some keyboard shortcuts on non-mobile devices

Hopefully this is easy to remember from left to right:
- run is F1
- stop is F2
- hide/show is F3
- save is F4
- load is F5

There are also tooltips to introduce these shortcuts to newcomers.

Most of the shortcuts are only enabled when code is visible. In keeping
with existing conventions for mouse events, we leave most event handlers
for the script when code is hidden. The only exception is 'F3' to show
code. So if you want to use a shortcut 'k' when code is hidden, you have
to instead use 'F3 k F3'.

This is all tentative and open to change. But I'll probably grow more
reluctant to change the shortcuts in a few weeks or months.

0012-on.draw

@@ -24,4 +24,5 @@ on.draw = function()
 	end
 	draw_menu()
 	draw_next_frames_of_animations()
+	draw_button_tooltips(Global_state)
 end

0051-run_button

@@ -1,5 +1,5 @@
 run_button = function(x, y)
-	styled_button('run', x,y, press_run_button)
+	styled_button('run', x,y, press_run_button, not Is_mobile and Show_code and 'F1')
 	local w = Font:getWidth('run')+10
 	return x+w+10, y
 end

0059-previous_pane_button

@@ -5,5 +5,8 @@ previous_pane_button = function()
 			love.graphics.polygon('fill', Menu_left+5, App.screen.height/2, Menu_left+25, App.screen.height/2-10, Menu_left+25, App.screen.height/2+10)
 		end,
 		onpress1 = press_previous_pane_button,
+		tooltip = function(x,y)
+			show_tooltip(x,y+20, not Is_mobile and Show_code and 'ctrl+left')
+		end,
 	})
 end

0060-next_pane_button

@@ -5,5 +5,9 @@ next_pane_button = function(r)
 			love.graphics.polygon('fill', r-25, App.screen.height/2-10, r-25, App.screen.height/2+10,  r-5, App.screen.height/2)
 		end,
 		onpress1 = press_next_pane_button,
+		tooltip = function(x,y)
+			local w = App.width('ctrl+right')
+			show_tooltip(x-w-10,y+20, not Is_mobile and Show_code and 'ctrl+right')
+		end,
 	})
 end

0064-show_code_button

@@ -1,3 +1,3 @@
 show_code_button = function(x, y, r)
-	return overflowable_button('show', x, y, r, press_show_button)
+	return overflowable_button('show', x, y, r, press_show_button, nil, not Is_mobile and 'F3')
 end

0065-hide_code_button

@@ -1,3 +1,3 @@
 hide_code_button = function(x, y, r)
-	return overflowable_button('hide', x, y, r, press_hide_button)
+	return overflowable_button('hide', x, y, r, press_hide_button, nil, not Is_mobile and 'F3')
 end

0106-stop_button

@@ -1,5 +1,5 @@
 stop_button = function(x, y)
-	styled_button('stop', x,y, press_stop_button)
+	styled_button('stop', x,y, press_stop_button, not Is_mobile and Show_code and 'F2')
 	local w = Font:getWidth('stop')+10
 	return x+w+10, y
 end

0116-save_button

@@ -1,3 +1,3 @@
 save_button = function(x, y, r)
-	return overflowable_button('save', x, y, r, press_save_button)
+	return overflowable_button('save', x, y, r, press_save_button, --[[final button?]] false, not Is_mobile and Show_code and 'F4')
 end

0117-load_button

@@ -1,19 +1,4 @@
 load_button = function(x, y, r)
 	return overflowable_button('load', x, y, r,
-		function()
-			Show_menu = nil
-			Show_file_dialog = true
-			File_dialog_callback = function(filename)
-				if filename == '' then
-					-- clear filename
-					Current_pane.filename = nil
-					return
-				end
-				Current_pane.filename = filename
-				one_time_load()
-				-- Load new filename in future sessions.
-				-- On mobile devices, we can't depend on on.save_settings() triggering on quit.
-				love.filesystem.write('config', json.encode(settings()))
-			end
-		end)
+		press_load_button, --[[final button?]] false, not Is_mobile and Show_code and 'F5')
 end

0118-overflowable_button

@@ -1,6 +1,6 @@
 -- draw a button in the menu if possible
 -- if not, stash it behind an overflow ('>>') button
-overflowable_button = function(name, x, y, r, onpress1, final_button)
+overflowable_button = function(name, x, y, r, onpress1, final_button, tooltip_text)
 	local w = Font:getWidth(name)+10
 	local x2, y2 = maybe_draw_overflow_button(x, y, w, r, final_button)
 	if Overflow_button then
@@ -11,10 +11,10 @@ overflowable_button = function(name, x, y, r, onpress1, final_button)
 			y = y2
 		end
 	end
-	styled_button(name, x,y, onpress1)
+	styled_button(name, x,y, onpress1, tooltip_text)
 	if Overflow_button then
 		return x, y+Line_height
 	else
 		return x+w+10, y
 	end
-end
+end

0124-styled_button

@@ -1,4 +1,4 @@
-styled_button = function(name, x, y, onpress1)
+styled_button = function(name, x, y, onpress1, tooltip_text)
 	local w = Font:getWidth(name)+10
 	button(Global_state, name, {x=x, y=y, w=w, h=Line_height, bg={r=0.6, g=0.8, b=0.6},
 		icon = function(p)
@@ -17,5 +17,8 @@ styled_button = function(name, x, y, onpress1)
 				expire=Current_time+0.1,
 			}
 		end,
+		tooltip = function(x,y)
+			show_tooltip(x,y+20, tooltip_text)
+		end,
 	})
-end
+end

0167-press_next_pane_button

@@ -1,5 +1,6 @@
 press_next_pane_button = function()
 	Show_menu = nil
+	if Current_pane_index >= #Panes then return end
 	Current_pane.car = car
 	Current_pane_index = Current_pane_index+1
 	Current_pane = Panes[Current_pane_index]

0168-press_previous_pane_button

@@ -1,5 +1,6 @@
 press_previous_pane_button = function()
 	Show_menu = nil
+	if Current_pane_index <=1 then return end
 	Current_pane.car = car
 	Current_pane_index = Current_pane_index-1
 	Current_pane = Panes[Current_pane_index]

0172-Tooltip_background

@@ -0,0 +1 @@
+Tooltip_background = {r=0.8, g=0.8, b=0.8}

0173-Tooltip_foreground

@@ -0,0 +1 @@
+Tooltip_foreground = {r=0, g=0, b=0}

0174-Is_mobile

@@ -0,0 +1 @@
+Is_mobile = (OS == 'Android' or OS == 'iOS')

0175-show_tooltip

@@ -0,0 +1,8 @@
+show_tooltip = function(x,y, tooltip_text)
+	if not tooltip_text then return end
+	App.color(Tooltip_background)
+	local w = App.width(tooltip_text)
+	love.graphics.rectangle('fill', x,y, w+10, Line_height+10, 2,2)
+	App.color(Tooltip_foreground)
+	love.graphics.print(tooltip_text, x+5, y+5)
+end

button.lua

@@ -33,3 +33,15 @@ function mouse_press_consumed_by_any_button(State, x, y, mouse_button)
   end
   return button_pressed and consume_press
 end
+
+function draw_button_tooltips(State)
+  if App.mouse_down(1) then return end
+  local x,y = love.mouse.getPosition()
+  for _,ev in ipairs(State.button_handlers) do
+    if ev.tooltip then
+      if x>ev.x and x<ev.x+ev.w and y>ev.y and y<ev.y+ev.h then
+        ev.tooltip(x,y)
+      end
+    end
+  end
+end