IMPLEMENTATION MODULE GtkDemo ;

FROM DemoImpl IMPORT DoLinks, DoListBox, DoFlowBox, DoExpander, DoCss;
FROM SYSTEM IMPORT ADDRESS;

TYPE
   Demo = RECORD
      title: ARRAY [0..63] OF CHAR;
      keywords: ARRAY [0..127] OF CHAR;
      build: BuildProc;
   END;

VAR
   demos: ARRAY [0..31] OF Demo;
   n: CARDINAL;

PROCEDURE Copy (VAR dst: ARRAY OF CHAR; src: ARRAY OF CHAR);
VAR
   i: CARDINAL;
BEGIN
   i := 0;
   WHILE (i < HIGH(dst)) AND (i <= HIGH(src)) AND (src[i] # 0C) DO
      dst[i] := src[i];
      INC(i)
   END;
   dst[i] := 0C
END Copy;

PROCEDURE Equal (a, b: ARRAY OF CHAR) : BOOLEAN;
VAR
   i: CARDINAL;
BEGIN
   i := 0;
   WHILE (a[i] # 0C) AND (b[i] # 0C) DO
      IF a[i] # b[i] THEN RETURN FALSE END;
      INC(i)
   END;
   RETURN a[i] = b[i]
END Equal;

PROCEDURE Register (title, keywords: ARRAY OF CHAR; build: BuildProc);
BEGIN
   IF n <= HIGH(demos) THEN
      Copy(demos[n].title, title);
      Copy(demos[n].keywords, keywords);
      demos[n].build := build;
      INC(n)
   END
END Register;

PROCEDURE Count () : CARDINAL;
BEGIN
   RETURN n
END Count;

PROCEDURE TitleOf (i: CARDINAL; VAR title: ARRAY OF CHAR);
BEGIN
   IF i < n THEN Copy(title, demos[i].title) ELSE title[0] := 0C END
END TitleOf;

PROCEDURE KeywordsOf (i: CARDINAL; VAR keywords: ARRAY OF CHAR);
BEGIN
   IF i < n THEN Copy(keywords, demos[i].keywords) ELSE keywords[0] := 0C END
END KeywordsOf;

PROCEDURE BuildByTitle (title: ARRAY OF CHAR; doWidget: ADDRESS) : ADDRESS;
VAR
   i: CARDINAL;
   buf: ARRAY [0..63] OF CHAR;
BEGIN
   i := 0;
   WHILE i < n DO
      TitleOf(i, buf);
      IF Equal(buf, title) THEN RETURN demos[i].build(doWidget) END;
      INC(i)
   END;
   RETURN NIL
END BuildByTitle;

BEGIN
   n := 0;
   Register("Links", "hyperlinks markup label uri anchor", DoLinks);
   Register("List Box", "list rows selection box", DoListBox);
   Register("Flow Box", "flow grid reflow colors swatches", DoFlowBox);
   Register("Expander", "disclosure triangle expand collapse", DoExpander);
   Register("CSS Basics", "css styling theme provider", DoCss)
END GtkDemo.