Merge pull request #23 from tboox/scrollbar

add scrollbar

src/ltui/action.lua

@@ -42,6 +42,7 @@ action:register("ac_max",
                 "ac_on_selected",
                 "ac_on_clicked",
                 "ac_on_resized",
+                "ac_on_scrolled",
                 "ac_on_enter",
                 "ac_on_load",
                 "ac_on_save",

src/ltui/boxdialog.lua

@@ -40,7 +40,6 @@ function boxdialog:init(name, bounds, title)
     self:text():bounds().ey = self._TEXT_EY
     self:text():invalidate(true)
     self:text():option_set("selectable", false)
-    self:text():option_set("progress", false)
 
     -- insert box
     self:panel():insert(self:box())

src/ltui/choicebox.lua

@@ -38,19 +38,125 @@ function choicebox:init(name, bounds)
     -- init panel
     panel.init(self, name, bounds)
 
-    -- init values
+    -- init items
-    self._VALUES = {}
+    self._ITEMS = {}
+
+    -- init start index
+    self._STARTINDEX = 1
+end
+
+-- load values
+function choicebox:load(values, selected)
+
+    -- clear the views first
+    self:clear()
+
+    -- load items
+    local items = {}
+    for idx, value in ipairs(values) do
+        table.insert(items, self:_load_item(value, idx, idx == selected))
+    end
+    self._ITEMS = items
+
+    -- insert top-n items
+    local startindex = self._STARTINDEX
+    for idx = startindex, startindex + self:height() - 1 do
+        local item = items[idx]
+        if item then
+            self:insert(item)
+        else
+            break
+        end
+    end
+
+    -- select the first item
+    self:select(self:first())
+
+    -- on loaded
+    self:action_on(action.ac_on_load)
+
+    -- invalidate
+    self:invalidate()
+end
+
+-- is scrollable?
+function choicebox:scrollable()
+    return #self:_items() > self:height()
+end
+
+-- scroll
+function choicebox:scroll(count)
+    if self:scrollable() then
+        local items = self:_items()
+        local totalcount = #items
+        local startindex = self._STARTINDEX + count
+        if startindex > totalcount then
+            return
+        elseif startindex < 1 then
+            startindex = 1
+        end
+        self._STARTINDEX = startindex
+        self:clear()
+        for idx = startindex, startindex + self:height() - 1 do
+            local item = items[idx]
+            if item then
+                item:bounds():move2(0, idx - startindex)
+                self:insert(item)
+            else
+                break
+            end
+        end
+        if count > 0 then
+            self:select(self:first())
+        else
+            self:select(self:last())
+        end
+        self:invalidate()
+    end
+end
+
+-- on resize
+function choicebox:on_resize()
+    local items = self:_items()
+    local totalcount = #items
+    local startindex = self._STARTINDEX
+    for idx = 1, totalcount do
+        local item = items[idx]
+        if item then
+            if idx >= startindex and idx < startindex + self:height() then
+                if not self:view(item:name()) then
+                    item:bounds():move2(0, idx - startindex)
+                    self:insert(item)
+                end
+            else
+                if self:view(item:name()) then
+                    self:remove(item)
+                end
+            end
+        end
+    end
+    panel.on_resize(self)
 end
 
 -- on event
 function choicebox:on_event(e)
-
-    -- select config
     if e.type == event.ev_keyboard then
         if e.key_name == "Down" then
-            return self:select_next()
+            if self:current() == self:last() then
+                self:scroll(self:height())
+            else
+                self:select_next()
+            end
+            self:_notify_scrolled()
+            return true
         elseif e.key_name == "Up" then
-            return self:select_prev()
+            if self:current() == self:first() then
+                self:scroll(-self:height())
+            else
+                self:select_prev()
+            end
+            self:_notify_scrolled()
+            return true
         elseif e.key_name == "Enter" or e.key_name == " " then
             self:_do_select()
             return true
@@ -61,44 +167,36 @@ function choicebox:on_event(e)
     end
 end
 
--- load values
+-- load a item with value
-function choicebox:load(values, selected)
+function choicebox:_load_item(value, index, selected)
-
-    -- clear the views first
-    self:clear()
-
-    -- insert values
-    self._VALUES = values
-    for idx, value in ipairs(values) do
-        self:_do_insert(value, idx, idx == selected)
-    end
-
-    -- select the first item
-    self:select(self:first())
-
-    -- invalidate
-    self:invalidate()
-end
-
--- do insert a value item
-function choicebox:_do_insert(value, index, selected)
 
     -- init text
     local text = (selected and "(X) " or "( ) ") .. tostring(value)
 
     -- init a value item view
-    local item = button:new("choicebox.value." .. self:count(),
+    local item = button:new("choicebox.value." .. index,
-                    rect:new(0, self:count(), self:width(), 1),
+                    rect:new(0, index - 1, self:width(), 1),
                     text,
                     function (v, e)
                         self:_do_select()
                     end)
 
-    -- attach this index
+    -- attach index and value
     item:extra_set("index", index)
+    item:extra_set("value", value)
+    return item
+end
 
-    -- insert this config item
+-- notify scrolled
-    self:insert(item)
+function choicebox:_notify_scrolled()
+    local totalcount = #self:_items()
+    local startindex = self:current():extra("index")
+    self:action_on(action.ac_on_scrolled, startindex / totalcount)
+end
+
+-- get all items
+function choicebox:_items()
+    return self._ITEMS
 end
 
 -- do select the current config
@@ -108,24 +206,17 @@ function choicebox:_do_select()
     for v in self:views() do
         local text = v:text()
         if text and text:startswith("(X) ") then
-            local i = v:extra("index")
+            local t = v:extra("value")
-            if i then
-                local t = self._VALUES[i]
             v:text_set("( ) " .. tostring(t))
         end
     end
-    end
 
     -- get the current item
     local item = self:current()
 
-    -- get the current index
-    local index = item:extra("index")
-
-    -- get the current value
-    local value = self._VALUES[index]
-
     -- do action: on selected
+    local index = item:extra("index")
+    local value = item:extra("value")
     self:action_on(action.ac_on_selected, index, value)
 
     -- update text

src/ltui/choicedialog.lua

@@ -25,6 +25,7 @@ local event       = require("ltui/event")
 local action      = require("ltui/action")
 local curses      = require("ltui/curses")
 local window      = require("ltui/window")
+local scrollbar   = require("ltui/scrollbar")
 local choicebox   = require("ltui/choicebox")
 local boxdialog   = require("ltui/boxdialog")
 
@@ -50,23 +51,63 @@ function choicedialog:init(name, bounds, title)
     end)
     self:buttons():select(self:button("select"))
 
+    -- insert scrollbar
+    self:box():panel():insert(self:scrollbar_box())
+
     -- insert choice box
     self:box():panel():insert(self:choicebox())
 
     -- disable to select to box (disable Tab switch and only response to buttons)
     self:box():option_set("selectable", false)
+
+    -- on resize for panel
+    self:box():panel():action_add(action.ac_on_resized, function (v)
+        self:choicebox():bounds_set(rect:new(0, 0, v:width() - 1, v:height()))
+        self:scrollbar_box():bounds_set(rect:new(v:width() - 1, 0, 1, v:height()))
+        if self:choicebox():scrollable() then
+            self:scrollbar_box():show(true)
+        else
+            self:scrollbar_box():show(false)
+        end
+    end)
+
+    -- show scrollbar?
+    self:choicebox():action_add(action.ac_on_load, function (v)
+        if v:scrollable() then
+            self:scrollbar_box():show(true)
+        else
+            self:scrollbar_box():show(false)
+        end
+    end)
+
+    -- on scroll
+    self:choicebox():action_add(action.ac_on_scrolled, function (v, progress)
+        if self:scrollbar_box():state("visible") then
+            self:scrollbar_box():progress_set(progress)
+        end
+    end)
 end
 
 -- get choice box
 function choicedialog:choicebox()
     if not self._CHOICEBOX then
         local bounds = self:box():panel():bounds()
-        self._CHOICEBOX = choicebox:new("choicedialog.choicebox", rect:new(0, 0, bounds:width(), bounds:height()))
+        self._CHOICEBOX = choicebox:new("choicedialog.choicebox", rect:new(0, 0, bounds:width() - 1, bounds:height()))
         self._CHOICEBOX:state_set("focused", true) -- we can select and highlight selected item
     end
     return self._CHOICEBOX
 end
 
+-- get box scrollbar
+function choicedialog:scrollbar_box()
+    if not self._SCROLLBAR_BOX then
+        local bounds = self:box():panel():bounds()
+        self._SCROLLBAR_BOX = scrollbar:new("choicedialog.scrollbar", rect:new(bounds:width() - 1, 0, 1, bounds:height()))
+        self._SCROLLBAR_BOX:show(false)
+    end
+    return self._SCROLLBAR_BOX
+end
+
 -- on event
 function choicedialog:on_event(e)
 

src/ltui/inputdialog.lua

@@ -45,7 +45,6 @@ function inputdialog:init(name, bounds, title)
     self:text():bounds().ey = 1
     self:text():invalidate(true)
     self:text():option_set("selectable", false)
-    self:text():option_set("progress", false)
 
     -- text changed
     self:text():action_set(action.ac_on_text_changed, function (v)

src/ltui/mconfdialog.lua

@@ -26,6 +26,7 @@ local event        = require("ltui/event")
 local action       = require("ltui/action")
 local curses       = require("ltui/curses")
 local window       = require("ltui/window")
+local scrollbar    = require("ltui/scrollbar")
 local menuconf     = require("ltui/menuconf")
 local boxdialog    = require("ltui/boxdialog")
 local textdialog   = require("ltui/textdialog")
@@ -54,6 +55,9 @@ Pressing <Y> includes, <N> excludes. Enter <Esc> or <Back> to go back, <?> for H
     self:button_add("save", "< Save >", function (v, e) self:action_on(action.ac_on_save) end)
     self:buttons():select(self:button("select"))
 
+    -- insert scrollbar
+    self:box():panel():insert(self:scrollbar_menuconf())
+
     -- insert menu config
     self:box():panel():insert(self:menuconf())
     self:box():panel():action_add(action.ac_on_resized, function (v)
@@ -64,6 +68,17 @@ Pressing <Y> includes, <N> excludes. Enter <Esc> or <Back> to go back, <?> for H
     -- disable to select to box (disable Tab switch and only response to buttons)
     self:box():option_set("selectable", false)
 
+    -- on resize for panel
+    self:box():panel():action_add(action.ac_on_resized, function (v)
+        self:menuconf():bounds_set(rect:new(0, 0, v:width() - 1, v:height()))
+        self:scrollbar_menuconf():bounds_set(rect:new(v:width() - 1, 0, 1, v:height()))
+        if self:menuconf():scrollable() then
+            self:scrollbar_menuconf():show(true)
+        else
+            self:scrollbar_menuconf():show(false)
+        end
+    end)
+
     -- on selected
     self:menuconf():action_set(action.ac_on_selected, function (v, config)
 
@@ -94,6 +109,22 @@ Pressing <Y> includes, <N> excludes. Enter <Esc> or <Back> to go back, <?> for H
             return true
         end
     end)
+
+    -- show scrollbar?
+    self:menuconf():action_add(action.ac_on_load, function (v)
+        if v:scrollable() then
+            self:scrollbar_menuconf():show(true)
+        else
+            self:scrollbar_menuconf():show(false)
+        end
+    end)
+
+    -- on scroll
+    self:menuconf():action_add(action.ac_on_scrolled, function (v, progress)
+        if self:scrollbar_menuconf():state("visible") then
+            self:scrollbar_menuconf():progress_set(progress)
+        end
+    end)
 end
 
 -- load configs
@@ -111,17 +142,28 @@ end
 function mconfdialog:menuconf()
     if not self._MENUCONF then
         local bounds = self:box():panel():bounds()
-        self._MENUCONF = menuconf:new("mconfdialog.menuconf", rect:new(0, 0, bounds:width(), bounds:height()))
+        self._MENUCONF = menuconf:new("mconfdialog.menuconf", rect:new(0, 0, bounds:width() - 1, bounds:height()))
         self._MENUCONF:state_set("focused", true) -- we can select and highlight selected item
     end
     return self._MENUCONF
 end
 
+-- get menu scrollbar
+function mconfdialog:scrollbar_menuconf()
+    if not self._SCROLLBAR_MENUCONF then
+        local bounds = self:box():panel():bounds()
+        self._SCROLLBAR_MENUCONF = scrollbar:new("mconfdialog.scrollbar", rect:new(bounds:width() - 1, 0, 1, bounds:height()))
+        self._SCROLLBAR_MENUCONF:show(false)
+    end
+    return self._SCROLLBAR_MENUCONF
+end
+
 -- get help dialog
 function mconfdialog:helpdialog()
     if not self._HELPDIALOG then
         local helpdialog = textdialog:new("mconfdialog.help", self:bounds(), "help")
         helpdialog:button_add("exit", "< Exit >", function (v) helpdialog:quit() end)
+        helpdialog:option_set("scrollable", true)
         self._HELPDIALOG = helpdialog
     end
     return self._HELPDIALOG
@@ -132,6 +174,7 @@ function mconfdialog:resultdialog()
     if not self._RESULTDIALOG then
         local resultdialog = textdialog:new("mconfdialog.result", self:bounds(), "result")
         resultdialog:button_add("exit", "< Exit >", function (v) resultdialog:quit() end)
+        resultdialog:option_set("scrollable", true)
         self._RESULTDIALOG = resultdialog
     end
     return self._RESULTDIALOG

src/ltui/menuconf.lua

@@ -40,18 +40,138 @@ function menuconf:init(name, bounds)
 
     -- init configs
     self._CONFIGS = {}
+
+    -- init items
+    self._ITEMS = {}
+
+    -- init start index
+    self._STARTINDEX = 1
+end
+
+-- load configs
+function menuconf:load(configs)
+
+    -- clear the views first
+    self:clear()
+
+    -- detach the previous config and view
+    local configs_prev = self._CONFIGS._PREV
+    if configs_prev then
+        for _, config in ipairs(configs_prev) do
+            config._view = nil
+        end
+    end
+
+    -- save configs
+    self._CONFIGS = configs
+
+    -- load items
+    local items = {}
+    for idx, config in ipairs(configs) do
+        table.insert(items, self:_load_item(config, idx))
+    end
+    self._ITEMS = items
+
+    -- insert top-n items
+    local startindex = self._STARTINDEX
+    for idx = startindex, startindex + self:height() - 1 do
+        local item = items[idx]
+        if item then
+            self:insert(item)
+        else
+            break
+        end
+    end
+
+    -- select the first item
+    self:select(self:first())
+
+    -- on loaded
+    self:action_on(action.ac_on_load)
+
+    -- invalidate
+    self:invalidate()
+end
+
+-- is scrollable?
+function menuconf:scrollable()
+    return #self:_items() > self:height()
+end
+
+-- scroll
+function menuconf:scroll(count)
+    if self:scrollable() then
+        local items = self:_items()
+        local totalcount = #items
+        local startindex = self._STARTINDEX + count
+        if startindex > totalcount then
+            return
+        elseif startindex < 1 then
+            startindex = 1
+        end
+        self._STARTINDEX = startindex
+        self:clear()
+        for idx = startindex, startindex + self:height() - 1 do
+            local item = items[idx]
+            if item then
+                item:bounds():move2(0, idx - startindex)
+                self:insert(item)
+            else
+                break
+            end
+        end
+        if count > 0 then
+            self:select(self:first())
+        else
+            self:select(self:last())
+        end
+        self:invalidate()
+    end
+end
+
+-- on resize
+function menuconf:on_resize()
+    local items = self:_items()
+    local totalcount = #items
+    local startindex = self._STARTINDEX
+    for idx = 1, totalcount do
+        local item = items[idx]
+        if item then
+            if idx >= startindex and idx < startindex + self:height() then
+                if not self:view(item:name()) then
+                    item:bounds():move2(0, idx - startindex)
+                    self:insert(item)
+                end
+            else
+                if self:view(item:name()) then
+                    self:remove(item)
+                end
+            end
+        end
+    end
+    panel.on_resize(self)
 end
 
 -- on event
 function menuconf:on_event(e)
-
-    -- select config
     local back = false
     if e.type == event.ev_keyboard then
         if e.key_name == "Down" then
-            return self:select_next()
+            if self:current() == self:last() then
+                self:scroll(self:height())
+            else
+                self:select_next()
+            end
+            self:_notify_scrolled()
+            return true
         elseif e.key_name == "Up" then
-            return self:select_prev()
+            if self:current() == self:first() then
+                self:scroll(-self:height())
+            else
+                self:select_prev()
+            end
+            self:_notify_scrolled()
+            return true
         elseif e.key_name == "Enter" or e.key_name == " " then
             self:_do_select()
             return true
@@ -85,54 +205,36 @@ function menuconf:on_event(e)
     end
 end
 
--- load configs
+-- load a config item
-function menuconf:load(configs)
+function menuconf:_load_item(config, index)
-
-    -- clear the views first
-    self:clear()
-
-    -- detach the previous config and view
-    local configs_prev = self._CONFIGS._PREV
-    if configs_prev then
-        for _, config in ipairs(configs_prev) do
-            config._view = nil
-        end
-    end
-
-    -- insert configs
-    self._CONFIGS = configs
-    for _, config in ipairs(configs) do
-        if self:count() < self:height() then
-            self:_do_insert(config)
-        end
-    end
-
-    -- select the first item
-    self:select(self:first())
-
-    -- invalidate
-    self:invalidate()
-end
-
--- do insert a config item
-function menuconf:_do_insert(config)
 
     -- init a config item view
-    local item = button:new("menuconf.config." .. self:count(),
+    local item = button:new("menuconf.config." .. index,
-                    rect:new(0, self:count(), self:width(), 1),
+                    rect:new(0, index - 1, self:width(), 1),
                     tostring(config),
                     function (v, e)
                         self:_do_select()
                     end)
 
-    -- attach this config
+    -- attach this index and config
+    item:extra_set("index", index)
     item:extra_set("config", config)
 
     -- attach this view
     config._view = item
+    return item
+end
 
-    -- insert this config item
+-- notify scrolled
-    self:insert(item)
+function menuconf:_notify_scrolled()
+    local totalcount = #self:_items()
+    local startindex = self:current():extra("index")
+    self:action_on(action.ac_on_scrolled, startindex / totalcount)
+end
+
+-- get all items
+function menuconf:_items()
+    return self._ITEMS
 end
 
 -- do select the current config

src/ltui/panel.lua

@@ -64,7 +64,7 @@ function panel:init(name, bounds)
 
         local p = v:last()
         while p do
-            if p:option('selectable') and p:bounds():contains(x, y) then
+            if p:option("selectable") and p:bounds():contains(x, y) then
                 if p:option("mouseable") then
                     v:select(p)
                     return p:action_on(action.ac_on_clicked, x, y)

src/ltui/scrollbar.lua

@@ -0,0 +1,215 @@
+---A cross-platform terminal ui library based on Lua
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+-- Copyright (C) 2015-2020, TBOOX Open Source Group.
+--
+-- @author      ruki
+-- @file        scrollbar.lua
+--
+
+-- load modules
+local log       = require("ltui/base/log")
+local view      = require("ltui/view")
+local event     = require("ltui/event")
+local curses    = require("ltui/curses")
+local action    = require("ltui/action")
+
+-- define module
+local scrollbar = scrollbar or view()
+
+-- init scrollbar
+function scrollbar:init(name, bounds, vertical)
+
+    -- init view
+    view.init(self, name, bounds)
+
+    -- init bar attribute
+    self:charattr_set("black on black")
+
+    -- init bar vertical
+    self:vertical_set(vertical)
+
+    -- init progress
+    self:progress_set(0)
+
+    -- init character
+    self:char_set(' ')
+end
+
+-- get bar attribute
+function scrollbar:charattr()
+    return self:attr("charattr")
+end
+
+-- set bar attribute, .e.g charattr_set("yellow onblue bold")
+function scrollbar:charattr_set(attr)
+    return self:attr_set("charattr", attr)
+end
+
+-- get the current char attribute value
+function scrollbar:charattr_val()
+
+    -- get text attribute
+    local charattr = self:charattr()
+    if not charattr then
+        return
+    end
+
+    -- no text background? use view's background
+    if self:background() and not charattr:find("on") then
+        charattr = charattr .. " on" .. self:background()
+    end
+
+    -- attempt to get the attribute value from the cache first
+    self._charattr = self._charattr or {}
+    local value = self._charattr[charattr]
+    if value then
+        return value
+    end
+
+    -- update the cache
+    value = curses.calc_attr(charattr:split("%s+"))
+    self._charattr[charattr] = value
+    return value
+end
+
+-- get bar character
+function scrollbar:char()
+    return self:attr("char") or ' '
+end
+
+-- set bar character
+function scrollbar:char_set(char)
+    if char ~= self:char() then
+        self:invalidate()
+    end
+    return self:attr_set("char", char)
+end
+
+-- is vertical bar?
+function scrollbar:vertical()
+    return self:attr("vertical") or true
+end
+
+-- set bar vertical
+function scrollbar:vertical_set(vertical)
+    return self:attr_set("vertical", vertical)
+end
+
+-- get bar progress
+function scrollbar:progress()
+    return self:attr("progress") or 0
+end
+
+-- set bar progress, [0, 1]
+function scrollbar:progress_set(progress)
+    if progress > 1 then
+        progress = 1
+    elseif progress < 0 then
+        progress = 0
+    end
+    if progress ~= self:progress() then
+        self:invalidate()
+    end
+    return self:attr_set("progress", progress)
+end
+
+-- get bar step width
+function scrollbar:stepwidth()
+    return self:attr("stepwidth") or 0.1
+end
+
+-- set bar step width, [0, 1]
+function scrollbar:stepwidth_set(stepwidth)
+    if stepwidth > 1 then
+        stepwidth = 1
+    elseif stepwidth < 0 then
+        stepwidth = 0
+    end
+    if stepwidth ~= self:stepwidth() then
+        self:invalidate()
+    end
+    return self:attr_set("stepwidth", stepwidth)
+end
+
+-- draw scrollbar
+function scrollbar:on_draw(transparent)
+
+    -- draw background
+    view.on_draw(self, transparent)
+
+    -- draw bar
+    local char      = self:char()
+    local charattr  = self:charattr_val()
+    if self:vertical() then
+        local sn = math.ceil(self:height() * self:stepwidth())
+        local sb = math.floor(self:height() * self:progress())
+        local se = sb + sn
+        if se > self:height() then
+            sb = self:height() - sn
+            se = self:height()
+        end
+        if se > sb and se - sb <= self:height() then
+            for x = 0, self:width() - 1 do
+                self:canvas():attr(charattr):move(x, sb):putchar(char, se - sb, true)
+            end
+        end
+    else
+        local sn = math.ceil(self:width() * self:stepwidth())
+        local sb = math.floor(self:width() * self:progress())
+        local se = sb + sn
+        if se > self:width() then
+            sb = self:width() - sn
+            se = self:width()
+        end
+        if se > sb and se - sb <= self:width() then
+            for y = 0, self:height() - 1 do
+                self:canvas():attr(charattr):move(sb, y):putchar(char, se - sb)
+            end
+        end
+    end
+end
+
+-- scroll bar, e.g. -1 * 0.1, 1 * 0.1
+function scrollbar:scroll(steps)
+    steps = steps or 1
+    self:progress_set(self:progress() + steps * self:stepwidth())
+    self:action_on(action.ac_on_scrolled, self:progress())
+end
+
+-- on event
+function scrollbar:on_event(e)
+    if e.type == event.ev_keyboard then
+        if self:vertical() then
+            if e.key_name == "Up" then
+                self:scroll(-1)
+                return true
+            elseif e.key_name == "Down" then
+                self:scroll(1)
+                return true
+            end
+        else
+            if e.key_name == "Left" then
+                self:scroll(-1)
+                return true
+            elseif e.key_name == "Right" then
+                self:scroll(1)
+                return true
+            end
+        end
+    end
+end
+
+-- return module
+return scrollbar

src/ltui/textarea.lua

@@ -24,6 +24,7 @@ local view      = require("ltui/view")
 local label     = require("ltui/label")
 local event     = require("ltui/event")
 local curses    = require("ltui/curses")
+local action    = require("ltui/action")
 
 -- define module
 local textarea = textarea or label()
@@ -37,9 +38,6 @@ function textarea:init(name, bounds, text)
     -- mark as selectable
     self:option_set("selectable", true)
 
-    -- enable progress
-    self:option_set("progress", true)
-
     -- init start line
     self._STARTLINE = 0
     self._LINECOUNT = 0
@@ -59,17 +57,6 @@ function textarea:on_draw(transparent)
     if strs and #strs > 0 and textattr then
         self:canvas():attr(textattr):move(0, 0):putstrs(strs, self._STARTLINE + 1)
     end
-
-    -- draw progress
-    if self:option("progress") then
-        local tb = self._STARTLINE
-        local fator = self:height() / self._LINECOUNT
-        local sb = math.min(math.floor(tb * fator), self:height() - 1)
-        local se = math.min(sb + math.ceil(self:height() * fator), self:height())
-        if se > sb and se - sb < self:height() then
-            self:canvas():attr("black"):move(self:width() - 1, sb):putchar(' ', se - sb, true)
-        end
-    end
 end
 
 -- set text
@@ -80,24 +67,33 @@ function textarea:text_set(text)
     return label.text_set(self, text)
 end
 
+-- is scrollable?
+function textarea:scrollable()
+    return self._LINECOUNT > self:height()
+end
+
 -- scroll
 function textarea:scroll(lines)
-    if self._LINECOUNT > self:height() then
+    if self:scrollable() then
         self._STARTLINE = self._STARTLINE + lines
         if self._STARTLINE < 0 then
             self._STARTLINE = 0
         end
-        if self._STARTLINE > self._LINECOUNT - self:height() then
+        local startline_end = self._LINECOUNT > self:height() and self._LINECOUNT - self:height() or self._LINECOUNT
-            self._STARTLINE = self._LINECOUNT - self:height()
+        if self._STARTLINE > startline_end then
+            self._STARTLINE = startline_end
         end
+        self:action_on(action.ac_on_scrolled, self._STARTLINE / startline_end)
         self:invalidate()
     end
 end
 
 -- scroll to end
 function textarea:scroll_to_end()
-    if self._LINECOUNT > self:height() then
+    if self:scrollable() then
-        self._STARTLINE = self._LINECOUNT - self:height()
+        local startline_end = self._LINECOUNT > self:height() and self._LINECOUNT - self:height() or self._LINECOUNT
+        self._STARTLINE = startline_end
+        self:action_on(action.ac_on_scrolled, self._STARTLINE / startline_end)
         self:invalidate()
     end
 end

src/ltui/textdialog.lua

@@ -25,6 +25,7 @@ local event    = require("ltui/event")
 local dialog    = require("ltui/dialog")
 local curses    = require("ltui/curses")
 local textarea  = require("ltui/textarea")
+local scrollbar = require("ltui/scrollbar")
 local action    = require("ltui/action")
 
 -- define module
@@ -36,16 +37,60 @@ function textdialog:init(name, bounds, title)
     -- init window
     dialog.init(self, name, bounds, title)
 
+    -- mark as scrollable, disabled by default
+    self:option_set("scrollable", false)
+
     -- insert text
     self:panel():insert(self:text())
 
+    -- insert scrollbar
+    self:panel():insert(self:scrollbar())
+
     -- select buttons by default
     self:panel():select(self:buttons())
 
     -- on resize for panel
     self:panel():action_add(action.ac_on_resized, function (v)
+        if self:option("scrollable") then
+            self:text():bounds_set(rect:new(0, 0, v:width() - 1, v:height() - 1))
+            self:scrollbar():bounds_set(rect:new(v:width() - 1, 0, 1, v:height() - 1))
+        else
             self:text():bounds_set(rect:new(0, 0, v:width(), v:height() - 1))
+        end
     end)
+
+    -- show scrollbar?
+    self:text():action_add(action.ac_on_text_changed, function (v)
+        if self:option("scrollable") then
+            if v:scrollable() then
+                self:scrollbar():show(true)
+            else
+                self:scrollbar():show(false)
+            end
+        end
+    end)
+
+    -- on scroll for text and scrollbar
+    self:text():action_add(action.ac_on_scrolled, function (v, progress)
+        if self:scrollbar():state("visible") then
+            self:scrollbar():progress_set(progress)
+        end
+    end)
+end
+
+-- enable or disable scrollbar
+function textdialog:option_set(name, value)
+    if name == "scrollable" then
+        local oldvalue = self:option(name)
+        if value ~= oldvalue then
+            if value then
+                self:text():bounds():resize(self:panel():width() - 1, self:panel():height() - 1)
+            else
+                self:text():bounds():resize(self:panel():width(), self:panel():height() - 1)
+            end
+        end
+    end
+    dialog.option_set(self, name, value)
 end
 
 -- get text
@@ -56,6 +101,15 @@ function textdialog:text()
     return self._TEXT
 end
 
+-- get scrollbar
+function textdialog:scrollbar()
+    if not self._SCROLLBAR then
+        self._SCROLLBAR = scrollbar:new("textdialog.scrollbar", rect:new(self:panel():width() - 1, 0, 1, self:panel():height() - 1))
+        self._SCROLLBAR:show(false)
+    end
+    return self._SCROLLBAR
+end
+
 -- on event
 function textdialog:on_event(e)
 

src/ltui/textedit.lua

@@ -47,9 +47,6 @@ function textedit:init(name, bounds, text)
     self:option_set("mouseable", true)
     self:action_set(action.ac_on_clicked, function () return true end)
 
-    -- disable progress
-    self:option_set("progress", false)
-
     -- enable multiple line
     self:option_set("multiline", true)
 end

tests/dialog.lua

@@ -76,6 +76,7 @@ function demo:dialog_help()
     local dialog_help = self._DIALOG_HELP
     if not dialog_help then
         dialog_help = textdialog:new("dialog.help", rect {1, 1, self:width() - 1, self:height() - 1}, "README")
+        dialog_help:option_set("scrollable", true)
         local helptext = nil
         local file = io.open("./LICENSE.md", 'r')
         if file then

tests/mconfdialog.lua

@@ -60,6 +60,27 @@ function demo:init()
     table.insert(configs_sub, menuconf.menu {description = "menu config sub-item", configs = configs_sub2})
     table.insert(configs_sub, menuconf.choice {value = 2, values = {2, 5, 16, 87}, description = "choice config sub-item"})
 
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item1"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item2"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item3"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item4"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item5"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item6"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item7"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item8"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item9"})
+
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item10"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item11"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item12"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item13"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item14"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item15"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item16"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item17"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item18"})
+    table.insert(configs_sub, menuconf.number {value = 6, default = 10, description = "number config item19"})
+
     local configs = {}
     table.insert(configs, menuconf.boolean {description = "boolean config item"})
     table.insert(configs, menuconf.boolean {default = true, new = false, description = {"boolean config item2",
@@ -69,7 +90,7 @@ function demo:init()
     table.insert(configs, menuconf.number {value = 6, default = 10, description = "number config item"})
     table.insert(configs, menuconf.string {value = "x86_64", description = "string config item"})
     table.insert(configs, menuconf.menu {description = "menu config item", configs = configs_sub})
-    table.insert(configs, menuconf.choice {value = 3, values = {1, 5, 6, 7}, default = 2, description = "choice config item"})
+    table.insert(configs, menuconf.choice {value = 3, values = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}, default = 2, description = "choice config item"})
 
     -- init menu config dialog
     self:dialog_mconf():load(configs)