right align hotkeys for list items

and combine hotkeys for identical commands
and don't hide the menu until the mouse has left the frame
and start the widget one tile closer to the edge so the mouse is already
on the list instead of on the frame

plugins/lua/hotkeys.lua

@@ -11,7 +11,7 @@ local widgets = require('gui.widgets')
 
 HotspotMenuWidget = defclass(HotspotMenuWidget, overlay.OverlayWidget)
 HotspotMenuWidget.ATTRS{
-    default_pos={x=1,y=2},
+    default_pos={x=1,y=3},
     hotspot=true,
     viewscreens={'dwarfmode'},
     overlay_onupdate_max_freq_seconds=0,
@@ -48,8 +48,8 @@ OVERLAY_WIDGETS = {menu=HotspotMenuWidget}
 -- ---------- --
 
 local ARROW = string.char(26)
-local MENU_WIDTH = 42
-local MENU_HEIGHT = 12
+local MAX_LIST_WIDTH = 45
+local MAX_LIST_HEIGHT = 15
 
 MenuScreen = defclass(MenuScreen, gui.Screen)
 MenuScreen.ATTRS{
@@ -59,32 +59,90 @@ MenuScreen.ATTRS{
     bindings=DEFAULT_NIL,
 }
 
+-- get a map from the binding string to a list of hotkey strings that all
+-- point to that binding
+local function get_bindings_to_hotkeys(hotkeys, bindings)
+    local bindings_to_hotkeys = {}
+    for _,hotkey in ipairs(hotkeys) do
+        local binding = bindings[hotkey]
+        table.insert(ensure_key(bindings_to_hotkeys, binding), hotkey)
+    end
+    return bindings_to_hotkeys
+end
+
+-- number of non-text tiles: icon, space, space between cmd and hk, scrollbar
+local LIST_BUFFER = 2 + 1 + 1
+
+local function get_choices(hotkeys, bindings, is_inverted)
+    local choices, max_width, seen = {}, 0, {}
+    local bindings_to_hotkeys = get_bindings_to_hotkeys(hotkeys, bindings)
+
+    -- build list choices
+    for _,hotkey in ipairs(hotkeys) do
+        local command = bindings[hotkey]
+        if seen[command] then goto continue end
+        seen[command] = true
+        local hk_width, tokens = 0, {}
+        for _,hk in ipairs(bindings_to_hotkeys[command]) do
+            if hk_width ~= 0 then
+                table.insert(tokens, ', ')
+                hk_width = hk_width + 2
+            end
+            table.insert(tokens, {text=hk, pen=COLOR_LIGHTGREEN})
+            hk_width = hk_width + #hk
+        end
+        local command_str = command
+        if hk_width + #command + LIST_BUFFER > MAX_LIST_WIDTH then
+            local max_command_len = MAX_LIST_WIDTH - hk_width - LIST_BUFFER
+            command_str = command:sub(1, max_command_len - 3) .. '...'
+        end
+        table.insert(tokens, 1, {text=command_str})
+        local choice = {icon=ARROW, command=command, text=tokens,
+                        hk_width=hk_width}
+        max_width = math.max(max_width, hk_width + #command_str + LIST_BUFFER)
+        table.insert(choices, is_inverted and 1 or #choices + 1, choice)
+        ::continue::
+    end
+
+    -- adjust width of command fields so the hotkey tokens are right justified
+    for _,choice in ipairs(choices) do
+        local command_token = choice.text[1]
+        command_token.width = max_width - choice.hk_width - 3
+    end
+
+    return choices, max_width
+end
+
 function MenuScreen:init()
     self.mouseover = false
 
-    local list_frame = copyall(self.hotspot_frame)
-    list_frame.w = MENU_WIDTH
-    list_frame.h = MENU_HEIGHT
+    local choices,list_width = get_choices(self.hotkeys, self.bindings,
+                                           self.hotspot_frame.b)
 
-    local help_frame = {w=MENU_WIDTH, l=list_frame.l, r=list_frame.r}
+    local list_frame = copyall(self.hotspot_frame)
+    list_frame.w = list_width + 2
+    list_frame.h = math.min(#choices, MAX_LIST_HEIGHT) + 2
     if list_frame.t then
-        help_frame.t = list_frame.t + MENU_HEIGHT + 1
+        list_frame.t = math.max(0, list_frame.t - 1)
     else
-        help_frame.b = list_frame.b + MENU_HEIGHT + 1
+        list_frame.b = math.max(0, list_frame.b - 1)
+    end
+    if list_frame.l then
+        list_frame.l = math.max(0, list_frame.l - 1)
+    else
+        list_frame.r = math.max(0, list_frame.r - 1)
     end
 
-    local bindings = self.bindings
-    local choices = {}
-    for _,hotkey in ipairs(self.hotkeys) do
-        local command = bindings[hotkey]
-        local choice_text = command .. (' (%s)'):format(hotkey)
-        local choice = {
-            icon=ARROW, text=choice_text, command=command}
-        table.insert(choices, list_frame.b and 1 or #choices + 1, choice)
+    local help_frame = {w=list_frame.w, l=list_frame.l, r=list_frame.r}
+    if list_frame.t then
+        help_frame.t = list_frame.t + list_frame.h + 1
+    else
+        help_frame.b = list_frame.b + list_frame.h + 1
     end
 
     self:addviews{
         widgets.ResizingPanel{
+            view_id='list_panel',
             autoarrange_subviews=true,
             frame=list_frame,
             frame_style=gui.GREY_LINE_FRAME,
@@ -164,6 +222,7 @@ function MenuScreen:onRenderFrame(dc, rect)
 end
 
 function MenuScreen:onRenderBody(dc)
+    local panel = self.subviews.list_panel
     local list = self.subviews.list
     local idx = list:getIdxUnderMouse()
     if idx and idx ~= self.last_mouse_idx then
@@ -173,8 +232,9 @@ function MenuScreen:onRenderBody(dc)
         list:setSelected(idx)
         self.mouseover = true
         self.last_mouse_idx = idx
-    elseif not idx and self.mouseover then
-        -- once the mouse has entered the list area, leaving it again should
+    elseif not panel:getMousePos(gui.ViewRect{rect=panel.frame_rect})
+            and self.mouseover then
+        -- once the mouse has entered the list area, leaving the frame should
         -- close the menu screen
         self:dismiss()
     end