awesome/lib/wibox/layout/ratio.lua

433 lines
14 KiB
Lua

---------------------------------------------------------------------------
--- A layout filling all the available space. Each widget is assigned a
-- ratio (percentage) of the total space. Multiple methods are available to
-- ajust this ratio.
--
--@DOC_wibox_layout_defaults_ratio_EXAMPLE@
-- @author Emmanuel Lepage Vallee
-- @copyright 2016 Emmanuel Lepage Vallee
-- @classmod wibox.layout.ratio
---------------------------------------------------------------------------
local base = require("wibox.widget.base" )
local flex = require("wibox.layout.flex" )
local table = table
local pairs = pairs
local floor = math.floor
local gmath = require("gears.math")
local gtable = require("gears.table")
local unpack = unpack or table.unpack -- luacheck: globals unpack (compatibility with Lua 5.1)
local ratio = {}
--@DOC_fixed_COMMON@
-- Compute the sum of all ratio (ideally, it should be 1)
local function gen_sum(self, i_s, i_e)
local sum, new_w = 0,0
for i = i_s or 1, i_e or #self._private.widgets do
if self._private.ratios[i] then
sum = sum + self._private.ratios[i]
else
new_w = new_w + 1
end
end
return sum, new_w
end
-- The ratios are expressed as percentages. For this to work, the sum of all
-- ratio must be 1. This function attempt to ajust them. Space can be taken
-- from or added to a ratio when widgets are being added or removed. If a
-- specific ratio must be enforced for a widget, it has to be done with the
-- `ajust_ratio` method after each insertion or deletion
local function normalize(self)
local count = #self._private.widgets
if count == 0 then return end
-- Instead of adding "if" everywhere, just handle this common case
if count == 1 then
self._private.ratios = { 1 }
return
end
local sum, new_w = gen_sum(self)
local old_count = #self._private.widgets - new_w
local to_add = (sum == 0) and 1 or (sum / old_count)
-- Make sure all widgets have a ratio
for i=1, #self._private.widgets do
if not self._private.ratios[i] then
self._private.ratios[i] = to_add
end
end
sum = sum + to_add*new_w
local delta, new_sum = (1 - sum) / count,0
-- Increase or decrease each ratio so it the sum become 1
for i=1, #self._private.widgets do
self._private.ratios[i] = self._private.ratios[i] + delta
new_sum = new_sum + self._private.ratios[i]
end
-- Floating points is not an exact science, but it should still be close
-- to 1.00.
assert(new_sum > 0.99 and new_sum < 1.01)
end
function ratio:layout(context, width, height)
local preliminary_results = {}
local pos,spacing = 0, self._private.spacing
local strategy = self:get_inner_fill_strategy()
local has_stragety = strategy ~= "default"
local to_redistribute, void_count = 0, 0
local dir = self._private.dir or "x"
for k, v in ipairs(self._private.widgets) do
local space, is_void
local x, y, w, h, fit_h, fit_w
if dir == "y" then
space = height * self._private.ratios[k]
x, y = 0, gmath.round(pos)
w, h = width, floor(space)
else
space = width * self._private.ratios[k]
x, y = gmath.round(pos), 0
w, h = floor(space), height
end
-- Keep track of the unused entries
if has_stragety then
fit_h, fit_w = base.fit_widget(
self, context, v,
dir == "x" and floor(space) or w,
dir == "y" and floor(space) or h
)
is_void = (v.visible == false)
or (dir == "x" and fit_w == 0)
or (dir == "y" and fit_h == 0)
if is_void then
to_redistribute = to_redistribute + space + spacing
void_count = void_count + 1
end
end
table.insert(preliminary_results, {v, x, y, w, h, is_void})
pos = pos + space + spacing
-- Make sure all widgets fit in the layout, if they aren't, something
-- went wrong
if (dir == "y" and gmath.round(pos) >= height) or
(dir ~= "y" and gmath.round(pos) >= width) then
break
end
end
local active = #preliminary_results - void_count
local result, real_pos, space_front = {}, 0, strategy == "right" and
to_redistribute or (
strategy == "center" and math.floor(to_redistribute/2) or 0
)
-- The number of spaces between `n` element is `n-1`, if there is spaces
-- outside, then it is `n+1`
if strategy == "spacing" then
space_front = (space_front+to_redistribute/(active + 1))
to_redistribute = (to_redistribute/(active + 1))*(active - 1)
end
spacing = strategy:match("spacing")
and to_redistribute/(active - 1) or 0
-- Only the `justify` strategy changes the original widget size.
to_redistribute = (strategy == "justify") and to_redistribute or 0
for _, entry in ipairs(preliminary_results) do
local v, x, y, w, h, is_void = unpack(entry)
-- Redistribute the space or move the widgets
if strategy ~= "default" then
if dir == "y" then
h = is_void and 0 or h + (to_redistribute / (active))
y = space_front + real_pos
real_pos = real_pos + h + (is_void and 0 or spacing)
else
w = is_void and 0 or w + (to_redistribute / (active))
x = space_front + real_pos
real_pos = real_pos + w + (is_void and 0 or spacing)
end
end
table.insert(result, base.place_widget_at(v, x, y, w, h))
end
return result
end
--- Increase the ratio of "widget"
-- If the increment produce an invalid ratio (not between 0 and 1), the method
-- do nothing.
--
--@DOC_wibox_layout_ratio_inc_ratio_EXAMPLE@
--
-- @tparam number index The widget index to change
-- @tparam number increment An floating point value between -1 and 1 where the
-- end result is within 0 and 1
function ratio:inc_ratio(index, increment)
if #self._private.widgets == 1 or (not index) or (not self._private.ratios[index])
or increment < -1 or increment > 1 then
return
end
assert(self._private.ratios[index])
self:set_ratio(index, self._private.ratios[index] + increment)
end
--- Increment the ratio of the first instance of `widget`
-- If the increment produce an invalid ratio (not between 0 and 1), the method
-- do nothing.
-- @param widget The widget to ajust
-- @tparam number increment An floating point value between -1 and 1 where the
-- end result is within 0 and 1
function ratio:inc_widget_ratio(widget, increment)
if not widget or not increment then return end
local index = self:index(widget)
self:inc_ratio(index, increment)
end
--- Set the ratio of the widget at position `index`
-- @tparam number index The index of the widget to change
-- @tparam number percent An floating point value between 0 and 1
function ratio:set_ratio(index, percent)
if not percent or #self._private.widgets == 1 or not index or not self._private.widgets[index]
or percent < 0 or percent > 1 then
return
end
local old = self._private.ratios[index]
-- Remove what has to be cleared from all widget
local delta = ( (percent-old) / (#self._private.widgets-1) )
for k in pairs(self._private.widgets) do
self._private.ratios[k] = self._private.ratios[k] - delta
end
-- Set the new ratio
self._private.ratios[index] = percent
-- As some widgets may now have a slightly negative ratio, normalize again
normalize(self)
self:emit_signal("widget::layout_changed")
end
--- Get the ratio at `index`.
-- @tparam number index The widget index to query
-- @treturn number The index (between 0 and 1)
function ratio:get_ratio(index)
if not index then return end
return self._private.ratios[index]
end
--- Set the ratio of `widget` to `percent`.
-- @tparam widget widget The widget to ajust.
-- @tparam number percent A floating point value between 0 and 1.
function ratio:set_widget_ratio(widget, percent)
local index = self:index(widget)
self:set_ratio(index, percent)
end
--- Update all widgets to match a set of a ratio.
-- The sum of before, itself and after must be 1 or nothing will be done.
--
--@DOC_wibox_layout_ratio_ajust_ratio_EXAMPLE@
--
-- @tparam number index The index of the widget to change
-- @tparam number before The sum of the ratio before the widget
-- @tparam number itself The ratio for "widget"
-- @tparam number after The sum of the ratio after the widget
function ratio:ajust_ratio(index, before, itself, after)
if not self._private.widgets[index] or not before or not itself or not after then
return
end
local sum = before + itself + after
-- As documented, it is the caller job to come up with valid numbers
if math.min(before, itself, after) < 0 then return end
if sum > 1.01 or sum < -0.99 then return end
-- Compute the before and after offset to be applied to each widgets
local before_count, after_count = index-1, #self._private.widgets - index
local b, a = gen_sum(self, 1, index-1), gen_sum(self, index+1)
local db, da = (before - b)/before_count, (after - a)/after_count
-- Apply the new ratio
self._private.ratios[index] = itself
-- Equality split the delta among widgets before and after
for i = 1, index -1 do
self._private.ratios[i] = self._private.ratios[i] + db
end
for i = index+1, #self._private.widgets do
self._private.ratios[i] = self._private.ratios[i] + da
end
-- Remove potential negative ratio
normalize(self)
self:emit_signal("widget::layout_changed")
end
--- Update all widgets to match a set of a ratio
-- @param widget The widget to ajust
-- @tparam number before The sum of the ratio before the widget
-- @tparam number itself The ratio for "widget"
-- @tparam number after The sum of the ratio after the widget
function ratio:ajust_widget_ratio(widget, before, itself, after)
local index = self:index(widget)
self:ajust_ratio(index, before, itself, after)
end
--- Add some widgets to the given fixed layout
-- **Signal:** widget::added The argument are the widgets
-- @tparam widget ... Widgets that should be added (must at least be one)
function ratio:add(...)
-- No table.pack in Lua 5.1 :-(
local args = { n=select('#', ...), ... }
assert(args.n > 0, "need at least one widget to add")
for i=1, args.n do
base.check_widget(args[i])
table.insert(self._private.widgets, args[i])
end
normalize(self)
self:emit_signal("widget::layout_changed")
self:emit_signal("widget::added", ...)
end
--- Remove a widget from the layout
-- **Signal:** widget::removed The arguments are the widget and the index
-- @tparam number index The widget index to remove
-- @treturn boolean index If the operation is successful
function ratio:remove(index)
if not index or not self._private.widgets[index] then return false end
local w = self._private.widgets[index]
table.remove(self._private.ratios, index)
table.remove(self._private.widgets, index)
normalize(self)
self:emit_signal("widget::layout_changed")
self:emit_signal("widget::removed", w, index)
return true
end
--- Insert a new widget in the layout at position `index`
-- **Signal:** widget::inserted The arguments are the widget and the index
-- @tparam number index The position
-- @param widget The widget
function ratio:insert(index, widget)
if not index or index < 1 or index > #self._private.widgets + 1 then return false end
base.check_widget(widget)
table.insert(self._private.widgets, index, widget)
normalize(self)
self:emit_signal("widget::layout_changed")
self:emit_signal("widget::inserted", widget, #self._private.widgets)
end
--- Set how the space of invisible or `0x0` sized widget is redistributed.
--
-- Possible values:
--
-- * "default": Honor the ratio and do not redistribute the space.
-- * "justify": Distribute the space among remaining widgets.
-- * "center": Squash remaining widgets and leave equal space on both side.
-- * "inner_spacing": Add equal spacing between all widgets.
-- * "spacing": Add equal spacing between all widgets and on the outside.
-- * "left": Squash remaining widgets and leave empty space on the left.
-- * "right": Squash remaining widgets and leave empty space on the right.
--
--@DOC_wibox_layout_ratio_strategy_EXAMPLE@
--
-- @property inner_fill_strategy
-- @tparam string inner_fill_strategy One of the value listed above.
function ratio:get_inner_fill_strategy()
return self._private.inner_fill_strategy or "default"
end
local valid_strategies = {
default = true,
justify = true,
center = true,
inner_spacing = true,
spacing = true,
left = true,
right = true
}
function ratio:set_inner_fill_strategy(strategy)
assert(valid_strategies[strategy] ~= nil, "Invalid strategy: "..(strategy or ""))
self._private.inner_fill_strategy = strategy
self:emit_signal("widget::layout_changed")
end
local function get_layout(dir, widget1, ...)
local ret = flex[dir](widget1, ...)
gtable.crush(ret, ratio, true)
ret._private.fill_space = nil
ret._private.ratios = {}
return ret
end
--- Returns a new horizontal ratio layout. A ratio layout shares the available space
-- equally among all widgets. Widgets can be added via :add(widget).
-- @tparam widget ... Widgets that should be added to the layout.
function ratio.horizontal(...)
return get_layout("horizontal", ...)
end
--- Returns a new vertical ratio layout. A ratio layout shares the available space
-- equally among all widgets. Widgets can be added via :add(widget).
-- @tparam widget ... Widgets that should be added to the layout.
function ratio.vertical(...)
return get_layout("vertical", ...)
end
--@DOC_widget_COMMON@
--@DOC_object_COMMON@
return ratio
-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80