Adds `linespacing()` to `Fl_Browser_` and all derived widgets

FL/Fl_Browser_.H

@@ -96,6 +96,7 @@ class FL_EXPORT Fl_Browser_ : public Fl_Group {
   void *redraw1,*redraw2; // minimal update pointers
   void* max_width_item; // which item has max_width_
   int scrollbar_size_;  // size of scrollbar trough
+  int linespacing_;
 
   void update_top();
 
@@ -400,6 +401,17 @@ public:
   */
   void scrollbar_left() { scrollbar.align(FL_ALIGN_LEFT); }
   void sort(int flags=0);
+
+  /**
+   Add some space between browser lines.
+   \param[in] pixels number of additional pixels between lines.
+   */
+  void linespacing(int pixels) { linespacing_ = pixels; }
+
+  /** Return the height of additional spacing between browser lines.
+   \return spacing height in pixel units.
+   */
+  int linespacing() const { return linespacing_; }
 };
 
 #endif

FL/Fl_File_Browser.H

@@ -46,7 +46,7 @@ class FL_EXPORT Fl_File_Browser : public Fl_Browser {
   int   item_height(void *) const FL_OVERRIDE;
   int   item_width(void *) const FL_OVERRIDE;
   void  item_draw(void *, int, int, int, int) const FL_OVERRIDE;
-  int   incr_height() const FL_OVERRIDE { return (item_height(0)); }
+  int   incr_height() const FL_OVERRIDE { return (item_height(0) + linespacing()); }
 
 public:
   enum { FILES, DIRECTORIES };

fltk-options/fltk-options.cxx

@@ -644,6 +644,7 @@ Fl_Window* build_ui() {
                                            "Groups");
   g_headline_browser->align(FL_ALIGN_TOP);
   g_headline_browser->textsize(FL_NORMAL_SIZE+1);
+  g_headline_browser->linespacing(4);
   add_headlines(g_headline_browser);
   // -- scrollable area for all options inside a group
   g_option_scroll = new Fl_Scroll(FO_GAP + FO_BROWSER_W + FO_GAP, FO_GAP + FO_TITLE_H,

fluid/widget_browser.cxx

@@ -252,7 +252,7 @@ int Widget_Browser::item_height(void *l) const {
  \return height in FLTK units
  */
 int Widget_Browser::incr_height() const {
-  return textsize()+5;
+  return textsize() + 5 + linespacing();
 }
 
 /**
@@ -552,15 +552,15 @@ void Widget_Browser::display(Fl_Type *inNode) {
   Fl_Type *p=Fl_Type::first;
   for ( ; p && p!=inNode; p=p->next) {
     if (p->visible)
-      nodeV += item_height(p);
+      nodeV += item_height(p) + linespacing();
   }
   if (p) {
     int xx, yy, ww, hh;
     bbox(xx, yy, ww, hh);
     int frame_top = xx-x();
     int frame_bottom = frame_top + hh;
-    int node_height = item_height(inNode);
-    int margin_height = 2 * item_quick_height(inNode);
+    int node_height = item_height(inNode) + linespacing();
+    int margin_height = 2 * (item_quick_height(inNode) + linespacing());
     if (margin_height>hh/2) margin_height = hh/2;
     // is the inNode above the current scroll position?
     if (nodeV<currentV+margin_height)

src/Fl_Browser.cxx

@@ -208,7 +208,7 @@ FL_BLINE* Fl_Browser::_remove(int line) {
   cacheline = line-1;
   cache = ttt->prev;
   lines--;
-  full_height_ -= item_height(ttt);
+  full_height_ -= item_height(ttt) + linespacing();
   if (ttt->prev) ttt->prev->next = ttt->next;
   else first = ttt->next;
   if (ttt->next) ttt->next->prev = ttt->prev;
@@ -264,7 +264,7 @@ void Fl_Browser::insert(int line, FL_BLINE* item) {
   cacheline = line;
   cache = item;
   lines++;
-  full_height_ += item_height(item);
+  full_height_ += item_height(item) + linespacing();
   redraw_line(item);
 }
 
@@ -489,7 +489,7 @@ int Fl_Browser::full_height() const {
        incr_height(), full_height()
 */
 int Fl_Browser::incr_height() const {
-  return textsize()+2;
+  return textsize() + 2 + linespacing();
 }
 
 /**
@@ -620,9 +620,9 @@ void Fl_Browser::lineposition(int line, Fl_Line_Position pos) {
 
   FL_BLINE* l;
   for (l=first; l && line>1; l = l->next) {
-    line--; p += item_height(l);
+    line--; p += item_height(l) + linespacing();
   }
-  if (l && (pos == BOTTOM)) p += item_height (l);
+  if (l && (pos == BOTTOM)) p += item_height(l) + linespacing();
 
   int final = p, X, Y, W, H;
   bbox(X, Y, W, H);
@@ -670,7 +670,7 @@ void Fl_Browser::textsize(Fl_Fontsize newSize) {
   full_height_ = 0;
   if (lines == 0) return;
   for (FL_BLINE* itm=(FL_BLINE *)item_first(); itm; itm=(FL_BLINE *)item_next(itm)) {
-    full_height_ += item_height(itm);
+    full_height_ += item_height(itm) + linespacing();
   }
 }
 
@@ -769,7 +769,7 @@ void Fl_Browser::show(int line) {
   FL_BLINE* t = find_line(line);
   if (t->flags & NOTDISPLAYED) {
     t->flags &= ~NOTDISPLAYED;
-    full_height_ += item_height(t);
+    full_height_ += item_height(t) + linespacing();
     if (Fl_Browser_::displayed(t)) redraw();
   }
 }
@@ -786,7 +786,7 @@ void Fl_Browser::show(int line) {
 void Fl_Browser::hide(int line) {
   FL_BLINE* t = find_line(line);
   if (!(t->flags & NOTDISPLAYED)) {
-    full_height_ -= item_height(t);
+    full_height_ -= item_height(t) + linespacing();
     t->flags |= NOTDISPLAYED;
     if (Fl_Browser_::displayed(t)) redraw();
   }

src/Fl_Browser_.cxx

@@ -148,13 +148,13 @@ void Fl_Browser_::update_top() {
       offset_ = 0;
       real_position_ = 0;
     } else {
-      int hh = item_quick_height(l);
+      int hh = item_quick_height(l) + linespacing();
       // step through list until we find line containing this point:
       while (ly > yy) {
         void* l1 = item_prev(l);
         if (!l1) {ly = 0; break;} // hit the top
         l  = l1;
-        hh = item_quick_height(l);
+        hh = item_quick_height(l) + linespacing();
         ly -= hh;
       }
       while ((ly+hh) <= yy) {
@@ -162,16 +162,16 @@ void Fl_Browser_::update_top() {
         if (!l1) {yy = ly+hh-1; break;}
         l = l1;
         ly += hh;
-        hh = item_quick_height(l);
+        hh = item_quick_height(l) + linespacing();
       }
       // top item must *really* be visible, use slow height:
       for (;;) {
-        hh = item_height(l);
+        hh = item_height(l) + linespacing();
         if ((ly+hh) > yy) break; // it is big enough to see
         // go up to top of previous item:
         void* l1 = item_prev(l);
         if (!l1) {ly = yy = 0; break;} // hit the top
-        l = l1; yy = position_ = ly = ly-item_quick_height(l);
+        l = l1; yy = position_ = ly = ly-item_quick_height(l) + linespacing();
       }
       // use it:
       top_ = l;
@@ -229,7 +229,7 @@ int Fl_Browser_::displayed(void* item) const {
   int yy = H+offset_;
   for (void* l = top_; l && yy > 0; l = item_next(l)) {
     if (l == item) return 1;
-    yy -= item_height(l);
+    yy -= item_height(l) + linespacing();
   }
   return 0;
 }
@@ -257,7 +257,7 @@ void Fl_Browser_::display(void* item) {
 
   // 3rd special case - want to display item just above top of browser?
   void* lp = item_prev(l);
-  if (lp == item) { vposition(real_position_+Y-item_quick_height(lp)); return; }
+  if (lp == item) { vposition(real_position_+Y-item_quick_height(lp)-linespacing()); return; }
 
 #ifdef DISPLAY_SEARCH_BOTH_WAYS_AT_ONCE
   // search for item.  We search both up and down the list at the same time,
@@ -265,7 +265,7 @@ void Fl_Browser_::display(void* item) {
   // much slower for going up than for going down.
   while (l || lp) {
     if (l) {
-      h1 = item_quick_height(l);
+      h1 = item_quick_height(l) + linespacing();
       if (l == item) {
         if (Y <= H) { // it is visible or right at bottom
           Y = Y+h1-H; // find where bottom edge is
@@ -279,7 +279,7 @@ void Fl_Browser_::display(void* item) {
       l = item_next(l);
     }
     if (lp) {
-      h1 = item_quick_height(lp);
+      h1 = item_quick_height(lp) + linespacing();
       Yp -= h1;
       if (lp == item) {
         if ((Yp + h1) >= 0) vposition(real_position_+Yp);
@@ -294,7 +294,7 @@ void Fl_Browser_::display(void* item) {
   // search forward for it:
   l = top_;
   for (; l; l = item_next(l)) {
-    h1 = item_quick_height(l);
+    h1 = item_quick_height(l) + linespacing();
     if (l == item) {
       if (Y <= H) { // it is visible or right at bottom
         Y = Y+h1-H; // find where bottom edge is
@@ -310,7 +310,7 @@ void Fl_Browser_::display(void* item) {
   l = lp;
   Y = -offset_;
   for (; l; l = item_prev(l)) {
-    h1 = item_quick_height(l);
+    h1 = item_quick_height(l) + linespacing();
     Y -= h1;
     if (l == item) {
       if ((Y + h1) >= 0) position(real_position_+Y);
@@ -395,7 +395,7 @@ J1:
   void* l = top();
   int yy = -offset_;
   for (; l && yy < H; l = item_next(l)) {
-    int hh = item_height(l);
+    int hh = item_height(l) + linespacing();
     if (hh <= 0) continue;
     if ((damage()&(FL_DAMAGE_SCROLL|FL_DAMAGE_ALL)) || l == redraw1 || l == redraw2) {
       if (item_selected(l)) {
@@ -448,7 +448,7 @@ J1:
 
   // update the scrollbars and redraw them:
   int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
-  int dy = top_ ? item_quick_height(top_) : 0; if (dy < 10) dy = 10;
+  int dy = top_ ? item_quick_height(top_) + linespacing() : 0; if (dy < 10) dy = 10;
   if (scrollbar.visible()) {
     scrollbar.damage_resize(
         scrollbar.align()&FL_ALIGN_LEFT ? X-scrollsize : X+W,
@@ -585,7 +585,7 @@ void* Fl_Browser_::find_item(int ypos) {
   int yy = Y-offset_;
   for (void *l = top_; l; l = item_next(l)) {
     int hh = item_height(l); if (hh <= 0) continue;
-    yy += hh;
+    yy += hh + linespacing();
     if (ypos <= yy || yy>=(Y+H)) return l;
   }
   return 0;
@@ -954,7 +954,8 @@ J1:
 Fl_Browser_::Fl_Browser_(int X, int Y, int W, int H, const char* L)
   : Fl_Group(X, Y, W, H, L),
     scrollbar(0, 0, 0, 0, 0), // they will be resized by draw()
-    hscrollbar(0, 0, 0, 0, 0)
+    hscrollbar(0, 0, 0, 0, 0),
+    linespacing_(0)
 {
   box(FL_NO_BOX);
   align(FL_ALIGN_BOTTOM);
@@ -1053,7 +1054,7 @@ int Fl_Browser_::item_quick_height(void* item) const {
   \returns The average height of items, in pixels.
 */
 int Fl_Browser_::incr_height() const {
-  return item_quick_height(item_first());
+  return item_quick_height(item_first()) + linespacing();
 }
 
 /**

src/Fl_Check_Browser.cxx

@@ -176,7 +176,8 @@ int Fl_Check_Browser::item_width(void *v) const {
   return int(fl_width(((cb_item *)v)->text)) + CHECK_SIZE + 8;
 }
 
-void Fl_Check_Browser::item_draw(void *v, int X, int Y, int, int) const {
+void Fl_Check_Browser::item_draw(void *v, int X, int Y, int, int H) const {
+  Y += (H - item_height(v)) / 2;
   cb_item *i = (cb_item *)v;
   char *s = i->text;
   int tsize = textsize();

src/Fl_File_Browser.cxx

@@ -76,7 +76,7 @@ Fl_File_Browser::full_height() const
 
 
   for (i = 0, th = 0; i < size(); i ++)
-    th += item_height(find_line(i));
+    th += item_height(find_line(i)) + linespacing();
 
   return (th);
 }
@@ -234,7 +234,7 @@ Fl_File_Browser::item_draw(void *p,     // I - List item data
                            int  X,      // I - Upper-lefthand X coordinate
                            int  Y,      // I - Upper-lefthand Y coordinate
                            int  W,      // I - Width of item
-                           int) const   // I - Height of item
+                           int  H) const// I - Height of item
 {
   int           i;                      // Looping var
   FL_BLINE      *line;                  // Pointer to line
@@ -271,25 +271,23 @@ Fl_File_Browser::item_draw(void *p,     // I - List item data
   {
     // Draw the icon if it is set...
     if (line->data)
-      ((Fl_File_Icon *)line->data)->draw(X, Y, iconsize_, iconsize_,
-                                        (line->flags & SELECTED) ? FL_YELLOW :
+      ((Fl_File_Icon *)line->data)->draw(X, Y + (H - iconsize_) / 2,
+                                         iconsize_, iconsize_,
+                                         (line->flags & SELECTED) ? FL_YELLOW :
                                                                    FL_LIGHT2,
-                                        active_r());
+                                         active_r());
 
     // Draw the text offset to the right...
     X += iconsize_ + 9;
     W -= iconsize_ - 10;
-
-    // Center the text vertically...
-    height = fl_height();
-
-    for (t = line->txt; *t != '\0'; t ++)
-      if (*t == '\n')
-        height += fl_height();
-
-    if (height < iconsize_)
-      Y += (iconsize_ - height) / 2;
   }
+  // Center the text vertically...
+  height = fl_height();
+
+  for (t = line->txt; *t != '\0'; t ++)
+    if (*t == '\n')
+      height += fl_height();
+  Y += (H - height) / 2;
 
   // Draw the text...
   line    = (FL_BLINE *)p;

test/grid_dialog.cxx

@@ -86,7 +86,7 @@ void button_cb(Fl_Widget *w, void *v) {
       break;
     case 1: {               // Copy
         const char *text = message_box->label();
-        const int len = strlen(text);
+        const int len = (int)strlen(text);
         Fl::copy(text, len, 1);
       }
       printf("Message copied to clipboard.\n");

test/unittests.cxx

@@ -454,6 +454,7 @@ int main(int argc, char** argv) {
   browser->align(FL_ALIGN_TOP|FL_ALIGN_LEFT);
   browser->when(FL_WHEN_CHANGED);
   browser->callback(ui_browser_cb);
+  browser->linespacing(2);
 
   int n = UnitTest::num_tests();
   for (i=0; i<n; i++) {