Calibre plugin - Series/Tag browser updated to show back button. (#8869)

* Calibre plugin - Series/Tag browser updated to show back button.

* Handling page number

* Few updates to search logic:
- Moved "find books" option from CalibreSearch:find(option)
into CalibreSearch:browse(option) function. This way all search options
are handled in one place only.

- Menu is created only once and it is in CalibreSearch:browse(option)
function. This is where it is also invoked with UIManager:show(w).
Switching between different menu content (tags/series/books) is
done using CalibreSearch:switchResults function which will internally
call Menu:switchItemTable. Previously menu was being instantiated
in 2 places depending on are we searching books or series/tags

- Return arrow navigation: Border around Menu is gone to give space
for back arrow. Navigation seems to be working fine so far but will
give it some time to test in case I find any other bugs

plugins/calibre.koplugin/search.lua

@@ -3,7 +3,6 @@
 --]]
 
 local CalibreMetadata = require("metadata")
-local CenterContainer = require("ui/widget/container/centercontainer")
 local ConfirmBox = require("ui/widget/confirmbox")
 local DataStorage = require("datastorage")
 local Device = require("device")
@@ -14,7 +13,6 @@ local InputContainer = require("ui/widget/container/inputcontainer")
 local Menu = require("ui/widget/menu")
 local Persist = require("persist")
 local Screen = require("device").screen
-local Size = require("ui/size")
 local TimeVal = require("ui/timeval")
 local UIManager = require("ui/uimanager")
 local lfs = require("libs/libkoreader-lfs")
@@ -328,13 +326,7 @@ function CalibreSearch:find(option)
 
     -- measure time elapsed searching
     local start = TimeVal:now()
-    if option == "find" then
-        local books = self:findBooks(self.search_value)
-        local result = self:bookCatalog(books)
-        self:showresults(result)
-    else
-        self:browse(option, 1)
-    end
+        self:browse(option)
     logger.info(string.format("search done in %.3f milliseconds (%s, %s, %s, %s, %s)",
         TimeVal:getDurationMs(start),
         option == "find" and "books" or option,
@@ -383,28 +375,19 @@ function CalibreSearch:findBooks(query)
 end
 
 -- browse tags or series
-function CalibreSearch:browse(option, run, chosen)
-    local menu_container = CenterContainer:new{
-        dimen = Screen:getSize(),
-    }
-    self.search_menu = Menu:new{
-        width = Screen:getWidth() - (Size.margin.fullscreen_popout * 2),
-        height = Screen:getHeight() - (Size.margin.fullscreen_popout * 2),
-        show_parent = menu_container,
-        onMenuHold = self.onMenuHold,
-        _manager = self,
-    }
-    table.insert(menu_container, self.search_menu)
-    self.search_menu.close_callback = function()
-        UIManager:close(menu_container)
-    end
-    if run == 1 then
-        local menu_entries = {}
-        local search_value
-        if self.search_value ~= "" then
-            search_value = self.search_value
-        end
-        local name, source
+function CalibreSearch:browse(option)
+    local search_value
+    if self.search_value ~= "" then
+        search_value = self.search_value
+    end
+    local name
+    local menu_entries = {}
+
+    if option == "find" then
+        name = _("Books")
+        menu_entries = self:bookCatalog(self:findBooks(self.search_value))
+    else
+        local source
         if option == "tags" then
             name = _("Browse by tags")
             source = searchByTag(self.books, search_value, self.case_insensitive)
@@ -416,51 +399,62 @@ function CalibreSearch:browse(option, run, chosen)
             local entry = {}
             entry.text = string.format("%s (%d)", k, v)
             entry.callback = function()
-                self:browse(option, 2, k)
+                self:expandTagOrSeries(option,k)
             end
             table.insert(menu_entries, entry)
         end
-        table.sort(menu_entries, function(v1,v2) return v1.text < v2.text end)
-        self.search_menu:switchItemTable(name, menu_entries)
-        UIManager:show(menu_container)
-    else
-        local results
-        if option == "tags" then
-            results = getBooksByTag(self.books, chosen)
-        elseif option == "series" then
-            results = getBooksBySeries(self.books, chosen)
-        end
-        if results then
-            local catalog = self:bookCatalog(results, option)
-            self:showresults(catalog, chosen)
+    end
+
+    self.search_menu = self.search_menu or Menu:new{
+        width = Screen:getWidth(),
+        height = Screen:getHeight(),
+        parent = nil,
+        is_borderless = true,
+        onMenuHold = self.onMenuHold,
+    }
+    self.search_menu.paths = {}
+    self.search_menu.onReturn = function ()
+        local path_entry = table.remove(self.search_menu.paths)
+        local page = path_entry.page or 1
+        if #self.search_menu.paths < 1 then
+            -- If nothing is left in paths we switch to original items and title
+            self.search_menu.paths = {}
+            self:switchResults(menu_entries, name, false, page)
         end
     end
 
+    self:switchResults(menu_entries, name)
+    UIManager:show(self.search_menu)
 end
 
--- show search results
-function CalibreSearch:showresults(t, title)
+function CalibreSearch:expandTagOrSeries(option, chosen_item)
+    local results
+
+    if option == "tags" then
+        results = getBooksByTag(self.books, chosen_item)
+    elseif option == "series" then
+        results = getBooksBySeries(self.books, chosen_item)
+    end
+    if results then
+        local catalog = self:bookCatalog(results, option)
+        self:switchResults(catalog, chosen_item, true)
+    end
+end
+
+-- update search results
+function CalibreSearch:switchResults(t, title, is_child, page)
     if not title then
         title = _("Search results")
     end
-    local menu_container = CenterContainer:new{
-        dimen = Screen:getSize(),
-    }
-    self.search_menu = Menu:new{
-        width = Screen:getWidth() - (Size.margin.fullscreen_popout * 2),
-        height = Screen:getHeight() - (Size.margin.fullscreen_popout * 2),
-        show_parent = menu_container,
-        onMenuHold = self.onMenuHold,
-        _manager = self,
-    }
-    table.insert(menu_container, self.search_menu)
-    self.search_menu.close_callback = function()
-        UIManager:close(menu_container)
-    end
 
     table.sort(t, function(v1,v2) return v1.text < v2.text end)
-    self.search_menu:switchItemTable(title, t)
-    UIManager:show(menu_container)
+
+    if is_child then
+        local path_entry = {}
+        path_entry.page = (self.search_menu.perpage or 1) * (self.search_menu.page or 1)
+        table.insert(self.search_menu.paths, path_entry)
+    end
+    self.search_menu:switchItemTable(title, t, page or 1)
 end
 
 -- prompt the user for a library scan