Clickable conky thingies

buttonpress.c

/* Compile with `make CFLAGS='-std=c99' LOADLIBES='-lX11' buttonpress` */

#include <X11/Xlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>

Window GetWindowFromID(Display *display, Window start, int targetid, int level) {
    Window root, parent, *children;
    unsigned int nchildren;

    //for (int i = 0; i < level; ++i) printf("  ");
    //printf("0x%lx", start);

    int status = XQueryTree(display, start, &root, &parent, &children, &nchildren);
    if (!status) {
        fprintf(stderr, "Failed to query tree\n");
        return 0;
    }
    //printf(" %d\n", nchildren);
    //fflush(stdout);

    for (int i = 0; i < nchildren; ++i) {
        if (children[i] == targetid) return children[i];
    }

    ++level;

    // Nothing matched, try for each child
    for (int i = 0; i < nchildren; ++i) {
        Window w = GetWindowFromID(display, children[i], targetid, level);
        if (w) return w;
    }

    return 0;
}

int main(int argc, char **argv) {
    if (argc < 2) return 1;

    Display *display = XOpenDisplay(NULL);

    int id = strtol(argv[1], NULL, 0);
    if (!id) return 3;

    //printf("Looking for window with id 0x%x\n", id);

    Window win = GetWindowFromID(display, DefaultRootWindow(display), id, 0);
    if (!win) return 2;

    XSelectInput(display, win, ButtonReleaseMask);

    bool quit = false;
    XEvent ev;
    while (!quit) {
        XNextEvent(display, &ev);
        switch (ev.type) {
            case ButtonRelease: {
                XButtonEvent bev = ev.xbutton;
                printf("win: %d,%d; root: %d,%d; state: %d; button: %d\n",
                        bev.x, bev.y,
                        bev.x_root, bev.y_root,
                        bev.state, bev.button);
                fflush(stdout);
                break;
            }
        }
    }

    XCloseDisplay(display);

    return 0;
}

buttonpress.lua

require 'cairo'

local initialized = false
local clickfile
local clickcommand

local hotspots = {}

local function context()
    if conky_window == nil then return nil end

    local surface = cairo_xlib_surface_create(conky_window.display, conky_window.drawable, conky_window.visual, conky_window.width, conky_window.height)
    local context = cairo_create(surface)

    return context
end

local function initialize()
    if initialized or conky_window == nil then return end

    local runtimedir = os.getenv("XDG_RUNTIME_DIR")
    if runtimedir == nil then runtimedir = "/tmp" end
    if runtimedir:sub(#runtimedir,#runtimedir) ~= "/" then
        runtimedir = runtimedir .. "/"
    end

    clickfile = string.format("%sconky_%d", runtimedir, conky_window.window)

    clickcommand = string.format("buttonpress 0x%x >>%s 2>&1 &", conky_window.window, clickfile)
    os.execute(clickcommand)
    clickcommand = string.format("buttonpress 0x%x", conky_window.window)

    table.insert(hotspots, { x1 = 10, y1 = 0, x2 = 30, y2 = 30, click = false})

    initialized = true
end

function conky_shutdown()
    local pidcmd = string.format("ps a | grep '%s' | grep -v grep | awk '{print $1}'", clickcommand)
    local ps = io.popen(pidcmd)
    local pid = ps:read("*l")
    if not pid == nil then
        print(string.format("killing pid %s", pid))
        os.execute(string.format("kill -s 15 %s", pid))
    end
    os.remove(clickfile)
end

local function read_clicks()
    local trunc = false
    local points = {}
    local f = io.open(clickfile, "r")
    for line in f:lines() do
        --print(line)
        -- win: 6,10; root: 6,29; state: 272; button: 1
        local x,y = line:match("win: (%d+),(%d+)")
        x = tonumber(x)
        y = tonumber(y)
        table.insert(points, {x = x, y = y})
    end
    f:close()

    -- trim the file
    f = io.open(clickfile, "w")
    f:close()

    --TODO see if repeated clicks should be ignored
    for i,p in ipairs(points) do
        --print(string.format("point: %d,%d", p.x, p.y))
        for j,h in ipairs(hotspots) do
            if p.x > h.x1 and p.x < h.x2 and
               p.y > h.y1 and p.y < h.y2 then
                --print("clicked")
                h.click = not h.click
            end
        end
    end

    points = {}
end

function conky_draw_pre()
    if conky_window == nil then return end
    if not initialized then initialize() end

    local c = context()
    if c == nil then return end

    read_clicks()

    if hotspots[1].click then
        cairo_set_source_rgb(c, 1, 0, 0)
    else
        cairo_set_source_rgb(c, 0, 1, 0)
    end
    cairo_rectangle(c, 10, 0, 20, 20)
    cairo_fill(c)
end

buttonpressrc

own_window yes
own_window_type panel

alignment tl
minimum_size 1366 10

lua_load dock.lua
lua_draw_hook_pre draw_pre
lua_shutdown_hook shutdown

TEXT
$updates