Improving logic of mod keys when releasing a key

applications/plugins/mousejacker/mousejacker_ducky.c

@@ -11,6 +11,10 @@ static uint8_t LOGITECH_HELLO[] = {0x00, 0x4F, 0x00, 0x04, 0xB0, 0x10, 0x00, 0x0
 static uint8_t LOGITECH_KEEPALIVE[] = {0x00, 0x40, 0x00, 0x55, 0x6B};
 
 uint8_t prev_hid = 0;
+static bool holding_ctrl = false;
+static bool holding_shift = false;
+static bool holding_alt = false;
+static bool holding_gui = false;
 
 #define RT_THRESHOLD 50
 #define LOGITECH_MIN_CHANNEL 2
@@ -152,6 +156,33 @@ static void build_hid_packet(uint8_t mod, uint8_t hid, uint8_t* payload) {
     checksum(payload, LOGITECH_HID_TEMPLATE_SIZE);
 }
 
+static void release_key(
+    FuriHalSpiBusHandle* handle,
+    uint8_t* addr,
+    uint8_t addr_size,
+    uint8_t rate,
+    PluginState* plugin_state
+) {
+    // This function release keys currently pressed, but keep pressing special keys
+    // if holding mod keys variable are set to true
+
+    uint8_t hid_payload[LOGITECH_HID_TEMPLATE_SIZE] = {0};
+    build_hid_packet(
+        0 | holding_ctrl 
+        | holding_shift << 1 
+        | holding_alt << 2 
+        | holding_gui << 3,
+        0, hid_payload);
+    inject_packet(
+            handle,
+            addr,
+            addr_size,
+            rate,
+            hid_payload,
+            LOGITECH_HID_TEMPLATE_SIZE,
+            plugin_state); // empty hid packet
+}
+
 static void send_hid_packet(
     FuriHalSpiBusHandle* handle,
     uint8_t* addr,
@@ -161,19 +192,15 @@ static void send_hid_packet(
     uint8_t hid,
     PluginState* plugin_state) {
     uint8_t hid_payload[LOGITECH_HID_TEMPLATE_SIZE] = {0};
-    build_hid_packet(0, 0, hid_payload);
+    if(hid == prev_hid )
-    if(hid == prev_hid)
+        release_key(handle, addr, addr_size, rate, plugin_state);
-        inject_packet(
-            handle,
-            addr,
-            addr_size,
-            rate,
-            hid_payload,
-            LOGITECH_HID_TEMPLATE_SIZE,
-            plugin_state); // empty hid packet
 
     prev_hid = hid;
-    build_hid_packet(mod, hid, hid_payload);
+    build_hid_packet(mod 
+        | holding_ctrl 
+        | holding_shift << 1 
+        | holding_alt << 2 
+        | holding_gui << 3, hid, hid_payload);
     inject_packet(
         handle, addr, addr_size, rate, hid_payload, LOGITECH_HID_TEMPLATE_SIZE, plugin_state);
     furi_delay_ms(12);
@@ -269,7 +296,9 @@ static bool mj_process_ducky_line(
     } else if(strncmp(line_tmp, "ALT", strlen("ALT")) == 0) {
         line_tmp = &line_tmp[mj_ducky_get_command_len(line_tmp) + 1];
         if(!mj_get_ducky_key(line_tmp, strlen(line_tmp), &dk)) return false;
-        send_hid_packet(handle, addr, addr_size, rate, dk.mod | 4, dk.hid, plugin_state);
+        holding_alt = true;
+        send_hid_packet(handle, addr, addr_size, rate, dk.mod, dk.hid, plugin_state);
+        holding_alt = false;
         return true;
     } else if(
         strncmp(line_tmp, "GUI", strlen("GUI")) == 0 ||
@@ -277,33 +306,47 @@ static bool mj_process_ducky_line(
         strncmp(line_tmp, "COMMAND", strlen("COMMAND")) == 0) {
         line_tmp = &line_tmp[mj_ducky_get_command_len(line_tmp) + 1];
         if(!mj_get_ducky_key(line_tmp, strlen(line_tmp), &dk)) return false;
-        send_hid_packet(handle, addr, addr_size, rate, dk.mod | 8, dk.hid, plugin_state);
+        holding_gui = true;
+        send_hid_packet(handle, addr, addr_size, rate, dk.mod, dk.hid, plugin_state);
+        holding_gui = false;
         return true;
     } else if(
         strncmp(line_tmp, "CTRL-ALT", strlen("CTRL-ALT")) == 0 ||
         strncmp(line_tmp, "CONTROL-ALT", strlen("CONTROL-ALT")) == 0) {
         line_tmp = &line_tmp[mj_ducky_get_command_len(line_tmp) + 1];
         if(!mj_get_ducky_key(line_tmp, strlen(line_tmp), &dk)) return false;
-        send_hid_packet(handle, addr, addr_size, rate, dk.mod | 4 | 1, dk.hid, plugin_state);
+        holding_ctrl = true;
+        holding_alt = true;
+        send_hid_packet(handle, addr, addr_size, rate, dk.mod, dk.hid, plugin_state);
+        holding_ctrl = false;
+        holding_alt = false;
         return true;
     } else if(
         strncmp(line_tmp, "CTRL-SHIFT", strlen("CTRL-SHIFT")) == 0 ||
         strncmp(line_tmp, "CONTROL-SHIFT", strlen("CONTROL-SHIFT")) == 0) {
         line_tmp = &line_tmp[mj_ducky_get_command_len(line_tmp) + 1];
         if(!mj_get_ducky_key(line_tmp, strlen(line_tmp), &dk)) return false;
-        send_hid_packet(handle, addr, addr_size, rate, dk.mod | 1 | 2, dk.hid, plugin_state);
+        holding_ctrl = true;
+        holding_shift = true;
+        send_hid_packet(handle, addr, addr_size, rate, dk.mod, dk.hid, plugin_state);
+        holding_ctrl = false;
+        holding_shift = false;
         return true;
     } else if(
         strncmp(line_tmp, "CTRL", strlen("CTRL")) == 0 ||
         strncmp(line_tmp, "CONTROL", strlen("CONTROL")) == 0) {
         line_tmp = &line_tmp[mj_ducky_get_command_len(line_tmp) + 1];
         if(!mj_get_ducky_key(line_tmp, strlen(line_tmp), &dk)) return false;
-        send_hid_packet(handle, addr, addr_size, rate, dk.mod | 1, dk.hid, plugin_state);
+        holding_ctrl = true;
+        send_hid_packet(handle, addr, addr_size, rate, dk.mod, dk.hid, plugin_state);
+        holding_ctrl = false;
         return true;
     } else if(strncmp(line_tmp, "SHIFT", strlen("SHIFT")) == 0) {
         line_tmp = &line_tmp[mj_ducky_get_command_len(line_tmp) + 1];
         if(!mj_get_ducky_key(line_tmp, strlen(line_tmp), &dk)) return false;
-        send_hid_packet(handle, addr, addr_size, rate, dk.mod | 2, dk.hid, plugin_state);
+        holding_shift = true;
+        send_hid_packet(handle, addr, addr_size, rate, dk.mod, dk.hid, plugin_state);
+        holding_shift = false;
         return true;
     } else if(
         strncmp(line_tmp, "ESC", strlen("ESC")) == 0 ||