ui overhaul

sys/apis/ui/components/ScrollBar.lua

@@ -0,0 +1,74 @@
+local class = require('class')
+local UI    = require('ui')
+local Util  = require('util')
+
+local colors = _G.colors
+
+UI.ScrollBar = class(UI.Window)
+UI.ScrollBar.defaults = {
+	UIElement = 'ScrollBar',
+	lineChar = '|',
+	sliderChar = '#',
+	upArrowChar = '^',
+	downArrowChar = 'v',
+	scrollbarColor = colors.lightGray,
+	width = 1,
+	x = -1,
+	ey = -1,
+}
+function UI.ScrollBar:draw()
+	local view = self.parent:getViewArea()
+
+	if view.totalHeight > view.height then
+		local maxScroll = view.totalHeight - view.height
+		local percent = view.offsetY / maxScroll
+		local sliderSize = math.max(1, Util.round(view.height / view.totalHeight * (view.height - 2)))
+		local x = self.width
+
+		local row = view.y
+		if not view.static then  -- does the container scroll ?
+			self.height = view.totalHeight
+		end
+
+		for i = 1, view.height - 2 do
+			self:write(x, row + i, self.lineChar, nil, self.scrollbarColor)
+		end
+
+		local y = Util.round((view.height - 2 - sliderSize) * percent)
+		for i = 1, sliderSize do
+			self:write(x, row + y + i, self.sliderChar, nil, self.scrollbarColor)
+		end
+
+		local color = self.scrollbarColor
+		if view.offsetY > 0 then
+			color = colors.white
+		end
+		self:write(x, row, self.upArrowChar, nil, color)
+
+		color = self.scrollbarColor
+		if view.offsetY + view.height < view.totalHeight then
+			color = colors.white
+		end
+		self:write(x, row + view.height - 1, self.downArrowChar, nil, color)
+	end
+end
+
+function UI.ScrollBar:eventHandler(event)
+	if event.type == 'mouse_click' or event.type == 'mouse_doubleclick' then
+		if event.x == 1 then
+			local view = self.parent:getViewArea()
+			if view.totalHeight > view.height then
+				if event.y == view.y then
+					self:emit({ type = 'scroll_up'})
+				elseif event.y == view.y + view.height - 1 then
+					self:emit({ type = 'scroll_down'})
+				else
+					local percent = (event.y - view.y) / (view.height - 2)
+					local y = math.floor((view.totalHeight - view.height) * percent)
+					self:emit({ type = 'scroll_to', offset = y })
+				end
+			end
+			return true
+		end
+	end
+end