cervantes: add usb storage on devices w/updated 3rd party tools

frontend/device/cervantes/device.lua

@@ -21,6 +21,14 @@ local function isConnected()
     return carrier
 end
 
+local function isMassStorageSupported()
+    -- we rely on 3rd party package for that. It should be installed as part of KOReader prerequisites,
+    local safemode_version = io.open("/usr/share/safemode/version", "rb")
+    if not safemode_version then return false end
+    safemode_version:close()
+    return true
+end
+
 local Cervantes = Generic:new{
     model = "Cervantes",
     isCervantes = yes,
@@ -33,6 +41,9 @@ local Cervantes = Generic:new{
     hasOTAUpdates = yes,
     hasKeys = yes,
 
+    -- do we support usb mass storage?
+    canToggleMassStorage = function() return isMassStorageSupported() end,
+
     -- all devices, except the original Cervantes Touch, have frontlight
     hasFrontlight = yes,
 

frontend/device/generic/device.lua

@@ -30,6 +30,7 @@ local Device = {
     hasColorScreen = no,
     hasBGRFrameBuffer = no,
     canToggleGSensor = no,
+    canToggleMassStorage = no,
 
     -- use these only as a last resort. We should abstract the functionality
     -- and have device dependent implementations in the corresponting

frontend/ui/elements/common_settings_menu_table.lua

@@ -21,6 +21,22 @@ if Device:hasFrontlight() then
     }
 end
 
+if Device:canToggleMassStorage() then
+    local MassStorage = require("ui/elements/mass_storage")
+
+    -- mass storage settings
+    common_settings.mass_storage_settings = {
+        text = _("USB mass storage"),
+        sub_item_table = MassStorage:getSettingsMenuTable()
+    }
+
+    -- mass storage actions
+    common_settings.mass_storage_actions = {
+        text = _("Start USB storage"),
+        callback = function() MassStorage:start() end,
+    }
+end
+
 if Device:setDateTime() then
     common_settings.time = {
         text = _("Time and date"),

frontend/ui/elements/filemanager_menu_order.lua

@@ -39,6 +39,7 @@ local order = {
         "time",
         "battery",
         "gesture",
+        "mass_storage_settings",
     },
     network = {
         "network_wifi",
@@ -95,6 +96,7 @@ local order = {
         "open_last_document",
         "----------------------------",
         "system_statistics",
+        "mass_storage_actions",
         "----------------------------",
         "ota_update", -- if Device:hasOTAUpdates()
         "version",

frontend/ui/elements/mass_storage.lua

@@ -0,0 +1,54 @@
+local UIManager = require("ui/uimanager")
+local _ = require("gettext")
+
+local MassStorage = {}
+
+-- if required a popup will ask before entering mass storage mode
+function MassStorage:requireConfirmation()
+    return not G_reader_settings:isTrue("mass_storage_confirmation_disabled")
+end
+
+-- mass storage settings menu
+function MassStorage:getSettingsMenuTable()
+    return {
+        {
+            text = _("Disable confirmation popup"),
+            checked_func = function() return not self:requireConfirmation() end,
+            callback = function()
+                G_reader_settings:saveSetting("mass_storage_confirmation_disabled", self:requireConfirmation())
+            end,
+        },
+    }
+end
+
+-- mass storage actions
+function MassStorage:getActionsMenuTable()
+    return {
+        {
+            text = _("Start USB storage"),
+            callback = function()
+                self:start()
+            end,
+        },
+    }
+end
+
+-- exit KOReader and start mass storage mode.
+function MassStorage:start()
+    if self:requireConfirmation() then
+        local ConfirmBox = require("ui/widget/confirmbox")
+        UIManager:show(ConfirmBox:new{
+            text = _("Share storage via USB?\n"),
+            ok_text = _("Share"),
+            ok_callback = function()
+                UIManager:quit()
+                UIManager._exit_code = 86
+            end,
+        })
+    else
+        UIManager:quit()
+        UIManager._exit_code = 86
+    end
+end
+
+return MassStorage

frontend/ui/elements/reader_menu_order.lua

@@ -61,6 +61,7 @@ local order = {
         "time",
         "battery",
         "gesture",
+        "mass_storage_settings",
     },
     network = {
         "network_wifi",
@@ -119,6 +120,7 @@ local order = {
         "book_info",
         "----------------------------",
         "system_statistics",
+        "mass_storage_actions",
         "----------------------------",
         "ota_update", -- if Device:hasOTAUpdates()
         "version",

platform/cervantes/koreader.sh

@@ -82,10 +82,25 @@ if [ "${STANDALONE}" != "true" ]; then
     [ -x /etc/init.d/connman ] && /etc/init.d/connman stop
 fi
 
-RETURN_VALUE=85
-while [ "${RETURN_VALUE}" -eq 85 ]; do
+# **magic** values to request shell stuff. It starts at 85,
+# any number lower than that will exit this script.
+RESTART_KOREADER=85
+ENTER_USBMS=86
+RETURN_VALUE="${RESTART_KOREADER}"
+
+# Loop forever until KOReader requests a normal exit.
+while [ "${RETURN_VALUE}" -ge "${RESTART_KOREADER}" ]; do
     ./reader.lua "${args}" >>crash.log 2>&1
     RETURN_VALUE=$?
+
+    # check if KOReader requested to enter in mass storage mode.
+    if [ "${RETURN_VALUE}" -eq "${ENTER_USBMS}" ]; then
+        # NOTE: at this point we're sure that the safemode tool
+        # is recent enough to support the "--force" flag.
+
+        safemode storage --force 2>/dev/null
+        # waiting forever for home button events.
+    fi
 done
 
 if [ "${STANDALONE}" != "true" ]; then