DVX_GUI/core/widgetClass.c

#define DVX_WIDGET_IMPL
// widgetClass.c -- Widget class table, API registry, and dynamic registration
//
// widgetClassTable is a stb_ds dynamic array.  Widget DXEs call
// wgtRegisterClass() during wgtRegister() to append their class
// definition and receive a runtime type ID.  No widget types are
// known at compile time.
//
// The API registry uses an stb_ds string hashmap for O(1) lookup.
// Each widget DXE calls wgtRegisterApi("name", &sApi) during
// wgtRegister().  App/core code calls wgtGetApi("name") to get
// the API pointer, then casts and calls through it.

#include "dvxWidgetPlugin.h"
#include "stb_ds_wrap.h"

#include <string.h>
#include <strings.h>

// stb_ds dynamic array of class pointers.  Grows on each
// wgtRegisterClass() call.  Index = type ID.
const WidgetClassT **widgetClassTable = NULL;

// stb_ds string hashmap: key = widget name, value = API pointer
typedef struct {
    char       *key;    // stb_ds string key (heap-allocated by shput)
    const void *value;
} ApiMapEntryT;

static ApiMapEntryT *sApiMap = NULL;

// stb_ds string hashmap: key = widget name, value = interface descriptor
typedef struct {
    char             *key;
    const WgtIfaceT  *value;
} IfaceMapEntryT;

static IfaceMapEntryT *sIfaceMap = NULL;


// ============================================================
// wgtGetApi
// ============================================================
//
// Look up a widget API by name.  O(1) via stb_ds string hashmap.
// Returns NULL if the widget is not loaded.  Callers should still
// cache the result in a static local to skip even the hash.

const void *wgtGetApi(const char *name) {
    if (!name) {
        return NULL;
    }

    int32_t idx = shgeti(sApiMap, name);

    if (idx < 0) {
        return NULL;
    }

    return sApiMap[idx].value;
}


// ============================================================
// wgtFindByBasName
// ============================================================
//
// Scan all registered interfaces for one whose basName matches
// (case-insensitive). Returns the widget type name, or NULL.

const char *wgtFindByBasName(const char *basName) {
    if (!basName || !sIfaceMap) {
        return NULL;
    }

    for (size_t i = 0; i < shlenu(sIfaceMap); i++) {
        if (sIfaceMap[i].value && sIfaceMap[i].value->basName) {
            if (strcasecmp(sIfaceMap[i].value->basName, basName) == 0) {
                return sIfaceMap[i].key;
            }
        }
    }

    return NULL;
}


// ============================================================
// wgtGetIface
// ============================================================
//
// Look up a widget interface descriptor by type name.

const WgtIfaceT *wgtGetIface(const char *name) {
    if (!name) {
        return NULL;
    }

    int32_t idx = shgeti(sIfaceMap, name);

    if (idx < 0) {
        return NULL;
    }

    return sIfaceMap[idx].value;
}


// ============================================================
// wgtRegisterApi
// ============================================================
//
// Register a widget's public API struct under a name.  Called by
// each widget DXE during wgtRegister().

void wgtRegisterApi(const char *name, const void *api) {
    if (!name || !api) {
        return;
    }

    shput(sApiMap, name, api);
}


// ============================================================
// wgtRegisterIface
// ============================================================
//
// Register a widget's interface descriptor under its type name.
// Called by widget DXEs during wgtRegister().

void wgtRegisterIface(const char *name, const WgtIfaceT *iface) {
    if (!name || !iface) {
        return;
    }

    shput(sIfaceMap, name, iface);
}


// ============================================================
// wgtRegisterClass
// ============================================================
//
// Appends a class to the table and returns the assigned type ID.
// The ID is simply the array index.

int32_t wgtRegisterClass(const WidgetClassT *wclass) {
    if (!wclass) {
        return -1;
    }

    int32_t id = arrlen(widgetClassTable);
    arrput(widgetClassTable, wclass);
    return id;
}