Add mouse event handling to classic terminal and avoid threads

Using `ReadConsoleInput` the mouse inputs work for conhost.exe as well.

Stopping the threads when calling out per `Kernel.system` is a problem, since they continue to run and eat the input characters of sub-processes.
This can be avoided by not using threads in favour of a single main_loop.

Author: larskanis

lib/ruby_installer/runtime/console_ui.rb

@@ -1,3 +1,4 @@
+require "stringio"
 require "io/console"
 require "fiddle"
 require "fiddle/import"
@@ -175,23 +176,26 @@ def repaint(width: @con.winsize[1], height: @con.winsize[0])
     ENABLE_QUICK_EDIT_MODE = 0x0040
     ENABLE_EXTENDED_FLAGS = 0x0080
     ENABLE_VIRTUAL_TERMINAL_INPUT = 0x200
+    KEY_EVENT = 0x01
+    MOUSE_EVENT = 0x02
+    WINDOW_BUFFER_SIZE_EVENT = 0x04
 
     attr_accessor :widget
 
     def initialize
       @GetStdHandle = Win32API.new('kernel32', 'GetStdHandle', ['L'], 'L')
       @GetConsoleMode = Win32API.new('kernel32', 'GetConsoleMode', ['L', 'P'], 'L')
       @SetConsoleMode = Win32API.new('kernel32', 'SetConsoleMode', ['L', 'L'], 'L')
+      @ReadConsoleInputW = Win32API.new('kernel32', 'ReadConsoleInputW', ['L', 'P', 'L', 'P'], 'L')
+      @GetConsoleScreenBufferInfo = Win32API.new('kernel32', 'GetConsoleScreenBufferInfo', ['L', 'P'], 'L')
 
       @hConsoleHandle = @GetStdHandle.call(STD_INPUT_HANDLE)
-      @ev_r, @ev_w = IO.pipe.map(&:binmode)
-      @read_request_queue = Thread::Queue.new
+      @hConsoleOutHandle = @GetStdHandle.call(STD_OUTPUT_HANDLE)
 
+      @mouse_state = 0
+      @old_winsize = IO.console.winsize
       set_consolemode
 
-      register_term_size_change
-      register_stdin
-
       at_exit do
         unset_consolemode
       end
@@ -240,49 +244,90 @@ def unset_consolemode
       call_with_console_handle(@SetConsoleMode, mode)
     end
 
-    private def register_term_size_change
-      if RUBY_PLATFORM =~ /mingw|mswin/
-        con = IO.console
-        old_size = con.winsize
-        Thread.new do
-          loop do
-            new_size = con.winsize
-            if old_size != new_size
-              old_size = new_size
-              @ev_w.write "\x01"
-            end
-            sleep 1
-          end
-        end
+    def get_console_screen_buffer_info
+      # CONSOLE_SCREEN_BUFFER_INFO
+      # [ 0,2] dwSize.X
+      # [ 2,2] dwSize.Y
+      # [ 4,2] dwCursorPositions.X
+      # [ 6,2] dwCursorPositions.Y
+      # [ 8,2] wAttributes
+      # [10,2] srWindow.Left
+      # [12,2] srWindow.Top
+      # [14,2] srWindow.Right
+      # [16,2] srWindow.Bottom
+      # [18,2] dwMaximumWindowSize.X
+      # [20,2] dwMaximumWindowSize.Y
+      csbi = 0.chr * 22
+      if @GetConsoleScreenBufferInfo.call(@hConsoleOutHandle, csbi) != 0
+        # returns [width, height, x, y, attributes, left, top, right, bottom]
+        csbi.unpack("s9")
       else
-        Signal.trap('SIGWINCH') do
-          @ev_w.write "\x01"
-        end
+        return nil
       end
     end
 
-    private def register_stdin
-      Thread.new do
-        str = +""
-        @read_request_queue.shift
-        c = IO.console
-        while char=c.read(1)
-          str << char
-          next if !str.valid_encoding? ||
-              str == "\e" ||
-              str == "\e[" ||
-              str == "\xE0" ||
-              str.match(/\A\e\x5b<[0-9;]*\z/)
+    private def winsize_changed?
+      con = IO.console
+      new_size = con.winsize
+      if @old_winsize != new_size
+        @old_winsize = new_size
+        true
+      else
+        false
+      end
+    end
 
-          @ev_w.write [2, str.size, str].pack("CCa*")
-          str = +""
-          @read_request_queue.shift
+    def read_input_event
+      # Wait for reception of at least one event
+      input_records = 0.chr * 20 * 1
+      read_event = 0.chr * 4
+
+      if @ReadConsoleInputW.(@hConsoleHandle, input_records, 1, read_event) != 0
+        read_events = read_event.unpack1('L')
+        0.upto(read_events-1) do |idx|
+          input_record = input_records[idx * 20, 20]
+          event = input_record[0, 2].unpack1('s*')
+          case event
+          when KEY_EVENT
+            key_down = input_record[4, 4].unpack1('l*')
+            repeat_count = input_record[8, 2].unpack1('s*')
+            virtual_key_code = input_record[10, 2].unpack1('s*')
+            virtual_scan_code = input_record[12, 2].unpack1('s*')
+            char_code = input_record[14, 2].unpack1('S*')
+            control_key_state = input_record[16, 2].unpack1('S*')
+            is_key_down = key_down.zero? ? false : true
+            if is_key_down
+              # p [repeat_count, virtual_key_code, virtual_scan_code, char_code, control_key_state]
+
+              return char_code.chr
+            end
+          when MOUSE_EVENT
+            click_x, click_y, state = input_record[4, 8].unpack("ssL")
+            if @mouse_state != state
+              # click state changed
+              @mouse_state = state
+              csbi = get_console_screen_buffer_info || raise("error at GetConsoleScreenBufferInfo")
+              click_y -= csbi[6]
+              # p mouse: [click_x, click_y, state]
+
+              if state == 1
+                # mouse button down
+                return "\e\x5b<0;#{click_x};#{click_y}M"
+              else
+                # mouse button up
+                return "\e\x5b<0;#{click_x};#{click_y}m"
+              end
+            end
+          when WINDOW_BUFFER_SIZE_EVENT
+            return :winsize_changed
+          end
         end
       end
+      false
     end
 
-    private def request_read
-      @read_request_queue.push true
+    private def windows_terminal?
+      !!ENV["WT_SESSION"]
     end
 
     private def handle_key_input(str)
@@ -299,35 +344,56 @@ def unset_consolemode
         unset_consolemode do
           widget.select
         end
-      when /\e\x5b<0;(\d+);(\d+)m/ # Mouse left button up
+      when /\A\e\x5b<0;(\d+);(\d+)m\z/ # Mouse left button up
         if widget.click($1.to_i - 1, $2.to_i - 2)
           widget.repaint
           unset_consolemode do
             widget.select
           end
         end
-      when /\e\x5b<\d+;(\d+);(\d+)[Mm]/ # other mouse events
+      when /\A\e\x5b<\d+;(\d+);(\d+)[Mm]\z/ # other mouse events
         return # no repaint
       end
       widget.repaint
     end
 
     private def main_loop
       str = +""
-      request_read
-      while char=@ev_r.read(1)
-        case char
-        when "\x01"
-          widget.repaint
-        when "\x02"
-          strlen = @ev_r.read(1).unpack1("C")
-          str = @ev_r.read(strlen)
-
-          handle_key_input(str)
+      console_buffer = StringIO.new
+      loop do
+        if windows_terminal?
+          c = IO.console
+
+          rs, = IO.select([c], [], [], 0.5)
+          if rs
+            char = c.read(1)
+            break unless char
+          else
+            # timeout -> check windows size change
+            widget.repaint if winsize_changed?
+          end
         else
-          raise "unexpected event: #{char.inspect}"
+          if console_buffer.eof?
+            input = read_input_event
+            if input == :winsize_changed
+              widget.repaint if winsize_changed?
+            elsif input
+              console_buffer = StringIO.new(input)
+            end
+          end
+          char = console_buffer.read(1)
         end
-        request_read
+        next unless char
+        str << char
+
+        next if !str.valid_encoding? ||
+              str == "\e" ||
+              str == "\e[" ||
+              str == "\xE0" ||
+              str.match(/\A\e\x5b<[0-9;]*\z/)
+
+        handle_key_input(str)
+        str = +""
       end
     end
 

resources/files/startmenu.rb

@@ -2,7 +2,7 @@
 
 app = RubyInstaller::Runtime::ConsoleUi.new
 bm = RubyInstaller::Runtime::ConsoleUi::ButtonMatrix.new ncols: 3
-bm.headline = "Ruby startmenu  -  Choose item by #{ENV["WT_SESSION"] && "mouse or "}cursor keys and press Enter"
+bm.headline = "Ruby startmenu  -  Choose item by mouse or cursor keys and press Enter"
 
 bt = <<~EOT
   irb:>