greatly simplify slider implementation

It now looks a lot like button.lua.

0004-on.update

@@ -5,10 +5,8 @@ on.update = function(dt)
 		Active_button = nil
 	end
 	-- == settings area
-	if Selected_slider then
-		update_any_sliders(App.mouse_x(), App.mouse_y())
-	end
-	-- main area
+	update_sliders(Global_state, App.mouse_x())
+	-- == main area
 	if Current_pane.editor_state.scrollbar_drag then
 		adjust_scrollbar(Current_pane.editor_state, App.mouse_y())
 	elseif Current_pane.output_editor_state.scrollbar_drag then

0012-on.draw

@@ -1,5 +1,6 @@
 on.draw = function()
 	Global_state.button_handlers = {}
+	Global_state.slider_handlers = {}
 	-- modal dialog
 	if Show_file_dialog then
 		draw_file_dialog()

0016-on.mouse_press

@@ -7,9 +7,12 @@ on.mouse_press = function(x,y, mouse_button)
 		return
 	end
 	-- == settings area
+	if mouse_press_consumed_by_any_slider(Global_state, x,y) then
+		return
+	end
 	if Show_menu == 'settings' then
 		if on_area(Settings_menu_area, x,y) then
-			select_settings_slider(x,y, mouse_button)
+			-- nothing atm in settings menu that isn't a button or slider
 		else
 			Show_menu = nil
 			-- On mobile devices, we can't depend on on.save_settings() triggering on quit.

0017-on.mouse_release

@@ -1,11 +1,11 @@
 on.mouse_release = function(x,y, mouse_button)
 	-- == menu area
-	Selected_slider = nil
 	if Button_pressed then
 		Button_pressed = nil
 		return
 	end
 	-- == settings area
+	Global_state.selected_slider = nil
 	if Show_menu == 'settings' then
 		if on_area(Settings_menu_area, x,y) then
 			return
@@ -37,4 +37,4 @@ on.mouse_release = function(x,y, mouse_button)
 			call_protected(car.mousereleased, x,y, mouse_button)
 		end
 	end
-end
+end

0081-draw_settings_menu

@@ -9,8 +9,8 @@ draw_settings_menu = function()
 	love.graphics.print('font size', x+10,y+10)
 	y = y+10+Line_height
 	local sx = x+App.width('bg')+50  -- align all sliders
-	Settings_font_slider = {
-		name='font',
+	slider(Global_state, 'font', {
+		fg=Normal_color,
 		-- x limits
 		x0=sx+20, x1=Safe_width-30-10,
 		-- central y
@@ -20,8 +20,8 @@ draw_settings_menu = function()
 		-- extremes
 		lo=12, hi=40,  -- font sizes
 		value=Current_pane.editor_state.font_height,
-	}
-	draw_slider(Settings_font_slider)
+		update=update_font_settings,
+	})
 	y = y+10
 	-- colors
 	love.graphics.print('colors', x+10,y+10)
@@ -30,71 +30,34 @@ draw_settings_menu = function()
 	love.graphics.print('fg', x+20, y)
 	App.color(Foreground_color)
 	love.graphics.rectangle('fill', sx-20,y+5, 20,20)
-	local prev = Settings_font_slider
-	Settings_foreground_sliders = {
-		r = {
-			name='fg/r',
+	local prev = Global_state.slider_handlers.font
+	for _,color in ipairs{'r', 'g', 'b'} do
+		slider(Global_state, 'fg/'..color, {
+			fg=Normal_color,
 			x0=prev.x0, x1=prev.x1,
 			y0=y,
 			w=prev.w, h=prev.h,
 			lo=0, hi=1,
-			value=Foreground_color.r,
-		},
-		g = {
-			name='fg/g',
-			x0=prev.x0, x1=prev.x1,
-			y0=y+15,
-			w=prev.w, h=prev.h,
-			lo=0, hi=1,
-			value=Foreground_color.g,
-		},
-		b = {
-			name='fg/b',
-			x0=prev.x0, x1=prev.x1,
-			y0=y+30,
-			w=prev.w, h=prev.h,
-			lo=0, hi=1,
-			value=Foreground_color.b,
-		},
-	}
-	App.color(Normal_color)
-	draw_slider(Settings_foreground_sliders.r)
-	draw_slider(Settings_foreground_sliders.g)
-	draw_slider(Settings_foreground_sliders.b)
-	y = y+50
+			value=Foreground_color[color],
+			update=function(v) Foreground_color[color] = v end,
+		})
+		y = y+15
+	end
+	y = y+5
 	-- colors/background
 	love.graphics.print('bg', x+20, y)
 	App.color(Background_color)
 	love.graphics.rectangle('fill', sx-20,y+5, 20,20)
-	App.color(Normal_color)
-	Settings_background_sliders = {
-		r = {
-			name='bg/r',
+	for _,color in ipairs{'r', 'g', 'b'} do
+		slider(Global_state, 'bg/'..color, {
+			fg=Normal_color,
 			x0=prev.x0, x1=prev.x1,
 			y0=y,
 			w=prev.w, h=prev.h,
 			lo=0, hi=1,
-			value=Background_color.r
-		},
-		g = {
-			name='bg/g',
-			x0=prev.x0, x1=prev.x1,
-			y0=y+15,
-			w=prev.w, h=prev.h,
-			lo=0, hi=1,
-			value=Background_color.g
-		},
-		b = {
-			name='bg/b',
-			x0 = prev.x0, x1=prev.x1,
-			y0 = y+30,
-			w=prev.w, h=prev.h,
-			lo = 0, hi=1,
-			value = Background_color.b
-		},
-	}
-	App.color(Normal_color)
-	draw_slider(Settings_background_sliders.r)
-	draw_slider(Settings_background_sliders.g)
-	draw_slider(Settings_background_sliders.b)
+			value=Background_color[color],
+			update=function(v) Background_color[color] = v end,
+		})
+		y = y+15
+	end
 end

0082-draw_slider

@@ -2,6 +2,7 @@
 -- position 'value' on the slider
 -- the leftmost point on the slider will have value 'lo', and the rightmost will have 'hi'. In between the value will be linearly interpolated.
 draw_slider = function(s)
+	App.color(s.fg)
 	love.graphics.line(s.x0, s.y0, s.x1, s.y0)
 	s.x = s.x0 + (s.x1-s.x0)*(s.value-s.lo)/(s.hi-s.lo)
 	love.graphics.rectangle('fill', s.x-s.h/2, s.y0-s.h/2, s.w,s.h)

0083-Settings_font_slider

@@ -1,11 +0,0 @@
-Settings_font_slider = {
-	name='font',
-	-- left extreme
-	x0=nil, y0=nil,
-	-- right extreme
-	x1=nil,
-	-- slider itself
-	x=nil,  -- y=y0
-	w=nil, h=nil,
-	lo=20, hi=40,
-}

0083-slider

@@ -0,0 +1,4 @@
+slider = function(State, name, params)
+	draw_slider(params)
+	State.slider_handlers[name] = params
+end

0084-update_any_sliders

@@ -1,18 +0,0 @@
-update_any_sliders = function(x,y)
-	if Selected_slider == Settings_font_slider.name then
-		update_font_settings(slider_value(Settings_font_slider, x))
-		return true
-	end
-	for color,slider in pairs(Settings_foreground_sliders) do
-		if Selected_slider == slider.name then
-			Foreground_color[color] = slider_value(slider, x)
-			return true
-		end
-	end
-	for color,slider in pairs(Settings_background_sliders) do
-		if Selected_slider == slider.name then
-			Background_color[color] = slider_value(slider, x)
-			return true
-		end
-	end
-end

0084-update_sliders

@@ -0,0 +1,8 @@
+update_sliders = function(State, x)
+	for name, slider in pairs(State.slider_handlers) do
+		if State.selected_slider == name then
+			slider.update(slider_value(slider, x))
+			break
+		end
+	end
+end

0086-mouse_press_consumed_by_any_slider

@@ -0,0 +1,8 @@
+mouse_press_consumed_by_any_slider = function(State, x, y)
+	for name, slider in pairs(State.slider_handlers) do
+		if on_slider(slider, x,y) then
+			State.selected_slider = name  -- used by update across frames; slider_handlers is recreated every frame
+			return true
+		end
+	end
+end

0086-select_settings_slider

@@ -1,20 +0,0 @@
-select_settings_slider = function(x,y, mouse_button)
-	local result = false
-	if on_slider(Settings_font_slider, x,y) then
-		Selected_slider = Settings_font_slider.name
-		result = true
-	end
-	for color,slider in pairs(Settings_foreground_sliders) do
-		if on_slider(slider, x,y) then
-			Selected_slider = slider.name
-			result = true
-		end
-	end
-	for color,slider in pairs(Settings_background_sliders) do
-		if on_slider(slider, x,y) then
-			Selected_slider = slider.name
-			result = true
-		end
-	end
-	return result
-end

0087-on_slider

@@ -1,5 +1,4 @@
 on_slider = function(slider, x,y)
-	if slider.x0 == nil then return end  -- slider uninitialized
 	if x < slider.x0-slider.w/2 or x > slider.x1+slider.w/2 then return end
 	if y < slider.y0-slider.h/2 or y > slider.y0+slider.h/2 then return end
 	return true

0088-Settings_foreground_sliders

@@ -1 +0,0 @@
-Settings_foreground_sliders = {}

0089-Settings_background_sliders

@@ -1 +0,0 @@
-Settings_background_sliders = {}

0095-Selected_slider

@@ -1 +0,0 @@
-Selected_slider = nil