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 +40,7 @@ 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)
+    self:text():option_set("scrollable", false)
 
     -- insert box
     self:panel():insert(self:box())

src/ltui/inputdialog.lua

@@ -45,7 +45,7 @@ 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)
+    self:text():option_set("scrollable", false)
 
     -- text changed
     self:text():action_set(action.ac_on_text_changed, function (v)

src/ltui/scrollbar.lua

@@ -0,0 +1,211 @@
+---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")
+
+    -- 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)
+
+    -- compute bar range
+    local char      = self:char()
+    local charattr  = self:charattr_val()
+    local progress  = self:progress()
+    local stepwidth = self:stepwidth()
+    local pb = progress
+    local pe = progress + stepwidth
+    if pe > 1 then
+        pb = 1 - stepwidth
+        pe = 1
+    end
+
+    -- draw bar
+    if self:vertical() then
+        local sb = math.floor(self:height() * pb)
+        local se = math.ceil(self:height() * pe)
+        if se > sb and se - sb < self:height() then
+            self:canvas():attr(charattr):move(0, sb):putchar(char, se - sb, true)
+        end
+    else
+        local sb = math.floor(self:width() * pb)
+        local se = math.ceil(self:width() * pe)
+        if se > sb and se - sb < self:width() then
+            self:canvas():attr(charattr):move(sb, 0):putchar(char, se - sb)
+        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 +24,8 @@ 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")
+local scrollbar = require("ltui/scrollbar")
 
 -- define module
 local textarea = textarea or label()
@@ -37,8 +39,8 @@ function textarea:init(name, bounds, text)
     -- mark as selectable
     self:option_set("selectable", true)
 
-    -- enable progress
+    -- mark as scrollable
-    self:option_set("progress", true)
+    self:option_set("scrollable", true)
 
     -- init start line
     self._STARTLINE = 0
@@ -60,8 +62,8 @@ function textarea:on_draw(transparent)
         self:canvas():attr(textattr):move(0, 0):putstrs(strs, self._STARTLINE + 1)
     end
 
-    -- draw progress
+    -- draw scrollable
-    if self:option("progress") then
+    if self:option("scrollable") then
         local tb = self._STARTLINE
         local fator = self:height() / self._LINECOUNT
         local sb = math.min(math.floor(tb * fator), self:height() - 1)

src/ltui/textedit.lua

@@ -47,8 +47,8 @@ function textedit:init(name, bounds, text)
     self:option_set("mouseable", true)
     self:action_set(action.ac_on_clicked, function () return true end)
 
-    -- disable progress
+    -- disable scrollbar
-    self:option_set("progress", false)
+    self:option_set("scrollable", false)
 
     -- enable multiple line
     self:option_set("multiline", true)