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108 lines
3.6 KiB
Lua
108 lines
3.6 KiB
Lua
--[[--
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A TextWidget puts a string on a single line.
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Example:
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UIManager:show(TextWidget:new{
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text = "Make it so.",
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face = Font:getFace("cfont"),
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bold = true,
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fgcolor = Blitbuffer.COLOR_DARK_GRAY,
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})
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--]]
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local Blitbuffer = require("ffi/blitbuffer")
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local Geom = require("ui/geometry")
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local Math = require("optmath")
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local RenderText = require("ui/rendertext")
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local Size = require("ui/size")
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local Widget = require("ui/widget/widget")
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local Screen = require("device").screen
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local TextWidget = Widget:new{
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text = nil,
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face = nil,
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bold = nil,
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fgcolor = Blitbuffer.COLOR_BLACK,
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padding = Size.padding.small, -- should padding be function of face.size ?
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max_width = nil,
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_bb = nil,
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_length = 0,
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_height = 0,
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_baseline_h = 0,
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_maxlength = 1200,
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}
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--function TextWidget:_render()
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--local h = self.face.size * 1.3
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--self._bb = Blitbuffer.new(self._maxlength, h)
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--self._bb:fill(Blitbuffer.COLOR_WHITE)
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--self._length = RenderText:renderUtf8Text(self._bb, 0, h*0.8, self.face, self.text, true, self.bold)
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--end
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function TextWidget:updateSize()
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local tsize = RenderText:sizeUtf8Text(0, self.max_width and self.max_width or Screen:getWidth(), self.face, self.text, true, self.bold)
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if not tsize then
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self._length = 0
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else
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-- As text length includes last glyph pen "advance" (for positionning
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-- next char), it's best to use math.floor() instead of math.ceil()
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-- to get rid of a fraction of it in case this text is to be
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-- horizontally centered
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self._length = math.floor(tsize.x)
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end
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-- Used to be:
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-- self._height = math.ceil(self.face.size * 1.5)
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-- self._baseline_h = self._height*0.7
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-- But better compute baseline alignment from freetype font metrics
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-- to get better vertical centering of text in box
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-- (Freetype doc on this at https://www.freetype.org/freetype2/docs/tutorial/step2.html)
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local face_height, face_ascender = self.face.ftface:getHeightAndAscender()
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self._height = math.ceil(face_height) + 2*self.padding
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self._baseline_h = Math.round(face_ascender) + self.padding
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-- With our UI fonts, this usually gives 0.72 to 0.74, so text is aligned
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-- a bit lower than before with the hardcoded 0.7
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-- require("logger").warn("1.5*face.size:", self.face.size * 1.5, "face_height:", face_height, "self._height:", self._height)
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-- require("logger").warn("self._height ratio:", 1.0*self._baseline_h/self._height)
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end
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function TextWidget:getSize()
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--if not self._bb then
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--self:_render()
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--end
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--return { w = self._length, h = self._bb:getHeight() }
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self:updateSize()
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return Geom:new{
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w = self._length,
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h = self._height,
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}
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end
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function TextWidget:setText(text)
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self.text = text
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self:updateSize()
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end
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function TextWidget:paintTo(bb, x, y)
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--if not self._bb then
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--self:_render()
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--end
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--bb:blitFrom(self._bb, x, y, 0, 0, self._length, self._bb:getHeight())
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--@TODO Don't use kerning for monospaced fonts. (houqp)
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if self.max_width and RenderText:sizeUtf8Text(0, Screen:getWidth(), self.face, self.text, true, self.bold).x > self.max_width then
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self.text = RenderText:truncateTextByWidth(self.text, self.face, self.max_width, true)
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end
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RenderText:renderUtf8Text(bb, x, y+self._baseline_h, self.face, self.text, true, self.bold,
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self.fgcolor, self.max_width and self.max_width or self.width)
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end
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function TextWidget:free()
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if self._bb then
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self._bb:free()
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self._bb = nil
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end
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end
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return TextWidget
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