Draw parent window backdrop on Fl_Tabs (#718)

FL/Fl_Window.H

@@ -587,8 +587,9 @@ public:
   virtual class Fl_Double_Window *as_double_window() {return 0L;}
 
   void shape(const Fl_Image* img);
-  void shape(const Fl_Image& b) ;
+  void shape(const Fl_Image& b);
   const Fl_Image *shape();
+  void draw_backdrop();
   int screen_num();
   void screen_num(int screen_num);
   static bool is_a_rescale();

src/Fl_Tabs.cxx

@@ -25,6 +25,7 @@
 #include <FL/fl_draw.H>
 #include <FL/Fl_Tooltip.H>
 #include <FL/Fl_Menu_Item.H>
+#include <FL/Fl_Window.H>
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -805,10 +806,12 @@ void Fl_Tabs::draw() {
     if (parent()) {
       Fl_Widget *p = parent();
       fl_push_clip(x(), tabs_y, w(), tabs_h);
-      if (p->as_window())
+      if (Fl_Window *win = p->as_window()) {
         fl_draw_box(p->box(), 0, 0, p->w(), p->h(), p->color());
-      else
+        win->draw_backdrop();
+      } else {
         fl_draw_box(p->box(), p->x(), p->y(), p->w(), p->h(), p->color());
+      }
       fl_pop_clip();
     } else {
       fl_rectf(x(), tabs_y, w(), tabs_h, color());

src/Fl_Window.cxx

@@ -507,16 +507,7 @@ void Fl_Window::draw()
 
   if (damage() & ~FL_DAMAGE_CHILD) {     // draw the entire thing
     draw_box(box(),0,0,w(),h(),color()); // draw box with x/y = 0
-
+    draw_backdrop();
-    if (image() && (align() & FL_ALIGN_INSIDE)) { // draw the image only
-      Fl_Label l1;
-      memset(&l1,0,sizeof(l1));
-      l1.align_ = align();
-      l1.image = image();
-      if (!active_r() && l1.image && l1.deimage) l1.image = l1.deimage;
-      l1.type = labeltype();
-      l1.draw(0,0,w(),h(),align());
-    }
   }
   draw_children();
 
@@ -524,6 +515,21 @@ void Fl_Window::draw()
   if (!to_display) current_ = save_current;
 }
 
+/**
+ Draw the background image if one is set and is aligned inside.
+ */
+void Fl_Window::draw_backdrop() {
+  if (image() && (align() & FL_ALIGN_INSIDE)) { // draw the image only
+    Fl_Label l1;
+    memset(&l1,0,sizeof(l1));
+    l1.align_ = align();
+    l1.image = image();
+    if (!active_r() && l1.image && l1.deimage) l1.image = l1.deimage;
+    l1.type = labeltype();
+    l1.draw(0,0,w(),h(),align());
+  }
+}
+
 void Fl_Window::make_current()
 {
   pWindowDriver->make_current();

test/unittest_schemes.cxx

@@ -315,16 +315,18 @@ public:
         o->labelcolor((Fl_Color)55);
         o->tooltip("Fl_Adjuster with up box");
       } // Fl_Adjuster* o
-      { Fl_Text_Editor* o = new Fl_Text_Editor(220, 53, 100, 29, "down frame");
+      { Fl_Text_Editor* o = new Fl_Text_Editor(220, 40, 100, 25);
         o->box(FL_DOWN_FRAME);
         o->color((Fl_Color)19);
         o->selection_color(FL_DARK1);
-        o->tooltip("Fl_Adjuster with down frame");
+        o->buffer(new Fl_Text_Buffer);
+        o->tooltip("Fl_Text_Editor with down frame");
       } // Fl_Text_Editor* o
-      { Fl_Text_Editor* o = new Fl_Text_Editor(220, 99, 100, 38, "up frame");
+      { Fl_Text_Editor* o = new Fl_Text_Editor(220, 70, 100, 25);
         o->box(FL_UP_FRAME);
         o->color((Fl_Color)19);
         o->selection_color(FL_DARK1);
+        o->buffer(new Fl_Text_Buffer);
         o->tooltip("Fl_Text_Editor with up frame");
       } // Fl_Text_Editor* o
     }