From 21c7a69812e40e8015b4c48a3d7e7dc1479d6371 Mon Sep 17 00:00:00 2001
From: Michael Stapelberg <michael@stapelberg.de>
Date: Fri, 1 Apr 2011 22:40:12 +0200
Subject: [PATCH] optimization: when moving floating windows, render/push only
 the floatingcon

---
 include/x.h    |  8 ++++++++
 src/floating.c |  8 ++++----
 src/x.c        | 10 ++++++----
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/include/x.h b/include/x.h
index 15d37420..827f6f85 100644
--- a/include/x.h
+++ b/include/x.h
@@ -60,6 +60,14 @@ void x_window_kill(xcb_window_t window);
  */
 void x_draw_decoration(Con *con);
 
+/**
+ * This function pushes the properties of each node of the layout tree to
+ * X11 if they have changed (like the map state, position of the window, …).
+ * It recursively traverses all children of the given node.
+ *
+ */
+void x_push_node(Con *con, bool skip_decoration);
+
 /**
  * Pushes all changes (state of each node, see x_push_node() and the window
  * stack) to X11.
diff --git a/src/floating.c b/src/floating.c
index 9d4e1cf8..6cc9a168 100644
--- a/src/floating.c
+++ b/src/floating.c
@@ -231,10 +231,10 @@ DRAGGING_CB(drag_window_callback) {
     /* Reposition the client correctly while moving */
     con->rect.x = old_rect->x + (new_x - event->root_x);
     con->rect.y = old_rect->y + (new_y - event->root_y);
-    /* TODO: don’t re-render the whole tree just because we change
-     * coordinates of a floating window */
-    tree_render();
-    x_push_changes(croot);
+
+    render_con(con, false);
+    x_push_node(con, true);
+    xcb_flush(conn);
 }
 
 /*
diff --git a/src/x.c b/src/x.c
index ee9e0a43..9ea87644 100644
--- a/src/x.c
+++ b/src/x.c
@@ -442,7 +442,7 @@ copy_pixmaps:
  * It recursively traverses all children of the given node.
  *
  */
-static void x_push_node(Con *con) {
+void x_push_node(Con *con, bool skip_decoration) {
     Con *current;
     con_state *state;
     Rect rect = con->rect;
@@ -582,9 +582,11 @@ static void x_push_node(Con *con) {
      * in focus order to display the focused client in a stack first when
      * switching workspaces (reduces flickering). */
     TAILQ_FOREACH(current, &(con->focus_head), focused)
-        x_push_node(current);
+        x_push_node(current, skip_decoration);
 
-    if (con->type != CT_ROOT && con->type != CT_OUTPUT && con->mapped)
+    if (!skip_decoration &&
+        (con->type != CT_ROOT && con->type != CT_OUTPUT) &&
+        con->mapped)
         x_draw_decoration(con);
 }
 
@@ -687,7 +689,7 @@ void x_push_changes(Con *con) {
     DLOG("Done, EnterNotify re-enabled\n");
 
     DLOG("\n\n PUSHING CHANGES\n\n");
-    x_push_node(con);
+    x_push_node(con, false);
 
     xcb_window_t to_focus = focused->frame;
     if (focused->window != NULL)