widgets: Add a piechart widget.

lib/wibox/widget/init.lua

@@ -16,6 +16,7 @@ return setmetatable({
     progressbar = require("wibox.widget.progressbar");
     graph = require("wibox.widget.graph");
     checkbox = require("wibox.widget.checkbox");
+    piechart = require("wibox.widget.piechart");
 }, {__call = function(_, args) return base.make_widget_declarative(args) end})
 
 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80

lib/wibox/widget/piechart.lua

@@ -0,0 +1,218 @@
+---------------------------------------------------------------------------
+-- Display percentage in a circle.
+--
+-- Note that this widget makes no attempts to prevent overlapping labels or
+-- labels drawn outside of the widget boundaries.
+--
+--@DOC_wibox_widget_defaults_piechart_EXAMPLE@
+-- @author Emmanuel Lepage Valle
+-- @copyright 2012 Emmanuel Lepage Vallee
+-- @release @AWESOME_VERSION@
+-- @classmod wibox.widget.piechart
+---------------------------------------------------------------------------
+
+local color     = require( "gears.color"       )
+local base      = require( "wibox.widget.base" )
+local beautiful = require( "beautiful"         )
+local util      = require( "awful.util"        )
+local pie       = require( "gears.shape"       ).pie
+local unpack    = unpack or table.unpack -- luacheck: globals unpack (compatibility with Lua 5.1)
+
+local module = {}
+
+local piechart = {}
+
+local function draw_label(cr,angle,radius,center_x,center_y,text)
+    local edge_x = center_x+(radius/2)*math.cos(angle)
+    local edge_y = center_y+(radius/2)*math.sin(angle)
+
+    cr:move_to(edge_x, edge_y)
+
+    cr:rel_line_to(radius*math.cos(angle), radius*math.sin(angle))
+
+    local x,y = cr:get_current_point()
+
+    cr:rel_line_to(x > center_x and radius/2 or -radius/2, 0)
+
+    local ext = cr:text_extents(text)
+
+    cr:rel_move_to(
+        (x>center_x and radius/2.5 or (-radius/2.5 - ext.width)),
+        ext.height/2
+    )
+
+    cr:show_text(text) --TODO eventually port away from the toy API
+    cr:stroke()
+
+    cr:arc(edge_x, edge_y,2,0,2*math.pi)
+    cr:arc(x+(x>center_x and radius/2 or -radius/2),y,2,0,2*math.pi)
+
+    cr:fill()
+end
+
+local function compute_sum(data)
+    local ret = 0
+    for _,v in pairs(data) do
+        ret = ret + v
+    end
+
+    return ret
+end
+
+local function draw(self, _, cr, width, height)
+    if not self._private.data then return end
+
+    local radius = (height > width and width or height) / 4
+    local sum, start, count = compute_sum(self._private.data),0,0
+    local has_label = self._private.display_labels ~= false
+
+    -- Labels need to be drawn later so the original source is kept
+    -- use get_source() wont work are the reference cannot be set from Lua(?)
+    local labels = {}
+
+    local border_width = self:get_border_width() or 1
+    local border_color = self:get_border_color()
+    border_color       = border_color and color(border_color)
+
+    -- Draw the pies
+    cr:save()
+    cr:set_line_width(border_width)
+
+    -- Alternate from a given sets or colors
+    local colors = self:get_colors()
+    local col_count = colors and #colors or 0
+
+    for k,v in pairs(self._private.data) do
+        local end_angle = start + 2*math.pi*(v/sum)
+
+        local col = colors and color(colors[math.fmod(count,col_count)+1]) or nil
+
+        pie(cr, width, height, start, end_angle, radius)
+
+        if col then
+            cr:save()
+            cr:set_source(color(col))
+        end
+
+        if border_width > 0 then
+            if col then
+                cr:fill_preserve()
+                cr:restore()
+            end
+
+            -- By default, it uses the fg color
+            if border_color then
+                cr:set_source(border_color)
+            end
+            cr:stroke()
+        elseif col then
+            cr:fill()
+            cr:restore()
+        end
+
+        -- Store the label position for later
+        if has_label then
+            table.insert(labels, {
+                --[[angle   ]] start+(end_angle-start)/2,
+                --[[radius  ]] radius,
+                --[[center_x]] width/2,
+                --[[center_y]] height/2,
+                --[[text    ]] k,
+            })
+        end
+        start,count = end_angle,count+1
+    end
+    cr:restore()
+
+    -- Draw the labels
+    if has_label then
+        for _, v in ipairs(labels) do
+            draw_label(cr, unpack(v))
+        end
+    end
+end
+
+local function fit(_, _, width, height)
+    return width, height
+end
+
+--- The pie chart data.
+-- @property data
+-- @tparam table data Labels as keys and number as value.
+
+--- The border color.
+-- If none is set, it will use current foreground (text) color.
+--@DOC_wibox_widget_piechart_border_color_EXAMPLE@
+-- @property border_color
+-- @param color
+-- @see gears.color
+
+--- The pie elements border width.
+--@DOC_wibox_widget_piechart_border_width_EXAMPLE@
+-- @property border_width
+-- @tparam[opt=1] number border_width
+
+--- The pie chart colors.
+-- If no color is set, only the border will be drawn. If less colors than
+-- required are set, colors will be re-used in order.
+-- @property colors
+-- @tparam table colors A table of colors, one for each elements
+-- @see gears.color
+
+--- The border color.
+-- If none is set, it will use current foreground (text) color.
+-- @beautiful beautiful.piechart_border_color
+-- @param color
+-- @see gears.color
+
+--- If the pie chart has labels.
+--@DOC_wibox_widget_piechart_label_EXAMPLE@
+-- @property display_labels
+-- @param[opt=true] boolean
+
+--- The pie elements border width.
+-- @beautiful beautiful.piechart_border_width
+-- @tparam[opt=1] number border_width
+
+--- The pie chart colors.
+-- If no color is set, only the border will be drawn. If less colors than
+-- required are set, colors will be re-used in order.
+-- @beautiful beautiful.piechart_colors
+-- @tparam table colors A table of colors, one for each elements
+-- @see gears.color
+
+for _, prop in ipairs {"data", "border_color", "border_width", "colors",
+    "display_labels"
+  } do
+    piechart["set_"..prop] = function(self, value)
+        self._private[prop] = value
+        self:emit_signal("property::"..prop)
+        self:emit_signal("widget::redraw_needed")
+    end
+    piechart["get_"..prop] = function(self)
+        return self._private[prop] or beautiful["piechart_"..prop]
+    end
+end
+
+local function new(data)
+
+    local ret = base.make_widget(nil, nil, {
+        enable_properties = true,
+    })
+
+    util.table.crush(ret, piechart)
+
+    rawset(ret, "fit" , fit )
+    rawset(ret, "draw", draw)
+
+    ret:set_data(data)
+
+    return ret
+end
+
+--@DOC_widget_COMMON@
+
+--@DOC_object_COMMON@
+
+return setmetatable(module, { __call = function(_, ...) return new(...) end })
+-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80

tests/examples/wibox/widget/defaults/piechart.lua

@@ -0,0 +1,24 @@
+local parent    = ... --DOC_HIDE
+local wibox     = require( "wibox"     ) --DOC_HIDE
+local beautiful = require( "beautiful" ) --DOC_HIDE
+
+parent:add( --DOC_HIDE
+
+wibox.widget {
+    data = {
+        ['L1'] = 100,
+        ['L2'] = 200,
+        ['L3'] = 300,
+    },
+    border_width = 1,
+    forced_height = 50, --DOC_HIDE
+    forced_width  = 100, --DOC_HIDE
+    colors = {
+        beautiful.bg_normal,
+        beautiful.bg_highlight,
+        beautiful.border_color,
+    },
+    widget = wibox.widget.piechart
+}
+
+) --DOC_HIDE