Merge pull request #2509 from Elv13/xmas_2k18_3

Fix some tag.layouts corner cases

lib/awful/layout/init.lua

@@ -22,6 +22,7 @@ local ascreen = require("awful.screen")
 local timer = require("gears.timer")
 local gmath = require("gears.math")
 local gtable = require("gears.table")
+local gdebug = require("gears.debug")
 local protected_call = require("gears.protected_call")
 
 local function get_screen(s)
@@ -108,36 +109,43 @@ function layout.inc(i, s, layouts)
     if type(i) == "table" then
         -- Older versions of this function had arguments (layouts, i, s), but
         -- this was changed so that 'layouts' can be an optional parameter
+        gdebug.deprecate("Use awful.layout.inc(increment, screen, layouts) instead"..
+            " of awful.layout.inc(layouts, increment, screen)", {deprecated_in=5})
+
         layouts, i, s = i, s, layouts
     end
     s = get_screen(s or ascreen.focused())
     local t = s.selected_tag
-    layouts = layouts or layout.layouts
-    if t then
-        local curlayout = layout.get(s)
-        local curindex
-        for k, v in ipairs(layouts) do
-            if v == curlayout or curlayout._type == v then
-                curindex = k
-                break
+
+    if not t then return end
+
+    layouts = layouts or t.layouts or {}
+
+    if #layouts == 0 then
+        layouts = layout.layouts
     end
-        end
-        if not curindex then
+
+    local cur_l = layout.get(s)
+
+    -- First try to match the object
+    local cur_idx =  gtable.find_first_key(
+        layouts, function(_, v) return v == cur_l or cur_l._type == v end, true
+    )
+
     -- Safety net: handle cases where another reference of the layout
     -- might be given (e.g. when (accidentally) cloning it).
-            for k, v in ipairs(layouts) do
-                if v.name == curlayout.name then
-                    curindex = k
-                    break
-                end
-            end
-        end
-        if curindex then
-            local newindex = gmath.cycle(#layouts, curindex + i)
+    cur_idx = cur_idx or gtable.find_first_key(
+        layouts, function(_, v) return v.name == cur_l.name end, true
+    )
+
+    -- Trying to come up with some kind of fallback layouts to iterate would
+    -- never produce a result the user expect, so if there is nothing to
+    -- iterate over, do not iterate.
+    if not cur_idx then return end
+
+    local newindex = gmath.cycle(#layouts, cur_idx + i)
     layout.set(layouts[newindex], t)
 end
-    end
-end
 
 --- Set the layout function of the current tag.
 -- @param _layout Layout name.

lib/awful/tag.lua

@@ -854,12 +854,21 @@ end
 function tag.object.set_layouts(self, layouts)
     tag.setproperty(self, "_custom_layouts", {})
     tag.setproperty(self, "_layouts", gtable.clone(layouts, false))
-    update_layouts(self, self.layout, self.layout)
+
+    local cur = tag.getproperty(self, "layout")
+    update_layouts(self, cur, cur)
+
     self:emit_signal("property::layouts")
 end
 
 function tag.object.get_layout(t)
-    return tag.getproperty(t, "layout") or require("awful.layout.suit.floating")
+    local l = tag.getproperty(t, "layout")
+    if l then return l end
+
+    local layouts = tag.getproperty(t, "_layouts")
+
+    return layouts and layouts[1]
+        or require("awful.layout.suit.floating")
 end
 
 --- Set layout.

lib/gears/table.lua

@@ -100,6 +100,48 @@ function gtable.hasitem(t, item)
     end
 end
 
+--- Get all matching table keys for a `matcher` function.
+--
+-- @tparam table t The table.
+-- @tparam function matcher A function taking the key and value as arguments and
+--   returning a boolean.
+-- @tparam[opt=false] boolean ordered If true, only look for continuous
+--   numeric keys.
+-- @tparam[opt=nil] number max The maximum number of entries to find.
+-- @treturn table|nil An ordered table with all the keys or `nil` if none were
+--   found.
+function gtable.find_keys(t, matcher, ordered, max)
+    if max == 0 then return nil end
+
+    ordered, max = ordered or false, 0
+    local ret, it = {}, ordered and ipairs or pairs
+
+    for k, v in it(t) do
+        if matcher(k,v) then
+            table.insert(ret, k)
+
+            if #ret == max then break end
+        end
+    end
+
+    return #ret > 0 and ret or nil
+end
+
+--- Find the first key that matches a function.
+--
+-- @tparam table t The table.
+-- @tparam function matcher A function taking the key and value as arguments and
+--   returning a boolean.
+-- @tparam[opt=false] boolean ordered If true, only look for continuous
+--   numeric keys.
+-- @return The table key or nil
+function gtable.find_first_key(t, matcher, ordered)
+    local ret = gtable.find_keys(t, matcher, ordered, 1)
+
+    return ret and ret[1] or nil
+end
+
+
 --- Get a sorted table with all integer keys from a table.
 -- @class function
 -- @name keys