[RTL UI] update low-level widgets to handle mirroring

These updated low-level widgets will handle 90%
of the needed UI mirroring.

frontend/ui/widget/container/framecontainer.lua

@@ -18,6 +18,7 @@ Example:
 
 --]]
 
+local BD = require("ui/bidi")
 local Blitbuffer = require("ffi/blitbuffer")
 local Geom = require("ui/geometry")
 local Size = require("ui/size")
@@ -38,6 +39,8 @@ local FrameContainer = WidgetContainer:new{
     width = nil,
     height = nil,
     invert = false,
+    allow_mirroring = true,
+    _mirroredUI = BD.mirroredUILayout(),
 }
 
 function FrameContainer:getSize()
@@ -46,6 +49,9 @@ function FrameContainer:getSize()
     self._padding_right = self.padding_right or self.padding
     self._padding_bottom = self.padding_bottom or self.padding
     self._padding_left = self.padding_left or self.padding
+    if self._mirroredUI and self.allow_mirroring then
+        self._padding_left, self._padding_right = self._padding_right, self._padding_left
+    end
     return Geom:new{
         w = content_size.w + ( self.margin + self.bordersize ) * 2 + self._padding_left + self._padding_right,
         h = content_size.h + ( self.margin + self.bordersize ) * 2 + self._padding_top + self._padding_bottom
@@ -62,6 +68,11 @@ function FrameContainer:paintTo(bb, x, y)
     local container_width = self.width or my_size.w
     local container_height = self.height or my_size.h
 
+    local shift_x = 0
+    if self._mirroredUI and self.allow_mirroring then
+        shift_x = container_width - my_size.w
+    end
+
     --- @todo get rid of margin here?  13.03 2013 (houqp)
     if self.background then
         bb:paintRoundedRect(x, y,
@@ -83,7 +94,7 @@ function FrameContainer:paintTo(bb, x, y)
     end
     if self[1] then
         self[1]:paintTo(bb,
-            x + self.margin + self.bordersize + self._padding_left,
+            x + self.margin + self.bordersize + self._padding_left + shift_x,
             y + self.margin + self.bordersize + self._padding_top)
     end
     if self.invert then

frontend/ui/widget/container/leftcontainer.lua

@@ -2,9 +2,13 @@
 LeftContainer aligns its content (1 widget) at the left of its own dimensions
 --]]
 
+local BD = require("ui/bidi")
 local WidgetContainer = require("ui/widget/container/widgetcontainer")
 
-local LeftContainer = WidgetContainer:new()
+local LeftContainer = WidgetContainer:new{
+    allow_mirroring = true,
+    _mirroredUI = BD.mirroredUILayout(),
+}
 
 function LeftContainer:paintTo(bb, x, y)
     local contentSize = self[1]:getSize()
@@ -13,6 +17,9 @@ function LeftContainer:paintTo(bb, x, y)
         -- throw error? paint to scrap buffer and blit partially?
         -- for now, we ignore this
     -- end
+    if self._mirroredUI and self.allow_mirroring then
+        x = x + (self.dimen.w - contentSize.w) -- as in RightContainer
+    end
     self[1]:paintTo(bb, x , y + math.floor((self.dimen.h - contentSize.h)/2))
 end
 

frontend/ui/widget/container/rightcontainer.lua

@@ -2,9 +2,13 @@
 RightContainer aligns its content (1 widget) at the right of its own dimensions
 --]]
 
+local BD = require("ui/bidi")
 local WidgetContainer = require("ui/widget/container/widgetcontainer")
 
-local RightContainer = WidgetContainer:new()
+local RightContainer = WidgetContainer:new{
+    allow_mirroring = true,
+    _mirroredUI = BD.mirroredUILayout(),
+}
 
 function RightContainer:paintTo(bb, x, y)
     local contentSize = self[1]:getSize()
@@ -13,8 +17,12 @@ function RightContainer:paintTo(bb, x, y)
         -- throw error? paint to scrap buffer and blit partially?
         -- for now, we ignore this
     -- end
+    if not self._mirroredUI or not self.allow_mirroring then
+        x = x + (self.dimen.w - contentSize.w)
+    -- else: keep x, as in LeftContainer
+    end
     self[1]:paintTo(bb,
-        x + (self.dimen.w - contentSize.w),
+        x,
         y + math.floor((self.dimen.h - contentSize.h)/2))
 end
 

frontend/ui/widget/horizontalgroup.lua

@@ -2,10 +2,14 @@
 A layout widget that puts objects besides each other.
 --]]
 
+local BD = require("ui/bidi")
 local WidgetContainer = require("ui/widget/container/widgetcontainer")
+local util = require("util")
 
 local HorizontalGroup = WidgetContainer:new{
     align = "center",
+    allow_mirroring = true,
+    _mirroredUI = BD.mirroredUILayout(),
     _size = nil,
 }
 
@@ -13,6 +17,9 @@ function HorizontalGroup:getSize()
     if not self._size then
         self._size = { w = 0, h = 0 }
         self._offsets = { }
+        if self._mirroredUI and self.allow_mirroring then
+            util.arrayReverse(self)
+        end
         for i, widget in ipairs(self) do
             local w_size = widget:getSize()
             self._offsets[i] = {
@@ -24,6 +31,9 @@ function HorizontalGroup:getSize()
                 self._size.h = w_size.h
             end
         end
+        if self._mirroredUI and self.allow_mirroring then
+            util.arrayReverse(self)
+        end
     end
     return self._size
 end
@@ -31,6 +41,9 @@ end
 function HorizontalGroup:paintTo(bb, x, y)
     local size = self:getSize()
 
+    if self._mirroredUI and self.allow_mirroring then
+        util.arrayReverse(self)
+    end
     for i, widget in ipairs(self) do
         if self.align == "center" then
             widget:paintTo(bb,
@@ -45,6 +58,9 @@ function HorizontalGroup:paintTo(bb, x, y)
                             self.align)
         end
     end
+    if self._mirroredUI and self.allow_mirroring then
+        util.arrayReverse(self)
+    end
 end
 
 function HorizontalGroup:clear()

frontend/ui/widget/overlapgroup.lua

@@ -2,9 +2,20 @@
 A layout widget that puts objects above each other.
 --]]
 
+local BD = require("ui/bidi")
 local WidgetContainer = require("ui/widget/container/widgetcontainer")
 
 local OverlapGroup = WidgetContainer:new{
+    -- Note: we default to allow_mirroring = true.
+    -- When using LeftContainer, RightContainer or HorizontalGroup
+    -- in an OverlapGroup, mostly when they take the whole width,
+    -- either OverlapGroup, or all the others, need to have
+    -- allow_mirroring=false (otherwise, some upper mirroring would
+    -- cancel a lower one...).
+    -- It's usually safer to set it to false on the OverlapGroup,
+    -- but some thinking is needed when many of them are nested.
+    allow_mirroring = true,
+    _mirroredUI = BD.mirroredUILayout(),
     _size = nil,
 }
 
@@ -45,10 +56,19 @@ function OverlapGroup:paintTo(bb, x, y)
     local size = self:getSize()
 
     for i, wget in ipairs(self) do
+        local overlap_align = wget.overlap_align
+        if self._mirroredUI and self.allow_mirroring then
+            if overlap_align == "right" then
+                overlap_align = "left"
+            elseif overlap_align ~= "center" then
+                overlap_align = "right"
+            end
+            -- see if something to do with wget.overlap_offset
+        end
         local wget_size = wget:getSize()
-        if wget.overlap_align == "right" then
+        if overlap_align == "right" then
             wget:paintTo(bb, x+size.w-wget_size.w, y)
-        elseif wget.overlap_align == "center" then
+        elseif overlap_align == "center" then
             wget:paintTo(bb, x+math.floor((size.w-wget_size.w)/2), y)
         elseif wget.overlap_offset then
             wget:paintTo(bb, x+wget.overlap_offset[1], y+wget.overlap_offset[2])

frontend/ui/widget/progresswidget.lua

@@ -27,6 +27,7 @@ Example:
 
 ]]
 
+local BD = require("ui/bidi")
 local Blitbuffer = require("ffi/blitbuffer")
 local Geom = require("ui/geometry")
 local Widget = require("ui/widget/widget")
@@ -46,6 +47,9 @@ local ProgressWidget = Widget:new{
     ticks = nil,
     tick_width = Screen:scaleBySize(3),
     last = nil,
+    fill_from_right = false,
+    allow_mirroring = true,
+    _mirroredUI = BD.mirroredUILayout(),
 }
 
 function ProgressWidget:getSize()
@@ -69,17 +73,30 @@ function ProgressWidget:paintTo(bb, x, y)
                    self.bordersize, self.bordercolor, self.radius)
     -- paint percentage infill
     if self.percentage >= 0 and self.percentage <= 1 then
-        bb:paintRect(x+self.margin_h, math.ceil(y+self.margin_v+self.bordersize),
-                 math.ceil((my_size.w-2*self.margin_h)*self.percentage),
-                 my_size.h-2*(self.margin_v+self.bordersize), self.rectcolor)
+        if self.fill_from_right or (self._mirroredUI and not self.fill_from_right) then
+            bb:paintRect(x+self.margin_h + math.ceil((my_size.w-2*self.margin_h)*(1-self.percentage)),
+                    math.ceil(y+self.margin_v+self.bordersize),
+                    math.ceil((my_size.w-2*self.margin_h)*self.percentage),
+                    my_size.h-2*(self.margin_v+self.bordersize),
+                    self.rectcolor)
+        else
+            bb:paintRect(x+self.margin_h,
+                    math.ceil(y+self.margin_v+self.bordersize),
+                    math.ceil((my_size.w-2*self.margin_h)*self.percentage),
+                    my_size.h-2*(self.margin_v+self.bordersize), self.rectcolor)
+        end
     end
     if self.ticks and self.last and self.last > 0 then
         local bar_width = (my_size.w-2*self.margin_h)
         local y_pos = y + self.margin_v + self.bordersize
         local bar_height = my_size.h-2*(self.margin_v+self.bordersize)
         for i=1, #self.ticks do
+            local tick_x = bar_width*(self.ticks[i]/self.last)
+            if self._mirroredUI then
+                tick_x = bar_width - tick_x
+            end
             bb:paintRect(
-                x + bar_width*(self.ticks[i]/self.last) + self.margin_h,
+                x + self.margin_h + tick_x,
                 y_pos,
                 self.tick_width,
                 bar_height,
@@ -92,6 +109,21 @@ function ProgressWidget:setPercentage(percentage)
     self.percentage = percentage
 end
 
+function ProgressWidget:getPercentageFromPosition(pos)
+    if not pos or not pos.x then
+        return nil
+    end
+    local width = self.dimen.w - 2*self.margin_h
+    local x = pos.x - self.dimen.x - self.margin_h
+    if x < 0 or x > width then
+        return nil
+    end
+    if BD.mirroredUILayout() then
+        x = width - x
+    end
+    return x / width
+end
+
 function ProgressWidget:updateStyle(thick, height)
     if thick then
         if height then

frontend/ui/widget/verticalgroup.lua

@@ -2,12 +2,15 @@
 A layout widget that puts objects under each other.
 --]]
 
+local BD = require("ui/bidi")
 local WidgetContainer = require("ui/widget/container/widgetcontainer")
 
 local VerticalGroup = WidgetContainer:new{
     align = "center",
+    allow_mirroring = true,
+    _mirroredUI = BD.mirroredUILayout(),
     _size = nil,
-    _offsets = {}
+    _offsets = {},
 }
 
 function VerticalGroup:getSize()
@@ -31,15 +34,23 @@ end
 
 function VerticalGroup:paintTo(bb, x, y)
     local size = self:getSize()
+    local align = self.align
+    if self._mirroredUI and self.allow_mirroring then
+        if align == "left" then
+            align = "right"
+        elseif align == "right" then
+            align = "left"
+        end
+    end
 
     for i, widget in ipairs(self) do
-        if self.align == "center" then
+        if align == "center" then
             widget:paintTo(bb,
                 x + math.floor((size.w - self._offsets[i].x) / 2),
                 y + self._offsets[i].y)
-        elseif self.align == "left" then
+        elseif align == "left" then
             widget:paintTo(bb, x, y + self._offsets[i].y)
-        elseif self.align == "right" then
+        elseif align == "right" then
             widget:paintTo(bb,
                 x + size.w - self._offsets[i].x,
                 y + self._offsets[i].y)

frontend/util.lua

@@ -280,6 +280,17 @@ function util.arrayAppend(t1, t2)
     end
 end
 
+-- Reverse array elements in-place in table t
+---- @param t Lua table
+function util.arrayReverse(t)
+    local i, j = 1, #t
+    while i < j do
+        t[i], t[j] = t[j], t[i]
+        i = i + 1
+        j = j - 1
+    end
+end
+
 -- Merge t2 into t1, overwriting existing elements if they already exist
 -- Probably not safe with nested tables (c.f., https://stackoverflow.com/q/1283388)
 ---- @param t1 Lua table