Gamepad (Linux): detect battery capacity

src/detection/gamepad/gamepad.h

@@ -6,6 +6,7 @@ typedef struct FFGamepadDevice
 {
     FFstrbuf identifier;
     FFstrbuf name;
+    uint8_t battery; // 0-100%
 } FFGamepadDevice;
 
 const char* ffDetectGamepad(FFlist* devices /* List of FFGamepadDevice */);

src/detection/gamepad/gamepad_apple.c

@@ -13,6 +13,7 @@ static void enumSet(const void* value, void *context)
     ffCfStrGetString(serialNumber, &device->identifier);
     ffStrbufInit(&device->name);
     ffCfStrGetString(product, &device->name);
+    device->battery = 0;
 }
 
 const char* ffDetectGamepad(FFlist* devices /* List of FFGamepadDevice */)

src/detection/gamepad/gamepad_bsd.c

@@ -44,6 +44,7 @@ const char* ffDetectGamepad(FFlist* devices /* List of FFGamepadDevice */)
                     FFGamepadDevice* device = (FFGamepadDevice*) ffListAdd(devices);
                     ffStrbufInitS(&device->identifier, di.udi_serial);
                     ffStrbufInitF(&device->name, "%s %s", di.udi_vendor, di.udi_product);
+                    device->battery = 0;
                 }
             }
         }

src/detection/gamepad/gamepad_linux.c

@@ -5,39 +5,72 @@
 #include <dirent.h>
 #include <ctype.h>
 
+static void detectGamepad(FFlist* devices, FFstrbuf* name, FFstrbuf* path)
+{
+    uint32_t baseLen = path->length;
+    FFGamepadDevice* device = (FFGamepadDevice*) ffListAdd(devices);
+    ffStrbufInit(&device->identifier);
+    ffStrbufInitMove(&device->name, name);
+    device->battery = 0;
+
+    ffStrbufAppendS(path, "uniq");
+    if (ffAppendFileBuffer(path->chars, &device->identifier))
+        ffStrbufTrimRightSpace(&device->identifier);
+
+    ffStrbufSubstrBefore(path, baseLen);
+    ffStrbufAppendS(path, "device/power_supply/"); // /sys/class/input/jsX/device/device/power_supply
+
+    FF_AUTO_CLOSE_DIR DIR* dirp = opendir(path->chars);
+    if (dirp)
+    {
+        struct dirent* entry;
+        while ((entry = readdir(dirp)) != NULL)
+        {
+            if (entry->d_name[0] == '.' || (entry->d_type != DT_DIR && entry->d_type != DT_UNKNOWN))
+                continue;
+            ffStrbufAppendS(path, entry->d_name);
+            ffStrbufAppendS(path, "/capacity"); // /sys/class/input/jsX/device/device/power_supply/XXX/capacity
+            char capacity[32];
+            ssize_t nRead = ffReadFileData(path->chars, sizeof(capacity) - 1, capacity);
+            if (nRead > 0)
+            {
+                capacity[nRead] = '\0';
+                device->battery = (uint8_t) strtoul(capacity, NULL, 10);
+            }
+        }
+    }
+}
+
 const char* ffDetectGamepad(FFlist* devices /* List of FFGamepadDevice */)
 {
-    DIR* dirp = opendir("/sys/class/input/");
-    if(dirp == NULL)
+    FF_AUTO_CLOSE_DIR DIR* dirp = opendir("/sys/class/input/");
+    if (dirp == NULL)
         return "opendir(\"/sys/class/input/\") == NULL";
 
     FF_STRBUF_AUTO_DESTROY path = ffStrbufCreateS("/sys/class/input/");
     uint32_t baseLen = path.length;
 
     struct dirent* entry;
-    while((entry = readdir(dirp)) != NULL)
+    while ((entry = readdir(dirp)) != NULL)
     {
-        if(!ffStrStartsWith(entry->d_name, "js"))
+        if (!ffStrStartsWith(entry->d_name, "js"))
             continue;
-        if(!isdigit(entry->d_name[2]))
+        if (!isdigit(entry->d_name[2]))
             continue;
 
         ffStrbufAppendS(&path, entry->d_name);
         ffStrbufAppendS(&path, "/device/name");
 
-        if (ffPathExists(path.chars, FF_PATHTYPE_FILE))
+        FF_STRBUF_AUTO_DESTROY name = ffStrbufCreate();
+        if (ffAppendFileBuffer(path.chars, &name))
         {
-            FFGamepadDevice* device = (FFGamepadDevice*) ffListAdd(devices);
-            ffStrbufInitS(&device->identifier, entry->d_name);
-            ffStrbufInit(&device->name);
-            if (ffAppendFileBuffer(path.chars, &device->name))
-                ffStrbufTrimRightSpace(&device->name);
+            ffStrbufTrimRightSpace(&name);
+            ffStrbufSubstrBefore(&path, path.length - 4);
+            detectGamepad(devices, &name, &path);
         }
 
         ffStrbufSubstrBefore(&path, baseLen);
     }
 
-    closedir(dirp);
-
     return NULL;
 }

src/detection/gamepad/gamepad_windows.c

@@ -119,6 +119,7 @@ const char* ffDetectGamepad(FFlist* devices /* List of FFGamepadDevice */)
         FFGamepadDevice* device = (FFGamepadDevice*) ffListAdd(devices);
         ffStrbufInitWS(&device->identifier, devName);
         ffStrbufInit(&device->name);
+        device->battery = 0;
 
         const char* knownGamepad = detectKnownGamepad(rdi.hid.dwVendorId, rdi.hid.dwProductId);
         if (knownGamepad)

src/modules/gamepad/gamepad.c

@@ -1,3 +1,4 @@
+#include "common/bar.h"
 #include "common/printing.h"
 #include "common/jsonconfig.h"
 #include "detection/gamepad/gamepad.h"
@@ -10,14 +11,21 @@ static void printDevice(FFGamepadOptions* options, const FFGamepadDevice* device
 {
     if(options->moduleArgs.outputFormat.length == 0)
     {
+        FF_STRBUF_AUTO_DESTROY buffer = ffStrbufCreateCopy(&device->name);
         ffPrintLogoAndKey(FF_GAMEPAD_MODULE_NAME, index, &options->moduleArgs, FF_PRINT_TYPE_DEFAULT);
-        ffStrbufPutTo(&device->name, stdout);
+        if (device->battery > 0 && device->battery <= 100)
+        {
+            ffStrbufAppendC(&buffer, ' ');
+            ffAppendPercentNum(&buffer, device->battery, 51, 21, true);
+        }
+        ffStrbufPutTo(&buffer, stdout);
     }
     else
     {
         ffPrintFormat(FF_GAMEPAD_MODULE_NAME, index, &options->moduleArgs, FF_GAMEPAD_NUM_FORMAT_ARGS, (FFformatarg[]) {
             {FF_FORMAT_ARG_TYPE_STRBUF, &device->name},
             {FF_FORMAT_ARG_TYPE_STRBUF, &device->identifier},
+            {FF_FORMAT_ARG_TYPE_UINT8, &device->battery},
         });
     }
 }
@@ -121,7 +129,8 @@ void ffPrintGamepadHelpFormat(void)
 {
     ffPrintModuleFormatHelp(FF_GAMEPAD_MODULE_NAME, "{1}", FF_GAMEPAD_NUM_FORMAT_ARGS, (const char* []) {
         "Name",
-        "Identifier"
+        "Identifier",
+        "Battery",
     });
 }