Initial TUI mouse support

Implements an overridable tui_win_info::click method whose arguments
are the mouse coordinates inside the specific window, and the mouse
button clicked.

And if the curses implementation supports 5 buttons, the 4th and 5th
buttons are used for scrolling.

gdb/ChangeLog:

2021-06-04  Hannes Domani  <ssbssa@yahoo.de>

	* ser-mingw.c (console_select_thread): Handle MOUSE_EVENT.
	* tui/tui-data.h (struct tui_win_info): Add click function.
	* tui/tui-io.c (tui_prep_terminal): Enable mouse events.
	(tui_deprep_terminal): Disable mouse events.
	(tui_dispatch_ctrl_char): Handle KEY_MOUSE.
	* tui/tui.c (tui_disable): Disable mouse events.

gdb/ChangeLog

@@ -1,3 +1,12 @@
+2021-06-04  Hannes Domani  <ssbssa@yahoo.de>
+
+	* ser-mingw.c (console_select_thread): Handle MOUSE_EVENT.
+	* tui/tui-data.h (struct tui_win_info): Add click function.
+	* tui/tui-io.c (tui_prep_terminal): Enable mouse events.
+	(tui_deprep_terminal): Disable mouse events.
+	(tui_dispatch_ctrl_char): Handle KEY_MOUSE.
+	* tui/tui.c (tui_disable): Disable mouse events.
+
 2021-06-03  Magne Hov  <mhov@undo.io>
 
 	PR python/27841

gdb/ser-mingw.c

@@ -599,6 +599,11 @@ console_select_thread (void *arg)
 		  break;
 		}
 	    }
+	  else if (record.EventType == MOUSE_EVENT)
+	    {
+	      SetEvent (state->read_event);
+	      break;
+	    }
 
 	  /* Otherwise discard it and wait again.  */
 	  ReadConsoleInput (h, &record, 1, &n_records);

gdb/tui/tui-data.h

@@ -137,6 +137,13 @@ public:
     return true;
   }
 
+  /* Called for each mouse click inside this window.  Coordinates MOUSE_X
+     and MOUSE_Y are 0-based relative to the window, and MOUSE_BUTTON can
+     be 1 (left), 2 (middle), or 3 (right).  */
+  virtual void click (int mouse_x, int mouse_y, int mouse_button)
+  {
+  }
+
   void check_and_display_highlight_if_needed ();
 
   /* Window handle.  */

gdb/tui/tui-io.c

@@ -639,6 +639,9 @@ tui_redisplay_readline (void)
 static void
 tui_prep_terminal (int notused1)
 {
+#ifdef NCURSES_MOUSE_VERSION
+  mousemask (ALL_MOUSE_EVENTS, NULL);
+#endif
 }
 
 /* Readline callback to restore the terminal.  It is called once each
@@ -646,6 +649,9 @@ tui_prep_terminal (int notused1)
 static void
 tui_deprep_terminal (void)
 {
+#ifdef NCURSES_MOUSE_VERSION
+  mousemask (0, NULL);
+#endif
 }
 
 #ifdef TUI_USE_PIPE_FOR_READLINE
@@ -978,6 +984,37 @@ tui_dispatch_ctrl_char (unsigned int ch)
     case KEY_LEFT:
       win_info->right_scroll (1);
       break;
+#ifdef NCURSES_MOUSE_VERSION
+    case KEY_MOUSE:
+	{
+	  MEVENT mev;
+	  if (getmouse (&mev) != OK)
+	    break;
+
+	  for (tui_win_info *wi : all_tui_windows ())
+	    if (mev.x > wi->x && mev.x < wi->x + wi->width - 1
+		&& mev.y > wi->y && mev.y < wi->y + wi->height - 1)
+	      {
+		if ((mev.bstate & BUTTON1_CLICKED) != 0
+		    || (mev.bstate & BUTTON2_CLICKED) != 0
+		    || (mev.bstate & BUTTON3_CLICKED) != 0)
+		  {
+		    int button = (mev.bstate & BUTTON1_CLICKED) != 0 ? 1
+		      :         ((mev.bstate & BUTTON2_CLICKED) != 0 ? 2
+				 : 3);
+		    wi->click (mev.x - wi->x - 1, mev.y - wi->y - 1, button);
+		  }
+#ifdef BUTTON5_PRESSED
+		else if ((mev.bstate & BUTTON4_PRESSED) != 0)
+		  wi->backward_scroll (3);
+		else if ((mev.bstate & BUTTON5_PRESSED) != 0)
+		  wi->forward_scroll (3);
+#endif
+		break;
+	      }
+	}
+      break;
+#endif
     case '\f':
       break;
     default:

gdb/tui/tui.c

@@ -508,6 +508,10 @@ tui_disable (void)
   rl_startup_hook = 0;
   rl_already_prompted = 0;
 
+#ifdef NCURSES_MOUSE_VERSION
+  mousemask (0, NULL);
+#endif
+
   /* Leave curses and restore previous gdb terminal setting.  */
   endwin ();