text entry, partial support

luigi/widget/text.lua

@@ -1,3 +1,160 @@
-return function (self)
+local utf8 = require 'utf8'
 
+local blendMultiply = love._version_minor < 10 and 'multiplicative'
+    or 'multiply'
+
+local function setCaretPosition (self, text)
+    local font = self.fontData.font
+    local x1, y1, x2, y2 = self:getRectangle(true, true)
+    self.startIndex = #text
+    self.startX = font:getWidth(text) + x1
+    self.endIndex, self.endX = self.startIndex, self.startX
+end
+
+-- return caret index and x position
+local function getCaretFromEvent (self, event)
+    local x1, y1, x2, y2 = self:getRectangle(true, true)
+
+    if event.x <= x1 then
+        return 0, x1
+    end
+
+    local font = self.fontData.font
+    local width, lastWidth = 0
+
+    for position in utf8.codes(self.value) do
+        local index = utf8.offset(self.value, position)
+        text = self.value:sub(1, index)
+        lastWidth = width
+        width = font:getWidth(text)
+        if width > event.x - x1 then
+            if position == 1 then
+                return 0, x1
+            end
+            return utf8.offset(self.value, position - 1), lastWidth + x1
+        end
+    end
+
+    return #self.value, width + x1
+end
+
+local function getRange (self)
+    if self.startIndex <= self.endIndex then
+        return self.startIndex, self.endIndex
+    end
+
+    return self.endIndex, self.startIndex
+end
+
+return function (self)
+    self.value = self.value or self.text or ''
+    self.text = ''
+    self:setValue(self.value)
+    self.highlight = self.highlight or { 0x80, 0x80, 0x80 }
+
+    self:onPressStart(function (event)
+        self.startIndex, self.startX = getCaretFromEvent(self, event)
+        self.endIndex, self.endX = self.startIndex, self.startX
+    end)
+
+    self:onPressMove(function (event)
+        self.endIndex, self.endX = getCaretFromEvent(self, event)
+    end)
+
+    self:onTextInput(function (event)
+        local text = self.value
+        local first, last = getRange(self)
+        local left = text:sub(1, first) .. event.text
+
+        self.value = left .. text:sub(last + 1)
+        self:setValue(self.value)
+        setCaretPosition(self, left)
+    end)
+
+    self:onKeyPress(function (event)
+        if event.key == 'backspace' then
+
+            local text = self.value
+            local first, last = getRange(self)
+
+            -- if expanded range is selected, delete text in range
+            if first ~= last then
+                local left = text:sub(1, first)
+                self.value = left .. text:sub(last + 1)
+                self:setValue(self.value)
+                setCaretPosition(self, left)
+                return false
+            end
+
+            -- if cursor is at beginning, do nothing
+            if first < 1 then
+                return false
+            end
+
+            -- delete character to the left
+            local offset = utf8.offset(self.value, -1, first) or 0
+            local left = self.value:sub(1, offset)
+            self.value = left .. self.value:sub(first + 1)
+            self:setValue(self.value)
+            setCaretPosition(self, left)
+
+        elseif event.key == 'left' then
+
+            local text, endIndex = self.value, self.endIndex
+
+            -- if cursor is at beginning, do nothing
+            if endIndex < 1 then
+                return false
+            end
+
+            -- move cursor left
+            local offset = utf8.offset(text, -1, endIndex) or 0
+
+            setCaretPosition(self, text:sub(1, offset))
+
+        elseif event.key == 'right' then
+
+            local text, endIndex = self.value, self.endIndex
+
+            -- if cursor is at end, do nothing
+            if endIndex == #text then
+                return false
+            end
+
+            local offset = endIndex < 1 and utf8.offset(text, 1)
+                or utf8.offset(text, 2, endIndex) or #text
+
+            -- move cursor right
+            setCaretPosition(self, text:sub(1, offset))
+
+        end
+        return false
+    end)
+
+    self:onDisplay(function (event)
+        local startX, endX = self.startX or 0, self.endX or 0
+        local x1, y1, x2, y2 = self:getRectangle(true, true)
+        local width, height = endX - startX, y2 - y1
+        local fontData = self.fontData
+        local font = fontData.font
+        local textColor = fontData.color
+        local textTop = math.floor(y1 + ((y2 - y1) - font:getHeight()) / 2)
+
+        love.graphics.push('all')
+        love.graphics.setFont(font)
+        love.graphics.setColor(textColor)
+        love.graphics.print(self.value, x1, textTop)
+        if not self.focused then
+            love.graphics.pop()
+            return
+        end
+        love.graphics.setBlendMode(blendMultiply)
+        love.graphics.setColor(self.highlight)
+        love.graphics.rectangle('fill', startX, y1, width, height)
+        if love.timer.getTime() % 2 < 1.75 then
+            love.graphics.setColor(textColor)
+            love.graphics.rectangle('fill', endX, y1, 1, height)
+        end
+        love.graphics.pop()
+    end)
 end