Qrcode support (#6844)

2 new widgets:

- QRWidget, that's like an ImageWidget, but with a text property that will be converted to a QR code ;
- QRMessage, that's like an InfoMessage, but shows the message as QR code.
Moreover, it adds the ability to export QR codes to the text editor.

1 new plugin:

- Generate QR codes from clipboard

Changes to text editor plugin:

- Add the ability to export QR codes.

frontend/ui/elements/filemanager_menu_order.lua

@@ -106,6 +106,7 @@ local order = {
         "send2ebook",
         "text_editor",
         "profiles",
+        "qrclipboard",
         "----------------------------",
         "more_tools",
     },

frontend/ui/elements/reader_menu_order.lua

@@ -130,6 +130,7 @@ local order = {
         "news_downloader",
         "send2ebook",
         "text_editor",
+        "qrclipboard",
         "profiles",
         "----------------------------",
         "more_tools",

frontend/ui/widget/qrmessage.lua

@@ -0,0 +1,114 @@
+--[[--
+Widget that displays a qr code.
+
+It vanishes on key press or after a given timeout.
+
+Example:
+    local UIManager = require("ui/uimanager")
+    local _ = require("gettext")
+    local Screen = require("device").screen
+    local sample
+    sample = QRMessage:new{
+        text = _("my message"),
+        height = Screen:scaleBySize(400),
+        width = Screen:scaleBySize(400),
+        timeout = 5,  -- This widget will vanish in 5 seconds.
+    }
+    UIManager:show(sample)
+]]
+
+local Blitbuffer = require("ffi/blitbuffer")
+local CenterContainer = require("ui/widget/container/centercontainer")
+local Device = require("device")
+local FrameContainer = require("ui/widget/container/framecontainer")
+local Geom = require("ui/geometry")
+local GestureRange = require("ui/gesturerange")
+local QRWidget = require("ui/widget/qrwidget")
+local InputContainer = require("ui/widget/container/inputcontainer")
+local UIManager = require("ui/uimanager")
+local Input = Device.input
+local Screen = Device.screen
+local Size = require("ui/size")
+
+local QRMessage = InputContainer:new{
+    modal = true,
+    timeout = nil, -- in seconds
+    text = nil,  -- The text to encode.
+    width = nil,  -- The width. Keep it nil to use original width.
+    height = nil,  -- The height. Keep it nil to use original height.
+    dismiss_callback = function() end,
+    alpha = nil,
+    scale_factor = 1,
+}
+
+function QRMessage:init()
+    if Device:hasKeys() then
+        self.key_events = {
+            AnyKeyPressed = { { Input.group.Any },
+                seqtext = "any key", doc = "close dialog" }
+        }
+    end
+    if Device:isTouchDevice() then
+        self.ges_events.TapClose = {
+            GestureRange:new{
+                ges = "tap",
+                range = Geom:new{
+                    x = 0, y = 0,
+                    w = Screen:getWidth(),
+                    h = Screen:getHeight(),
+                }
+            }
+        }
+    end
+
+    local padding = Size.padding.fullscreen
+
+    local image_widget = QRWidget:new{
+        text = self.text,
+        width = self.width and (self.width - 2 * padding),
+        height = self.height and (self.height - 2 * padding),
+        alpha = self.alpha,
+        scale_factor = self.scale_factor,
+    }
+
+    local frame = FrameContainer:new{
+        background = Blitbuffer.COLOR_WHITE,
+        padding = padding,
+        image_widget,
+    }
+    self[1] = CenterContainer:new{
+        dimen = Screen:getSize(),
+        frame,
+    }
+end
+
+function QRMessage:onCloseWidget()
+    UIManager:setDirty(nil, function()
+        return "ui", self[1][1].dimen
+    end)
+    return true
+end
+
+function QRMessage:onShow()
+    -- triggered by the UIManager after we got successfully shown (not yet painted)
+    UIManager:setDirty(self, function()
+        return "ui", self[1][1].dimen
+    end)
+    if self.timeout then
+        UIManager:scheduleIn(self.timeout, function() UIManager:close(self) end)
+    end
+    return true
+end
+
+function QRMessage:onAnyKeyPressed()
+    -- triggered by our defined key events
+    self.dismiss_callback()
+    UIManager:close(self)
+end
+
+function QRMessage:onTapClose()
+    self.dismiss_callback()
+    UIManager:close(self)
+end
+
+return QRMessage

frontend/ui/widget/qrwidget.lua

@@ -0,0 +1,54 @@
+--[[
+QRWidget shows a QR code for a given text.
+]]
+
+local Blitbuffer = require("ffi/blitbuffer")
+local ImageWidget = require("ui/widget/imagewidget")
+local logger = require("logger")
+local qrencode = require("ffi/qrencode")
+local _ = require("gettext")
+
+local QRWidget = ImageWidget:extend{
+    scale_factor = nil,
+    text = ""
+    -- see ImageWidget for other options.
+}
+
+function QRWidget:init()
+    local text = self.text
+    if #text > 2953 then
+        local truncated = _("... (truncated...)")
+        text = text:sub(1, 2953 - #truncated) .. truncated
+    end
+    local ok, grid = qrencode.qrcode(text)
+    if not ok then
+        logger.info("QRWidget: failed to generate QR code.")
+        return
+    else
+        local sq_size
+        if self.width then
+            if self.height then
+                sq_size = math.min(self.width, self.height)/#grid
+            else
+                sq_size = self.width/#grid
+            end
+        elseif self.height then
+            sq_size = self.height/#grid
+        else sq_size = 1
+        end
+        sq_size = math.floor(sq_size)
+        local grid_size = sq_size * #grid
+        local bb = Blitbuffer.new(grid_size, grid_size)
+        local white = Blitbuffer.COLOR_WHITE
+        for x, col in ipairs(grid) do
+            for y, lgn in ipairs(col) do
+                if lgn < 0 then
+                    bb:paintRect((x - 1) * sq_size, (y - 1) * sq_size, sq_size, sq_size, white)
+                end
+            end
+        end
+        self.image = bb
+    end
+end
+
+return QRWidget

plugins/qrclipboard.koplugin/_meta.lua

@@ -0,0 +1,6 @@
+local _ = require("gettext")
+return {
+    name = "qrclipboard",
+    fullname = _("QR from clipboard"),
+    description = _([[This plugin generates a QR code from clipboard content.]]),
+}

plugins/qrclipboard.koplugin/main.lua

@@ -0,0 +1,33 @@
+--[[--
+This plugin generates a QR code from clipboard content.
+--]]--
+
+local Device = require("device")
+local QRMessage = require("ui/widget/qrmessage")
+local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
+local _ = require("gettext")
+
+local QRClipboard = WidgetContainer:new{
+    name = "qrclipboard",
+    is_doc_only = false,
+}
+
+function QRClipboard:init()
+    self.ui.menu:registerToMainMenu(self)
+end
+
+function QRClipboard:addToMainMenu(menu_items)
+    menu_items.qrclipboard = {
+        text = _("QR from clipboard"),
+        callback = function()
+            UIManager:show(QRMessage:new{
+                text = Device.input.getClipboardText(),
+                width = Device.screen:getWidth(),
+                height = Device.screen:getHeight()
+            })
+        end,
+    }
+end
+
+return QRClipboard

plugins/texteditor.koplugin/main.lua

@@ -3,6 +3,7 @@ local ConfirmBox = require("ui/widget/confirmbox")
 local DataStorage = require("datastorage")
 local Dispatcher = require("dispatcher")
 local Font = require("ui/font")
+local QRMessage = require("ui/widget/qrmessage")
 local InfoMessage = require("ui/widget/infomessage")
 local InputDialog = require("ui/widget/inputdialog")
 local LuaSettings = require("luasettings")
@@ -63,6 +64,7 @@ function TextEditor:loadSettings()
     end
     self.auto_para_direction = self.settings:readSetting("auto_para_direction") or true
     self.force_ltr_para_direction = self.settings:readSetting("force_ltr_para_direction") or false
+    self.qr_code_export = self.settings:readSetting("qr_code_export") or true
 end
 
 function TextEditor:onFlushSettings()
@@ -74,6 +76,7 @@ function TextEditor:onFlushSettings()
         self.settings:saveSetting("font_size", self.font_size)
         self.settings:saveSetting("auto_para_direction", self.auto_para_direction)
         self.settings:saveSetting("force_ltr_para_direction", self.force_ltr_para_direction)
+        self.settings:saveSetting("qr_code_export", self.qr_code_export)
         self.settings:flush()
     end
 end
@@ -152,6 +155,17 @@ Enable this if you are mostly editing code, HTML, CSS…]]),
                         self.force_ltr_para_direction = not self.force_ltr_para_direction
                     end,
                 },
+                {
+                    text = _("Enable QR code export"),
+                    help_text = _([[
+Export text to QR code, that can be scanned, for example, by a phone.]]),
+                    checked_func = function()
+                        return self.qr_code_export
+                    end,
+                    callback = function()
+                        self.qr_code_export = not self.qr_code_export
+                    end,
+                },
             },
             separator = true,
         },
@@ -447,6 +461,37 @@ function TextEditor:editFile(file_path, readonly)
     if self.force_ltr_para_direction then
         para_direction_rtl = false -- force LTR
     end
+    local buttons_first_row = {}  -- First button on first row, that will be filled with Reset|Save|Close
+    if is_lua then
+        table.insert(buttons_first_row, {
+            text = _("Check Lua"),
+            callback = function()
+                local parse_error = util.checkLuaSyntax(input:getInputText())
+                if parse_error then
+                    UIManager:show(InfoMessage:new{
+                        text = T(_("Lua syntax check failed:\n\n%1"), parse_error)
+                    })
+                else
+                    UIManager:show(Notification:new{
+                        text = T(_("Lua syntax OK")),
+                        timeout = 2,
+                    })
+                end
+            end,
+        })
+    end
+    if self.qr_code_export then
+        table.insert(buttons_first_row, {
+            text = _("QR"),
+            callback = function()
+                UIManager:show(QRMessage:new{
+                    text = input:getInputText(),
+                    height = Screen:getHeight(),
+                    width = Screen:getWidth()
+                })
+            end,
+        })
+    end
     input = InputDialog:new{
         title =  filename,
         input = self:readFileContent(file_path),
@@ -460,25 +505,7 @@ function TextEditor:editFile(file_path, readonly)
         readonly = readonly,
         add_nav_bar = true,
         scroll_by_pan = true,
-        buttons = is_lua and {{
-            -- First button on first row, that will be filled with Reset|Save|Close
-            {
-                text = _("Check Lua"),
-                callback = function()
-                    local parse_error = util.checkLuaSyntax(input:getInputText())
-                    if parse_error then
-                        UIManager:show(InfoMessage:new{
-                            text = T(_("Lua syntax check failed:\n\n%1"), parse_error)
-                        })
-                    else
-                        UIManager:show(Notification:new{
-                            text = T(_("Lua syntax OK")),
-                            timeout = 2,
-                        })
-                    end
-                end,
-            },
-        }},
+        buttons = {buttons_first_row},
         -- Set/save view and cursor position callback
         view_pos_callback = function(top_line_num, charpos)
             -- This same callback is called with no argument to get initial position,