add inactive touch zones around buttons on Kindle Voyage

This should fix #1801.

frontend/device/input.lua

@@ -159,10 +159,22 @@ function Input:registerEventAdjustHook(hook, hook_params)
     end
 end
 
+function Input:registerGestureAdjustHook(hook, hook_params)
+    local old = self.gestureAdjustHook
+    self.gestureAdjustHook = function(this, ges)
+        old(this, ges)
+        hook(this, ges, hook_params)
+    end
+end
+
 function Input:eventAdjustHook(ev)
     -- do nothing by default
 end
 
+function Input:gestureAdjustHook(ges)
+    -- do nothing by default
+end
+
 -- catalogue of predefined hooks:
 function Input:adjustTouchSwitchXY(ev)
     if ev.type == EV_ABS then
@@ -363,6 +375,7 @@ function Input:handleTouchEv(ev)
             self.MTSlots = {}
             if touch_ges then
                 --DEBUG("ges", touch_ges)
+                self:gestureAdjustHook(touch_ges)
                 return Event:new("Gesture",
                     self.gesture_detector:adjustGesCoordinate(touch_ges)
                 )
@@ -427,6 +440,7 @@ function Input:handleTouchEvPhoenix(ev)
             local touch_ges = self.gesture_detector:feedEvent(self.MTSlots)
             self.MTSlots = {}
             if touch_ges then
+                self:gestureAdjustHook(touch_ges)
                 return Event:new("Gesture",
                     self.gesture_detector:adjustGesCoordinate(touch_ges)
                 )
@@ -495,6 +509,7 @@ function Input:waitEvent(timeout_us)
                             -- Do we really need to clear all setTimeout after
                             -- decided a gesture? FIXME
                             self.timer_callbacks = {}
+                            self:gestureAdjustHook(touch_ges)
                             return Event:new("Gesture",
                                 self.gesture_detector:adjustGesCoordinate(touch_ges)
                             )

frontend/device/kindle/device.lua

@@ -234,6 +234,35 @@ function KindleVoyage:init()
             [109] = "LPgFwd",
         },
     }
+    -- touch gestures fall into these cold spots defined by (x, y, r)
+    -- will be rewritten to 'none' ges thus being ignored
+    -- x, y is the absolute position disregard of screen mode, r is spot radius
+    self.cold_spots = {
+        {
+            x = 1080 + 50, y = 485, r = 80
+        },
+        {
+            x = 1080 + 70, y = 910, r = 120
+        },
+        {
+            x = -50, y = 485, r = 80
+        },
+        {
+            x = -70, y = 910, r = 120
+        },
+    }
+
+    self.input:registerGestureAdjustHook(function(_, ges)
+        if ges then
+            local pos = ges.pos
+            for _, spot in ipairs(self.cold_spots) do
+                if (spot.x - pos.x) * (spot.x - pos.x) +
+                   (spot.y - pos.y) * (spot.y - pos.y) < spot.r * spot.r then
+                   ges.ges = "none"
+                end
+            end
+        end
+    end)
 
     Kindle.init(self)