CRE: fix to Top/Bottom margins fine tuning

Rework eb66856d so that "Sync T/B Margins" is disabled
when set Top and Bottom margins differ (previously,
the bottom one was taking over the top one when
it was enabled).

frontend/apps/reader/modules/readertypeset.lua

@@ -455,6 +455,17 @@ function ReaderTypeset:onSetPageBottomMargin(b_margin, refresh_callback)
     self.ui:handleEvent(Event:new("SetPageMargins", self.unscaled_margins, refresh_callback))
 end
 
+function ReaderTypeset:onSetPageTopAndBottomMargin(t_b_margins, refresh_callback)
+    local t_margin, b_margin = t_b_margins[1], t_b_margins[2]
+    self.unscaled_margins = { self.unscaled_margins[1], t_margin, self.unscaled_margins[3], b_margin }
+    if t_margin ~= b_margin then
+        -- Set Sync T/B Margins toggle to off, as user explicitly made them differ
+        self.sync_t_b_page_margins = false
+        self.ui.document.configurable.sync_t_b_page_margins = 0
+    end
+    self.ui:handleEvent(Event:new("SetPageMargins", self.unscaled_margins, refresh_callback))
+end
+
 function ReaderTypeset:onSyncPageTopBottomMargins(toggle, refresh_callback)
     self.sync_t_b_page_margins = not self.sync_t_b_page_margins
     if self.sync_t_b_page_margins then

frontend/ui/data/creoptions.lua

@@ -155,13 +155,12 @@ In the top menu → Settings → Status bar, you can choose whether the bottom m
                 name_text_hold_callback = optionsutil.showValues,
                 more_options = true,
                 more_options_param = {
-                    -- Allow this to tune both top and bottom margins,
-                    -- handling 2 setting names and sending 2 events
-                    -- (we'll get the exact same DoubleSpinWidget in
-                    -- the b_page_margin setting just below)
+                    -- Allow this to tune both top and bottom margins, handling
+                    -- 2 setting names (we'll get the exact same DoubleSpinWidget
+                    -- in the b_page_margin setting just below)
                     name_text = _("Top/Bottom Margins"),
                     names = { "t_page_margin", "b_page_margin" },
-                    events = { "SetPageTopMargin", "SetPageBottomMargin" },
+                    event = "SetPageTopAndBottomMargin",
                     left_text = _("Top"),
                     left_min = 0,
                     left_max = 140,
@@ -211,7 +210,7 @@ In the top menu → Settings → Status bar, you can choose whether the bottom m
                     -- Similar as for t_page_margin above
                     name_text = _("Top/Bottom Margins"),
                     names = { "t_page_margin", "b_page_margin" },
-                    events = { "SetPageTopMargin", "SetPageBottomMargin" },
+                    event = "SetPageTopAndBottomMargin",
                     left_text = _("Top"),
                     left_min = 0,
                     left_max = 140,

frontend/ui/widget/configdialog.lua

@@ -1172,11 +1172,7 @@ function ConfigDialog:onConfigMoreChoose(values, name, event, args, name_text, d
                         else
                             self:onConfigChoice(name, value_tables)
                         end
-                        if more_options_param.events then
-                            self:onConfigEvent(more_options_param.events[1], left_value, nil)
-                            self:onConfigEvent(more_options_param.events[2], right_value, refresh_callback)
-                            self:update()
-                        elseif event then
+                        if event then
                             args = args or {}
                             self:onConfigEvent(event, value_tables, refresh_callback)
                             self:update()