Add a lua api for setting a wibox' shape

When the SHAPE extension is not available, this code prints
a harmless warn() on stderr.

Signed-off-by: Uli Schlachter <psychon@znc.in>
Signed-off-by: Julien Danjou <julien@danjou.info>

awesomeConfig.cmake

@@ -139,6 +139,7 @@ pkg_check_modules(AWESOME_REQUIRED REQUIRED
     xcb-randr
     xcb-xtest
     xcb-xinerama
+    xcb-shape
     xcb-event>=0.3.4
     xcb-aux>=0.3.0
     xcb-atom>=0.3.0

common/tokenize.gperf

@@ -89,6 +89,8 @@ role
 screen
 selected
 session
+shape_bounding
+shape_clip
 Shift
 size_hints
 size_hints_honor

swindow.c

@@ -22,12 +22,67 @@
 #include <math.h>
 
 #include <xcb/xcb.h>
+#include <xcb/shape.h>
 
 #include "structs.h"
 #include "swindow.h"
 #include "draw.h"
 #include "common/xutil.h"
 
+static int
+have_shape(void)
+{
+    const xcb_query_extension_reply_t *reply;
+
+    reply = xcb_get_extension_data(globalconf.connection, &xcb_shape_id);
+    if (!reply || !reply->present)
+        return 0;
+
+    /* We don't need a specific version of SHAPE, no version check required */
+    return 1;
+}
+
+static void
+do_update_shape(xcb_window_t win, xcb_shape_kind_t kind, image_t *image, int offset)
+{
+    xcb_pixmap_t shape;
+
+    if(image)
+        shape = image_to_1bit_pixmap(image, win);
+    else
+        /* Reset the shape */
+        shape = XCB_NONE;
+
+    xcb_shape_mask(globalconf.connection, XCB_SHAPE_SO_SET, kind,
+                   win, offset, offset, shape);
+
+    if (shape != XCB_NONE)
+        xcb_free_pixmap(globalconf.connection, shape);
+}
+
+/** Update the window's shape.
+ * \param sw The simplw window whose shape should be updated.
+ */
+void
+simplewindow_update_shape(simple_window_t *sw)
+{
+    if(sw->window == XCB_NONE)
+        return;
+
+    if(!have_shape())
+    {
+        static bool warned = false;
+        if (!warned)
+            warn("The X server doesn't have the SHAPE extension; "
+                    "can't change window's shape");
+        warned = true;
+        return;
+    }
+
+    do_update_shape(sw->window, XCB_SHAPE_SK_CLIP, sw->shape.clip, 0);
+    do_update_shape(sw->window, XCB_SHAPE_SK_BOUNDING, sw->shape.bounding, -sw->border.width);
+}
+
 static void
 simplewindow_draw_context_update(simple_window_t *sw, xcb_screen_t *s)
 {
@@ -127,6 +182,8 @@ simplewindow_init(simple_window_t *sw,
     /* The default GC is just a newly created associated to the root window */
     sw->gc = xcb_generate_id(globalconf.connection);
     xcb_create_gc(globalconf.connection, sw->gc, s->root, gc_mask, gc_values);
+
+    simplewindow_update_shape(sw);
 }
 
 /** Destroy all resources of a simple window.

swindow.h

@@ -55,6 +55,14 @@ typedef struct simple_window_t
     orientation_t orientation;
     /** Opacity */
     double opacity;
+    /** The window's shape */
+    struct
+    {
+        /** The window's content */
+        image_t *clip;
+        /** The window's content and border */
+        image_t *bounding;
+    } shape;
 } simple_window_t;
 
 void simplewindow_init(simple_window_t *s,
@@ -71,6 +79,7 @@ void simplewindow_border_width_set(simple_window_t *, uint32_t);
 void simplewindow_border_color_set(simple_window_t *, const xcolor_t *);
 void simplewindow_orientation_set(simple_window_t *, orientation_t);
 void simplewindow_cursor_set(simple_window_t *, xcb_cursor_t);
+void simplewindow_update_shape(simple_window_t *);
 
 /** Refresh the window content by copying its pixmap data to its window.
  * \param sw The simple window to refresh.

wibox.c

@@ -326,8 +326,15 @@ void
 wibox_refresh(void)
 {
     foreach(w, globalconf.wiboxes)
+    {
+        if((*w)->need_shape_update)
+        {
+            simplewindow_update_shape(&(*w)->sw);
+            (*w)->need_shape_update = false;
+        }
         if((*w)->need_update)
             wibox_draw(*w);
+    }
 
     foreach(_c, globalconf.clients)
     {
@@ -568,6 +575,8 @@ luaA_wibox_invalidate_byitem(lua_State *L, const void *item)
  * \lfield opacity The opacity of the wibox, between 0 and 1.
  * \lfield mouse_enter A function to execute when the mouse enter the widget.
  * \lfield mouse_leave A function to execute when the mouse leave the widget.
+ * \lfield shape_clip Image describing the window's content shape.
+ * \lfield shape_bounding Image describing the window's border shape.
  */
 static int
 luaA_wibox_index(lua_State *L)
@@ -652,6 +661,12 @@ luaA_wibox_index(lua_State *L)
         else
             return 0;
         return 1;
+      case A_TK_SHAPE_BOUNDING:
+        image_push(L, wibox->sw.shape.bounding);
+        break;
+      case A_TK_SHAPE_CLIP:
+        image_push(L, wibox->sw.shape.clip);
+        break;
       default:
         return 0;
     }
@@ -855,6 +870,16 @@ luaA_wibox_newindex(lua_State *L)
       case A_TK_MOUSE_LEAVE:
         luaA_registerfct(L, 3, &wibox->mouse_leave);
         return 0;
+      case A_TK_SHAPE_BOUNDING:
+        image_unref(L, wibox->sw.shape.bounding);
+        wibox->sw.shape.bounding = image_ref(L, 3);
+        wibox->need_shape_update = true;
+        break;
+      case A_TK_SHAPE_CLIP:
+        image_unref(L, wibox->sw.shape.clip);
+        wibox->sw.shape.clip = image_ref(L, 3);
+        wibox->need_shape_update = true;
+        break;
       default:
         switch(wibox->type)
         {

wibox.h

@@ -59,6 +59,8 @@ struct wibox_t
     luaA_ref mouse_enter, mouse_leave;
     /** Need update */
     bool need_update;
+    /** Need shape update */
+    bool need_shape_update;
     /** Cursor */
     char *cursor;
     /** Background image */