CCGUI textinput

--[[

    ComputerCraft GUI
    Text input controls

--]]

ccgui = ccgui or {}

local TextArea = common.newClass({
    -- Colors
    background          = colours.white,

    -- Scrolling
    horizontal          = true,
    vertical            = true,
    mouseScroll         = true,

    -- Text lines
    lines               = nil,
    longestLineLength   = 0,

    -- Cursor position
    cursorLine          = 1, -- [1, #(lines)]
    cursorChar          = 1  -- [1, #(lines[cursorLine])]
}, ccgui.ScrollElement, ccgui.FocusElement)
ccgui.TextArea = TextArea

function TextArea:init()
    ccgui.FocusElement.init(self)
    ccgui.ScrollElement.init(self)

    self.lines = {""}

    self:on("mouse_click", self.textClick, self)
    self:on("key", self.textKey, self)
    self:on("char", self.textChar, self)

    self:on("paint", self.drawText, self)
    self:on("afterframe", self.drawCursor, self)
end

local function splitLines(str)
    local t = {}
    local function helper(line)
        table.insert(t, line)
        return ""
    end
    helper((string.gsub(str, "(.-)\n", helper)))
    return t
end

function TextArea:text()
    local text = ""
    -- Join lines
    for i,line in ipairs(self.lines) do
        if i > 1 then
            text = text.."\n"
        end
        text = text..line
    end
    return text
end

function TextArea:setText(text)
    -- Split lines
    self.lines = splitLines(text or "")
    -- Reset cursor
    if self.bbox then
        self:setCursor(1, 1)
    end
    -- Mark for repaint
    --self:markRepaint()
end

function TextArea:multiline()
    return true
end

function TextArea:readonly()
    return false
end

--[[

    Scroll

]]--

function TextArea:scrollVisible()
    return self:inner(self.bbox):size()
end

function TextArea:scrollTotal()
    local bbox = self:inner(self.bbox)
    return vector.new(
        math.max(bbox.w, self.longestLineLength + 1), -- for cursor at end of line
        math.max(bbox.h, #(self.lines))
    )
end

function TextArea:updateScroll()
    -- Update longest line length
    local maxLen = 0
    for i,line in ipairs(self.lines) do
        maxLen = math.max(maxLen, #line)
    end
    self.longestLineLength = maxLen
end

--[[

    Focus

]]--

function TextArea:canFocus()
    return ccgui.FocusElement.canFocus(self)
end

function TextArea:textBlur()
    if not self.hasFocus then
        self:getOutput().setCursorBlink(false)
    end
end

function TextArea:textClick(button, x, y)
    if button == 1 then
        -- Left mouse button, set cursor
        if self:canFocus() and self:contains(x, y) then
            local cursor = self:fromScreen(x, y)
            self:setCursor(cursor.x, cursor.y)
        end
    end
end

--[[

    Cursor

]]--

function TextArea:moveCursor(dx, dy)
    return self:setCursor(self.cursorChar + dx, self.cursorLine + dy)
end

function TextArea:setCursor(x, y)
    y = math.max(1, math.min(y, #self.lines))

    -- Keep cursor in text bounds
    if x <= 0 then
        if y > 1 then
            -- Move to end of previous line
            y = y - 1
            x = #(self.lines[y]) + 1
        else
            -- Clip to start of first line
            x = 1
        end
    elseif x > #(self.lines[y]) + 1 then
        if y < #self.lines then
            -- Move to start of next line
            y = y + 1
            x = 1
        else
            -- Clip to end of last line
            x = #(self.lines[y]) + 1
        end
    end

    self.cursorChar = x
    self.cursorLine = y

    -- Adjust scroll position
    local scrollX, scrollY = self.scrollPosition.x, self.scrollPosition.y
    local scrollVis = self:scrollVisible()

    if x <= scrollX then
        scrollX = x - 1
    elseif x >= scrollX + scrollVis.x then
        scrollX = x - scrollVis.x
    end

    if y <= scrollY then
        scrollY = y - 1
    elseif y >= scrollY + scrollVis.y then
        scrollY = y - scrollVis.y
    end

    self.scrollPosition = vector.new(scrollX, scrollY)
end

--[[

    Manipulations

]]--

function TextArea:insert(char)
    -- Insert character
    local line = self.lines[self.cursorLine]
    line = string.sub(line, 1, self.cursorChar-1) .. char .. string.sub(line, self.cursorChar, -1)
    self.lines[self.cursorLine] = line
    -- Move cursor
    self:moveCursor(1, 0)
    self:updateScroll()
end

function TextArea:delete(before)
    if before == nil then
        before = true
    else
        before = not not before
    end

    if before then
        if self.cursorChar == 1 and self.cursorLine > 1 then
            -- Concat with previous line
            self.lines[self.cursorLine-1] = self.lines[self.cursorLine-1] .. self.lines[self.cursorLine]
            table.remove(self.lines, self.cursorLine)
            local x = #(self.lines[self.cursorLine-1]) + 1
            self:setCursor(x, self.cursorLine-1)
        elseif self.cursorChar > 1 then
            -- Remove previous in current line
            local line = self.lines[self.cursorLine]
            line = string.sub(line, 1, self.cursorChar-2) .. string.sub(line, self.cursorChar, -1)
            self.lines[self.cursorLine] = line
            self:moveCursor(-1, 0)
        end
    else
        local line = self.lines[self.cursorLine]
        if self.cursorChar == #line + 1 and self.cursorLine < #(self.lines) then
            -- Concat with next line
            self.lines[self.cursorLine] = self.lines[self.cursorLine] .. self.lines[self.cursorLine + 1]
            table.remove(self.lines, self.cursorLine + 1)
        elseif self.cursorChar <= #line then
            -- Remove next in current line
            line = string.sub(line, 1, self.cursorChar-1) .. string.sub(line, self.cursorChar + 1, -1)
            self.lines[self.cursorLine] = line
        end
    end
    self:updateScroll()
end

function TextArea:newline()
    if not self:multiline() then return end

    -- Split current line
    local line = self.lines[self.cursorLine]
    self.lines[self.cursorLine] = string.sub(line, 1,self.cursorChar-1)
    table.insert(self.lines, self.cursorLine + 1, string.sub(line, self.cursorChar, -1))

    -- Move to new next line
    self:setCursor(1, self.cursorLine + 1)
    self:updateScroll()
end

--[[

    Drawing

]]--

function TextArea:fromScreen(x, y)
    local screenPos = type(x) == "table" and x or vector.new(x, y)
    return screenPos + vector.new(1, 1) - self:inner(self.bbox):tl() + self.scrollPosition
end

function TextArea:toScreen(x, y)
    local textPos = type(x) == "table" and x or vector.new(x, y)
    return textPos - vector.new(1, 1) + self:inner(self.bbox):tl() - self.scrollPosition
end

function TextArea:calcSize(size)
    -- Get inner bounding box
    local bbox = self:inner(size)
    local w, h = bbox.w, bbox.h

    -- Limit inner height when single line
    if not self:multiline() then h = 1 end

    -- Get inner bounding box with new size
    bbox = ccgui.newRectangle(bbox.x, bbox.y, w, h)
    -- Use outer size box
    self.size = self:outer(bbox)
end

function TextArea:drawCursor()
    if self.hasFocus then
        local out = self:getOutput()
        -- Get screen position
        local pos = self:toScreen(self.cursorChar, self.cursorLine)
        if self:contains(pos) then
            -- Show blinking cursor
            out.setTextColor(self.foreground)
            out.setBackgroundColor(self.background)
            out.setCursorPos(pos.x, pos.y)
            out.setCursorBlink(true)
        else
            -- Hide blinking cursor
            out.setCursorBlink(false)
        end
    end
end

function TextArea:drawText()
    local bbox = self:inner(self.bbox)
    -- Get screen position
    local pos = self:toScreen(1, 1)
    local x, y = pos.x, pos.y
    -- Draw lines
    for i,line in ipairs(self.lines) do
        self:draw(x, y, line, self.foreground, self.background, bbox)
        y = y + 1
    end
end

function TextArea:textKey(key)
    -- Translate key to action
    if key == keys.up then
        self:moveCursor(0, -1)
    elseif key == keys.down then
        self:moveCursor(0, 1)
    elseif key == keys.left then
        self:moveCursor(-1, 0)
    elseif key == keys.right then
        self:moveCursor(1, 0)
    elseif key == keys.home then
        self:setCursor(1, self.cursorLine)
    elseif key == keys["end"] then
        self:setCursor(#(self.lines[self.cursorLine]) + 1, self.cursorLine)
    elseif not self:readonly() then
        if key == keys.backspace then
            self:delete(true)
        elseif key == keys.delete then
            self:delete(false)
        elseif key == keys.enter or key == keys.numPadEnter then
            self:newline()
        end
    end
    -- Mark for repaint
    --self:markRepaint()
end

function TextArea:textChar(char)
    if not self:readonly() then
        -- Insert character
        self:insert(char)
        -- Mark for repaint
        --self:markRepaint()
    end
end

--[[

    Single line text input

]]--

local TextInput = common.newClass(ccgui.TextArea)
ccgui.TextInput = TextInput

function TextInput:init()
    self.horizontal = true
    self.vertical = false
    self.mouseScroll = false
    self.showScrollBars = false

    ccgui.TextArea.init(self)
end

function TextInput:multiline()
    return false
end

--[[

    Multiline text viewer

]]--
local TextViewer = common.newClass(ccgui.TextArea)
ccgui.TextViewer = TextViewer

function TextViewer:readonly()
    return true
end