ReaderFooter: Cleanup some more messy dimensions handling (#6898)

Some stuff was still hacked on manually instead of trusting the widget system to do things right, which it does, if you update the right stuff at the right time the right way ;). *This Is The Way*.

Fix #6893 (and address https://github.com/koreader/koreader/pull/6878#discussion_r523411883, because it was indeed redundant ^^).

Includes a bonus fix for a number of (footer) settings not being applied immediately in PDFs.

frontend/apps/reader/modules/readerfooter.lua

@@ -504,7 +504,6 @@ function ReaderFooter:init()
         self.mode = self.mode_list.off
         self.view.footer_visible = false
         self:resetLayout()
-        self.footer_container.dimen.h = 0
         self.footer_text.height = 0
     end
     if self.settings.all_at_once then
@@ -512,9 +511,6 @@ function ReaderFooter:init()
         self:updateFooterTextGenerator()
         if self.settings.progress_bar_position and self.has_no_mode then
             self.footer_text.height = 0
-            if self.settings.disable_progress_bar then
-                self.footer_container.dimen.h = 0
-            end
         end
     else
         self:applyFooterMode()
@@ -673,13 +669,17 @@ function ReaderFooter:resetLayout(force_reset)
     if self.separator_line then
         self.separator_line.dimen.w = new_screen_width - 2 * self.horizontal_margin
     end
-    local bar_height
+    if self.settings.disable_progress_bar then
-    if self.settings.progress_style_thin then
+        self.progress_bar.height = 0
-        bar_height = self.settings.progress_style_thin_height or PROGRESS_BAR_STYLE_THIN_DEFAULT_HEIGHT
     else
-        bar_height = self.settings.progress_style_thick_height or PROGRESS_BAR_STYLE_THICK_DEFAULT_HEIGHT
+        local bar_height
+        if self.settings.progress_style_thin then
+            bar_height = self.settings.progress_style_thin_height or PROGRESS_BAR_STYLE_THIN_DEFAULT_HEIGHT
+        else
+            bar_height = self.settings.progress_style_thick_height or PROGRESS_BAR_STYLE_THICK_DEFAULT_HEIGHT
+        end
+        self.progress_bar:setHeight(bar_height)
     end
-    self.progress_bar:setHeight(bar_height)
 
     self.horizontal_group:resetLayout()
     self.footer_positioner.dimen.w = new_screen_width
@@ -834,16 +834,11 @@ function ReaderFooter:addToMainMenu(menu_items)
                 self.reclaim_height = self.settings.reclaim_height or false
                 -- refresh margins position
                 if self.has_no_mode then
-                    if self.settings.disable_progress_bar then
-                        self.footer_container.dimen.h = 0
-                    end
                     self.footer_text.height = 0
                     should_signal = true
                     self.genFooterText = footerTextGeneratorMap.empty
                     self.mode = self.mode_list.off
                 elseif prev_has_no_mode then
-                    self.footer_container.dimen.h = self.height
-                    self.footer_text.height = self.height
                     if self.settings.all_at_once then
                         self.mode = self.mode_list.page_progress
                         self:applyFooterMode()
@@ -1381,8 +1376,6 @@ function ReaderFooter:addToMainMenu(menu_items)
                 callback = function()
                     self.settings.disable_progress_bar = not self.settings.disable_progress_bar
                     if not self.settings.disable_progress_bar then
-                        self.footer_container.dimen.h = self.height
-                        self.footer_text.height = self.height
                         self:setTocMarkers()
                         self.mode = self.mode_list.page_progress
                         self:applyFooterMode()
@@ -1847,12 +1840,12 @@ function ReaderFooter:_updateFooterText(force_repaint, force_recompute)
     if self.settings.disable_progress_bar then
         if self.has_no_mode or text == "" then
             self.text_width = 0
-            self.footer_container.dimen.h = 0
             self.footer_text.height = 0
         else
             self.text_width = self.footer_text:getSize().w
             self.footer_text.height = self.footer_text:getSize().h
         end
+        self.progress_bar.height = 0
         self.progress_bar.width = 0
     elseif self.settings.progress_bar_position then
         if self.has_no_mode or text == "" then
@@ -1876,13 +1869,6 @@ function ReaderFooter:_updateFooterText(force_repaint, force_recompute)
         self.progress_bar.width = math.floor(
             self._saved_screen_width - self.text_width - self.settings.progress_margin_width*2)
     end
-    local bar_height
-    if self.settings.progress_style_thin then
-        bar_height = self.settings.progress_style_thin_height or PROGRESS_BAR_STYLE_THIN_DEFAULT_HEIGHT
-    else
-        bar_height = self.settings.progress_style_thick_height or PROGRESS_BAR_STYLE_THICK_DEFAULT_HEIGHT
-    end
-    self.progress_bar:setHeight(bar_height)
 
     if self.separator_line then
         self.separator_line.dimen.w = self._saved_screen_width - 2 * self.horizontal_margin
@@ -2134,7 +2120,13 @@ function ReaderFooter:refreshFooter(refresh, signal)
     -- We *do* need to ensure we at least re-compute the footer layout, though, especially when going from visible to invisible...
     self:onUpdateFooter(refresh and not signal, refresh and signal)
     if signal then
-        self.ui:handleEvent(Event:new("SetPageBottomMargin", self.ui.document.configurable.b_page_margin))
+        if self.ui.document.provider == "crengine" then
+            -- This will ultimately trigger an UpdatePos, hence a ReaderUI repaint.
+            self.ui:handleEvent(Event:new("SetPageBottomMargin", self.ui.document.configurable.b_page_margin))
+        else
+            -- No fancy chain of events outside of CRe, just ask for a ReaderUI repaint ourselves ;).
+            UIManager:setDirty(self.view.dialog, "partial")
+        end
     end
 end