AltStatusBar/Footer: add the read timer value (#12002)

Closes #11950

frontend/apps/reader/modules/readercoptlistener.lua

@@ -12,6 +12,10 @@ local ReaderCoptListener = EventListener:extend{}
 
 local CRE_HEADER_DEFAULT_SIZE = 20
 
+function ReaderCoptListener:init()
+    self.additional_header_content = {} -- place, where additional header content can be inserted.
+end
+
 function ReaderCoptListener:onReadSettings(config)
     local view_mode_name = self.document.configurable.view_mode == 0 and "page" or "scroll"
     -- Let crengine know of the view mode before rendering, as it can
@@ -44,6 +48,7 @@ function ReaderCoptListener:onReadSettings(config)
     -- We will build the top status bar page info string ourselves,
     -- if we have to display any chunk of it
     self.page_info_override = self.page_number == 1 or self.page_count == 1 or self.reading_percent == 1
+        or (self.battery == 1 and self.battery_percent == 1) -- don't forget a sole battery
     self.document:setPageInfoOverride("") -- an empty string lets crengine display its own page info
 
     self:onTimeFormatChanged()
@@ -84,7 +89,10 @@ end
 function ReaderCoptListener:updatePageInfoOverride(pageno)
     pageno = pageno or self.ui.view.footer.pageno
 
-    if not (self.document.configurable.status_line == 0 and self.view.view_mode == "page" and self.page_info_override) then
+    if self.document.configurable.status_line ~= 0 or self.view.view_mode ~= "page"
+        or not self.page_info_override or not next(self.additional_header_content) then
+
+        self.document:setPageInfoOverride("")
         return
     end
     -- There are a few cases where we may not be updated on change, at least:
@@ -126,7 +134,18 @@ function ReaderCoptListener:updatePageInfoOverride(pageno)
         end
     end
 
-    local page_info = ""
+    local additional_content = ""
+    for dummy, v in ipairs(self.additional_header_content) do
+        local value = v()
+        if value and value ~= "" then
+            additional_content = additional_content .. value
+            if self.page_number == 1 or self.page_count == 1 then
+                additional_content = additional_content .. "  " -- double spaces as crengine's own drawing
+            end
+        end
+    end
+
+    local page_info = additional_content
     if self.page_number == 1 or self.page_count == 1 then
         page_info = page_info .. page_pre
         if self.page_number == 1 then
@@ -158,13 +177,13 @@ function ReaderCoptListener:updatePageInfoOverride(pageno)
             if Device:hasAuxBattery() and powerd:isAuxBatteryConnected() then
                 local aux_batt_lvl = powerd:getAuxCapacity()
                 if powerd:isAuxCharging() then
-                    batt_pre = "[\u{21AF}"
+                    batt_pre = "[\u{21AF}" -- ↯-symbol
                 end
                 -- Sum both batteries for the actual text
                 batt_lvl = batt_lvl + aux_batt_lvl
             else
                 if powerd:isCharging() then
-                    batt_pre = "[\u{21AF}"
+                    batt_pre = "[\u{21AF}" -- ↯-symbol
                 end
             end
             batt_val = string.format("%2d%%", batt_lvl)
@@ -300,15 +319,30 @@ end
 ReaderCoptListener.onCloseDocument = ReaderCoptListener.unscheduleHeaderRefresh
 ReaderCoptListener.onSuspend = ReaderCoptListener.unscheduleHeaderRefresh
 
+function ReaderCoptListener:addAdditionalHeaderContent(content_func)
+    table.insert(self.additional_header_content, content_func)
+end
+
+function ReaderCoptListener:removeAdditionalHeaderContent(content_func)
+    for i, v in ipairs(self.additional_header_content) do
+        if v == content_func then
+            table.remove(self.additional_header_content, i)
+            return true
+        end
+    end
+end
+
 function ReaderCoptListener:setAndSave(setting, property, value)
     self.document._document:setIntProperty(property, value)
     G_reader_settings:saveSetting(setting, value)
+    self:onUpdateHeader()
+end
+
+function ReaderCoptListener:onUpdateHeader()
     self.page_info_override = self.page_number == 1 or self.page_count == 1 or self.reading_percent == 1
-    if self.page_info_override then
-        self:updatePageInfoOverride()
-    else
-        self.document:setPageInfoOverride("") -- Don't forget to restore CRE default behaviour.
-    end
+        or (self.battery == 1 and self.battery_percent == 1) -- don't forget a sole battery
+
+    self:updatePageInfoOverride()
     -- Have crengine redraw it (even if hidden by the menu at this time)
     self.ui.rolling:updateBatteryState()
     self:updateHeader()

frontend/apps/reader/modules/readerfooter.lua

@@ -341,10 +341,10 @@ local footerTextGeneratorMap = {
             prefix .. " ", left)
     end,
     mem_usage = function(footer)
-        local symbol_type = footer.settings.item_prefix
-        local prefix = symbol_prefix[symbol_type].mem_usage
         local statm = io.open("/proc/self/statm", "r")
         if statm then
+            local symbol_type = footer.settings.item_prefix
+            local prefix = symbol_prefix[symbol_type].mem_usage
             local dummy, rss = statm:read("*number", "*number")
             statm:close()
             -- we got the nb of 4Kb-pages used, that we convert to MiB
@@ -516,6 +516,8 @@ ReaderFooter.default_settings = {
 function ReaderFooter:init()
     self.settings = G_reader_settings:readSetting("footer", self.default_settings)
 
+    self.additional_footer_content = {} -- place, where additional header content can be inserted.
+
     -- Remove items not supported by the current device
     if not Device:hasFastWifiStatusQuery() then
         MODE.wifi_status = nil
@@ -1981,6 +1983,19 @@ function ReaderFooter:genAlignmentMenuItems(value)
     }
 end
 
+function ReaderFooter:addAdditionalFooterContent(content_func)
+    table.insert(self.additional_footer_content, content_func)
+end
+
+function ReaderFooter:removeAdditionalFooterContent(content_func)
+    for i, v in ipairs(self.additional_footer_content) do
+        if v == content_func then
+            table.remove(self.additional_footer_content, i)
+            return true
+        end
+    end
+end
+
 -- this method will be updated at runtime based on user setting
 function ReaderFooter:genFooterText() end
 
@@ -2153,6 +2168,13 @@ function ReaderFooter:_updateFooterText(force_repaint, full_repaint)
         return
     end
     local text = self:genFooterText()
+    for dummy, v in ipairs(self.additional_footer_content) do
+        local value = v()
+        if value and value ~= "" then
+            text = value .. " " .. self:get_separator_symbol() .. " " .. text
+        end
+    end
+
     if not text then text = "" end
     self.footer_text:setText(text)
     if self.settings.disable_progress_bar then