hex-editor/src/hlist.c

#include "hlist.h"
#include <justui/jwidget.h>
#include <justui/jwidget-api.h>

#include <gint/display.h>
#include <stdlib.h>

/* Type identifier for hlist */
static int hlist_type_id = -1;

/* Events */
uint16_t HLIST_VALIDATED;
uint16_t HLIST_CANCELED;

hlist *hlist_create(void *parent)
{
    if(hlist_type_id < 0) return NULL;

    hlist *l = malloc(sizeof *l);
    if(!l) return NULL;

    jwidget_init(&l->widget, hlist_type_id, parent);

    l->entries = NULL;
    l->entry_size = 0;
    l->entry_count = 0;

    l->render_height = 0;
    l->render_func = NULL;

    l->selected_index = -1;

    l->cursor = 0;
    l->scroll = 0;
    l->visible_lines = 0;

    return l;
}

static void count_visible_lines(hlist *l)
{
    int ch = jwidget_content_height(l);
    l->visible_lines = ch / l->render_height;
}

void hlist_set_entries(hlist *l, void *entries, size_t entry_size, int count)
{
    l->entries = entries;
    l->entry_size = entry_size;
    l->entry_count = count;
    l->cursor = 0;
    l->scroll = 0;
    l->widget.update = true;
}

void hlist_set_renderer(hlist *l, int render_height, void *render)
{
    if(l->render_height != render_height)
        l->widget.dirty = true;

    l->render_height = render_height;
    l->render_func = render;
    l->widget.update = true;
}

int hlist_selected_index(hlist *l)
{
    return l->selected_index;
}

// Polymorphic widget operations //

static void hlist_poly_csize(void *l0)
{
    hlist *l = l0;
    int lines = l->entry_count;
    int lheight = l->render_height;

    l->widget.w = 128;
    l->widget.h = (lines && lheight) ? lines * lheight : 64;
}

static void hlist_poly_layout(void *l0)
{
    hlist *l = l0;
    count_visible_lines(l);
}

static void hlist_poly_render(void *l0, int x, int y)
{
    hlist *l = l0;
    if(!l->entries)
        return;

    int cw = jwidget_content_width(l);

    for(int i = 0; i < l->visible_lines && l->scroll+i < l->entry_count; i++) {
        bool selected = (l->cursor == l->scroll + i);
        void *entry = l->entries + l->entry_size * i;

        int line_y = y + l->render_height * i;
        if(l->render_func)
            l->render_func(x, line_y, cw, l->render_height, entry, selected);
    }
}

static bool hlist_poly_event(void *l0, jevent e)
{
    hlist *l = l0;
    if(!l->entries || e.type != JWIDGET_KEY)
        return false;

    key_event_t ev = e.key;
    if(ev.type != KEYEV_DOWN && ev.type != KEYEV_HOLD)
        return false;
    int key = ev.key;

    bool moved = false;

    if(key == KEY_UP && l->cursor > 0) {
        l->cursor = ev.shift ? 0 : l->cursor - 1;
        moved = true;
    }
    if(key == KEY_DOWN && l->cursor < l->entry_count - 1) {
        l->cursor = ev.shift ? l->entry_count - 1 : l->cursor + 1;
        moved = true;
    }

    if(l->scroll > 0 && l->cursor <= l->scroll)
        l->scroll = max(l->cursor - 1, 0);
    if(l->scroll + l->visible_lines < l->entry_count
            && l->cursor >= l->scroll + l->visible_lines - 2) {
        l->scroll = min(l->cursor - l->visible_lines + 2,
                        l->entry_count - l->visible_lines);
    }

    if(moved) {
        l->widget.update = true;
        return true;
    }

    if(key == KEY_EXIT) {
        jwidget_emit(l, (jevent){ .type = HLIST_CANCELED });
        return true;
    }
    else if(key == KEY_EXE) {
        l->selected_index = l->cursor;
        jwidget_emit(l, (jevent){ .type = HLIST_VALIDATED });
        return true;
    }

    return false;
}

/* hlist type definition */
static jwidget_poly type_hlist = {
    .name   = "hlist",
    .csize  = hlist_poly_csize,
    .layout = hlist_poly_layout,
    .render = hlist_poly_render,
    .event  = hlist_poly_event,
};

__attribute__((constructor(1004)))
static void j_register_hlist(void)
{
    hlist_type_id = j_register_widget(&type_hlist, "jwidget");
    HLIST_VALIDATED = j_register_event();
    HLIST_CANCELED = j_register_event();
}