[feat] Add MuPDF EPUB/FB2 dynamic font size (#5282)

Closes #4368.

frontend/apps/reader/modules/readerconfig.lua

@@ -82,6 +82,7 @@ end
 function ReaderConfig:onShowConfigMenu()
     self.config_dialog = ConfigDialog:new{
         dimen = self.dimen:copy(),
+        document = self.document,
         ui = self.ui,
         configurable = self.configurable,
         config_options = self.options,

frontend/apps/reader/modules/readerpaging.lua

@@ -970,9 +970,12 @@ function ReaderPaging:_gotoPage(number, orig_mode)
         self.view.footer:updateFooter()
         return true
     end
-    if number > self.number_of_pages or number < 1 then
-        logger.warn("wrong page number: "..number.."!")
-        return false
+    if number > self.number_of_pages then
+        logger.warn("page number too high: "..number.."!")
+        number = self.number_of_pages
+    elseif number < 1 then
+        logger.warn("page number too low: "..number.."!")
+        number = 1
     end
     -- this is an event to allow other controllers to be aware of this change
     self.ui:handleEvent(Event:new("PageUpdate", number, orig_mode))

frontend/apps/reader/modules/readerview.lua

@@ -812,8 +812,8 @@ function ReaderView:onGammaUpdate(gamma)
     end
 end
 
-function ReaderView:onFontSizeUpdate()
-    self.ui:handleEvent(Event:new("ReZoom"))
+function ReaderView:onFontSizeUpdate(font_size)
+    self.ui:handleEvent(Event:new("ReZoom", font_size))
 end
 
 function ReaderView:onDefectSizeUpdate()

frontend/apps/reader/modules/readerzooming.lua

@@ -211,7 +211,11 @@ function ReaderZooming:onPageUpdate(new_page_no)
     self:setZoom()
 end
 
-function ReaderZooming:onReZoom()
+function ReaderZooming:onReZoom(font_size)
+    if self.document.is_reflowable then
+        local reflowable_font_size = self.document:convertKoptToReflowableFontSize(font_size)
+        self.document:layoutDocument(reflowable_font_size)
+    end
     self:setZoom()
     self.ui:handleEvent(Event:new("InitScrollPageStates"))
     return true

frontend/apps/reader/readerui.lua

@@ -250,6 +250,7 @@ function ReaderUI:init()
         -- zooming controller
         self:registerModule("zooming", ReaderZooming:new{
             dialog = self.dialog,
+            document = self.document,
             view = self.view,
             ui = self
         })

frontend/document/document.lua

@@ -310,6 +310,7 @@ end
 function Document:getFullPageHash(pageno, zoom, rotation, gamma, render_mode, color)
     return "renderpg|"..self.file.."|"..self.mod_time.."|"..pageno.."|"
                     ..zoom.."|"..rotation.."|"..gamma.."|"..render_mode..(color and "|color" or "")
+                    ..(self.reflowable_font_size and "|"..self.reflowable_font_size or "")
 end
 
 function Document:renderPage(pageno, rect, zoom, rotation, gamma, render_mode)

frontend/document/pdfdocument.lua

@@ -9,13 +9,10 @@ local ffi = require("ffi")
 local C = ffi.C
 local pdf = nil
 
-
 local PdfDocument = Document:new{
     _document = false,
     is_pdf = true,
     dc_null = DrawContext.new(),
-    epub_font_size = G_reader_settings:readSetting("copt_font_size")
-            or DCREREADER_CONFIG_DEFAULT_FONT_SIZE or 22,
     koptinterface = nil,
     provider = "mupdf",
     provider_name = "MuPDF",
@@ -36,11 +33,10 @@ function PdfDocument:init()
     if not ok then
         error(self._document)  -- will contain error message
     end
+    self.is_reflowable = self._document:isDocumentReflowable()
+    self.reflowable_font_size = self:convertKoptToReflowableFontSize()
     -- no-op on PDF
-    self._document:layoutDocument(
-        CanvasContext:getWidth(),
-        CanvasContext:getHeight(),
-        CanvasContext:scaleBySize(self.epub_font_size))
+    self:layoutDocument()
     self.is_open = true
     self.info.has_pages = true
     self.info.configurable = true
@@ -51,6 +47,37 @@ function PdfDocument:init()
     end
 end
 
+function PdfDocument:layoutDocument(font_size)
+    if font_size then
+        self.reflowable_font_size = font_size
+    end
+    self._document:layoutDocument(
+        CanvasContext:getWidth(),
+        CanvasContext:getHeight(),
+        CanvasContext:scaleBySize(self.reflowable_font_size))
+end
+
+local default_font_size = 22
+-- the koptreader config goes from 0.1 to 3.0, but we want a regular font size
+function PdfDocument:convertKoptToReflowableFontSize(font_size)
+    if font_size then
+        return font_size * default_font_size
+    end
+
+    local docsettings = require("docsettings"):open(self.file)
+    local size = docsettings:readSetting("kopt_font_size")
+    docsettings:close()
+    if size then
+        return size * default_font_size
+    elseif G_reader_settings:readSetting("kopt_font_size") then
+        return G_reader_settings:readSetting("kopt_font_size") * default_font_size
+    elseif DKOPTREADER_CONFIG_FONT_SIZE then
+        return DKOPTREADER_CONFIG_FONT_SIZE * default_font_size
+    else
+        return default_font_size
+    end
+end
+
 function PdfDocument:preRenderPage()
     pdf.color = self.render_color
 end
@@ -104,7 +131,7 @@ function PdfDocument:getPageBlock(pageno, x, y)
 end
 
 function PdfDocument:getUsedBBox(pageno)
-    local hash = "pgubbox|"..self.file.."|"..pageno
+    local hash = "pgubbox|"..self.file.."|"..self.reflowable_font_size.."|"..pageno
     local cached = Cache:check(hash)
     if cached then
         return cached.ubbox
@@ -127,7 +154,7 @@ function PdfDocument:getUsedBBox(pageno)
 end
 
 function PdfDocument:getPageLinks(pageno)
-    local hash = "pglinks|"..self.file.."|"..pageno
+    local hash = "pgubbox|"..self.file.."|"..self.reflowable_font_size.."|"..pageno
     local cached = Cache:check(hash)
     if cached then
         return cached.links

frontend/ui/data/koptoptions.lua

@@ -128,10 +128,12 @@ local KoptOptions = {
                 spacing = 15,
                 height = 60,
                 item_font_size = {24,28,32,34,36,38,42,46},
+                args = {0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.6, 2.0},
                 values = {0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.6, 2.0},
                 default_value = DKOPTREADER_CONFIG_FONT_SIZE,
                 event = "FontSizeUpdate",
-                enabled_func = function(configurable)
+                enabled_func = function(configurable, document)
+                    if document.is_reflowable then return true end
                     return optionsutil.enableIfEquals(configurable, "text_wrap", 1)
                 end,
             },
@@ -145,7 +147,8 @@ local KoptOptions = {
                 event = "FineTuningFontSize",
                 args = {-0.05, 0.05},
                 alternate = false,
-                enabled_func = function(configurable)
+                enabled_func = function(configurable, document)
+                    if document.is_reflowable then return true end
                     return optionsutil.enableIfEquals(configurable, "text_wrap", 1)
                 end,
                 name_text_hold_callback = function(configurable, __, prefix)

frontend/ui/widget/configdialog.lua

@@ -254,7 +254,7 @@ function ConfigOption:init()
                 item_align = 0.5
             end
             if self.options[c].enabled_func then
-                enabled = self.options[c].enabled_func(self.config.configurable)
+                enabled = self.options[c].enabled_func(self.config.configurable, self.config.document)
             end
             local horizontal_group = HorizontalGroup:new{}
 
@@ -463,6 +463,7 @@ function ConfigOption:init()
                     option_item.event = self.options[c].event
                     option_item.current_item = d
                     option_item.config = self.config
+                    option_item.document = self.document
                     table.insert(option_items_group, option_item)
                 end
             end
@@ -621,6 +622,7 @@ function ConfigPanel:init()
     local panel = ConfigOption:new{
         options = self.index and config_options[self.index].options or default_option,
         config = self.config_dialog,
+        document = self.document,
     }
     self.dimen = panel:getSize()
     table.insert(self, panel)