Initial commit

.gitignore

@@ -0,0 +1,2 @@
+tmp/
+texec

LICENSE

@@ -0,0 +1,13 @@
+Copyright 2025 Johannes Findeisen
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

Makefile

@@ -0,0 +1,12 @@
+all:
+	gcc -o texec texec.c -lX11 -lpng
+
+clean:
+	rm -rf texec
+
+install:
+	install -g 0 -o 0 -m 0655 ./texec /usr/bin/
+
+uninstall:
+	rm -rf /usr/bin/texec
+

texec.c

@@ -0,0 +1,171 @@
+/*
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * .c - Minimal X11 tray applet with mandatory PNG icon (32x32)
+ *
+ * Compile:
+ *   gcc -o gexec_xembed gexec_xembed.c -lX11 -lXrender -lpng
+ *
+ * Usage:
+ *   ./gexec_xembed "<command>" <icon.png>
+ *
+ * Left-click: execute command
+ * Right-click: quit applet
+ */
+
+#include <X11/Xlib.h>
+#include <X11/Xatom.h>
+#include <X11/Xutil.h>
+//#include <X11/extensions/Xrender.h>
+#include <png.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+
+#define WIDTH 24
+#define HEIGHT 24
+
+static Display *dpy;
+static int screen;
+static Window icon_win;
+static char *g_command;
+
+void execute_command() {
+    if (!g_command) return;
+    pid_t pid = fork();
+    if (pid == 0) {
+        setsid();
+        execl("/bin/sh", "sh", "-c", g_command, (char *)NULL);
+        _exit(127);
+    }
+}
+
+/* Minimal PNG loader into XImage */
+XImage *load_png(const char *filename) {
+    FILE *fp = fopen(filename, "rb");
+    if (!fp) return NULL;
+
+    png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING,NULL,NULL,NULL);
+    png_infop info = png_create_info_struct(png);
+    if (setjmp(png_jmpbuf(png))) return NULL;
+
+    png_init_io(png, fp);
+    png_read_info(png, info);
+
+    int w = png_get_image_width(png, info);
+    int h = png_get_image_height(png, info);
+    png_byte color_type = png_get_color_type(png, info);
+    png_byte bit_depth = png_get_bit_depth(png, info);
+
+    if (bit_depth == 16) png_set_strip_16(png);
+    if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_palette_to_rgb(png);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png);
+    if (png_get_valid(png, info, PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png);
+    png_set_filler(png, 0xFF, PNG_FILLER_AFTER);
+    png_read_update_info(png, info);
+
+    png_bytep *rows = (png_bytep*)malloc(sizeof(png_bytep) * h);
+    for (int y=0; y<h; y++) {
+        rows[y] = (png_byte*)malloc(4*w);
+    }
+
+    png_read_image(png, rows);
+    fclose(fp);
+
+    XImage *img = XCreateImage(dpy, CopyFromParent, 24, ZPixmap, 0,
+                               malloc(w*h*4), w, h, 32, 0);
+
+    for (int y=0; y<h; y++) {
+        for (int x=0; x<w; x++) {
+            png_bytep px = &(rows[y][x*4]);
+            unsigned long pixel = (px[0]<<16) | (px[1]<<8) | px[2];
+            XPutPixel(img, x, y, pixel);
+        }
+    }
+
+    for (int y=0; y<h; y++) {
+        free(rows[y]);
+    }
+    free(rows);
+    png_destroy_read_struct(&png, &info, NULL);
+    return img;
+}
+
+void draw_icon(Window win, const char *icon_path) {
+    GC gc = XCreateGC(dpy, win, 0, NULL);
+    XImage *img = load_png(icon_path);
+    if (!img) {
+        fprintf(stderr,"Failed to load PNG icon: %s\n", icon_path);
+        exit(1);
+    }
+    XPutImage(dpy, win, gc, img, 0,0,0,0, img->width, img->height);
+    XDestroyImage(img);
+    XFreeGC(dpy,gc);
+}
+
+int main(int argc, char *argv[]) {
+    if (argc < 3) {
+        fprintf(stderr,"Usage: %s <command> <icon.png>\n",argv[0]);
+        return 1;
+    }
+    g_command = argv[1];
+    char *icon_path = argv[2];
+
+    signal(SIGCHLD, SIG_IGN);
+
+    dpy = XOpenDisplay(NULL);
+    if (!dpy) {
+        fprintf(stderr,"Cannot open display\n");
+        return 1;
+    }
+    screen = DefaultScreen(dpy);
+
+    Atom _NET_SYSTEM_TRAY_S0 = XInternAtom(dpy, "_NET_SYSTEM_TRAY_S0", False);
+    Window tray_win = XGetSelectionOwner(dpy, _NET_SYSTEM_TRAY_S0);
+    if (tray_win == None) {
+        fprintf(stderr,"No system tray found\n");
+        return 1;
+    }
+
+    icon_win = XCreateSimpleWindow(dpy, DefaultRootWindow(dpy),
+                                   0,0, WIDTH, HEIGHT, 1,
+                                   BlackPixel(dpy,screen),
+                                   WhitePixel(dpy,screen));
+    XSelectInput(dpy, icon_win, ExposureMask | ButtonPressMask);
+
+    // Send dock request
+    XEvent ev;
+    memset(&ev, 0, sizeof(ev));
+    ev.xclient.type = ClientMessage;
+    ev.xclient.window = icon_win;
+    ev.xclient.message_type = XInternAtom(dpy,"_NET_SYSTEM_TRAY_OPCODE",False);
+    ev.xclient.format = 32;
+    ev.xclient.data.l[0] = CurrentTime;
+    ev.xclient.data.l[1] = 0; // SYSTEM_TRAY_REQUEST_DOCK
+    ev.xclient.data.l[2] = icon_win;
+    XSendEvent(dpy, tray_win, False, NoEventMask, &ev);
+
+    XMapWindow(dpy, icon_win);
+    draw_icon(icon_win, icon_path);
+
+    XEvent xev;
+    while (1) {
+        XNextEvent(dpy, &xev);
+        if (xev.xany.window == icon_win) {
+            if (xev.type == Expose) draw_icon(icon_win, icon_path);
+            else if (xev.type == ButtonPress) {
+                if (xev.xbutton.button == 1) execute_command(); // left-click
+                else if (xev.xbutton.button == 3) break;        // right-click: quit
+            }
+        }
+    }
+
+    XDestroyWindow(dpy, icon_win);
+    XCloseDisplay(dpy);
+    return 0;
+}
+