[feat] Open unsupported documents as text (#5497)

frontend/apps/filemanager/filemanager.lua

@@ -291,8 +291,8 @@ function FileManager:init()
             {
                 {
                     text = _("Open with…"),
-                    enabled = lfs.attributes(file, "mode") == "file" and DocumentRegistry:getProviders(file) ~= nil
+                    enabled = lfs.attributes(file, "mode") == "file" and (DocumentRegistry:getProviders(file) == nil
-                        and #(DocumentRegistry:getProviders(file)) > 1,
+                        or #(DocumentRegistry:getProviders(file)) > 1),
                     callback = function()
                         UIManager:close(self.file_dialog)
                         self:showSetProviderButtons(file, FileManager.instance, ReaderUI)

frontend/apps/reader/readerui.lua

@@ -447,7 +447,7 @@ function ReaderUI:showReader(file, provider)
         return
     end
 
-    if not DocumentRegistry:hasProvider(file) then
+    if not DocumentRegistry:hasProvider(file) and provider == nil then
         UIManager:show(InfoMessage:new{
             text = T(_("File '%1' is not supported."), file)
         })

frontend/document/documentregistry.lua

@@ -56,9 +56,17 @@ end
 function DocumentRegistry:hasProvider(file)
     local filename_suffix = string.lower(util.getFileNameSuffix(file))
 
-    if self.filetype_provider[filename_suffix] then
+    local filetype_provider = G_reader_settings:readSetting("provider") or {}
+    if self.filetype_provider[filename_suffix] or filetype_provider[filename_suffix] then
         return true
     end
+    local DocSettings = require("docsettings")
+    if DocSettings:hasSidecarFile(file) then
+        local doc_settings_provider = DocSettings:open(file):readSetting("provider")
+        if doc_settings_provider then
+            return true
+        end
+    end
     return false
 end
 
@@ -96,6 +104,12 @@ function DocumentRegistry:getProvider(file)
 
         -- highest weighted provider
         return providers[1].provider
+    else
+        for _, provider in ipairs(self.providers) do
+            if provider.extension == "txt" then
+                return provider.provider
+            end
+        end
     end
 end
 

frontend/ui/widget/filechooser.lua

@@ -394,15 +394,27 @@ function FileChooser:showSetProviderButtons(file, filemanager_instance, reader_u
 
     local buttons = {}
     local radio_buttons = {}
+    local filetype_provider = G_reader_settings:readSetting("provider") or {}
     local providers = DocumentRegistry:getProviders(file)
-
+    if providers ~= nil then
-    for ___, provider in ipairs(providers) do
+        for ___, provider in ipairs(providers) do
-        -- we have no need for extension, mimetype, weights, etc. here
+            -- we have no need for extension, mimetype, weights, etc. here
-        provider = provider.provider
+            provider = provider.provider
+            table.insert(radio_buttons, {
+                {
+                    text = provider.provider_name,
+                    checked = DocumentRegistry:getProvider(file) == provider,
+                    provider = provider,
+                },
+            })
+        end
+    else
+        local provider = DocumentRegistry:getProvider(file)
         table.insert(radio_buttons, {
             {
-                text = provider.provider_name,
+                -- @translators %1 is the provider name, such as Cool Reader Engine or MuPDF.
-                checked = DocumentRegistry:getProvider(file) == provider,
+                text = T(_("%1 ~Unsupported"), provider.provider_name),
+                checked = true,
                 provider = provider,
             },
         })
@@ -459,6 +471,19 @@ function FileChooser:showSetProviderButtons(file, filemanager_instance, reader_u
         },
     })
 
+    if filetype_provider[filename_suffix] ~= nil then
+        table.insert(buttons, {
+           {
+               text = _("Reset default"),
+                callback = function()
+                    filetype_provider[filename_suffix] = nil
+                    G_reader_settings:saveSetting("provider", filetype_provider)
+                    UIManager:close(self.set_provider_dialog)
+                end,
+            },
+        })
+    end
+
     self.set_provider_dialog = OpenWithDialog:new{
         title = T(_("Open %1 with:"), filename_pure),
         radio_buttons = radio_buttons,