readerrolling(fix): do not emit PageUpdate event until document is ready

frontend/apps/reader/modules/readerfont.lua

@@ -97,7 +97,7 @@ function ReaderFont:onReadSettings(config)
             or DCREREADER_CONFIG_DEFAULT_FONT_GAMMA
     self.ui.document:setGammaIndex(self.gamma_index)
 
-    -- Dirty hack: we have to add folloing call in order to set
+    -- Dirty hack: we have to add following call in order to set
     -- m_is_rendered(member of LVDocView) to true. Otherwise position inside
     -- document will be reset to 0 on first view render.
     -- So far, I don't know why this call will alter the value of m_is_rendered.

frontend/apps/reader/modules/readerrolling.lua

@@ -174,17 +174,17 @@ function ReaderRolling:onReadSettings(config)
     local last_xp = config:readSetting("last_xpointer")
     local last_per = config:readSetting("last_percent")
     if last_xp then
-        table.insert(self.ui.postInitCallback, function()
-            self.xpointer = last_xp
+        self.xpointer = last_xp
+        self.onReaderReady = function()
             self:_gotoXPointer(self.xpointer)
             -- we have to do a real jump in self.ui.document._document to
             -- update status information in CREngine.
             self.ui.document:gotoXPointer(self.xpointer)
-        end)
+        end
     -- we read last_percent just for backward compatibility
     -- FIXME: remove this branch with migration script
     elseif last_per then
-        table.insert(self.ui.postInitCallback, function()
+        self.onReaderReady = function()
             self:_gotoPercent(last_per)
             -- _gotoPercent calls _gotoPos, which only updates self.current_pos
             -- and self.view.
@@ -198,12 +198,14 @@ function ReaderRolling:onReadSettings(config)
                     Event:new("PageUpdate", self.ui.document:getCurrentPage()))
             end
             self.xpointer = self.ui.document:getXPointer()
-        end)
+        end
     else
-        if self.view.view_mode == "page" then
-            self.ui:handleEvent(Event:new("PageUpdate", 1))
+        self.onReaderReady = function()
+            self.xpointer = self.ui.document:getXPointer()
+            if self.view.view_mode == "page" then
+                self.ui:handleEvent(Event:new("PageUpdate", 1))
+            end
         end
-        self.xpointer = self.ui.document:getXPointer()
     end
     self.show_overlap_enable = config:readSetting("show_overlap_enable")
     if self.show_overlap_enable == nil then

spec/unit/readerlink_spec.lua

@@ -39,6 +39,7 @@ describe("ReaderLink module", function()
         }
         readerui:handleEvent(Event:new("SetScrollMode", true))
         readerui.paging:onGotoPage(1)
+        assert.is.same(1, readerui.paging.current_page)
         readerui.link:onTap(nil, {pos = {x = 250, y = 534}})
         UIManager:run()
         -- its really hard to get the exact page number in scroll mode
@@ -79,6 +80,7 @@ describe("ReaderLink module", function()
         }
         readerui:handleEvent(Event:new("SetScrollMode", true))
         readerui.paging:onGotoPage(1)
+        assert.is.same(1, readerui.paging.current_page)
         readerui.link:onTap(nil, {pos = {x = 250, y = 534}})
         UIManager:run()
         assert.truthy(readerui.paging.current_page == 21
@@ -87,7 +89,7 @@ describe("ReaderLink module", function()
         assert.is.same(1, readerui.paging.current_page)
     end)
 
-    it("should be able to go back after link jump in pdf in scroll mode", function()
+    it("should be able to go back to the same position after link jump in pdf scroll mode", function()
         UIManager:quit()
         local expected_page_states = {
             {
@@ -123,6 +125,7 @@ describe("ReaderLink module", function()
         }
         -- disable footer
         G_reader_settings:saveSetting("reader_footer_mode", 0)
+        require("docsettings"):open(sample_pdf):purge()
         local readerui = ReaderUI:new{
             document = DocumentRegistry:openDocument(sample_pdf),
         }

spec/unit/readerrolling_spec.lua

@@ -182,4 +182,20 @@ describe("Readerrolling module", function()
             end
         end)
     end)
+
+    describe("test initialization", function()
+        it("should emit PageUpdate event after book is rendered", function()
+            local ReaderView = require("apps/reader/modules/readerview")
+            local saved_handler = ReaderView.onPageUpdate
+            ReaderView.onPageUpdate = function(_self)
+                assert.are.same(7, _self.ui.document:getPageCount())
+            end
+            local test_book = "spec/front/unit/data/sample.txt"
+            require("docsettings"):open(test_book):purge()
+            ReaderUI:new{
+                document = DocumentRegistry:openDocument(test_book),
+            }
+            ReaderView.onPageUpdate = saved_handler
+        end)
+    end)
 end)