ui overhaul

sys/apis/ui/components/Viewport.lua

@@ -0,0 +1,96 @@
+local class = require('class')
+local UI    = require('ui')
+
+local colors = _G.colors
+
+--[[-- Viewport --]]--
+UI.Viewport = class(UI.Window)
+UI.Viewport.defaults = {
+	UIElement = 'Viewport',
+	backgroundColor = colors.cyan,
+	accelerators = {
+		down            = 'scroll_down',
+		up              = 'scroll_up',
+		home            = 'scroll_top',
+		[ 'end' ]       = 'scroll_bottom',
+		pageUp          = 'scroll_pageUp',
+		[ 'control-b' ] = 'scroll_pageUp',
+		pageDown        = 'scroll_pageDown',
+		[ 'control-f' ] = 'scroll_pageDown',
+	},
+}
+function UI.Viewport:setParent()
+	UI.Window.setParent(self)
+	self.canvas = self:addLayer()
+end
+
+function UI.Viewport:enable()
+	UI.Window.enable(self)
+	self.canvas:setVisible(true)
+end
+
+function UI.Viewport:disable()
+	UI.Window.disable(self)
+	self.canvas:setVisible(false)
+end
+
+function UI.Viewport:setScrollPosition(offset)
+	local oldOffset = self.offy
+	self.offy = math.max(offset, 0)
+	self.offy = math.min(self.offy, math.max(#self.canvas.lines, self.height) - self.height)
+	if self.offy ~= oldOffset then
+		if self.scrollBar then
+			self.scrollBar:draw()
+		end
+		self.canvas.offy = offset
+		self.canvas:dirty()
+	end
+end
+
+function UI.Viewport:write(x, y, text, bg, tc)
+	if y > #self.canvas.lines then
+		for i = #self.canvas.lines, y do
+			self.canvas.lines[i + 1] = { }
+			self.canvas:clearLine(i + 1, self.backgroundColor, self.textColor)
+		end
+	end
+	return UI.Window.write(self, x, y, text, bg, tc)
+end
+
+function UI.Viewport:reset()
+	self.offy = 0
+	self.canvas.offy = 0
+	for i = self.height + 1, #self.canvas.lines do
+		self.canvas.lines[i] = nil
+	end
+end
+
+function UI.Viewport:getViewArea()
+	return {
+		y           = (self.offy or 0) + 1,
+		height      = self.height,
+		totalHeight = #self.canvas.lines,
+		offsetY     = self.offy or 0,
+	}
+end
+
+function UI.Viewport:eventHandler(event)
+	if event.type == 'scroll_down' then
+		self:setScrollPosition(self.offy + 1)
+	elseif event.type == 'scroll_up' then
+		self:setScrollPosition(self.offy - 1)
+	elseif event.type == 'scroll_top' then
+		self:setScrollPosition(0)
+	elseif event.type == 'scroll_bottom' then
+		self:setScrollPosition(10000000)
+	elseif event.type == 'scroll_pageUp' then
+		self:setScrollPosition(self.offy - self.height)
+	elseif event.type == 'scroll_pageDown' then
+		self:setScrollPosition(self.offy + self.height)
+	elseif event.type == 'scroll_to' then
+		self:setScrollPosition(event.offset)
+	else
+		return false
+	end
+	return true
+end