source/interposer/interposer-x11.cpp

   1 /*
   2  * Carla Interposer for X11 Window Mapping
   3  * Copyright (C) 2014-2022 Filipe Coelho <falktx@falktx.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of
   8  * the License, or any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * For a full copy of the GNU General Public License see the doc/GPL.txt file.
  16  */
  17
  18 #include "CarlaUtils.hpp"
  19
  20 #include <dlfcn.h>
  21 #include <X11/Xlib.h>
  22
  23 // --------------------------------------------------------------------------------------------------------------------
  24 // Function typedefs
  25
  26 typedef int (*XWindowFunc)(Display*, Window);
  27
  28 // --------------------------------------------------------------------------------------------------------------------
  29 // Calling the real functions
  30
  31 static int real_XMapWindow(Display* display, Window window)
  32 {
  33     static const XWindowFunc func = (XWindowFunc)::dlsym(RTLD_NEXT, "XMapWindow");
  34     CARLA_SAFE_ASSERT_RETURN(func != nullptr, 0);
  35
  36     return func(display, window);
  37 }
  38
  39 static int real_XMapRaised(Display* display, Window window)
  40 {
  41     static const XWindowFunc func = (XWindowFunc)::dlsym(RTLD_NEXT, "XMapRaised");
  42     CARLA_SAFE_ASSERT_RETURN(func != nullptr, 0);
  43
  44     return func(display, window);
  45 }
  46
  47 static int real_XMapSubwindows(Display* display, Window window)
  48 {
  49     static const XWindowFunc func = (XWindowFunc)::dlsym(RTLD_NEXT, "XMapSubwindows");
  50     CARLA_SAFE_ASSERT_RETURN(func != nullptr, 0);
  51
  52     return func(display, window);
  53 }
  54
  55 static int real_XUnmapWindow(Display* display, Window window)
  56 {
  57     static const XWindowFunc func = (XWindowFunc)::dlsym(RTLD_NEXT, "XUnmapWindow");
  58     CARLA_SAFE_ASSERT_RETURN(func != nullptr, 0);
  59
  60     return func(display, window);
  61 }
  62
  63 // --------------------------------------------------------------------------------------------------------------------
  64 // Custom carla window handling
  65
  66 static int carlaWindowMap(Display* const display, const Window window, const int fallbackFnType)
  67 {
  68     for (;;)
  69     {
  70         if (const char* const winIdStr = std::getenv("CARLA_ENGINE_OPTION_FRONTEND_WIN_ID"))
  71         {
  72             CARLA_SAFE_ASSERT_BREAK(winIdStr[0] != '\0');
  73
  74             const long long winIdLL(std::strtoll(winIdStr, nullptr, 16));
  75             CARLA_SAFE_ASSERT_BREAK(winIdLL > 0);
  76
  77             const Window winId(static_cast<Window>(winIdLL));
  78             XSetTransientForHint(display, window, static_cast<Window>(winId));
  79
  80             carla_stdout("Transient hint correctly applied before mapping window");
  81         }
  82
  83         break;
  84     }
  85
  86     switch (fallbackFnType)
  87     {
  88     case 1:
  89         return real_XMapWindow(display, window);
  90     case 2:
  91         return real_XMapRaised(display, window);
  92     case 3:
  93         return real_XMapSubwindows(display, window);
  94     default:
  95         return 0;
  96     }
  97 }
  98
  99 // --------------------------------------------------------------------------------------------------------------------
 100 // Our custom X11 functions
 101
 102 CARLA_PLUGIN_EXPORT
 103 int XMapWindow(Display* display, Window window)
 104 {
 105     carla_debug("XMapWindow(%p, %lu)", display, window);
 106     return carlaWindowMap(display, window, 1);
 107 }
 108
 109 CARLA_PLUGIN_EXPORT
 110 int XMapRaised(Display* display, Window window)
 111 {
 112     carla_debug("XMapRaised(%p, %lu)", display, window);
 113     return carlaWindowMap(display, window, 2);
 114 }
 115
 116 CARLA_PLUGIN_EXPORT
 117 int XMapSubwindows(Display* display, Window window)
 118 {
 119     carla_debug("XMapSubwindows(%p, %lu)", display, window);
 120     return carlaWindowMap(display, window, 3);
 121 }
 122
 123 CARLA_PLUGIN_EXPORT
 124 int XUnmapWindow(Display* display, Window window)
 125 {
 126     carla_debug("XUnmapWindow(%p, %lu)", display, window);
 127     return real_XUnmapWindow(display, window);
 128 }
 129
 130 // --------------------------------------------------------------------------------------------------------------------