3 files changed, 60 insertions, 9 deletions

diff --git a/src/main.cc b/src/main.cc
index 50fe463..a00d4c7 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -104,18 +104,32 @@ public:
     wnd_.reset(conn);
     pixmap_.reset(conn);
     gcontext_.reset(conn);
+    cmap_.reset();
 
-    uint32_t values[2];
-    values[0] = screen->black_pixel;
-    values[1] = XCB_EVENT_MASK_KEY_PRESS | XCB_EVENT_MASK_EXPOSURE
+    uint32_t values[4];
+    size_t i = 0;
+    uint32_t mask = XCB_CW_BACK_PIXEL;
+    values[i++] = screen->black_pixel;
+    if (format.need_border()) {
+      mask |= XCB_CW_BORDER_PIXEL;
+      values[i++] = screen->black_pixel;
+    }
+    mask |= XCB_CW_EVENT_MASK;
+    values[i++] = XCB_EVENT_MASK_KEY_PRESS | XCB_EVENT_MASK_EXPOSURE
       | XCB_EVENT_MASK_STRUCTURE_NOTIFY;
+    if (format.need_colormap()) {
+      mask |= XCB_CW_COLORMAP;
+      cmap_.reset(conn);
+      xcb_create_colormap(cmap_.conn(), XCB_COLORMAP_ALLOC_NONE, cmap_.get(),
+                          screen->root, format.visual->visual_id);
+      values[i++] = cmap_.get();
+    }
     xcb_create_window(wnd_.conn(), format.depth,
                       wnd_.get(), screen->root,
                       0, 0, width, height, 0,
                       XCB_WINDOW_CLASS_INPUT_OUTPUT,
                       format.visual->visual_id,
-                      XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK,
-                      values);
+                      mask, values);
     if (!normal) {
       if (atoms->get("_MOTIF_WM_INFO", false) != XCB_ATOM_NONE) {
         auto atom = atoms->get("_MOTIF_WM_HINTS");
@@ -779,6 +793,7 @@ private:
   std::shared_ptr<x::Atoms> atoms_;
   x::unique_window wnd_;
   x::unique_gcontext gcontext_;
+  x::unique_colormap cmap_;
   uint8_t depth_;
   uint32_t black_pixel_;
   xcb_screen_t const* screen_;
diff --git a/src/x.cc b/src/x.cc
index 53b09d4..3749f81 100644
--- a/src/x.cc
+++ b/src/x.cc
@@ -177,6 +177,7 @@ Format get_best_format(xcb_connection_t* conn, xcb_screen_t const* screen,
   xcb_render_pictforminfo_t* render = nullptr;
   xcb_render_pictforminfo_t* render_alpha = nullptr;
   xcb_render_query_pict_formats_reply_t* render_formats = nullptr;
+  uint8_t flags = 0;
   PixelFormat format;
 
   auto render_reply = xcb_get_extension_data(conn, &xcb_render_id);
@@ -265,6 +266,15 @@ Format get_best_format(xcb_connection_t* conn, xcb_screen_t const* screen,
     free(render_formats);
     return Format();
   }
+
+  if (depth != screen->root_depth) {
+    flags |= Format::FLAG_NEED_BORDER;
+  }
+  if (visual->visual_id != screen->root_visual
+      || screen->default_colormap == XCB_NONE) {
+    flags |= Format::FLAG_NEED_COLORMAP;
+  }
+
   if (render && render_formats) {
     auto info = xcb_render_query_pict_formats_formats(render_formats);
     auto count = xcb_render_query_pict_formats_formats_length(render_formats);
@@ -313,7 +323,10 @@ Format get_best_format(xcb_connection_t* conn, xcb_screen_t const* screen,
   // as xcb_render_pictforminfo_t pointers
   // free(render_formats);
 
-  return Format(depth, visual, render, render_alpha);
+  return Format(depth, visual, render, render_alpha, flags);
 }
 
+const uint8_t Format::FLAG_NEED_BORDER = 1 << 0;
+const uint8_t Format::FLAG_NEED_COLORMAP = 1 << 1;
+
 }  // namespace x
diff --git a/src/x.hh b/src/x.hh
index ce4f812..00751c2 100644
--- a/src/x.hh
+++ b/src/x.hh
@@ -41,6 +41,12 @@ struct XcbRenderPictureDelete {
   }
 };
 
+struct XcbColormapDelete {
+  void operator()(xcb_connection_t* conn, xcb_colormap_t id) const {
+    xcb_free_colormap(conn, id);
+  }
+};
+
 }  // priv
 
 class shared_connection {
@@ -194,24 +200,41 @@ typedef unique_resource<xcb_gcontext_t,
                         priv::XcbGContextDelete> unique_gcontext;
 typedef unique_resource<xcb_render_picture_t,
                         priv::XcbRenderPictureDelete> unique_picture;
+typedef unique_resource<xcb_colormap_t,
+                        priv::XcbColormapDelete> unique_colormap;
 
 struct Format {
+  static uint8_t const FLAG_NEED_BORDER;
+  static uint8_t const FLAG_NEED_COLORMAP;
+
   uint8_t depth;
   xcb_visualtype_t* visual;
   xcb_render_pictforminfo_t* render;
   xcb_render_pictforminfo_t* render_alpha;
+  uint8_t flags;
 
   bool good() const {
     return depth > 0 && visual;
   }
 
+  bool need_border() const {
+    return flags & FLAG_NEED_BORDER;
+  }
+
+  bool need_colormap() const {
+    return flags & FLAG_NEED_COLORMAP;
+  }
+
   Format(uint8_t depth, xcb_visualtype_t* visual,
          xcb_render_pictforminfo_t* render,
-         xcb_render_pictforminfo_t* render_alpha)
-    : depth(depth), visual(visual), render(render), render_alpha(render_alpha) {
+         xcb_render_pictforminfo_t* render_alpha,
+         uint8_t flags)
+    : depth(depth), visual(visual), render(render), render_alpha(render_alpha),
+      flags(flags) {
   }
   Format()
-    : depth(0), visual(nullptr), render(nullptr), render_alpha(nullptr) {
+    : depth(0), visual(nullptr), render(nullptr), render_alpha(nullptr),
+      flags(0) {
   }
 };