bump crengine: adds support for dpi-based css units (#4040)

Adds a new toggle to the bottom menu: Zoom (dpi), which
allows for scaling CSS absolute units and image sizes.

frontend/apps/reader/modules/readertypeset.lua

@@ -49,6 +49,14 @@ function ReaderTypeset:onReadSettings(config)
     end
     self.ui.document:setEmbeddedStyleSheet(self.embedded_css and 1 or 0)
 
+    -- set render DPI
+    self.render_dpi = config:readSetting("render_dpi") or
+        G_reader_settings:readSetting("copt_render_dpi") or 96
+    self:setRenderDPI(self.render_dpi)
+
+    -- uncomment if we want font size to follow DPI changes
+    -- self.ui.document:setRenderScaleFontWithDPI(1)
+
     -- set page margins
     self:onSetPageMargins(
         config:readSetting("copt_page_margins") or
@@ -74,6 +82,7 @@ function ReaderTypeset:onSaveSettings()
     self.ui.doc_settings:saveSetting("embedded_css", self.embedded_css)
     self.ui.doc_settings:saveSetting("floating_punctuation", self.floating_punctuation)
     self.ui.doc_settings:saveSetting("embedded_fonts", self.embedded_fonts)
+    self.ui.doc_settings:saveSetting("render_dpi", self.render_dpi)
 end
 
 function ReaderTypeset:onToggleEmbeddedStyleSheet(toggle)
@@ -102,6 +111,11 @@ local OBSOLETED_CSS = {
     "txt.css",
 }
 
+function ReaderTypeset:onSetRenderDPI(dpi)
+    self:setRenderDPI(dpi)
+    return true
+end
+
 function ReaderTypeset:genStyleSheetMenu()
     local getStyleMenuItem = function(text, css_file, separator)
         return {
@@ -251,6 +265,12 @@ function ReaderTypeset:toggleTxtPreFormatted(toggle)
     self.ui:handleEvent(Event:new("UpdatePos"))
 end
 
+function ReaderTypeset:setRenderDPI(dpi)
+    self.render_dpi = dpi
+    self.ui.document:setRenderDPI(dpi)
+    self.ui:handleEvent(Event:new("UpdatePos"))
+end
+
 function ReaderTypeset:addToMainMenu(menu_items)
     -- insert table to main reader menu
     menu_items.set_render_style = {

frontend/document/credocument.lua

@@ -452,6 +452,21 @@ function CreDocument:setTrustSoftHyphens(toggle)
     self._document:setIntProperty("crengine.hyphenation.trust.soft.hyphens", toggle and 1 or 0)
 end
 
+function CreDocument:setRenderDPI(value)
+    -- set DPI used for scaling css units (with 96, 1 css px = 1 screen px)
+    -- it can be different from KOReader screen DPI
+    -- it has no relation to the default fontsize (which is already
+    -- scaleBySize()'d when provided to crengine)
+    logger.dbg("CreDocument: set render dpi", value or 96)
+    self._document:setIntProperty("crengine.render.dpi", value or 96)
+end
+
+function CreDocument:setRenderScaleFontWithDPI(toggle)
+    -- wheter to scale font with DPI, or keep the current size
+    logger.dbg("CreDocument: set render scale font with dpi", toggle)
+    self._document:setIntProperty("crengine.render.scale.font.with.dpi", toggle)
+end
+
 function CreDocument:clearSelection()
     logger.dbg("clear selection")
     self._document:clearSelection()

frontend/ui/data/creoptions.lua

@@ -47,6 +47,16 @@ local CreOptions = {
                 event = "SetViewMode",
                 name_text_hold_callback = optionsutil.showValues,
             },
+            {
+                name = "render_dpi",
+                name_text = S.ZOOM_DPI,
+                toggle = {S.OFF, "48", "96¹’¹", "167", "212", "300"},
+                values = {0, 48, 96, 167, 212, 300},
+                default_value = 96,
+                args = {0, 48, 96, 167, 212, 300},
+                event = "SetRenderDPI",
+                name_text_hold_callback = optionsutil.showValues,
+            },
             {
                 name = "line_spacing",
                 name_text = S.LINE_SPACING,

frontend/ui/data/strings.lua

@@ -6,6 +6,7 @@ S.SCREEN_MODE = _("Orientation")
 S.PAGE_CROP = _("Page Crop")
 S.FULL_SCREEN = _("Full Screen")
 S.SCROLL_MODE = _("Scroll Mode")
+S.ZOOM_DPI = _("Zoom (dpi)")
 S.PAGE_MARGIN = _("Margin")
 S.LINE_SPACING = _("Line Spacing")
 S.COLUMNS = _("Columns")

spec/unit/readerlink_spec.lua

@@ -16,9 +16,9 @@ describe("ReaderLink module", function()
         local readerui = ReaderUI:new{
             document = DocumentRegistry:openDocument(sample_epub),
         }
-        readerui.rolling:onGotoPage(4)
-        readerui.link:onTap(nil, {pos = {x = 306, y = 710}})
-        assert.is.same(37, readerui.rolling.current_page)
+        readerui.rolling:onGotoPage(5)
+        readerui.link:onTap(nil, {pos = {x = 326, y = 220}})
+        assert.is.same(44, readerui.rolling.current_page)
     end)
 
     it("should jump to links in pdf page mode", function()
@@ -53,11 +53,11 @@ describe("ReaderLink module", function()
         local readerui = ReaderUI:new{
             document = DocumentRegistry:openDocument(sample_epub),
         }
-        readerui.rolling:onGotoPage(4)
-        readerui.link:onTap(nil, {pos = {x = 306, y = 710}})
-        assert.is.same(37, readerui.rolling.current_page)
+        readerui.rolling:onGotoPage(5)
+        readerui.link:onTap(nil, {pos = {x = 326, y = 220}})
+        assert.is.same(44, readerui.rolling.current_page)
         readerui.link:onGoBackLink()
-        assert.is.same(4, readerui.rolling.current_page)
+        assert.is.same(5, readerui.rolling.current_page)
     end)
 
     it("should be able to go back after link jump in pdf page mode", function()