Fl_Help_View: Refactor to use PIMPL

- using a Pointer to Implementation instead of having
a huge Fl_Help_View class. This improves build speed
(smaller header fiel) and allows us to fix the
implementation while keeping the ABI unchanged.

FL/Fl_Help_View.H

@@ -122,150 +122,12 @@ typedef const char *(Fl_Help_Func)(Fl_Widget *, const char *);
 */
 class FL_EXPORT Fl_Help_View : public Fl_Group
 {
-private: // classes, structs, and types
+private:
-
+  class Impl;
-  /** Private struct to describe blocks of text. */
+  std::unique_ptr<Impl> impl_;          ///< Pointer to the implementation details
-  struct Text_Block {
-    const char    *start;               // Start of text
-    const char    *end;                 // End of text
-    uchar         border;               // Draw border?
-    Fl_Color      bgcolor;              // Background color
-    int           x;                    // Indentation/starting X coordinate
-    int           y;                    // Starting Y coordinate
-    int           w;                    // Width
-    int           h;                    // Height
-    int           line[32];             // Left starting position for each line
-    int           ol;                   // is ordered list <OL> element
-    int           ol_num;               // item number in ordered list
-  };
-
-  /** Private class to hold a link with target and its position on screen. */
-  struct Link {
-    std::string   filename_;            // Filename part of a link
-    std::string   target;               // Target part of a link
-    Fl_Rect       box;                  // Clickable rectangle that defines the link area
-  };
-
-  /** Private font stack element definition. */
-  struct Font_Style {
-    Fl_Font       f;                    ///< Font
-    Fl_Fontsize   s;                    ///< Font Size
-    Fl_Color      c;                    ///< Font Color
-    Font_Style(Fl_Font afont, Fl_Fontsize asize, Fl_Color acolor);
-    Font_Style() = default;             ///< Default constructor
-    void          get(Fl_Font &afont, Fl_Fontsize &asize, Fl_Color &acolor);
-    void          set(Fl_Font afont, Fl_Fontsize asize, Fl_Color acolor);
-  };
-
-  /** Private class to hold font information on a stack. */
-  struct Font_Stack {
-    void          init(Fl_Font f, Fl_Fontsize s, Fl_Color c);
-    void          top(Fl_Font &f, Fl_Fontsize &s, Fl_Color &c);
-    void          push(Fl_Font f, Fl_Fontsize s, Fl_Color c);
-    void          pop(Fl_Font &f, Fl_Fontsize &s, Fl_Color &c);
-    size_t        count() const;
-  private:
-    std::vector<Font_Style> elts_;    ///< font elements
-  };
-
-  enum class Align { RIGHT = -1, CENTER, LEFT };  ///< Alignments
-  enum class Mode { DRAW, PUSH, DRAG };           ///< Draw modes
-
-private: // data members
-
-  // HTML source and raw data
-
-  const char    *value_;                ///< Copy of raw HTML text, as set by `value()` or `load()`
-  std::string   directory_;             ///< Directory for current document
-  std::string   filename_;              ///< Original file name from `load()`
-
-  // HTML document data
-
-  std::string   title_;                 ///< Title string from <title> tag
-  Font_Stack    fstack_;                ///< Font and style stack
-  std::vector<Text_Block> blocks_;      ///< List of all text blocks on screen
-  std::vector<std::shared_ptr<Link> > link_list_; ///< List of all clickable links and their position on screen
-  std::map<std::string, int> target_line_map_;    ///< List of vertical position of all HTML Targets in a document
-
-  int           topline_;               ///< Vertical offset of document, measure in pixels
-  int           leftline_;              ///< Horizontal offset of document, measure in pixels
-  int           size_;                  ///< Total document height in pixels
-  int           hsize_;                 ///< Maximum document width in pixels
-
-  // Default visual attributes
-
-  Fl_Color      defcolor_;              ///< Default text color, defaults to FL_FOREGROUND_COLOR
-  Fl_Color      bgcolor_;               ///< Background color, defaults to FL_BACKGROUND_COLOR
-  Fl_Color      textcolor_;             ///< Text color, defaults to FL_FOREGROUND_COLOR
-  Fl_Color      linkcolor_;             ///< Link color, FL_SELECTION_COLOR
-  Fl_Font       textfont_;              ///< Default font for text, FL_TIMES
-  Fl_Fontsize   textsize_;              ///< Default font size, defaults to 12, should be FL_NORMAL_SIZE
-
-  // Text selection and mouse handling
-
-  Mode          selection_mode_;        ///< Remember election mode between FL_PUSH, FL_DRAG, and FL_RELEASE
-  bool          selected_;              ///< True if there is text selected
-  int           selection_first_;       ///< First character of selection, offset in value_
-  int           selection_last_;        ///< Last character of selection, offset in value_
-  Fl_Color      tmp_selection_color_;   ///< Selection color during draw operation
-  Fl_Color      selection_text_color_;  ///< Selection text color during draw operation
-  // The following members are static because we need them only once during mouse events
-  static int    selection_push_first_;  ///< First character of selection during mouse down
-  static int    selection_push_last_;   ///< Last character of selection during mouse down
-  static int    selection_drag_first_;  ///< First character of selection during mouse drag
-  static int    selection_drag_last_;   ///< Last character of selection during mouse drag
-  static Mode   draw_mode_;             ///< Temporarily modify `draw()` method to measure selection start or end during `handle()`
-  static int    current_pos_;           ///< Temporarily store text offset while measuring during `handle()`
-
-  // Callback
-
-  Fl_Help_Func  *link_;                 ///< Link transform function
-
-  // Scrollbars
 
   Fl_Scrollbar  scrollbar_;             ///< Vertical scrollbar for document
   Fl_Scrollbar  hscrollbar_;            ///< Horizontal scrollbar
-  int           scrollbar_size_;        ///< Size for both scrollbars
-
-private: // methods
-
-  // HTML source and raw data, getter
-
-  void          free_data();
-  std::shared_ptr<Link> find_link(int, int);
-  void          follow_link(std::shared_ptr<Link>);
-
-  // HTML interpretation and formatting
-
-  Text_Block    *add_block(const char *s, int xx, int yy, int ww, int hh, uchar border = 0);
-  void          add_link(const std::string &link, int xx, int yy, int ww, int hh);
-  void          add_target(const std::string &n, int yy);
-  int           do_align(Text_Block *block, int line, int xx, Align a, int &l);
-  void          format();
-  void          format_table(int *table_width, int *columns, const char *table);
-  Align         get_align(const char *p, Align a);
-  const char    *get_attr(const char *p, const char *n, char *buf, int bufsize);
-  Fl_Color      get_color(const char *n, Fl_Color c);
-  Fl_Shared_Image *get_image(const char *name, int W, int H);
-  int           get_length(const char *l);
-
-  // Font and font stack
-
-  /// Initialize the font stack with default values.
-  void          initfont(Fl_Font &f, Fl_Fontsize &s, Fl_Color &c) { f = textfont_; s = textsize_; c = textcolor_; fstack_.init(f, s, c); }
-  /// Push the current font and size onto the stack.
-  void          pushfont(Fl_Font f, Fl_Fontsize s) {fstack_.push(f, s, textcolor_);}
-  /// Push the current font, size, and color onto the stack.
-  void          pushfont(Fl_Font f, Fl_Fontsize s, Fl_Color c) {fstack_.push(f, s, c);}
-  /// Get the current font, size, and color from the stack.
-  void          popfont(Fl_Font &f, Fl_Fontsize &s, Fl_Color &c) {fstack_.pop(f, s, c);}
-
-  // Text selection
-
-  void          hv_draw(const char *t, int x, int y, int entity_extra_length = 0);
-  char          begin_selection();
-  char          extend_selection();
-  void          end_selection();
 
 protected:
 
@@ -284,14 +146,12 @@ public:
 
   int           handle(int) override;
   void          resize(int,int,int,int) override;
-  /** Changes the size of the widget. \see Fl_Widget::size(int, int) */
   void          size(int W, int H) { Fl_Widget::size(W, H); }
 
   // HTML source and raw data
 
   void          value(const char *val);
-  /** Return a pointer to the internal text buffer. */
+  const char    *value() const;
-  const char    *value() const { return (value_); }
   int           load(const char *f);
   int           find(const char *s, int p = 0);
   void          link(Fl_Help_Func *fn);
@@ -302,27 +162,18 @@ public:
 
   // Rendering attributes
 
-  /** Return the document height in pixels. */
+  int           size() const;
-  int           size() const { return (size_); }
+  void          textcolor(Fl_Color c);
-  /** Set the default text color. */
+  Fl_Color      textcolor() const;
-  void          textcolor(Fl_Color c) { if (textcolor_ == defcolor_) textcolor_ = c; defcolor_ = c; }
+  void          textfont(Fl_Font f);
-  /** Return the current default text color. */
+  Fl_Font       textfont() const;
-  Fl_Color      textcolor() const { return (defcolor_); }
+  void          textsize(Fl_Fontsize s);
-  /** Set the default text font. */
+  Fl_Fontsize   textsize() const;
-  void          textfont(Fl_Font f) { textfont_ = f; format(); }
-  /** Return the default text font. */
-  Fl_Font       textfont() const { return (textfont_); }
-  /** Set the default text size. */
-  void          textsize(Fl_Fontsize s) { textsize_ = s; format(); }
-  /** Get the default text size. */
-  Fl_Fontsize   textsize() const { return (textsize_); }
   void          topline(const char *n);
   void          topline(int);
-  /** Get the current top line in pixels. */
+  int           topline() const;
-  int           topline() const { return (topline_); }
   void          leftline(int);
-  /** Get the left position in pixels. */
+  int           leftline() const;
-  int           leftline() const { return (leftline_); }
 
   // Text selection