refactor: add touch zone subsystem to inputcontainer

Touch zone decouples screen size from gesture event registration.

The win here is each individual widget does not need to update
gesture range on screen rotate/resize anymore.

Another advantage is we now have a centralized ordered array to handle
all registered touch event listeners, makes it much easier to resolve
gesture range conflicts between multiple widgets.

This patch also includes the following changes:

* migrate readerpaging to use readerui's touch zone
* migrate readerfooter to use readerui's touch zone
* move inverse read direction setting to touch menu's setting tab
* moved kobolight widget from readerview into readerui
* various dead code cleanups and comments

frontend/apps/reader/modules/readercropping.lua

@@ -77,6 +77,7 @@ function PageCropDialog:onShow()
     return true
 end
 
+
 local ReaderCropping = InputContainer:new{}
 
 function ReaderCropping:onPageCrop(mode)

frontend/apps/reader/modules/readerfooter.lua

@@ -1,4 +1,4 @@
-local InputContainer = require("ui/widget/container/inputcontainer")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
 local RightContainer = require("ui/widget/container/rightcontainer")
 local BottomContainer = require("ui/widget/container/bottomcontainer")
 local FrameContainer = require("ui/widget/container/framecontainer")
@@ -6,7 +6,6 @@ local ProgressWidget = require("ui/widget/progresswidget")
 local HorizontalGroup = require("ui/widget/horizontalgroup")
 local HorizontalSpan = require("ui/widget/horizontalspan")
 local TextWidget = require("ui/widget/textwidget")
-local GestureRange = require("ui/gesturerange")
 local Blitbuffer = require("ffi/blitbuffer")
 local UIManager = require("ui/uimanager")
 local Device = require("device")
@@ -88,7 +87,7 @@ local footerTextGeneratorMap = {
     end,
 }
 
-local ReaderFooter = InputContainer:new{
+local ReaderFooter = WidgetContainer:new{
     mode = MODE.page_progress,
     pageno = nil,
     pages = nil,
@@ -152,27 +151,31 @@ function ReaderFooter:init()
         last = nil, -- last will be initialized in self:updateFooterText
     }
 
-    local margin_span = HorizontalSpan:new{width = self.horizontal_margin}
-    self.horizontal_group = HorizontalGroup:new{margin_span}
+    local margin_span = HorizontalSpan:new{ width = self.horizontal_margin }
+    self.horizontal_group = HorizontalGroup:new{ margin_span }
     self.text_container = RightContainer:new{
-        dimen = Geom:new{w = 0, h = self.height},
+        dimen = Geom:new{ w = 0, h = self.height },
         self.footer_text,
     }
     table.insert(self.horizontal_group, self.progress_bar)
     table.insert(self.horizontal_group, self.text_container)
     table.insert(self.horizontal_group, margin_span)
-    self[1] = BottomContainer:new{
+
+    self.footer_content = FrameContainer:new{
+        self.horizontal_group,
+        background = Blitbuffer.COLOR_WHITE,
+        bordersize = 0,
+        padding = 0,
+    }
+    self.footer_container = BottomContainer:new{
+        dimen = Geom:new{ w = 0, h = self.height*2 },
+        self.footer_content,
+    }
+    self.footer_positioner = BottomContainer:new{
         dimen = Geom:new{},
-        BottomContainer:new{
-            dimen = Geom:new{w = 0, h = self.height*2},
-            FrameContainer:new{
-                self.horizontal_group,
-                background = Blitbuffer.COLOR_WHITE,
-                bordersize = 0,
-                padding = 0,
-            }
-        }
+        self.footer_container,
     }
+    self[1] = self.footer_positioner
 
     self.mode = G_reader_settings:readSetting("reader_footer_mode") or self.mode
     if self.settings.all_at_once then
@@ -181,7 +184,6 @@ function ReaderFooter:init()
     else
         self:applyFooterMode()
     end
-    self:resetLayout()
 
     if self.settings.auto_refresh_time then
         self:setupAutoRefreshTime()
@@ -201,7 +203,30 @@ function ReaderFooter:setupAutoRefreshTime()
     UIManager:scheduleIn(61 - tonumber(os.date("%S")), self.autoRefreshTime)
 end
 
--- call this method whenever the screen size changed
+function ReaderFooter:setupTouchZones()
+    if not Device:isTouchDevice() then return end
+    local footer_screen_zone = {
+        ratio_x = DTAP_ZONE_MINIBAR.x, ratio_y = DTAP_ZONE_MINIBAR.y,
+        ratio_w = DTAP_ZONE_MINIBAR.w, ratio_h = DTAP_ZONE_MINIBAR.h,
+    }
+    self.ui:registerTouchZones({
+        {
+            id = "footer_tap",
+            ges = "tap",
+            screen_zone = footer_screen_zone,
+            handler = function() return self:onTapFooter() end,
+            overrides = { 'tap_forward', 'tap_backward', },
+        },
+        {
+            id = "footer_hold",
+            ges = "hold",
+            screen_zone = footer_screen_zone,
+            handler = function() return self:onHoldFooter() end,
+        },
+    })
+end
+
+-- call this method whenever the screen size changes
 function ReaderFooter:resetLayout()
     local new_screen_width = Screen:getWidth()
     if new_screen_width == self._saved_screen_width then return end
@@ -209,34 +234,12 @@ function ReaderFooter:resetLayout()
 
     self.progress_bar.width = math.floor(new_screen_width - self.text_width - self.horizontal_margin*2)
     self.horizontal_group:resetLayout()
-    self[1].dimen.w = new_screen_width
-    self[1].dimen.h = new_screen_height
-    self[1][1].dimen.w = new_screen_width
-    self.dimen = self[1]:getSize()
+    self.footer_positioner.dimen.w = new_screen_width
+    self.footer_positioner.dimen.h = new_screen_height
+    self.footer_container.dimen.w = new_screen_width
+    self.dimen = self.footer_positioner:getSize()
 
     self._saved_screen_width = new_screen_width
-    if Device:isTouchDevice() then
-        local range = Geom:new{
-            x = new_screen_width*DTAP_ZONE_MINIBAR.x,
-            y = new_screen_height*DTAP_ZONE_MINIBAR.y,
-            w = new_screen_width*DTAP_ZONE_MINIBAR.w,
-            h = new_screen_height*DTAP_ZONE_MINIBAR.h
-        }
-        self.ges_events = {
-            TapFooter = {
-                GestureRange:new{
-                    ges = "tap",
-                    range = range,
-                },
-            },
-            HoldFooter = {
-                GestureRange:new{
-                    ges = "hold",
-                    range = range,
-                },
-            },
-        }
-    end
 end
 
 function ReaderFooter:getHeight()
@@ -481,7 +484,7 @@ function ReaderFooter:_updateFooterText()
         self._saved_screen_width - self.text_width - self.horizontal_margin*2)
     self.text_container.dimen.w = self.text_width
     self.horizontal_group:resetLayout()
-    UIManager:setDirty(self.view.dialog, "ui", self[1][1][1].dimen)
+    UIManager:setDirty(self.view.dialog, "ui", self.footer_content.dimen)
 end
 
 function ReaderFooter:onPageUpdate(pageno)
@@ -501,6 +504,8 @@ end
 ReaderFooter.onUpdatePos = ReaderFooter.updateFooter
 
 function ReaderFooter:onReaderReady()
+    self:setupTouchZones()
+    self:resetLayout()  -- set widget dimen
     self:setTocMarkers()
     self.updateFooterText = self._updateFooterText
     self:updateFooter()
@@ -574,7 +579,7 @@ function ReaderFooter:onTapFooter(arg, ges)
     return true
 end
 
-function ReaderFooter:onHoldFooter(arg, ges)
+function ReaderFooter:onHoldFooter()
     if self.mode == MODE.off then return end
     self.ui:handleEvent(Event:new("ShowGotoDialog"))
     return true

frontend/apps/reader/modules/readerpaging.lua

@@ -1,7 +1,6 @@
 local InputContainer = require("ui/widget/container/inputcontainer")
 local Geom = require("ui/geometry")
 local Input = require("device").input
-local GestureRange = require("ui/gesturerange")
 local Device = require("device")
 local Screen = Device.screen
 local Event = require("ui/event")
@@ -11,6 +10,9 @@ local DEBUG = require("dbg")
 local _ = require("gettext")
 
 
+local pan_rate = Screen.eink and 4.0 or 10.0
+
+
 local function copyPageState(page_state)
     return {
         page = page_state.page,
@@ -75,64 +77,77 @@ function ReaderPaging:init()
     self.ui.menu:registerToMainMenu(self)
 end
 
--- This method will  be called in onSetDimensions handler
-function ReaderPaging:initGesListener()
-    self.ges_events = {
-        TapForward = {
-            GestureRange:new{
-                ges = "tap",
-                range = Geom:new{
-                    x = Screen:getWidth()*DTAP_ZONE_FORWARD.x,
-                    y = Screen:getHeight()*DTAP_ZONE_FORWARD.y,
-                    w = Screen:getWidth()*DTAP_ZONE_FORWARD.w,
-                    h = Screen:getHeight()*DTAP_ZONE_FORWARD.h,
-                }
-            }
+function ReaderPaging:onReaderReady()
+    self:setupTouchZones()
+end
+
+function ReaderPaging:setupTapTouchZones()
+    local forward_zone = {
+        ratio_x = DTAP_ZONE_FORWARD.x, ratio_y = DTAP_ZONE_FORWARD.y,
+        ratio_w = DTAP_ZONE_FORWARD.w, ratio_h = DTAP_ZONE_FORWARD.h,
+    }
+    local backward_zone = {
+        ratio_x = DTAP_ZONE_BACKWARD.x, ratio_y = DTAP_ZONE_BACKWARD.y,
+        ratio_w = DTAP_ZONE_BACKWARD.w, ratio_h = DTAP_ZONE_BACKWARD.h,
+    }
+
+    if self.inverse_reading_order then
+        forward_zone.ratio_x = 1 - forward_zone.ratio_x - forward_zone.ratio_w
+        backward_zone.ratio_x = 1 - backward_zone.ratio_x - backward_zone.ratio_w
+    end
+
+    self.ui:registerTouchZones({
+        {
+            id = "tap_forward",
+            ges = "tap",
+            screen_zone = forward_zone,
+            handler = function() return self:onTapForward() end
         },
-        TapBackward = {
-            GestureRange:new{
-                ges = "tap",
-                range = Geom:new{
-                    x = Screen:getWidth()*DTAP_ZONE_BACKWARD.x,
-                    y = Screen:getHeight()*DTAP_ZONE_BACKWARD.y,
-                    w = Screen:getWidth()*DTAP_ZONE_BACKWARD.w,
-                    h = Screen:getHeight()*DTAP_ZONE_BACKWARD.h,
-                }
-            }
+        {
+            id = "tap_backward",
+            ges = "tap",
+            screen_zone = backward_zone,
+            handler = function() return self:onTapBackward() end
         },
-        Swipe = {
-            GestureRange:new{
-                ges = "swipe",
-                range = Geom:new{
-                    x = 0, y = 0,
-                    w = Screen:getWidth(),
-                    h = Screen:getHeight(),
-                }
-            }
+    })
+end
+
+-- This method will be called in onSetDimensions handler
+function ReaderPaging:setupTouchZones()
+    -- deligate gesture listener to readerui
+    self.ges_events = {}
+    self.onGesture = nil
+
+    if not Device:isTouchDevice() then return end
+
+    self:setupTapTouchZones()
+    self.ui:registerTouchZones({
+        {
+            id = "paging_swipe",
+            ges = "swipe",
+            screen_zone = {
+                ratio_x = 0, ratio_y = 0, ratio_w = 1, ratio_h = 1,
+            },
+            handler = function(ges) return self:onSwipe(nil, ges) end
         },
-        Pan = {
-            GestureRange:new{
-                ges = "pan",
-                range = Geom:new{
-                    x = 0, y = 0,
-                    w = Screen:getWidth(),
-                    h = Screen:getHeight(),
-                },
-                rate = Screen.eink and 4.0 or 10.0,
-            }
+        {
+            id = "paging_pan",
+            ges = "pan",
+            rate = pan_rate,
+            screen_zone = {
+                ratio_x = 0, ratio_y = 0, ratio_w = 1, ratio_h = 1,
+            },
+            handler = function(ges) return self:onPan(nil, ges) end
         },
-        PanRelease = {
-            GestureRange:new{
-                ges = "pan_release",
-                range = Geom:new{
-                    x = 0, y = 0,
-                    w = Screen:getWidth(),
-                    h = Screen:getHeight(),
-                },
-            }
+        {
+            id = "paging_pan_release",
+            ges = "pan_release",
+            screen_zone = {
+                ratio_x = 0, ratio_y = 0, ratio_w = 1, ratio_h = 1,
+            },
+            handler = function(ges) return self:onPanRelease(nil, ges) end
         },
-    }
-    self:updateReadOrder()
+    })
 end
 
 function ReaderPaging:onReadSettings(config)
@@ -145,7 +160,6 @@ function ReaderPaging:onReadSettings(config)
     self.flipping_zoom_mode = config:readSetting("flipping_zoom_mode") or "page"
     self.flipping_scroll_mode = config:readSetting("flipping_scroll_mode") or false
     self.inverse_reading_order = config:readSetting("inverse_reading_order") or false
-    self:updateReadOrder()
 end
 
 function ReaderPaging:onSaveSettings()
@@ -197,12 +211,12 @@ function ReaderPaging:addToMainMenu(tab_item_table)
         end,
         sub_item_table = page_overlap_menu,
     })
-    table.insert(tab_item_table.typeset, {
+    table.insert(tab_item_table.setting, {
         text = _("Read from right to left"),
         checked_func = function() return self.inverse_reading_order end,
         callback = function()
             self.inverse_reading_order = not self.inverse_reading_order
-            self:updateReadOrder()
+            self:setupTapTouchZones()
         end,
     })
 end
@@ -335,7 +349,7 @@ function ReaderPaging:bookmarkFlipping(flipping_page, flipping_ges)
     UIManager:setDirty(self.view.dialog, "partial")
 end
 
-function ReaderPaging:onSwipe(arg, ges)
+function ReaderPaging:onSwipe(_, ges)
     if self.bookmark_flipping_mode then
         self:bookmarkFlipping(self.current_page, ges)
     elseif self.page_flipping_mode and self.original_page then
@@ -358,7 +372,7 @@ function ReaderPaging:onSwipe(arg, ges)
     end
 end
 
-function ReaderPaging:onPan(arg, ges)
+function ReaderPaging:onPan(_, ges)
     if self.bookmark_flipping_mode then
         return true
     elseif self.page_flipping_mode then
@@ -374,7 +388,7 @@ function ReaderPaging:onPan(arg, ges)
     return true
 end
 
-function ReaderPaging:onPanRelease(arg, ges)
+function ReaderPaging:onPanRelease(_, ges)
     if self.page_flipping_mode then
         if self.view.zoom_mode == "page" then
             self:updateFlippingPage(self.current_page)
@@ -832,13 +846,6 @@ function ReaderPaging:onRedrawCurrentPage()
     return true
 end
 
-function ReaderPaging:onSetDimensions()
-    -- update listening according to new screen dimen
-    if Device:isTouchDevice() then
-        self:initGesListener()
-    end
-end
-
 -- wrapper for bounds checking
 function ReaderPaging:_gotoPage(number, orig_mode)
     if number == self.current_page or not number then
@@ -870,55 +877,4 @@ function ReaderPaging:onGotoPercentage(percentage)
     return true
 end
 
-function ReaderPaging:updateReadOrder()
-    local width, height = Screen:getWidth(), Screen:getHeight()
-    if self.inverse_reading_order then
-        self.ges_events.TapForward = {
-            GestureRange:new{
-                ges = "tap",
-                range = Geom:new{
-                    x = width * (1-DTAP_ZONE_FORWARD.x - DTAP_ZONE_FORWARD.w),
-                    y = height * DTAP_ZONE_FORWARD.y,
-                    w = width * DTAP_ZONE_FORWARD.w,
-                    h = height * DTAP_ZONE_FORWARD.h,
-                }
-            }
-        }
-        self.ges_events.TapBackward = {
-            GestureRange:new{
-                ges = "tap",
-                range = Geom:new{
-                    x = width * (1-DTAP_ZONE_BACKWARD.x - DTAP_ZONE_BACKWARD.w),
-                    y = height * DTAP_ZONE_BACKWARD.y,
-                    w = width * DTAP_ZONE_BACKWARD.w,
-                    h = height * DTAP_ZONE_BACKWARD.h,
-                }
-            }
-        }
-    else
-        self.ges_events.TapForward = {
-            GestureRange:new{
-                ges = "tap",
-                range = Geom:new{
-                    x = width * DTAP_ZONE_FORWARD.x,
-                    y = height * DTAP_ZONE_FORWARD.y,
-                    w = width * DTAP_ZONE_FORWARD.w,
-                    h = height * DTAP_ZONE_FORWARD.h,
-                }
-            }
-        }
-        self.ges_events.TapBackward = {
-            GestureRange:new{
-                ges = "tap",
-                range = Geom:new{
-                    x = width * DTAP_ZONE_BACKWARD.x,
-                    y = height * DTAP_ZONE_BACKWARD.y,
-                    w = width * DTAP_ZONE_BACKWARD.w,
-                    h = height * DTAP_ZONE_BACKWARD.h,
-                }
-            }
-        }
-    end
-end
-
 return ReaderPaging

frontend/apps/reader/modules/readerview.lua

@@ -12,7 +12,6 @@ local Event = require("ui/event")
 local dbg = require("dbg")
 local Blitbuffer = require("ffi/blitbuffer")
 local _ = require("gettext")
-local ReaderKoboLight = require("apps/reader/modules/readerkobolight")
 
 local ReaderView = OverlapGroup:new{
     document = nil,
@@ -115,13 +114,6 @@ function ReaderView:addWidgets()
     self[1] = self.dogear
     self[2] = self.footer
     self[3] = self.flipping
-    if (Device:isKobo() and Device:hasFrontlight()) then
-        self.kobolight = ReaderKoboLight:new{
-            view = self,
-            ui = self.ui,
-        }
-        self[4] = self.kobolight
-    end
 end
 
 function ReaderView:resetLayout()
@@ -609,7 +601,9 @@ function ReaderView:onSetScreenMode(new_mode, rotation)
             Screen:setScreenMode(new_mode)
         end
         UIManager:setDirty(self.dialog, "full")
-        self.ui:handleEvent(Event:new("SetDimensions", Screen:getSize()))
+        local new_screen_size = Screen:getSize()
+        self.ui:handleEvent(Event:new("SetDimensions", new_screen_size))
+        self.ui:onScreenResize(new_screen_size)
         self.ui:handleEvent(Event:new("InitScrollPageStates"))
     end
     self.cur_rotation_mode = Screen.cur_rotation_mode

frontend/apps/reader/readerui.lua

@@ -317,7 +317,15 @@ function ReaderUI:init()
         })
     end
 
-    --dbg(self.doc_settings)
+    local ReaderKoboLight = require("apps/reader/modules/readerkobolight")
+    if (Device:isKobo() and Device:hasFrontlight()) then
+        self:registerModule('kobolight', ReaderKoboLight:new{
+            dialog = self.dialog,
+            view = self.view,
+            ui = self,
+        })
+    end
+
     -- we only read settings after all the widgets are initialized
     self:handleEvent(Event:new("ReadSettings", self.doc_settings))
 
@@ -445,8 +453,9 @@ function ReaderUI:closeDialog()
     UIManager:close(self.password_dialog)
 end
 
-function ReaderUI:onSetDimensions(dimen)
+function ReaderUI:onScreenResize(dimen)
     self.dimen = dimen
+    self:updateTouchZonesOnScreenResize(dimen)
 end
 
 function ReaderUI:saveSettings()

frontend/device/gesturedetector.lua

@@ -4,7 +4,8 @@ local DEBUG = require("dbg")
 
 --[[
 Current detectable gestures:
-    * tap
+    * touch (user touched screen)
+    * tap (touch action detected as single tap)
     * pan
     * hold
     * swipe

frontend/ui/geometry.lua

@@ -265,9 +265,7 @@ Check size of dimension/rectangle for equality
 @tparam Geom rect_b
 ]]
 function Geom:equalSize(rect_b)
-    if self.w == rect_b.w
-    and self.h == rect_b.h
-    then
+    if self.w == rect_b.w and self.h == rect_b.h then
         return true
     end
     return false
@@ -279,12 +277,9 @@ Check if our size is smaller than the size of the given dimension/rectangle
 @tparam Geom rect_b
 ]]
 function Geom:__lt(rect_b)
-    DEBUG("lt:",self,rect_b)
     if self.w < rect_b.w and self.h < rect_b.h then
-DEBUG("lt+")
         return true
     end
-DEBUG("lt-")
     return false
 end
 

frontend/ui/widget/container/inputcontainer.lua

@@ -1,17 +1,10 @@
-local WidgetContainer = require("ui/widget/container/widgetcontainer")
-local UIManager = require("ui/uimanager")
-local Geom = require("ui/geometry")
-local Event = require("ui/event")
-local _ = require("gettext")
+--[[--
+An InputContainer is an WidgetContainer that handles user input events including multi touches
+and key presses.
 
-if require("device"):isAndroid() then
-    require("jit").off(true, true)
-end
-
---[[
-an InputContainer is an WidgetContainer that handles input events
+See @{InputContainer:registerTouchZones} for example on how to listen for multi touch inputs.
 
-an example for a key_event is this:
+An example for listening on key press input event is this:
 
     PanBy20 = {
         { "Shift", Input.group.Cursor },
@@ -26,9 +19,23 @@ an example for a key_event is this:
     },
     Quit = { {"Home"} },
 
-it is suggested to reference configurable sequences from another table
+It is suggested to reference configurable sequences from another table
 and store that table as configuration setting
---]]
+
+]]
+
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
+local GestureRange = require("ui/gesturerange")
+local UIManager = require("ui/uimanager")
+local Screen = require("device").screen
+local Geom = require("ui/geometry")
+local Event = require("ui/event")
+local _ = require("gettext")
+
+if require("device"):isAndroid() then
+    require("jit").off(true, true)
+end
+
 local InputContainer = WidgetContainer:new{
     vertical_align = "top",
 }
@@ -50,6 +57,8 @@ function InputContainer:_init()
         end
     end
     self.ges_events = new_ges_events
+    self._touch_zones = {}
+    self._touch_zone_pos_idx = {}
 end
 
 function InputContainer:paintTo(bb, x, y)
@@ -71,6 +80,108 @@ function InputContainer:paintTo(bb, x, y)
     end
 end
 
+--[[--
+
+Register touch zones into this InputContainer.
+
+See gesturedetector for list of supported gestures.
+
+NOTE: You are responsible for calling self:@{updateTouchZonesOnScreenResize} with the new
+screen dimension whenever the screen is rotated or resized.
+
+@tparam table zones list of touch zones to register
+
+@usage
+local InputContainer = require("ui/widget/container/inputcontainer")
+local test_widget = InputContainer:new{}
+test_widget:registerTouchZones({
+    {
+        id = "foo_tap",
+        ges = "tap",
+        -- This binds handler to the full screen
+        screen_zone = {
+            ratio_x = 0, ratio_y = 0, ratio_w = 1, ratio_h = 1,
+        },
+        handler = function(ges)
+            print('User tapped on screen!')
+            return true
+        end
+    },
+    {
+        id = "foo_swipe",
+        ges = "swipe",
+        -- This binds handler to bottom half of the screen
+        screen_zone = {
+            ratio_x = 0, ratio_y = 0.5, ratio_w = 1, ratio_h = 0.5,
+        },
+        handler = function(ges)
+            print("User swiped at the bottom with direction:", ges.direction)
+            return true
+        end
+    },
+})
+require("ui/uimanager"):show(test_widget)
+
+]]
+function InputContainer:registerTouchZones(zones)
+    local screen_width, screen_height = Screen:getWidth(), Screen:getHeight()
+    for _, zone in ipairs(zones) do
+        if self._touch_zone_pos_idx[zone.id] then
+            table.remove(self._touch_zones, self._touch_zone_pos_idx[zone.id])
+            self._touch_zone_pos_idx[zone.id] = nil
+        end
+        local tzone = {
+            def = zone,
+            handler = zone.handler,
+            gs_range = GestureRange:new{
+                ges = zone.ges,
+                rate = zone.rate,
+                range = Geom:new{
+                    x = screen_width * zone.screen_zone.ratio_x,
+                    y = screen_height * zone.screen_zone.ratio_y,
+                    w = screen_width * zone.screen_zone.ratio_w,
+                    h = screen_height * zone.screen_zone.ratio_h,
+                },
+            },
+        }
+        local insert_pos = #self._touch_zones
+        if insert_pos ~= 0 then
+            if zone.overrides then
+                for _, override_id in ipairs(zone.overrides) do
+                    local zone_idx = self._touch_zone_pos_idx[override_id]
+                    if zone_idx and zone_idx < insert_pos then
+                        insert_pos = zone_idx
+                    end
+                end
+            else
+                insert_pos = 0
+            end
+        end
+        if insert_pos == 0 then
+            table.insert(self._touch_zones, tzone)
+            self._touch_zone_pos_idx[zone.id] = 1
+        else
+            table.insert(self._touch_zones, insert_pos, tzone)
+            self._touch_zone_pos_idx[zone.id] = insert_pos
+        end
+    end
+end
+
+--[[--
+Update touch zones based on new screen dimension.
+
+@tparam ui.geometry.Geom new_screen_dimen new screen dimension
+]]
+function InputContainer:updateTouchZonesOnScreenResize(new_screen_dimen)
+    for _, tzone in ipairs(self._touch_zones) do
+        local range = tzone.gs_range
+        range.x = new_screen_dimen.w * tzone.def.screen_zone.ratio_x
+        range.y = new_screen_dimen.h * tzone.def.screen_zone.ratio_y
+        range.w = new_screen_dimen.w * tzone.def.screen_zone.ratio_w
+        range.h = new_screen_dimen.h * tzone.def.screen_zone.ratio_h
+    end
+end
+
 --[[
 the following handler handles keypresses and checks if they lead to a command.
 if this is the case, we retransmit another event within ourselves
@@ -89,6 +200,11 @@ function InputContainer:onKeyPress(key)
 end
 
 function InputContainer:onGesture(ev)
+    for _, tzone in ipairs(self._touch_zones) do
+        if tzone.gs_range:match(ev) then
+            return tzone.handler(ev)
+        end
+    end
     for name, gsseq in pairs(self.ges_events) do
         for _, gs_range in ipairs(gsseq) do
             if gs_range:match(ev) then

spec/unit/widget_inputcontainer_spec.lua

@@ -0,0 +1,77 @@
+describe("InputContainer widget", function()
+    local InputContainer, Screen
+    setup(function()
+        require("commonrequire")
+        InputContainer = require("ui/widget/container/inputcontainer")
+        Screen = require("device").screen
+    end)
+
+    it("should register touch zones", function()
+        local ic = InputContainer:new{}
+        assert.is.same(#ic._touch_zones, 0)
+
+        ic:registerTouchZones({
+            {
+                id = "foo",
+                ges = "swipe",
+                screen_zone = {
+                    ratio_x = 0, ratio_y = 0, ratio_w = 1, ratio_h = 1,
+                },
+                handler = function() end,
+            },
+            {
+                id = "bar",
+                ges = "tap",
+                screen_zone = {
+                    ratio_x = 0, ratio_y = 0.1, ratio_w = 0.5, ratio_h = 1,
+                },
+                handler = function() end,
+            },
+        })
+
+        local screen_width, screen_height = Screen:getWidth(), Screen:getHeight()
+        assert.is.same(#ic._touch_zones, 2)
+        assert.is.same("foo", ic._touch_zones[1].def.id)
+        assert.is.same(ic._touch_zones[1].def.handler, ic._touch_zones[1].handler)
+        assert.is.same("bar", ic._touch_zones[2].def.id)
+        assert.is.same("tap", ic._touch_zones[2].gs_range.ges)
+        assert.is.same(0, ic._touch_zones[2].gs_range.range.x)
+        assert.is.same(screen_height * 0.1, ic._touch_zones[2].gs_range.range.y)
+        assert.is.same(screen_width / 2, ic._touch_zones[2].gs_range.range.w)
+        assert.is.same(screen_height, ic._touch_zones[2].gs_range.range.h)
+    end)
+
+    it("should support overrides for touch zones", function()
+        local ic = InputContainer:new{}
+        ic:registerTouchZones({
+            {
+                id = "foo",
+                ges = "tap",
+                screen_zone = {
+                    ratio_x = 0, ratio_y = 0, ratio_w = 1, ratio_h = 1,
+                },
+                handler = function() end,
+            },
+            {
+                id = "bar",
+                ges = "tap",
+                screen_zone = {
+                    ratio_x = 0, ratio_y = 0, ratio_w = 0.5, ratio_h = 1,
+                },
+                handler = function() end,
+            },
+            {
+                id = "baz",
+                ges = "tap",
+                screen_zone = {
+                    ratio_x = 0, ratio_y = 0, ratio_w = 0.5, ratio_h = 1,
+                },
+                overrides = { 'foo' },
+                handler = function() end,
+            },
+        })
+        assert.is.same(ic._touch_zones[1].def.id, 'baz')
+        assert.is.same(ic._touch_zones[2].def.id, 'foo')
+        assert.is.same(ic._touch_zones[3].def.id, 'bar')
+    end)
+end)