Improvement #41: Enable/disable redirection through D-Bus

- Add "redirected_force" to D-Bus opts_get to forcefully
  redirect/unredirect windows.

- Add D-Bus method "repaint", to, namely, repaint the screen.

common.h

@@ -460,6 +460,8 @@ typedef struct {
   /// Whether to unredirect all windows if a full-screen opaque window
   /// is detected.
   bool unredir_if_possible;
+  /// Forced redirection setting through D-Bus.
+  switch_t redirected_force;
   /// Whether to enable D-Bus support.
   bool dbus;
   /// Path to log file.
@@ -647,9 +649,6 @@ typedef struct {
   XserverRegion all_damage_last[CGLX_MAX_BUFFER_AGE];
   /// Whether all windows are currently redirected.
   bool redirected;
-  /// Whether there's a highest full-screen window, and all windows could
-  /// be unredirected.
-  bool unredir_possible;
   /// Pre-generated alpha pictures.
   Picture *alpha_picts;
   /// Whether all reg_ignore of windows should expire in this paint.

compton.c

@@ -1076,7 +1076,7 @@ get_alpha_pict_o(session_t *ps, opacity_t o) {
 static win *
 paint_preprocess(session_t *ps, win *list) {
   // Initialize unredir_possible
-  ps->unredir_possible = false;
+  bool unredir_possible = false;
 
   win *w;
   win *t = NULL, *next = NULL;
@@ -1229,13 +1229,13 @@ paint_preprocess(session_t *ps, win *list) {
 
       last_reg_ignore = w->reg_ignore;
 
-      if (is_highest && to_paint) {
+      if (ps->o.unredir_if_possible && is_highest && to_paint) {
         is_highest = false;
         // Disable unredirection for multi-screen setups
         if (WMODE_SOLID == w->mode
             && (!w->frame_opacity || !win_has_frame(w))
             && win_is_fullscreen(ps, w))
-          ps->unredir_possible = true;
+          unredir_possible = true;
       }
 
       // Reset flags
@@ -1259,12 +1259,13 @@ paint_preprocess(session_t *ps, win *list) {
   }
 
   // If possible, unredirect all windows and stop painting
-  if (ps->o.unredir_if_possible && ps->unredir_possible) {
+  if (UNSET != ps->o.redirected_force)
+    unredir_possible = !ps->o.redirected_force;
+
+  if (unredir_possible)
     redir_stop(ps);
-  }
-  else {
+  else
     redir_start(ps);
-  }
 
   return t;
 }
@@ -6365,6 +6366,7 @@ session_init(session_t *ps_old, int argc, char **argv) {
       .paint_on_overlay = false,
       .resize_damage = 0,
       .unredir_if_possible = false,
+      .redirected_force = UNSET,
       .dbus = false,
       .benchmark = 0,
       .benchmark_wid = None,
@@ -6435,7 +6437,6 @@ session_init(session_t *ps_old, int argc, char **argv) {
     .all_damage_last = { None },
     .time_start = { 0, 0 },
     .redirected = false,
-    .unredir_possible = false,
     .alpha_picts = NULL,
     .reg_ignore_expire = false,
     .idling = false,

dbus.c

@@ -582,6 +582,12 @@ cdbus_process(session_t *ps, DBusMessage *msg) {
       cdbus_reply_bool(ps, msg, true);
     success = true;
   }
+  else if (cdbus_m_ismethod("repaint")) {
+    force_repaint(ps);
+    if (!dbus_message_get_no_reply(msg))
+      cdbus_reply_bool(ps, msg, true);
+    success = true;
+  }
   else if (cdbus_m_ismethod("list_win")) {
     success = cdbus_process_list_win(ps, msg);
   }
@@ -892,6 +898,7 @@ cdbus_process_opts_get(session_t *ps, DBusMessage *msg) {
   cdbus_m_opts_get_do(detect_rounded_corners, cdbus_reply_bool);
   cdbus_m_opts_get_do(paint_on_overlay, cdbus_reply_bool);
   cdbus_m_opts_get_do(unredir_if_possible, cdbus_reply_bool);
+  cdbus_m_opts_get_do(redirected_force, cdbus_reply_enum);
   cdbus_m_opts_get_do(logpath, cdbus_reply_string);
   cdbus_m_opts_get_do(synchronize, cdbus_reply_bool);
 
@@ -1064,6 +1071,16 @@ cdbus_process_opts_set(session_t *ps, DBusMessage *msg) {
     return true;
   }
 
+  // redirected_force
+  if (!strcmp("redirected_force", target)) {
+    cdbus_enum_t val = UNSET;
+    if (!cdbus_msg_get_arg(msg, 1, CDBUS_TYPE_ENUM, &val))
+      return false;
+    ps->o.redirected_force = val;
+    force_repaint(ps);
+    goto cdbus_process_opts_set_success;
+  }
+
 #undef cdbus_m_opts_set_do
 
   printf_errf("(): " CDBUS_ERROR_BADTGT_S, target);
@@ -1117,6 +1134,7 @@ cdbus_process_introspect(session_t *ps, DBusMessage *msg) {
     "      <arg name='wid' type='" CDBUS_TYPE_WINDOW_STR "'/>\n"
     "    </signal>\n"
     "    <method name='reset' />\n"
+    "    <method name='repaint' />\n"
     "  </interface>\n"
     "</node>\n";