Change icon in About window (#4233)

frontend/ui/elements/common_info_menu_table.lua

@@ -46,6 +46,7 @@ common_info.about = {
     callback = function()
         UIManager:show(InfoMessage:new{
             text = T(_("KOReader %1\n\nA document viewer for E Ink devices.\n\nLicensed under Affero GPL v3. All dependencies are free software.\n\nhttp://koreader.rocks/"), version),
+            icon_file = "resources/ko-icon.png"
         })
     end
 }

frontend/ui/widget/infomessage.lua

@@ -57,6 +57,7 @@ local InfoMessage = InputContainer:new{
     image_height = nil,  -- The image height if image is used. Keep it nil to use original height.
     -- Whether the icon should be shown. If it is false, self.image will be ignored.
     show_icon = true,
+    icon_file = nil, -- use this file instead of "resources/info-i.png"
     dismiss_callback = function() end,
 }
 
@@ -93,8 +94,9 @@ function InfoMessage:init()
             }
         else
             image_widget = ImageWidget:new{
-                file = "resources/info-i.png",
+                file = self.icon_file or "resources/info-i.png",
                 scale_for_dpi = true,
+                alpha = true,
             }
         end
     else