Add awful.widget.clienticon

This adds a new widget that displays the icon of a client. This widget
tries to use the best fitting of the available icons.

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

lib/awful/titlebar.lua

@@ -12,6 +12,7 @@ local util = require("awful.util")
 local abutton = require("awful.button")
 local aclient = require("awful.client")
 local atooltip = require("awful.tooltip")
+local clienticon = require("awful.widget.clienticon")
 local beautiful = require("beautiful")
 local drawable = require("wibox.drawable")
 local imagebox = require("wibox.widget.imagebox")
@@ -572,14 +573,7 @@ end
 -- @param c The client for which an icon widget should be created.
 -- @return The icon widget.
 function titlebar.widget.iconwidget(c)
-    local ret = imagebox()
-    local function update()
-        ret:set_image(c.icon)
-    end
-    c:connect_signal("property::icon", update)
-    update()
-
-    return ret
+    return clienticon(c)
 end
 
 --- Create a new button widget. A button widget displays an image and reacts to

lib/awful/widget/clienticon.lua

@@ -0,0 +1,118 @@
+--- Container showing the icon of a client.
+-- @author Uli Schlachter
+-- @copyright 2017 Uli Schlachter
+-- @classmod awful.widget.clienticon
+
+local base = require("wibox.widget.base")
+local surface = require("gears.surface")
+local util = require("awful.util")
+
+local clienticon = {}
+local instances = setmetatable({}, { __mode = "k" })
+
+local function find_best_icon(sizes, width, height)
+    local best, best_size
+    for k, size in ipairs(sizes) do
+        if not best then
+            best, best_size = k, size
+        else
+            local best_too_small = best_size[1] < width or best_size[2] < height
+            local best_too_large = best_size[1] > width or best_size[2] > height
+            local better_because_bigger = best_too_small and size[1] > best_size[1] and size[2] > best_size[2]
+            local better_because_smaller = best_too_large and size[1] < best_size[1] and size[2] < best_size[2]
+                and size[1] >= width and size[2] >= height
+            if better_because_bigger or better_because_smaller then
+                best, best_size = k, size
+            end
+        end
+    end
+    return best, best_size
+end
+
+function clienticon:draw(_, cr, width, height)
+    local c = self._private.client
+    if not c.valid then
+        return
+    end
+
+    local index, size = find_best_icon(c.icon_sizes, width, height)
+    if not index then
+        return
+    end
+
+    local aspect_w = width / size[1]
+    local aspect_h = height / size[2]
+    local aspect = math.min(aspect_w, aspect_h)
+    cr:scale(aspect, aspect)
+
+    local s = surface(c:get_icon(index))
+    cr:set_source_surface(s, 0, 0)
+    cr:paint()
+end
+
+function clienticon:fit(_, width, height)
+    local c = self._private.client
+    if not c.valid then
+        return 0, 0
+    end
+
+    local index, size = find_best_icon(c.icon_sizes, width, height)
+    if not index then
+        return 0, 0
+    end
+
+    local w, h = size[1], size[2]
+
+    if w > width then
+        h = h * width / w
+        w = width
+    end
+    if h > height then
+        w = w * height / h
+        h = height
+    end
+
+    if h == 0 or w == 0 then
+        return 0, 0
+    end
+
+    local aspect = math.min(width / w, height / h)
+    return w * aspect, h * aspect
+end
+
+--- Returns a new clienticon.
+-- @tparam client c The client whose icon should be displayed.
+-- @treturn widget A new `widget`
+-- @function awful.widget.clienticon
+local function new(c)
+    local ret = base.make_widget(nil, nil, {enable_properties = true})
+
+    util.table.crush(ret, clienticon, true)
+
+    ret._private.client = c
+
+    instances[ret] = true
+
+    return ret
+end
+
+client.connect_signal("property::icon", function(c)
+    for obj in pairs(instances) do
+        if obj._private.client.valid and obj._private.client == c then
+            obj:emit_signal("widget::layout_changed")
+            obj:emit_signal("widget::redraw_needed")
+        end
+    end
+end)
+
+--@DOC_widget_COMMON@
+
+--@DOC_object_COMMON@
+
+return setmetatable(clienticon, {
+    __call = function(_, ...)
+        return new(...)
+    end
+})
+
+-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80

lib/awful/widget/init.lua

@@ -20,6 +20,7 @@ return
     keyboardlayout = require("awful.widget.keyboardlayout");
     watch = require("awful.widget.watch");
     only_on_screen = require("awful.widget.only_on_screen");
+    clienticon = require("awful.widget.clienticon");
 }
 
 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80