[UX] Add cropping: none mapped to page width zoom (#4696)

Fixes #1923.

frontend/apps/reader/modules/readercropping.lua

@@ -85,6 +85,11 @@ function ReaderCropping:onPageCrop(mode)
             self:setCropZoomMode(true)
         end
         return
+    elseif mode == "none" then
+        if self.document.configurable.text_wrap ~= 1 then
+            self.ui:handleEvent(Event:new("SetZoomMode", "pagewidth", "cropping"))
+        end
+        return
     end
     -- backup original view dimen
     self.orig_view_dimen = Geom:new{w = self.view.dimen.w, h = self.view.dimen.h}

frontend/ui/data/koptoptions.lua

@@ -28,13 +28,13 @@ local KoptOptions = {
             {
                 name = "trim_page",
                 name_text = S.PAGE_CROP,
-                toggle = {S.MANUAL, S.AUTO, S.SEMIAUTO},
+                toggle = {S.MANUAL, S.AUTO, S.SEMIAUTO, S.NONE},
                 alternate = false,
-                values = {0, 1, 2},
+                values = {0, 1, 2, 3},
                 default_value = DKOPTREADER_CONFIG_TRIM_PAGE,
                 enabled_func = Device.isTouchDevice,
                 event = "PageCrop",
-                args = {"manual", "auto", "semi-auto"},
+                args = {"manual", "auto", "semi-auto", "none"},
                 name_text_hold_callback = optionsutil.showValues,
             }
         }

frontend/ui/data/strings.lua

@@ -40,6 +40,7 @@ S.OFF = _("off")
 S.AUTO = _("auto")
 S.MANUAL = _("manual")
 S.SEMIAUTO = _("semi-auto")
+S.NONE = _("none")
 S.SMALL = _("small")
 S.MEDIUM = _("medium")
 S.LARGE = _("large")