o Added Fl_Tree::item_draw_callback(), letting one define a custom draw function for Fl_Tree_Item's.

o Added examples/tree-custom-draw-items.cxx to demonstrate its use.
o Fixed small doc error for recent Fl_Tree::get_selected_items()



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10018 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

3 files changed, 96 insertions, 36 deletions

diff --git a/src/Fl_Tree.cxx b/src/Fl_Tree.cxx
index ba37dab3f..455aba716 100644
--- a/src/Fl_Tree.cxx
+++ b/src/Fl_Tree.cxx
@@ -936,7 +936,7 @@ Fl_Tree_Item *Fl_Tree::next_selected_item(Fl_Tree_Item *item) {
 ///       ..do stuff with each selected item..
 ///   }
 /// \endcode
-/// \param[in] items The returned array of selected items.
+/// \param[in] ret_items The returned array of selected items.
 /// \returns The number of items in the returned array.
 /// \see first_selected_item(), next_selected_item()
 ///
@@ -1787,7 +1787,9 @@ Fl_Tree_Item_Reselect_Mode Fl_Tree::item_reselect_mode() const {
 void Fl_Tree::item_reselect_mode(Fl_Tree_Item_Reselect_Mode mode) {
   _prefs.item_reselect_mode(mode);
 }
+#endif
 
+#if FLTK_ABI_VERSION >= 10303
 /// Get the 'item draw mode' used for the tree
 Fl_Tree_Item_Draw_Mode Fl_Tree::item_draw_mode() const {
   return(_prefs.item_draw_mode());
@@ -1804,7 +1806,51 @@ void Fl_Tree::item_draw_mode(Fl_Tree_Item_Draw_Mode val) {
 void Fl_Tree::item_draw_mode(int val) {
   _prefs.item_draw_mode(Fl_Tree_Item_Draw_Mode(val));
 }
-#endif /*FLTK_ABI_VERSION*/
+
+/// Set a callback to be invoked to handle drawing the Fl_Tree_Item
+/// instead of the default label drawing behavior. Lets one define
+/// custom drawing behavior for Fl_Tree_Item's. eg:
+/// \code
+///    static void draw_item(Fl_Tree_Item *item, void *data) {
+///        Fl_Tree *tree = (Fl_Tree*)data;
+///        int X=item->label_x(), Y=item->label_y(),
+///            W=item->label_w(), H=item->label_h();
+///        // Draw the background
+///        fl_color(item->is_selected() ? tree->selection_color() : item->labelbgcolor());
+///        fl_rectf(X,Y,W,H);
+///        // Draw text
+///        fl_font(item->labelfont(), item->labelsize());
+///        fl_color(item->labelfgcolor());
+///        fl_draw("Some text", X+tree->labelmarginleft(),Y,W,H, FL_ALIGN_LEFT);
+///    }
+///    ..
+/// int main() {
+///    Fl_Tree *tree = new Fl_Tree(0,0,100,100);
+///    tree->item_draw_callback(draw_item, (void*)tree);
+///    [..]
+/// \endcode
+///
+/// Note: This only affects the drawing of item's labels;
+/// it does not affect the drawing of widgets assigned with
+/// Fl_Tree_Item::widget().
+///
+void Fl_Tree::item_draw_callback(Fl_Tree_Item_Draw_Callback *cb, void *data) {
+  _prefs.item_draw_callback(cb,data);
+}
+/// Get the current item draw callback. Returns 0 if none.
+Fl_Tree_Item_Draw_Callback* Fl_Tree::item_draw_callback() const {
+  return(_prefs.item_draw_callback());
+}
+/// Get the current item draw callback's user data.
+void* Fl_Tree::item_draw_user_data() const {
+  return(_prefs.item_draw_user_data());
+}
+/// Invoke the configured item_draw_callback().
+//  Do NOT call this if no item_draw_callback() was configured.
+void Fl_Tree::do_item_draw_callback(Fl_Tree_Item *o) const {
+  _prefs.do_item_draw_callback(o);
+}
+#endif
 
 /// See if \p item is currently displayed on-screen (visible within the widget).
 /// This can be used to detect if the item is scrolled off-screen.
diff --git a/src/Fl_Tree_Item.cxx b/src/Fl_Tree_Item.cxx
index daccbdbde..2bbbb107c 100644
--- a/src/Fl_Tree_Item.cxx
+++ b/src/Fl_Tree_Item.cxx
@@ -529,7 +529,7 @@ Fl_Tree_Item *Fl_Tree_Item::find_clicked(const Fl_Tree_Prefs &prefs) {
   return(0);
 }
 
-static void draw_item_focus(Fl_Boxtype B, Fl_Color C, int X, int Y, int W, int H) {
+static void draw_item_focus(Fl_Boxtype B, Fl_Color fg, Fl_Color bg, int X, int Y, int W, int H) {
   if (!Fl::visible_focus()) return;
   switch (B) {
     case FL_DOWN_BOX:
@@ -541,7 +541,7 @@ static void draw_item_focus(Fl_Boxtype B, Fl_Color C, int X, int Y, int W, int H
     default:
       break;
   }
-  fl_color(fl_contrast(FL_BLACK, C));
+  fl_color(fl_contrast(fg, bg));
 
 #if defined(USE_X11) || defined(__APPLE_QUARTZ__)
   fl_line_style(FL_DOT);
@@ -719,41 +719,51 @@ void Fl_Tree_Item::draw(int X, int &Y, int W, Fl_Widget *tree,
 	    prefs.openicon()->draw(icon_x,icon_y);
 	  }
 	}
-	// Background for this item
-	// Draw bg only if different from tree's bg
-	if ( bg != tree->color() || is_selected() ) {
-	  if ( is_selected() ) {			// Selected? Use selectbox() style
-	    fl_draw_box(prefs.selectbox(),bg_x,bg_y,bg_w,bg_h,bg);
-	  } else {					// Not Selected? use plain filled rectangle
-	    fl_color(bg);
-	    fl_rectf(bg_x,bg_y,bg_w,bg_h);
+	// Draw the item
+#if FLTK_ABI_VERSION >= 10303
+	if ( !widget() && prefs.item_draw_callback() ) {
+	  // Draw item using user supplied custom item draw callback
+	  prefs.do_item_draw_callback(this);
+        }
+	else
+#endif
+	{
+	  // Background for this item
+	  // Draw bg only if different from tree's bg
+	  if ( bg != tree->color() || is_selected() ) {
+	    if ( is_selected() ) {			// Selected? Use selectbox() style
+	      fl_draw_box(prefs.selectbox(),bg_x,bg_y,bg_w,bg_h,bg);
+	    } else {					// Not Selected? use plain filled rectangle
+	      fl_color(bg);
+	      fl_rectf(bg_x,bg_y,bg_w,bg_h);
+	    }
+	    if ( widget() ) widget()->damage(FL_DAMAGE_ALL);	// if there's a child widget, we just damaged it
 	  }
-	  if ( widget() ) widget()->damage(FL_DAMAGE_ALL);	// if there's a child widget, we just damaged it
-	}
-	// Draw user icon (if any)
-	if ( usericon() ) {
-	  // Item has user icon? Use it
-	  int uicon_y = item_y_center - (usericon()->h() >> 1);
-	  usericon()->draw(uicon_x,uicon_y);
-	} else if ( prefs.usericon() ) {
-	  // Prefs has user icon? Use it
-	  int uicon_y = item_y_center - (prefs.usericon()->h() >> 1);
-	  prefs.usericon()->draw(uicon_x,uicon_y);
-	}
-	// Draw label
+	  // Draw user icon (if any)
+	  if ( usericon() ) {
+	    // Item has user icon? Use it
+	    int uicon_y = item_y_center - (usericon()->h() >> 1);
+	    usericon()->draw(uicon_x,uicon_y);
+	  } else if ( prefs.usericon() ) {
+	    // Prefs has user icon? Use it
+	    int uicon_y = item_y_center - (prefs.usericon()->h() >> 1);
+	    prefs.usericon()->draw(uicon_x,uicon_y);
+	  }
+	  // Draw label
 #if FLTK_ABI_VERSION >= 10301
-        if ( _label && 
-	     ( !widget() || 
-	       (prefs.item_draw_mode() & FL_TREE_ITEM_DRAW_LABEL_AND_WIDGET) ) )
+	  if ( _label && 
+	       ( !widget() || 
+		 (prefs.item_draw_mode() & FL_TREE_ITEM_DRAW_LABEL_AND_WIDGET) ) )
 #else /*FLTK_ABI_VERSION*/
-        if ( _label && !widget() )	// back compat: don't draw label if widget() present
+	  if ( _label && !widget() )	// back compat: don't draw label if widget() present
 #endif /*FLTK_ABI_VERSION*/
-        {
-	  fl_color(fg);
-	  fl_font(_labelfont, _labelsize);
-	  int label_y = Y+(H/2)+(_labelsize/2)-fl_descent()/2;
-	  fl_draw(_label, label_x, label_y);
-	}
+	  {
+	    fl_color(fg);
+	    fl_font(_labelfont, _labelsize);
+	    int label_y = Y+(H/2)+(_labelsize/2)-fl_descent()/2;
+	    fl_draw(_label, label_x, label_y);
+	  }
+        }		// end non-custom draw
       }			// end non-child damage
       // Draw child FLTK widget?
       if ( widget() ) {
@@ -766,7 +776,7 @@ void Fl_Tree_Item::draw(int X, int &Y, int W, Fl_Widget *tree,
            Fl::visible_focus() && 
 	   Fl::focus() == tree &&
 	   prefs.selectmode() != FL_TREE_SELECT_NONE ) {
-	draw_item_focus(FL_NO_BOX,bg,bg_x+1,bg_y+1,bg_w-1,bg_h-1);
+	draw_item_focus(FL_NO_BOX,fg,bg,bg_x+1,bg_y+1,bg_w-1,bg_h-1);
       }
     }			// end drawthis
   }			// end clipped
diff --git a/src/Fl_Tree_Prefs.cxx b/src/Fl_Tree_Prefs.cxx
index b52724aef..3fc9c4355 100644
--- a/src/Fl_Tree_Prefs.cxx
+++ b/src/Fl_Tree_Prefs.cxx
@@ -156,6 +156,10 @@ Fl_Tree_Prefs::Fl_Tree_Prefs() {
   _itemreselectmode       = FL_TREE_SELECTABLE_ONCE;
   _itemdrawmode           = FL_TREE_ITEM_DRAW_DEFAULT;
 #endif
+#if FLTK_ABI_VERSION >= 10303
+  _itemdrawcallback       = 0;
+  _itemdrawuserdata       = 0;
+#endif
   // Let fltk's current 'scheme' affect defaults
   if ( Fl::scheme() ) {
     if ( strcmp(Fl::scheme(), "gtk+") == 0 ) {