1 ------------------------------------------------------------------------------
3 -- GNAT ncurses Binding Samples --
5 -- Sample.Explanation --
9 ------------------------------------------------------------------------------
10 -- Copyright 2019,2020 Thomas E. Dickey --
12 -- Permission is hereby granted, free of charge, to any person obtaining a --
13 -- copy of this software and associated documentation files (the --
14 -- "Software"), to deal in the Software without restriction, including --
15 -- without limitation the rights to use, copy, modify, merge, publish, --
16 -- distribute, distribute with modifications, sublicense, and/or sell --
17 -- copies of the Software, and to permit persons to whom the Software is --
18 -- furnished to do so, subject to the following conditions: --
20 -- The above copyright notice and this permission notice shall be included --
21 -- in all copies or substantial portions of the Software. --
23 -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS --
24 -- OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF --
25 -- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. --
26 -- IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, --
27 -- DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR --
28 -- OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR --
29 -- THE USE OR OTHER DEALINGS IN THE SOFTWARE. --
31 -- Except as contained in this notice, the name(s) of the above copyright --
32 -- holders shall not be used in advertising or otherwise to promote the --
33 -- sale, use or other dealings in this Software without prior written --
35 ------------------------------------------------------------------------------
36 -- Author: Juergen Pfeifer, 1996
39 -- $Date: 2020/02/02 23:34:34 $
40 -- Binding Version 01.00
41 ------------------------------------------------------------------------------
42 -- Poor mans help system. This scans a sequential file for key lines and
43 -- then reads the lines up to the next key. Those lines are presented in
44 -- a window as help or explanation.
46 with Ada.Text_IO; use Ada.Text_IO;
47 with Ada.Unchecked_Deallocation;
48 with Terminal_Interface.Curses; use Terminal_Interface.Curses;
49 with Terminal_Interface.Curses.Panels; use Terminal_Interface.Curses.Panels;
51 with Sample.Keyboard_Handler; use Sample.Keyboard_Handler;
52 with Sample.Manifest; use Sample.Manifest;
53 with Sample.Function_Key_Setting; use Sample.Function_Key_Setting;
54 with Sample.Helpers; use Sample.Helpers;
56 package body Sample.Explanation is
58 Help_Keys : constant String := "HELPKEYS";
59 In_Help : constant String := "INHELP";
61 File_Name : constant String := "explain.txt";
65 type Help_Line_Access is access Help_Line;
66 pragma Controlled (Help_Line_Access);
67 type String_Access is access String;
68 pragma Controlled (String_Access);
72 Prev, Next : Help_Line_Access;
76 procedure Explain (Key : String;
79 procedure Release_String is
80 new Ada.Unchecked_Deallocation (String,
82 procedure Release_Help_Line is
83 new Ada.Unchecked_Deallocation (Help_Line,
86 function Search (Key : String) return Help_Line_Access;
87 procedure Release_Help (Root : in out Help_Line_Access);
89 function Check_File (Name : String) return Boolean;
91 procedure Explain (Key : String)
94 Explain (Key, Null_Window);
97 procedure Explain (Key : String;
100 -- Retrieve the text associated with this key and display it in this
101 -- window. If no window argument is passed, the routine will create
102 -- a temporary window and use it.
104 function Filter_Key return Real_Key_Code;
105 procedure Unknown_Key;
107 procedure To_Window (C : in out Help_Line_Access;
108 More : in out Boolean);
110 Frame : Window := Null_Window;
117 Width : Column_Count;
118 Help : Help_Line_Access := Search (Key);
119 Current : Help_Line_Access;
120 Top_Line : Help_Line_Access;
122 Has_More : Boolean := True;
124 procedure Unknown_Key
127 Add (W, "Help message with ID ");
129 Add (W, " not found.");
130 Add (W, Character'Val (10));
131 Add (W, "Press the Function key labeled 'Quit' key to continue.");
136 H : Help_Line_Access := Top_Line;
138 if Top_Line /= null then
139 for L in 0 .. (Height - 1) loop
140 Add (W, L, 0, H.all.Line.all);
141 exit when H.all.Next = null;
149 function Filter_Key return Real_Key_Code
155 if K in Special_Key_Code'Range then
158 if not Find_Context (In_Help) then
159 Push_Environment (In_Help, False);
160 Explain (In_Help, W);
165 if not Find_Context (Help_Keys) then
166 Push_Environment (Help_Keys, False);
167 Explain (Help_Keys, W);
180 procedure To_Window (C : in out Help_Line_Access;
181 More : in out Boolean)
183 L : Line_Position := 0;
186 Add (W, L, 0, C.all.Line.all);
188 exit when C.all.Next = null or else L = Height;
191 if C.all.Next /= null then
192 pragma Assert (L = Height);
200 if W = Null_Window then
201 Push_Environment ("HELP");
203 Frame := New_Window (Lines - 2, Columns, 0, 0);
205 Set_Background (Win => Frame,
208 Attr => Normal_Video));
209 Set_Character_Attributes (Win => Frame,
210 Attr => Normal_Video,
211 Color => Help_Color);
215 Set_Character_Attributes (Frame, (Reverse_Video => True,
217 Add (Frame, Lines - 3, 2, "Cursor Up/Down scrolls");
218 Set_Character_Attributes (Frame); -- Back to default.
219 Window_Title (Frame, "Explanation");
220 W := Derived_Window (Frame, Lines - 4, Columns - 2, 1, 1);
221 Refresh_Without_Update (Frame);
222 Get_Size (W, Height, Width);
225 Allow_Scrolling (W, True);
226 Set_Echo_Mode (False);
232 Refresh_Without_Update (W);
235 Current := Help; Top_Line := Help;
241 exit when K = QUIT_CODE;
244 To_Window (Current, Has_More);
246 -- This means there are more lines available, so we have to go
247 -- into a scroll manager.
250 if K in Special_Key_Code'Range then
252 when Key_Cursor_Down =>
253 if Current.all.Next /= null then
254 Move_Cursor (W, Height - 1, 0);
256 Current := Current.all.Next;
257 Top_Line := Top_Line.all.Next;
258 Add (W, Current.all.Line.all);
260 when Key_Cursor_Up =>
261 if Top_Line.all.Prev /= null then
262 Move_Cursor (W, 0, 0);
264 Top_Line := Top_Line.all.Prev;
265 Current := Current.all.Prev;
266 Add (W, Top_Line.all.Line.all);
268 when QUIT_CODE => exit;
276 exit when K = QUIT_CODE;
283 if Frame /= Null_Window then
298 function Search (Key : String) return Help_Line_Access
301 Buffer : String (1 .. 256);
302 Root : Help_Line_Access := null;
303 Current : Help_Line_Access;
304 Tail : Help_Line_Access := null;
306 function Next_Line return Boolean;
308 function Next_Line return Boolean
310 H_End : constant String := "#END";
312 Get_Line (F, Buffer, Last);
313 if Last = H_End'Length and then H_End = Buffer (1 .. Last) then
323 exit Outer when not Next_Line;
324 if Last = (1 + Key'Length)
325 and then Key = Buffer (2 .. Last)
326 and then Buffer (1) = '#'
329 exit when not Next_Line;
330 exit when Buffer (1) = '#';
331 Current := new Help_Line'(null, null,
332 new String'(Buffer (1 .. Last)));
337 Tail.all.Next := Current;
338 Current.all.Prev := Tail;
348 procedure Release_Help (Root : in out Help_Line_Access)
350 Next : Help_Line_Access;
353 exit when Root = null;
354 Next := Root.all.Next;
355 Release_String (Root.all.Line);
356 Release_Help_Line (Root);
361 procedure Explain_Context
367 procedure Notepad (Key : String)
369 H : constant Help_Line_Access := Search (Key);
370 T : Help_Line_Access := H;
372 L : Line_Position := 0;
382 W := New_Window (N + 2, Columns, Lines - N - 2, 0);
384 Set_Background (Win => W,
386 Color => Notepad_Color,
387 Attr => Normal_Video));
388 Set_Character_Attributes (Win => W,
389 Attr => Normal_Video,
390 Color => Notepad_Color);
394 Window_Title (W, "Notepad");
398 Add (W, L + 1, 1, T.all.Line.all, Integer (Columns - 2));
405 Refresh_Without_Update (W);
406 Notepad_To_Context (P);
410 function Check_File (Name : String) return Boolean is
411 The_File : File_Type;
413 Open (The_File, In_File, Name);
429 elsif Check_File (File_Name) then
430 Open (F, In_File, File_Name);
432 Put_Line (Standard_Error,
435 & " was not found in "
440 end Sample.Explanation;