PageBrowser: allow changing nb of chapter levels shown (#8772)

Instead of using the depth configured in Book map, start
with max depth, and allow decreasing (and reseting when
at 0) with long-press on the (i) top left icon.

frontend/ui/widget/pagebrowserwidget.lua

@@ -104,6 +104,12 @@ function PageBrowserWidget:init()
         title = self.title,
         left_icon = "info",
         left_icon_tap_callback = function() self:showHelp() end,
+        left_icon_hold_callback = function()
+            -- Cycle nb of toc span levels shown in bottom row
+            if self:updateNbTocSpans(-1, true) then
+                self:updateLayout()
+            end
+        end,
         close_callback = function() self:onClose() end,
         close_hold_callback = function() self:onClose(true) end,
         show_parent = self,
@@ -128,16 +134,48 @@ function PageBrowserWidget:init()
     self.min_nb_cols = 1
     self.max_nb_cols = 6
 
+    -- Get some info that shouldn't change across calls to update() and updateLayout()
     self.ui.toc:fillToc()
     self.max_toc_depth = self.ui.toc.toc_depth
-    -- We show the toc depth chosen in BookMapWidget, or all of it if not set
-    -- (nothing in this PageBrowserWidget to allow changing it)
-    self.nb_toc_spans = self.ui.doc_settings:readSetting("book_map_toc_depth", self.max_toc_depth)
+    self.nb_pages = self.ui.document:getPageCount()
+    self.cur_page = self.ui.toc.pageno
+    -- Get bookmarks and highlights from ReaderBookmark
+    self.bookmarked_pages = self.ui.bookmark:getBookmarkedPages()
+    -- Get read page from the statistics plugin if enabled
+    self.read_pages = self.ui.statistics and self.ui.statistics:getCurrentBookReadPages()
+    self.current_session_duration = self.ui.statistics and (os.time() - self.ui.statistics.start_current_period)
+    -- Hidden flows, for first page display, and to draw them gray
+    self.has_hidden_flows = self.ui.document:hasHiddenFlows()
+    if self.has_hidden_flows and #self.ui.document.flows > 0 then
+        self.hidden_flows = {}
+        -- Pick into credocument internal data to build a table
+        -- of {first_page_number, last_page_number) for each flow
+        for flow, tab in ipairs(self.ui.document.flows) do
+            table.insert(self.hidden_flows, { tab[1], tab[1]+tab[2]-1 })
+        end
+    end
+    -- Reference page numbers, for first row page display
+    self.page_labels = nil
+    if self.ui.pagemap and self.ui.pagemap:wantsPageLabels() then
+        self.page_labels = self.ui.document:getPageMap()
+    end
+    -- Location stack
+    self.previous_locations = self.ui.link:getPreviousLocationPages()
+
+    -- Compute settings-dependant sizes and options, and build the inner widgets
+    -- (this will call self:update())
+    self:updateLayout()
+end
+
+function PageBrowserWidget:updateLayout()
+    -- We start with showing all toc levels (we could use book_map_toc_depth,
+    -- but we might want to have it different here).
+    self.nb_toc_spans = self.ui.doc_settings:readSetting("page_browser_toc_depth") or self.max_toc_depth
 
     -- Row will contain: nb_toc_spans + page slots + spacing (+ some borders)
-    self.statistics_enabled = self.ui.statistics and self.ui.statistics:isEnabled()
+    local statistics_enabled = self.ui.statistics and self.ui.statistics:isEnabled()
     local page_slots_height_ratio = 1 -- default to 1 * span_height
-    if not self.statistics_enabled and self.nb_toc_spans > 0 then
+    if not statistics_enabled and self.nb_toc_spans > 0 then
         -- Just enough to show page separators below toc spans
         page_slots_height_ratio = 0.2
     end
@@ -155,6 +193,9 @@ function PageBrowserWidget:init()
     -- And put its bottom rounded corner outside of screen
     self.view_finder_h = self.row_height + 2*self.view_finder_bw + Size.radius.window
 
+    if self.grid then
+        self.grid:free()
+    end
     self.grid = OverlapGroup:new{
         dimen = Geom:new{
             w = self.grid_width,
@@ -162,6 +203,9 @@ function PageBrowserWidget:init()
         },
         allow_mirroring = false,
     }
+    if self.row then
+        self.row:free()
+    end
     self.row = CenterContainer:new{
         dimen = Geom:new{
             w = self.dimen.w,
@@ -185,39 +229,6 @@ function PageBrowserWidget:init()
         }
     }
 
-
-    -- Get some info that shouldn't change across calls to update() and updateLayout()
-    self.nb_pages = self.ui.document:getPageCount()
-    self.cur_page = self.ui.toc.pageno
-    -- Get bookmarks and highlights from ReaderBookmark
-    self.bookmarked_pages = self.ui.bookmark:getBookmarkedPages()
-    -- Get read page from the statistics plugin if enabled
-    self.read_pages = self.ui.statistics and self.ui.statistics:getCurrentBookReadPages()
-    self.current_session_duration = self.ui.statistics and (os.time() - self.ui.statistics.start_current_period)
-    -- Hidden flows, for first page display, and to draw them gray
-    self.has_hidden_flows = self.ui.document:hasHiddenFlows()
-    if self.has_hidden_flows and #self.ui.document.flows > 0 then
-        self.hidden_flows = {}
-        -- Pick into credocument internal data to build a table
-        -- of {first_page_number, last_page_number) for each flow
-        for flow, tab in ipairs(self.ui.document.flows) do
-            table.insert(self.hidden_flows, { tab[1], tab[1]+tab[2]-1 })
-        end
-    end
-    -- Reference page numbers, for first row page display
-    self.page_labels = nil
-    if self.ui.pagemap and self.ui.pagemap:wantsPageLabels() then
-        self.page_labels = self.ui.document:getPageMap()
-    end
-    -- Location stack
-    self.previous_locations = self.ui.link:getPreviousLocationPages()
-
-    -- Compute settings-dependant sizes and options, and build the inner widgets
-    -- (this will call self:update())
-    self:updateLayout()
-end
-
-function PageBrowserWidget:updateLayout()
     self.nb_rows = self.ui.doc_settings:readSetting("page_browser_nb_rows")
                    or G_reader_settings:readSetting("page_browser_nb_rows")
     self.nb_cols = self.ui.doc_settings:readSetting("page_browser_nb_cols")
@@ -609,7 +620,8 @@ Swipe along the top or left screen edge to change the number of columns or rows
 Swipe vertically to move one row, horizontally to move one page.
 Swipe horizontally in the bottom ribbon to move by the full stripe.
 Tap in the bottom ribbon on a page to focus thumbnails on this page.
-Tap on a thumbnail to go read this page.
+Tap on a thumbnail to read this page.
+Long-press on ⓘ to decrease or reset the number of chapter levels shown in the bottom ribbon.
 Any multiswipe will close the page browser.]]),
     })
 end
@@ -651,17 +663,41 @@ end
 
 function PageBrowserWidget:saveSettings(reset)
     if reset then
+        self.nb_toc_spans = nil
         self.nb_rows = nil
         self.nb_cols = nil
     end
+    self.ui.doc_settings:saveSetting("page_browser_toc_depth", self.nb_toc_spans)
     self.ui.doc_settings:saveSetting("page_browser_nb_rows", self.nb_rows)
     self.ui.doc_settings:saveSetting("page_browser_nb_cols", self.nb_cols)
-    -- We also save them as global settings, so they will apply on other books
+    -- We also save nb_rows/nb_cols as global settings, so they will apply on other books
     -- where they were not already set
     G_reader_settings:saveSetting("page_browser_nb_rows", self.nb_rows)
     G_reader_settings:saveSetting("page_browser_nb_cols", self.nb_cols)
 end
 
+function PageBrowserWidget:updateNbTocSpans(value, relative)
+    local new_nb_toc_spans
+    if relative then
+        new_nb_toc_spans = self.nb_toc_spans + value
+    else
+        new_nb_toc_spans = value
+    end
+    -- We don't cap, we cycle
+    if new_nb_toc_spans < 0 then
+        new_nb_toc_spans = self.max_toc_depth
+    end
+    if new_nb_toc_spans > self.max_toc_depth then
+        new_nb_toc_spans = 0
+    end
+    if new_nb_toc_spans == self.nb_toc_spans then
+        return false
+    end
+    self.nb_toc_spans = new_nb_toc_spans
+    self:saveSettings()
+    return true
+end
+
 function PageBrowserWidget:updateNbCols(value, relative)
     local new_nb_cols
     if relative then