Error opening GIF file");
+        return -1;
+    }
+
+    return 0;
+}
+
+
+// Return a random animated gif path/filename from the specified directory
+void chooseRandomGIFFilename(const char *directoryName, char *pnBuffer) {
+
+    int index = random(numberOfFiles);
+    getGIFFilenameByIndex(directoryName, index, pnBuffer);
+}