feat: Added command line interface support (#1172)

System design has been discussed on discord

Should fix #948

---------

Co-authored-by: WerWolv <werwolv98@gmail.com>

lib/libimhex/include/hex/api/event.hpp

@@ -232,4 +232,10 @@ namespace hex {
     EVENT_DEF(RequestOpenInfoPopup, const std::string);
     EVENT_DEF(RequestOpenErrorPopup, const std::string);
     EVENT_DEF(RequestOpenFatalPopup, const std::string);
+
+
+    /**
+     * @brief Send an event to the main Imhex instance
+     */
+    EVENT_DEF(SendMessageToMainInstance, const std::string, const std::vector<u8>&);
 }

lib/libimhex/include/hex/api/imhex_api.hpp

@@ -322,7 +322,10 @@ namespace hex {
         /* Functions to interact with various ImHex system settings */
         namespace System {
 
+            bool isMainInstance();
+
             namespace impl {
+                void setMainInstanceStatus(bool status);
 
                 void setMainWindowPosition(i32 x, i32 y);
                 void setMainWindowSize(u32 width, u32 height);
@@ -331,8 +334,6 @@ namespace hex {
                 void setGlobalScale(float scale);
                 void setNativeScale(float scale);
 
-                void setProgramArguments(int argc, char **argv, char **envp);
-
                 void setBorderlessWindowMode(bool enabled);
 
                 void setCustomFontPath(const std::fs::path &path);
@@ -383,20 +384,6 @@ namespace hex {
             void setTaskBarProgress(TaskProgressState state, TaskProgressType type, u32 progress);
 
 
-            /**
-             * @brief Gets the current program arguments
-             * @return The current program arguments
-             */
-            const ProgramArguments &getProgramArguments();
-
-            /**
-             * @brief Gets a program argument
-             * @param index The index of the argument to get
-             * @return The argument at the given index
-             */
-            std::optional<std::u8string> getProgramArgument(int index);
-
-
             /**
              * @brief Gets the current target FPS
              * @return The current target FPS
@@ -545,6 +532,26 @@ namespace hex {
             std::string getCommitBranch();
         }
 
+        /**
+         * @brief Cross-instance messaging system
+         * This allows you to send messages to the "main" instance of ImHex running, from any other instance
+         */
+        namespace Messaging {
+            
+            namespace impl {
+                using MessagingHandler = std::function<void(const std::vector<u8> &)>;
+
+                std::map<std::string, MessagingHandler> &getHandlers();
+
+                void runHandler(const std::string &eventName, const std::vector<u8> &args);
+            }
+
+            /**
+             * @brief Register the handler for this specific event name
+             */
+            void registerHandler(const std::string &eventName, const impl::MessagingHandler &handler);
+        }
+
     }
 
 }

lib/libimhex/include/hex/api/plugin_manager.hpp

@@ -5,6 +5,7 @@
 #include <hex/helpers/fmt.hpp>
 #include <hex/helpers/fs.hpp>
 
+#include <span>
 #include <string>
 
 #if defined(OS_WINDOWS)
@@ -17,6 +18,17 @@ struct ImGuiContext;
 
 namespace hex {
 
+    struct SubCommand {
+        std::string commandKey;
+        std::string commandDesc;
+        std::function<void(const std::vector<std::string>&)> callback;
+    };
+
+    struct SubCommandList {
+        hex::SubCommand *subCommands;
+        size_t size;
+    };
+
     class Plugin {
     public:
         explicit Plugin(const std::fs::path &path);
@@ -36,6 +48,8 @@ namespace hex {
 
         [[nodiscard]] bool isLoaded() const;
 
+        [[nodiscard]] std::span<SubCommand> getSubCommands() const;
+
     private:
         using InitializePluginFunc     = void (*)();
         using GetPluginNameFunc        = const char *(*)();
@@ -44,6 +58,7 @@ namespace hex {
         using GetCompatibleVersionFunc = const char *(*)();
         using SetImGuiContextFunc      = void (*)(ImGuiContext *);
         using IsBuiltinPluginFunc      = bool (*)();
+        using GetSubCommandsFunc       = SubCommandList* (*)();
 
         #if defined(OS_WINDOWS)
             HMODULE m_handle = nullptr;
@@ -61,6 +76,7 @@ namespace hex {
         GetCompatibleVersionFunc m_getCompatibleVersionFunction = nullptr;
         SetImGuiContextFunc m_setImGuiContextFunction           = nullptr;
         IsBuiltinPluginFunc m_isBuiltinPluginFunction           = nullptr;
+        GetSubCommandsFunc m_getSubCommandsFunction             = nullptr;
 
         template<typename T>
         [[nodiscard]] auto getPluginFunction(const std::string &symbol) {

lib/libimhex/include/hex/plugin.hpp

@@ -1,9 +1,14 @@
 #pragma once
 
+#include <string>
+
 #include <imgui.h>
 #include <imgui_internal.h>
 
 #include <hex.hpp>
+#include <hex/api/plugin_manager.hpp>
+
+#include <wolv/utils/string.hpp>
 
 /**
  * This macro is used to define all the required entry points for a plugin.
@@ -21,3 +26,23 @@
         GImGui = ctx;                                                                                      \
     }                                                                                                      \
     extern "C" [[gnu::visibility("default")]] void initializePlugin()
+
+/**
+ * This macro is used to define subcommands defined by the plugin
+ * A subcommand consists of a key, a description, and a callback
+ * The key is what the first argument to ImHex should be, prefixed by `--`
+ * For example, if the key if `help`, ImHex should be started with `--help` as its first argument to trigger the subcommand
+ * when the subcommand is triggerred, it's callback will be executed. The callback is executed BEFORE most of ImHex initialization
+ * so to do anything meaningful, you should subscribe to an event (like EventImHexStartupFinished) and run your code there.
+ */
+#define IMHEX_PLUGIN_SUBCOMMANDS() IMHEX_PLUGIN_SUBCOMMANDS_IMPL()
+
+#define IMHEX_PLUGIN_SUBCOMMANDS_IMPL()                                                 \
+    extern std::vector<hex::SubCommand> g_subCommands;                                  \
+    extern "C" [[gnu::visibility("default")]] hex::SubCommandList getSubCommands() {    \
+        return hex::SubCommandList {                                                    \
+            g_subCommands.data(),                                                       \
+            g_subCommands.size()                                                        \
+        };                                                                              \
+    }                                                                                   \
+    std::vector<hex::SubCommand> g_subCommands

lib/libimhex/include/hex/subcommands/subcommands.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include<vector>
+#include<string>
+#include<functional>
+
+namespace hex::subcommands {
+    /**
+     * @brief Internal method - takes all the arguments ImHex received from the command line,
+     * and determine which subcommands to run, with which arguments.
+     * In some cases, the subcommand or this function directly might exit the program
+     * (e.g. --help, or when forwarding providers to open to another instance)
+     * and so this function might not return
+     */
+    void processArguments(const std::vector<std::string> &args);
+
+    
+    /**
+     * @brief Forward the given command to the main instance (might be this instance)
+     * The callback will be executed after EventImHexStartupFinished
+     */
+    void forwardSubCommand(const std::string &cmdName, const std::vector<std::string> &args);
+
+    using ForwardCommandHandler = std::function<void(const std::vector<std::string> &)>;
+    
+    /**
+     * @brief Register the handler for this specific command name
+     */
+    void registerSubCommand(const std::string &cmdName, const ForwardCommandHandler &handler);
+}