cursor-lin.c

/*
 * CDDL HEADER START
 *
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 *
 * CDDL HEADER END
*/
/*
 * Copyright 2020 Saso Kiselkov. All rights reserved.
 */
 
#include <X11/Xcursor/Xcursor.h>
 
#include "acfutils/cursor.h"
#include "acfutils/dr.h"
#include "acfutils/helpers.h"
#include "acfutils/png.h"
#include "acfutils/safe_alloc.h"
 
struct cursor_s {
    Cursor      crs;
};
 
/*
 * Because cursors are only ever created & used from the main rendering
 * thread, it is safe to use a simple unprotected global var with a refcount.
 */
static int  dpy_refcount = 0;
static Display  *dpy = NULL;
 
cursor_t *
cursor_read_from_file(const char *filename_png)
{
    cursor_t *cursor;
    uint8_t *buf;
    int w, h;
    XcursorImage img = { .pixels = NULL };
 
    ASSERT(filename_png != NULL);
 
    buf = png_load_from_file_rgba(filename_png, &w, &h);
    if (buf == NULL)
        return (NULL);
 
    if (dpy_refcount == 0)
        dpy = XOpenDisplay(NULL);
    if (dpy == NULL) {
        logMsg("Can't open display");
        free(buf);
        return (NULL);
    }
    dpy_refcount++;
 
    img.size = w;
    img.width = w;
    img.height = h;
    img.xhot = w / 2;
    img.yhot = h / 2;
    img.pixels = (XcursorPixel *)buf;
    cursor = safe_calloc(1, sizeof (*cursor));
    cursor->crs = XcursorImageLoadCursor(dpy, &img);
 
    free(buf);
 
    return (cursor);
}
 
void
cursor_free(cursor_t *cursor)
{
    if (cursor == NULL)
        return;
 
    ASSERT(dpy != NULL);
    XFreeCursor(dpy, cursor->crs);
    free(cursor);
 
    dpy_refcount--;
    ASSERT3S(dpy_refcount, >=, 0);
    if (dpy_refcount == 0) {
        XCloseDisplay(dpy);
        dpy = NULL;
    }
}
 
void
cursor_make_current(cursor_t *cursor)
{
    dr_t system_window_dr;
    int win_ptr[2];
    Window win;
 
    ASSERT(cursor != NULL);
    ASSERT(dpy != NULL);
    fdr_find(&system_window_dr, "sim/operation/windows/system_window_64");
    VERIFY3S(dr_getvi(&system_window_dr, win_ptr, 0, 2), ==, 2);
    memcpy(&win, win_ptr, sizeof (void *));
 
    XDefineCursor(dpy, win, cursor->crs);
    XFlush(dpy);
}