Move selection API under the "selection" global

This moves selection_acquire to selection.acquire, selection_getter to
selection.getter and selection_watcher to selection.watcher. The only
user-visible change due to this is that type(selection) is now "table"
instead of "function". If that breaks something for you, tough luck.

Signed-off-by: Uli Schlachter <psychon@znc.in>

.luacheckrc

@@ -27,10 +27,7 @@ read_globals = {
     "keygrabber",
     "mousegrabber",
     "root",
-    "selection_acquire",
-    "selection_getter",
     "selection",
-    "selection_watcher",
     "tag",
     "window",
     "table.unpack",

selection.c

@@ -132,10 +132,48 @@ luaA_selection_get(lua_State *L)
     return 0;
 }
 
+static void
+move_global_to_table(lua_State *L, int index, const char *global_name, const char *local_name)
+{
+    index = luaA_absindex(L, index);
+
+    /* Get the global */
+    lua_getglobal(L, global_name);
+    assert(!lua_isnil(L, -1));
+
+    /* Save it locally */
+    lua_setfield(L, index, local_name);
+
+    /* Set the global to nil */
+    lua_pushnil(L);
+    lua_setglobal(L, global_name);
+}
+
 void
 selection_setup(lua_State *L)
 {
+    /* This table will be the "selection" global */
+    lua_newtable(L);
+
+    /* Setup a metatable */
+    lua_newtable(L);
+
+    /* metatable.__index = metatable */
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -2, "__index");
+
+    /* Set some more fields */
     lua_pushcfunction(L, luaA_selection_get);
+    lua_setfield(L, -2, "__call");
+
+    move_global_to_table(L, -2, "selection_acquire", "acquire");
+    move_global_to_table(L, -2, "selection_getter", "getter");
+    move_global_to_table(L, -2, "selection_watcher", "watcher");
+
+    /* Set the metatable */
+    lua_setmetatable(L, -2);
+
+    /* Set the "selection" global */
     lua_setglobal(L, "selection");
 }
 

tests/test-selection-getter.lua

@@ -61,7 +61,7 @@ runner.run_steps{
 
         -- Now query the state of the clipboard (should be empty)
         continue = false
-        local s = selection_getter{ selection = "CLIPBOARD", target = "TARGETS" }
+        local s = selection.getter{ selection = "CLIPBOARD", target = "TARGETS" }
         s:connect_signal("data", function(...) error("Got unexpected data: " .. dump_return{...}) end)
         s:connect_signal("data_end", function()
             assert(not continue)
@@ -97,7 +97,7 @@ runner.run_steps{
 
         -- Query whether the clipboard contains a text (UTF8_STRING)
         continue = false
-        local s = selection_getter{ selection = "CLIPBOARD", target = "TARGETS" }
+        local s = selection.getter{ selection = "CLIPBOARD", target = "TARGETS" }
         local data = nil
         s:connect_signal("data", function(_, d)
             assert(not data)
@@ -120,7 +120,7 @@ runner.run_steps{
 
         -- Query the text in the clipboard
         continue = false
-        local s = selection_getter{ selection = "CLIPBOARD", target = "UTF8_STRING" }
+        local s = selection.getter{ selection = "CLIPBOARD", target = "UTF8_STRING" }
         local data = nil
         s:connect_signal("data", function(_, d)
             assert(data == nil)
@@ -161,7 +161,7 @@ runner.run_steps{
 
         -- Query the image in the clipboard
         continue = false
-        local s = selection_getter{ selection = "CLIPBOARD", target = "image/bmp" }
+        local s = selection.getter{ selection = "CLIPBOARD", target = "image/bmp" }
         local data = {}
         s:connect_signal("data", function(_, d)
             table.insert(data, d)

tests/test-selection-transfer.lua

@@ -53,7 +53,7 @@ assert_equal(clipboard:wait_for_targets(), nil)
 assert_equal(clipboard:wait_for_text(), nil)
 ]] .. done_footer
 
-local selection
+local selection_object
 local selection_released
 local continue
 
@@ -66,22 +66,22 @@ end
 runner.run_steps{
     function()
         -- Get the selection
-        local s = assert(selection_acquire{ selection = "CLIPBOARD" },
+        local s = assert(selection.acquire{ selection = "CLIPBOARD" },
             "Failed to acquire the clipboard selection")
 
         -- Steal selection ownership from ourselves and test that it works
         local s_released
         s:connect_signal("release", function() s_released = true end)
 
-        selection = assert(selection_acquire{ selection = "CLIPBOARD" },
+        selection_object = assert(selection.acquire{ selection = "CLIPBOARD" },
             "Failed to acquire the clipboard selection")
 
         assert(s_released)
 
         -- Now test selection transfers
-        selection = assert(selection_acquire{ selection = "CLIPBOARD" },
+        selection_object = assert(selection.acquire{ selection = "CLIPBOARD" },
             "Failed to acquire the clipboard selection")
-        selection:connect_signal("request", function(_, target, transfer)
+        selection_object:connect_signal("request", function(_, target, transfer)
             if target == "TARGETS" then
                 transfer:send{
                     format = "atom",
@@ -108,9 +108,9 @@ runner.run_steps{
         continue = false
 
         -- Now test piece-wise selection transfers
-        selection = assert(selection_acquire{ selection = "CLIPBOARD" },
+        selection_object = assert(selection.acquire{ selection = "CLIPBOARD" },
             "Failed to acquire the clipboard selection")
-        selection:connect_signal("request", function(_, target, transfer)
+        selection_object:connect_signal("request", function(_, target, transfer)
             if target == "TARGETS" then
                 transfer:send{
                     format = "atom",
@@ -148,9 +148,9 @@ runner.run_steps{
         continue = false
 
         -- Now test a huge transfer
-        selection = assert(selection_acquire{ selection = "CLIPBOARD" },
+        selection_object = assert(selection.acquire{ selection = "CLIPBOARD" },
             "Failed to acquire the clipboard selection")
-        selection:connect_signal("request", function(_, target, transfer)
+        selection_object:connect_signal("request", function(_, target, transfer)
             if target == "TARGETS" then
                 transfer:send{
                     format = "atom",
@@ -195,7 +195,7 @@ runner.run_steps{
         continue = false
 
         -- Now test that :release() works
-        selection:release()
+        selection_object:release()
         awesome.sync()
         spawn.with_line_callback({ "lua", "-e", check_empty_selection },
             { stdout = function(line)
@@ -214,9 +214,9 @@ runner.run_steps{
         continue = false
 
         -- Test for "release" signal when we lose selection
-        selection = assert(selection_acquire{ selection = "CLIPBOARD" },
+        selection_object = assert(selection.acquire{ selection = "CLIPBOARD" },
             "Failed to acquire the clipboard selection")
-        selection:connect_signal("release", function() selection_released = true end)
+        selection_object:connect_signal("release", function() selection_released = true end)
         awesome.sync()
         spawn.with_line_callback({ "lua", "-e", acquire_and_clear_clipboard },
             { exit = function() continue = true end })

tests/test-selection-watcher.lua

@@ -29,9 +29,9 @@ Gtk.main()
 local had_error = false
 local owned_clipboard_changes, unowned_clipboard_changes = 0, 0
 
-local clipboard_watcher = selection_watcher("CLIPBOARD")
-local clipboard_watcher_inactive = selection_watcher("CLIPBOARD")
-local primary_watcher = selection_watcher("PRIMARY")
+local clipboard_watcher = selection.watcher("CLIPBOARD")
+local clipboard_watcher_inactive = selection.watcher("CLIPBOARD")
+local primary_watcher = selection.watcher("PRIMARY")
 
 clipboard_watcher:connect_signal("selection_changed", function(_, owned)
     if owned then