Added sharedtags-greedyview to recipes

recipes/sharedtags-greedyview.lua

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+--- Provides functionality to share tags across all screens in awesome WM.
+-- @module sharedtags
+-- @author Albert Diserholt
+-- @copyright 2016 Albert Diserholt
+-- @license MIT
+
+-- Grab environment we need
+local awful = require("awful")
+local capi = {
+    screen = screen
+}
+
+local sharedtags = {
+    _VERSION = "sharedtags v1.0.0 for v4.0",
+    _DESCRIPTION = "Share tags for awesome window manager v4.0 with greedyview",
+    _URL = "https://github.com/dakling/dakling/awesome-www",
+    _LICENSE = [[
+        MIT LICENSE
+
+        Copyright (c) 2018 Albert Diserholt
+
+        Permission is hereby granted, free of charge, to any person obtaining a
+        copy of this software and associated documentation files (the "Software"),
+        to deal in the Software without restriction, including without limitation
+        the rights to use, copy, modify, merge, publish, distribute, sublicense,
+        and/or sell copies of the Software, and to permit persons to whom the
+        Software is furnished to do so, subject to the following conditions:
+
+        The above copyright notice and this permission notice shall be included in
+        all copies or substantial portions of the Software.
+
+        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+        IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+        FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+        AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+        LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+        FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+        IN THE SOFTWARE.
+    ]]
+}
+
+-- Add a signal for each new screen, which just listens for the remove
+-- event, and moves over all tags when it happens.
+awful.screen.connect_for_each_screen(function(s)
+    -- When the screen is removed, all tags need to be moved over to an existing
+    -- screen. If they are not, accessing the tags will result in an error. It
+    -- doesn't make sense to fix the error, since clients on the now-hidden tags
+    -- will automatically be moved to a tag on a visible screen.
+    s:connect_signal("removed",function()
+        -- The screen to move the orphaned tags to.
+        local newscreen = capi.screen.primary
+        -- The currently selected tags on that screen.
+        local seltags = newscreen.selected_tags
+
+        -- Move over all tags to an existing screen.
+        for _,tag in ipairs(s.tags) do
+            sharedtags.movetag(tag, newscreen)
+        end
+
+        -- Restore the viewed tags on the new screen.
+        for i,tag in ipairs(seltags) do
+            if i == 1 then
+                tag:view_only()
+            else
+                awful.tag.viewtoggle(tag)
+            end
+        end
+    end)
+end)
+
+--- Create new tag objects.
+-- The first tag defined for each screen will be automatically selected.
+-- @tparam table def A list of tables with the optional keys `name`, `layout`
+-- and `screen`. The `name` value is used to name the tag and defaults to the
+-- list index. The `layout` value sets the starting layout for the tag and
+-- defaults to the first layout. The `screen` value sets the starting screen
+-- for the tag and defaults to the first screen. The tags will be sorted in this
+-- order in the default taglist.
+-- @treturn table A list of all created tags. Tags are assigned numeric values
+-- corresponding to the input list, and all tags with non-numerical names are
+-- also assigned to a key with the same name.
+-- @usage local tags = sharedtags(
+--   -- "main" is the first tag starting on screen 2 with the tile layout.
+--   { name = "main", layout = awful.layout.suit.tile, screen = 2 },
+--   -- "www" is the second tag on screen 1 with the floating layout.
+--   { name = "www" },
+--   -- Third tag is named "3" on screen 1 with the floating layout.
+--   {})
+-- -- tags[2] and tags["www"] both refer to the same tag.
+function sharedtags.new(def)
+    local tags = {}
+
+    for i,t in ipairs(def) do
+        tags[i] = awful.tag.add(t.name or i, {
+            screen = (t.screen and t.screen <= capi.screen.count()) and t.screen or capi.screen.primary,
+            layout = t.layout,
+            sharedtagindex = i
+        })
+
+        -- Create an alias between the index and the name.
+        if t.name and type(t.name) ~= "number" then
+            tags[t.name] = tags[i]
+        end
+
+        -- If no tag is selected for this screen, then select this one.
+        if not tags[i].screen.selected_tag then
+            tags[i]:view_only() -- Updates the history as well.
+        end
+    end
+
+    return tags
+end
+
+--- Move the specified tag to a new screen, if necessary.
+-- @param tag The tag to move.
+-- @tparam[opt=awful.screen.focused()] number screen The screen to move the tag to.
+-- @treturn bool Whether the tag was moved.
+function sharedtags.movetag(tag, screen)
+    screen = screen or awful.screen.focused()
+    local oldscreen = tag.screen
+
+    -- If the specified tag is allocated to another screen, we need to move it.
+    if oldscreen ~= screen then
+        -- greedyview xmonad-style
+        if tag.selected then
+            local newsel = screen.selected_tag
+            newsel.screen = oldscreen
+        end
+        local oldsel = oldscreen.selected_tag
+        tag.screen = screen
+
+        if oldsel == tag then
+            -- The tag has been moved away. In most cases the tag history
+            -- function will find the best match, but if we really want we can
+            -- try to find a fallback tag as well.
+            if not oldscreen.selected_tag then
+                local newtag = awful.tag.find_fallback(oldscreen)
+                if newtag then
+                    newtag:view_only()
+                end
+            end
+        --else
+            -- NOTE: A bug in awesome 4.0 is causing all tags to be deselected
+            -- here. A shame, but I haven't found a nice way to work around it
+            -- except by fixing the bug (history seems to be in a weird state).
+        end
+
+        -- Also sort the tag in the taglist, by reapplying the index. This is just a nicety.
+        local unpack = unpack or table.unpack
+        for _,s in ipairs({ screen, oldscreen }) do
+            local tags = { unpack(s.tags) } -- Copy
+            table.sort(tags, function(a, b) return a.sharedtagindex < b.sharedtagindex end)
+            for i,t in ipairs(tags) do
+                t.index = i
+            end
+        end
+
+        return true
+    end
+
+    return false
+end
+
+--- View the specified tag on the specified screen.
+-- @param tag The only tag to view.
+-- @tparam[opt=awful.screen.focused()] number screen The screen to view the tag on.
+function sharedtags.viewonly(tag, screen)
+    sharedtags.movetag(tag, screen)
+    tag:view_only()
+end
+
+--- Toggle the specified tag on the specified screen.
+-- The tag will be selected if the screen changes, and toggled if it does not
+-- change the screen.
+-- @param tag The tag to toggle.
+-- @tparam[opt=awful.screen.focused()] number screen The screen to toggle the tag on.
+function sharedtags.viewtoggle(tag, screen)
+    local oldscreen = tag.screen
+
+    if sharedtags.movetag(tag, screen) then
+        -- Always mark the tag selected if the screen changed. Just feels a lot
+        -- more natural.
+        tag.selected = true
+        -- Update the history on the old and new screens.
+        oldscreen:emit_signal("tag::history::update")
+        tag.screen:emit_signal("tag::history::update")
+    else
+        -- Only toggle the tag unless the screen moved.
+        awful.tag.viewtoggle(tag)
+    end
+end
+
+return setmetatable(sharedtags, { __call = function(...) return sharedtags.new(select(2, ...)) end })
+
+-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80