diff --git a/Readme.md b/Readme.md
index fbd2fbe..c6ae0ff 100644
--- a/Readme.md
+++ b/Readme.md
@@ -38,7 +38,7 @@ have to be either executed or optionally converted into a vertex buffer to
 draw the GUI.
 
 ## Gallery
-![gui demo](https://cloud.githubusercontent.com/assets/8057201/9937241/24f55e7e-5d60-11e5-9957-c010cf763f15.png)
+![demo](https://cloud.githubusercontent.com/assets/8057201/10187981/584ecd68-675c-11e5-897c-822ef534a876.png)
 ![gui explorer](https://cloud.githubusercontent.com/assets/8057201/9937240/24f509ce-5d60-11e5-894a-e7e9e228de30.png)
 ![node](https://cloud.githubusercontent.com/assets/8057201/9976995/e81ac04a-5ef7-11e5-872b-acd54fbeee03.gif)
 
@@ -62,8 +62,7 @@ zr_window_init(&window, 50, 50, 220, 180,
 /* setup widget data */
 enum {EASY, HARD};
 zr_size option = EASY;
-zr_size item = 0;
-zr_state active = 0;
+zr_float value = 0.6f;
 
 struct zr_input input = {0};
 while (1) {
@@ -84,8 +83,14 @@ while (1) {
         zr_layout_row_dynamic(&context, 30, 2);
         if (zr_option(&context, "easy", option == EASY)) option = EASY;
         if (zr_option(&context, "hard", option == HARD)) option = HARD;
-        zr_label(&context, "Weapon:", ZR_TEXT_LEFT);
-        zr_combo(&context, items, LEN(items), &item, 20, &active);
+        zr_layout_row_begin(&context, ZR_STATIC, 30, 2);
+        {
+            zr_layout_row_push(&context, 50);
+            zr_label(&context, "Volume:", ZR_TEXT_LEFT);
+            zr_layout_row_push(&context, 110);
+            value = zr_slider(&context, 0, value, 1.0f, 0.1f);
+        }
+        zr_layout_row_end(&context);
     }
     zr_end(&context, &window);
 
diff --git a/demo/demo.c b/demo/demo.c
index 38f1215..835c97b 100644
--- a/demo/demo.c
+++ b/demo/demo.c
@@ -307,7 +307,7 @@ color_picker(struct zr_context *panel, struct color_picker* control,
             ret = zr_false;
         }
     }
-    zr_popup_end(panel, &popup);
+    zr_popup_end(panel, &popup, NULL);
     control->active = (zr_state)ret;
     return ret;
 }
@@ -356,14 +356,16 @@ combo_box(struct zr_context *panel, struct combobox *combo,
     zr_size i = 0;
     struct zr_context layout;
     zr_combo_begin(panel, &layout, values[combo->selected], &combo->active);
-    zr_layout_row_dynamic(&layout, 25, 1);
-    for (i = 0; i < count; ++i) {
-        if (combo->selected == i) continue;
-        if (zr_combo_item(&layout, ZR_TEXT_LEFT, values[i])) {
-            combo->selected = i;
+    {
+        zr_layout_row_dynamic(&layout, 25, 1);
+        for (i = 0; i < count; ++i) {
+            if (combo->selected == i) continue;
+            if (zr_combo_item(&layout, ZR_TEXT_LEFT, values[i])) {
+                combo->selected = i;
+            }
         }
     }
-    combo->active = zr_combo_end(panel, &layout);
+    zr_combo_end(panel, &layout, &combo->active);
 }
 
 static void
@@ -385,7 +387,7 @@ prog_combo_box(struct zr_context *panel, zr_size *values, zr_size count,
         for (i = 0; i < count; ++i)
             values[i] = zr_progress(&combo, values[i], 100, zr_true);
     }
-    zr_combo_end(panel, &combo);
+    zr_combo_end(panel, &combo, NULL);
 }
 
 static void
@@ -411,7 +413,7 @@ color_combo_box(struct zr_context *panel, struct color_combo_box *demo)
             *iter = (zr_byte)t;
         }
     }
-    zr_combo_end(panel, &combo);
+    zr_combo_end(panel, &combo, NULL);
 }
 
 static void
@@ -434,7 +436,7 @@ check_combo_box(struct zr_context *panel, zr_bool *values, zr_size count,
         for (i = 0; i < count; ++i)
             values[i] = zr_check(&combo, weapons[i], values[i]);
     }
-    zr_combo_end(panel, &combo);
+    zr_combo_end(panel, &combo, NULL);
 }
 
 /* -----------------------------------------------------------------
@@ -509,6 +511,7 @@ struct state {
     zr_state popup;
     zr_size cur;
     zr_size op;
+    zr_float value;
 
     /* subpanels */
     struct zr_vec2 shelf;
@@ -794,6 +797,7 @@ init_demo(struct demo_gui *gui)
     win->slider = 2.0f;
     win->progressbar = 50;
     win->spinner = 100;
+    win->value = 0.6f;
 }
 
 /* -----------------------------------------------------------------
@@ -894,7 +898,7 @@ run_demo(struct demo_gui *gui)
                     state->popup = zr_false;
                 }
             }
-            zr_popup_end(&layout, &tab);
+            zr_popup_end(&layout, &tab, NULL);
         }
 
         {
@@ -915,7 +919,7 @@ run_demo(struct demo_gui *gui)
                 default: break;
                 }
             }
-            state->shelf = zr_shelf_end(&layout, &tab);
+            zr_shelf_end(&layout, &tab, &state->shelf);
         }
 
         {
@@ -924,7 +928,7 @@ run_demo(struct demo_gui *gui)
             zr_layout_row_dynamic(&layout, 250, 1);
             zr_tree_begin(&layout, &tree, "Tree", 20, state->tree);
             upload_tree(&state->test, &tree, &state->test.root);
-            state->tree = zr_tree_end(&layout, &tree);
+            zr_tree_end(&layout, &tree, &state->tree);
         }
     }
     zr_end(&layout, &gui->panel);
@@ -941,6 +945,14 @@ run_demo(struct demo_gui *gui)
         zr_layout_row_dynamic(&layout, 30, 2);
         if (zr_option(&layout, "easy", state->op == EASY)) state->op = EASY;
         if (zr_option(&layout, "hard", state->op == HARD)) state->op = HARD;
+        zr_layout_row_begin(&layout, ZR_STATIC, 30, 2);
+        {
+            zr_layout_row_push(&layout, 50);
+            zr_label(&layout, "Volume:", ZR_TEXT_LEFT);
+            zr_layout_row_push(&layout, 110);
+            state->value = zr_slider(&layout, 0, state->value, 1.0f, 0.1f);
+        }
+        zr_layout_row_end(&layout);
     }
     zr_end(&layout, &gui->sub);
 }
diff --git a/demo/nanovg/nanovg.c b/demo/nanovg/nanovg.c
index 4fb1ca5..5c7a48c 100644
--- a/demo/nanovg/nanovg.c
+++ b/demo/nanovg/nanovg.c
@@ -254,7 +254,6 @@ main(int argc, char *argv[])
 
     /* GUI */
     struct demo_gui gui;
-
     if (argc < 2) {
         fprintf(stdout,"Missing TTF Font file argument: gui <path>\n");
         exit(EXIT_FAILURE);
diff --git a/example/nodedit/nodedit.c b/example/nodedit/nodedit.c
index 5e6a4fb..f219a1c 100644
--- a/example/nodedit/nodedit.c
+++ b/example/nodedit/nodedit.c
@@ -200,6 +200,7 @@ node_editor_draw(struct zr_context *layout, struct node_editor *nodedit,
     struct zr_command_buffer *canvas = zr_canvas(layout);
     struct node *updated = 0;
 
+    /* allocate complete window space */
     total_space = zr_space(layout);
     zr_layout_row_space_begin(layout, ZR_STATIC, total_space.h, (zr_size)nodedit->node_count);
     {
@@ -218,7 +219,7 @@ node_editor_draw(struct zr_context *layout, struct node_editor *nodedit,
                 zr_command_buffer_push_line(canvas, size.x, y+size.y, size.x+size.w, y+size.y, grid_color);
         }
 
-        /* execute each node */
+        /* execute each node as a moveable group */
         zr_style_push_color(config, ZR_COLOR_WINDOW, zr_rgb(48, 48, 48));
         while (it) {
             /* draw node */
@@ -347,30 +348,29 @@ node_editor_draw(struct zr_context *layout, struct node_editor *nodedit,
             node_editor_push(nodedit, updated);
         }
 
-        {
-            /* right click popup context menu activation */
-            if (nodedit->menu == ZR_INACTIVE &&
-                zr_input_mouse_clicked(in, ZR_BUTTON_RIGHT, zr_layout_row_space_bounds(layout))) {
-                it = nodedit->begin;
-                nodedit->selected = NULL;
-                nodedit->menu = ZR_ACTIVE;
-                nodedit->bounds = zr_rect(in->mouse.pos.x, in->mouse.pos.y, 100, 200);
-                while (it) {
-                    struct zr_rect b = zr_layout_row_space_rect_to_screen(layout, it->bounds);
-                    b.x -= nodedit->scrolling.x;
-                    b.y -= nodedit->scrolling.y;
-                    if (zr_input_is_mouse_hovering_rect(in, b))
-                        nodedit->selected = it;
-                    it = it->next;
-                }
+        /* node selection + right click popup context menu activation */
+        if (nodedit->menu == ZR_INACTIVE &&
+            zr_input_mouse_clicked(in, ZR_BUTTON_RIGHT, zr_layout_row_space_bounds(layout))) {
+            it = nodedit->begin;
+            nodedit->selected = NULL;
+            nodedit->menu = ZR_ACTIVE;
+            nodedit->bounds = zr_rect(in->mouse.pos.x, in->mouse.pos.y, 100, 200);
+            while (it) {
+                struct zr_rect b = zr_layout_row_space_rect_to_screen(layout, it->bounds);
+                b.x -= nodedit->scrolling.x;
+                b.y -= nodedit->scrolling.y;
+                if (zr_input_is_mouse_hovering_rect(in, b))
+                    nodedit->selected = it;
+                it = it->next;
             }
+        }
 
-            /* popup context menu */
-            if (nodedit->menu == ZR_ACTIVE) {
-                struct zr_context menu;
-                const char *grid_option[] = {"Show Grid", "Hide Grid"};
-                zr_contextual_begin(layout, &menu, ZR_WINDOW_NO_SCROLLBAR, &nodedit->menu,
-                    nodedit->bounds);
+        /* popup context menu */
+        if (nodedit->menu == ZR_ACTIVE) {
+            struct zr_context menu;
+            const char *grid_option[] = {"Show Grid", "Hide Grid"};
+            zr_contextual_begin(layout, &menu, ZR_WINDOW_NO_SCROLLBAR, &nodedit->menu, nodedit->bounds);
+            {
                 zr_layout_row_dynamic(&menu, 25, 1);
                 if (!nodedit->selected) {
                     /* menu content if no selected node */
@@ -389,8 +389,8 @@ node_editor_draw(struct zr_context *layout, struct node_editor *nodedit,
                     if (zr_contextual_item(&menu, "Copy", ZR_TEXT_CENTERED))
                         fprintf(stdout, "pressed copy!\n");
                 }
-                nodedit->menu = zr_contextual_end(layout, &menu);
             }
+            nodedit->menu = zr_contextual_end(layout, &menu);
         }
     }
     zr_layout_row_space_end(layout);
diff --git a/zahnrad.c b/zahnrad.c
index 18ee237..80b3d85 100644
--- a/zahnrad.c
+++ b/zahnrad.c
@@ -360,10 +360,10 @@ zr_hsv(zr_float h, zr_float s, zr_float v)
 zr_uint
 zr_color32(struct zr_color in)
 {
-    zr_uint out = (zr_draw_vertex_color)in.r;
-    out |= ((zr_draw_vertex_color)in.g << 8);
-    out |= ((zr_draw_vertex_color)in.b << 16);
-    out |= ((zr_draw_vertex_color)in.a << 24);
+    zr_uint out = (zr_uint)in.r;
+    out |= ((zr_uint)in.g << 8);
+    out |= ((zr_uint)in.b << 16);
+    out |= ((zr_uint)in.a << 24);
     return out;
 }
 
@@ -2932,7 +2932,7 @@ zr_font_bake_pack(zr_size *image_memory, zr_size *width, zr_size *height,
 
     *height = 0;
     *width = (total_glyph_count > 1000) ? 1024 : 512;
-    stbtt_PackBegin(&baker->spc, NULL, (zr_int)*width, (int)max_height, 0, 1, 0);
+    stbtt_PackBegin(&baker->spc, 0, (zr_int)*width, (int)max_height, 0, 1, 0);
     {
         zr_size input_i = 0;
         zr_size range_n = 0, rect_n = 0, char_n = 0;
@@ -7521,9 +7521,9 @@ zr_tree_end_node(struct zr_tree *tree)
         tree->skip = -1;
 }
 
-struct zr_vec2
-zr_tree_end(struct zr_context *p, struct zr_tree* tree)
-{return zr_group_end(p, &tree->group);}
+void
+zr_tree_end(struct zr_context *p, struct zr_tree* tree, struct zr_vec2 *scrollbar)
+{zr_group_end(p, &tree->group, scrollbar);}
 /*
  * -------------------------------------------------------------
  *
@@ -7595,8 +7595,8 @@ failed:
     g->queue = p->queue;
 }
 
-struct zr_vec2
-zr_group_end(struct zr_context *p, struct zr_context *g)
+void
+zr_group_end(struct zr_context *p, struct zr_context *g, struct zr_vec2 *scrollbar)
 {
     struct zr_window pan;
     struct zr_command_buffer *out;
@@ -7604,8 +7604,8 @@ zr_group_end(struct zr_context *p, struct zr_context *g)
 
     ZR_ASSERT(p);
     ZR_ASSERT(g);
-    if (!p || !g) return zr_vec2(0,0);
-    if (!p->valid) return zr_vec2(0,0);
+    if (!p || !g) return;
+    if (!p->valid) return;
     zr_zero(&pan, sizeof(pan));
 
     out = p->buffer;
@@ -7621,7 +7621,8 @@ zr_group_end(struct zr_context *p, struct zr_context *g)
     zr_command_buffer_push_scissor(out, clip);
     zr_end(g, &pan);
     zr_command_buffer_push_scissor(out, p->clip);
-    return pan.offset;
+    if (scrollbar)
+        *scrollbar = pan.offset;
 }
 /*
  * -------------------------------------------------------------
@@ -7765,8 +7766,8 @@ failed:
     return active;
 }
 
-struct zr_vec2
-zr_shelf_end(struct zr_context *p, struct zr_context *s)
+void
+zr_shelf_end(struct zr_context *p, struct zr_context *s, struct zr_vec2 *scrollbar)
 {
     struct zr_command_buffer *out;
     struct zr_rect clip;
@@ -7774,8 +7775,8 @@ zr_shelf_end(struct zr_context *p, struct zr_context *s)
 
     ZR_ASSERT(p);
     ZR_ASSERT(s);
-    if (!p || !s) return zr_vec2(0,0);
-    if (!p->valid) return zr_vec2(0,0);
+    if (!p || !s) return;
+    if (!p->valid) return;
     zr_zero(&pan, sizeof(pan));
 
     out = p->buffer;
@@ -7787,7 +7788,8 @@ zr_shelf_end(struct zr_context *p, struct zr_context *s)
     zr_command_buffer_push_scissor(out, clip);
     zr_end(s, &pan);
     zr_command_buffer_push_scissor(out, p->clip);
-    return pan.offset;
+    if (scrollbar)
+        *scrollbar = pan.offset;
 }
 /*
  * -------------------------------------------------------------
@@ -7848,16 +7850,17 @@ zr_popup_close(struct zr_context *popup)
     popup->valid = zr_false;
 }
 
-struct zr_vec2
-zr_popup_end(struct zr_context *parent, struct zr_context *popup)
+void
+zr_popup_end(struct zr_context *parent, struct zr_context *popup,
+    struct zr_vec2 *scrollbar)
 {
     struct zr_window pan;
     struct zr_command_buffer *out;
 
     ZR_ASSERT(parent);
     ZR_ASSERT(popup);
-    if (!parent || !popup) return zr_vec2(0,0);
-    if (!parent->valid) return zr_vec2(0,0);
+    if (!parent || !popup) return;
+    if (!parent->valid) return;
 
     zr_zero(&pan, sizeof(pan));
     if (popup->flags & ZR_WINDOW_HIDDEN) {
@@ -7878,7 +7881,8 @@ zr_popup_end(struct zr_context *parent, struct zr_context *popup)
     zr_end(popup, &pan);
     zr_command_queue_finish_child(parent->queue, parent->buffer);
     zr_command_buffer_push_scissor(out, parent->clip);
-    return pan.offset;
+    if (scrollbar)
+        *scrollbar = pan.offset;
 }
 /*
  * -------------------------------------------------------------
@@ -7890,7 +7894,7 @@ zr_popup_end(struct zr_context *parent, struct zr_context *popup)
 static zr_bool
 zr_popup_nonblocking_begin(struct zr_context *parent,
     struct zr_context *popup, zr_flags flags, zr_state *active, zr_state is_active,
-    struct zr_rect body)
+    struct zr_rect body, struct zr_vec2 scrollbar)
 {
     /* deactivate popup if user clicked outside the popup*/
     const struct zr_input *in = parent->input;
@@ -7907,7 +7911,7 @@ zr_popup_nonblocking_begin(struct zr_context *parent,
 
     /* if active create popup otherwise deactive the panel layout  */
     if (!is_active && *active) {
-        zr_popup_begin(parent, popup, ZR_POPUP_DYNAMIC, flags, body, zr_vec2(0,0));
+        zr_popup_begin(parent, popup, ZR_POPUP_DYNAMIC, flags, body, scrollbar);
         zr_popup_close(popup);
         popup->flags &= ~(zr_flags)ZR_WINDOW_MINIMIZED;
         parent->flags &= ~(zr_flags)ZR_WINDOW_ROM;
@@ -7925,14 +7929,14 @@ zr_popup_nonblocking_begin(struct zr_context *parent,
 
 static void
 zr_popup_nonblocking_end(struct zr_context *parent,
-    struct zr_context *popup)
+    struct zr_context *popup, struct zr_vec2 *scrollbar)
 {
     ZR_ASSERT(parent);
     ZR_ASSERT(popup);
     if (!parent || !popup) return;
     if (!parent->valid) return;
     if (!(popup->flags & ZR_WINDOW_MINIMIZED))
-        zr_popup_end(parent, popup);
+        zr_popup_end(parent, popup, scrollbar);
 }
 
 void
@@ -7943,7 +7947,7 @@ zr_contextual_begin(struct zr_context *parent, struct zr_context *popup,
     ZR_ASSERT(popup);
     ZR_ASSERT(active);
     if (!parent || !popup || !active) return;
-    zr_popup_nonblocking_begin(parent, popup, flags, active, *active, body);
+    zr_popup_nonblocking_begin(parent, popup, flags, active, *active, body, zr_vec2(0,0));
 }
 
 static zr_bool
@@ -8066,19 +8070,24 @@ zr_contextual_close(struct zr_context *popup)
     popup->flags |= ZR_WINDOW_HIDDEN;
 }
 
-zr_state
-zr_contextual_end(struct zr_context *parent, struct zr_context *menu)
+void
+zr_contextual_end(struct zr_context *parent, struct zr_context *menu, zr_state *state)
 {
     ZR_ASSERT(parent);
     ZR_ASSERT(menu);
-    if (!parent || !menu) return zr_false;
-    if (!parent->valid) return zr_false;
+    if (!parent || !menu)
+        goto failed;
+    if (!parent->valid)
+        goto failed;
     if ((!parent->valid) || (!menu->valid && !(menu->flags & ZR_WINDOW_HIDDEN)))
-        return zr_false;
-    zr_popup_nonblocking_end(parent, menu);
+        goto failed;
+    zr_popup_nonblocking_end(parent, menu, 0);
     if (menu->flags & ZR_WINDOW_HIDDEN)
-        return zr_false;
-    return zr_true;
+        goto failed;
+    if (state) *state = zr_true;
+    return;
+failed:
+    if (state) *state = zr_false;
 }
 /*
  * -------------------------------------------------------------
@@ -8170,7 +8179,7 @@ zr_combo_begin(struct zr_context *parent, struct zr_context *combo,
         body.y = header.y + header.h;
         body.h = zr_null_rect.h;
         if (!zr_popup_nonblocking_begin(parent, combo, ZR_WINDOW_NO_SCROLLBAR,
-                active, is_active, body)) goto failed;
+                active, is_active, body, zr_vec2(0,0))) goto failed;
         combo->flags |= ZR_WINDOW_COMBO_MENU;
     }
     return;
@@ -8195,8 +8204,8 @@ zr_bool zr_combo_item_symbol(struct zr_context *menu, enum zr_symbol symbol,
     const char *title, enum zr_text_align align)
 {return zr_contextual_item_symbol(menu, symbol, title, align);}
 
-zr_state zr_combo_end(struct zr_context *parent, struct zr_context *menu)
-{return zr_contextual_end(parent, menu);}
+void zr_combo_end(struct zr_context *parent, struct zr_context *menu, zr_state *state)
+{zr_contextual_end(parent, menu, state);}
 
 void zr_combo_close(struct zr_context *combo)
 {zr_contextual_close(combo);}
@@ -8253,7 +8262,7 @@ zr_menu_begin(struct zr_context *parent, struct zr_context *menu,
         body.y = header.y + header.h;
         body.h = (parent->bounds.y + parent->bounds.h) - body.y;
         if (!zr_popup_nonblocking_begin(parent, menu, ZR_WINDOW_NO_SCROLLBAR, active,
-            is_active, body)) goto failed;
+            is_active, body, zr_vec2(0,0))) goto failed;
         menu->flags |= ZR_WINDOW_COMBO_MENU;
     }
     return;
@@ -8288,7 +8297,7 @@ zr_menu_end(struct zr_context *parent, struct zr_context *menu)
     ZR_ASSERT(menu);
     if (!parent || !menu) return;
     if (!parent->valid) return;
-    zr_popup_nonblocking_end(parent, menu);
+    zr_popup_nonblocking_end(parent, menu, 0);
 }
 /*
  * -------------------------------------------------------------
@@ -8308,11 +8317,10 @@ zr_tooltip_begin(struct zr_context *parent, struct zr_context *tip, zr_float wid
         return;
 
     in = parent->input;
-
     bounds.w = width;
     bounds.h = zr_null_rect.h;
-    bounds.x = in->mouse.pos.x - parent->clip.x;
-    bounds.y = in->mouse.pos.y - parent->clip.y;
+    bounds.x = (in->mouse.pos.x + 1) - parent->clip.x;
+    bounds.y = (in->mouse.pos.y + 1) - parent->clip.y;
     zr_popup_begin(parent, tip, ZR_POPUP_DYNAMIC, ZR_WINDOW_NO_SCROLLBAR, bounds, zr_vec2(0,0));
 }
 
@@ -8320,7 +8328,7 @@ void
 zr_tooltip_end(struct zr_context *parent, struct zr_context *tip)
 {
     zr_popup_close(tip);
-    zr_popup_end(parent, tip);
+    zr_popup_end(parent, tip, 0);
 }
 
 void
diff --git a/zahnrad.h b/zahnrad.h
index 1b78222..937457e 100644
--- a/zahnrad.h
+++ b/zahnrad.h
@@ -2448,16 +2448,14 @@ struct zr_color zr_style_color(const struct zr_style*, enum zr_style_colors);
     Output:
     - color value that has been asked for
 */
-void zr_style_push_property(struct zr_style*, enum zr_style_properties,
-                                struct zr_vec2);
+void zr_style_push_property(struct zr_style*, enum zr_style_properties, struct zr_vec2);
 /*  this function temporarily changes a property in a stack to be reseted later
     Input:
     - Configuration structure to push the change to
     - Property idenfifier to change
     - new value of the property
 */
-void zr_style_push_color(struct zr_style*, enum zr_style_colors,
-                            struct zr_color);
+void zr_style_push_color(struct zr_style*, enum zr_style_colors, struct zr_color);
 /*  this function temporarily changes a color in a stack like fashion to be reseted later
     Input:
     - Configuration structure to push the change to
@@ -2743,9 +2741,9 @@ struct zr_window {
     /* input state for updating the window and all its widgets */
 };
 
-void zr_window_init(struct zr_window*, struct zr_rect bounds,
-                    zr_flags flags, struct zr_command_queue*,
-                    const struct zr_style*, const struct zr_input *in);
+void zr_window_init(struct zr_window*, struct zr_rect bounds, zr_flags flags,
+                    struct zr_command_queue*, const struct zr_style*,
+                    const struct zr_input *in);
 /*  this function initilizes and setups the window
     Input:
     - bounds of the window with x,y position and width and height
@@ -2995,8 +2993,8 @@ enum zr_header_align {
     /* header elements are added at the right side of the header */
 };
 
-zr_flags zr_header(struct zr_context*, const char *title,
-                    zr_flags show, zr_flags notify, enum zr_header_align);
+zr_flags zr_header(struct zr_context*, const char *title, zr_flags show,
+                    zr_flags notify, enum zr_header_align);
 /*  this function is a shorthand for the header build up process
     flag by the user
     Input:
@@ -3137,8 +3135,7 @@ void zr_layout_row_static(struct zr_context*, zr_float row_height,
     - number of widget inside the row that will divide the space
 */
 /* ------------------------------ Custom ----------------------------------- */
-void zr_layout_row_begin(struct zr_context*,
-                        enum zr_layout_format,
+void zr_layout_row_begin(struct zr_context*, enum zr_layout_format,
                         zr_float row_height, zr_size cols);
 /*  this function start a new scaleable row that can be filled with different
     sized widget
@@ -3155,8 +3152,8 @@ void zr_layout_row_push(struct zr_context*, zr_float value);
 */
 void zr_layout_row_end(struct zr_context*);
 /*  this function ends the previously started scaleable row */
-void zr_layout_row(struct zr_context*, enum zr_layout_format,
-                    zr_float height, zr_size cols, const zr_float *ratio);
+void zr_layout_row(struct zr_context*, enum zr_layout_format, zr_float height,
+                    zr_size cols, const zr_float *ratio);
 /*  this function sets the row layout as an array of ratios/width for
     every widget that will be inserted into that row
     Input:
@@ -3166,8 +3163,7 @@ void zr_layout_row(struct zr_context*, enum zr_layout_format,
     - window ratio/pixel width array for each widget
 */
 /* ------------------------------ User ----------------------------------- */
-void zr_layout_row_space_begin(struct zr_context*,
-                                enum zr_layout_format,
+void zr_layout_row_space_begin(struct zr_context*, enum zr_layout_format,
                                 zr_float height, zr_size widget_count);
 /*  this functions starts a space where widgets can be added
     at any given position and the user has to make sure no overlap occures
@@ -3311,8 +3307,7 @@ void zr_spacing(struct zr_context*, zr_size cols);
 */
 void zr_seperator(struct zr_context*);
 /*  this function creates a seperator line */
-void zr_text(struct zr_context*, const char*, zr_size,
-                    enum zr_text_align);
+void zr_text(struct zr_context*, const char*, zr_size, enum zr_text_align);
 /*  this function creates a bounded non terminated text widget with either
     left, centered or right alignment
     Input:
@@ -3320,8 +3315,8 @@ void zr_text(struct zr_context*, const char*, zr_size,
     - number of bytes the text is long
     - text alignment with either left, centered or right alignment
 */
-void zr_text_colored(struct zr_context*, const char*, zr_size,
-                            enum zr_text_align, struct zr_color);
+void zr_text_colored(struct zr_context*, const char*, zr_size, enum zr_text_align,
+                    struct zr_color);
 /*  this function creates a bounded non terminated color text widget with either
     left, centered or right alignment
     Input:
@@ -3337,8 +3332,7 @@ void zr_label(struct zr_context*, const char*, enum zr_text_align);
     - string pointer to text that should be drawn
     - text alignment with either left, centered or right alignment
 */
-void zr_label_colored(struct zr_context*, const char*,
-                            enum zr_text_align, struct zr_color);
+void zr_label_colored(struct zr_context*, const char*, enum zr_text_align, struct zr_color);
 /*  this function creates a zero terminated colored text widget with either
     left, centered or right alignment
     Input:
@@ -3367,8 +3361,7 @@ zr_bool zr_option(struct zr_context*, const char*, zr_bool active);
     Output:
     - from user input updated state of the radiobutton
 */
-zr_size zr_option_group(struct zr_context*, const char**,
-                                zr_size cnt, zr_size cur);
+zr_size zr_option_group(struct zr_context*, const char**, zr_size cnt, zr_size cur);
 /*  this function creates a radiobutton group widget with only one active radiobutton
     Input:
     - radiobutton label array describing the content of each radiobutton
@@ -3377,8 +3370,7 @@ zr_size zr_option_group(struct zr_context*, const char**,
     Output:
     - the from user input updated index of the active radiobutton
 */
-zr_bool zr_button_text(struct zr_context*, const char*,
-                                enum zr_button_behavior);
+zr_bool zr_button_text(struct zr_context*, const char*, enum zr_button_behavior);
 /*  this function creates a text button
     Input:
     - button label describing the button
@@ -3388,8 +3380,7 @@ zr_bool zr_button_text(struct zr_context*, const char*,
     - zr_true if the button was transistioned from unpressed to pressed with
         default button behavior or pressed if repeater behavior.
 */
-zr_bool zr_button_color(struct zr_context*, struct zr_color,
-                                enum zr_button_behavior);
+zr_bool zr_button_color(struct zr_context*, struct zr_color, enum zr_button_behavior);
 /*  this function creates a colored button without content
     Input:
     - color the button should be drawn with
@@ -3407,8 +3398,7 @@ zr_bool zr_button_symbol(struct zr_context*, enum zr_symbol, enum zr_button_beha
     - zr_true if the button was transistioned from unpressed to pressed with
         default button behavior or pressed if repeater behavior.
 */
-zr_bool zr_button_image(struct zr_context*, struct zr_image img,
-                                enum zr_button_behavior);
+zr_bool zr_button_image(struct zr_context*, struct zr_image img, enum zr_button_behavior);
 /*  this function creates a button with an icon as content
     Input:
     - icon image handle to draw into the button
@@ -3417,9 +3407,8 @@ zr_bool zr_button_image(struct zr_context*, struct zr_image img,
     - zr_true if the button was transistioned from unpressed to pressed with
         default button behavior or pressed if repeater behavior.
 */
-zr_bool zr_button_text_symbol(struct zr_context*, enum zr_symbol,
-                                const char*, enum zr_text_align,
-                                enum zr_button_behavior);
+zr_bool zr_button_text_symbol(struct zr_context*, enum zr_symbol, const char*,
+                                enum zr_text_align, enum zr_button_behavior);
 /*  this function creates a button with a triangle and text
     Input:
     - symbol to draw with the text
@@ -3431,8 +3420,8 @@ zr_bool zr_button_text_symbol(struct zr_context*, enum zr_symbol,
         default button behavior or pressed if repeater behavior.
 */
 zr_bool zr_button_text_image(struct zr_context *layout, struct zr_image img,
-                                    const char *text, enum zr_text_align align,
-                                    enum zr_button_behavior behavior);
+                            const char *text, enum zr_text_align align,
+                            enum zr_button_behavior behavior);
 /*  this function creates a button with an icon and text
     Input:
     - image or subimage to use as an icon
@@ -3459,8 +3448,8 @@ zr_bool zr_button_toggle_fitting(struct zr_context*, const char*,zr_bool value);
     Output:
     - from user input updated toggle state
 */
-zr_float zr_slider(struct zr_context*, zr_float min, zr_float val,
-                            zr_float max, zr_float step);
+zr_float zr_slider(struct zr_context*, zr_float min, zr_float val, zr_float max,
+                    zr_float step);
 /*  this function creates a slider for value manipulation
     Input:
     - minimal slider value that will not be underflown
@@ -3470,8 +3459,7 @@ zr_float zr_slider(struct zr_context*, zr_float min, zr_float val,
     Output:
     - the from user input updated slider value
 */
-zr_size zr_progress(struct zr_context*, zr_size cur, zr_size max,
-                            zr_bool modifyable);
+zr_size zr_progress(struct zr_context*, zr_size cur, zr_size max, zr_bool modifyable);
 /*  this function creates an either user or program controlled progressbar
     Input:
     - current progressbar value
@@ -3482,9 +3470,8 @@ zr_size zr_progress(struct zr_context*, zr_size cur, zr_size max,
 */
 void zr_editbox(struct zr_context*, struct zr_edit_box*);
 /*  this function creates an editbox with copy & paste functionality and text buffering */
-zr_size zr_edit(struct zr_context*, zr_char *buffer, zr_size len,
-                        zr_size max, zr_state *active, zr_size *cursor,
-                        enum zr_input_filter);
+zr_size zr_edit(struct zr_context*, zr_char *buffer, zr_size len, zr_size max,
+                zr_state *active, zr_size *cursor, enum zr_input_filter);
 /*  this function creates an editbox to updated/insert user text input
     Input:
     - buffer to fill with user input
@@ -3496,9 +3483,8 @@ zr_size zr_edit(struct zr_context*, zr_char *buffer, zr_size len,
     - length of the buffer after user input update
     - current state of the editbox with active(zr_true) or inactive(zr_false)
 */
-zr_size zr_edit_filtered(struct zr_context*, zr_char *buffer,
-                                zr_size len, zr_size max,  zr_state *active,
-                                zr_size *cursor, zr_filter);
+zr_size zr_edit_filtered(struct zr_context*, zr_char *buffer, zr_size len,
+                        zr_size max,  zr_state *active, zr_size *cursor, zr_filter);
 /*  this function creates an editbox to updated/insert filtered user text input
     Input:
     - buffer to fill with user input
@@ -3510,8 +3496,8 @@ zr_size zr_edit_filtered(struct zr_context*, zr_char *buffer,
     - length of the buffer after user input update
     - current state of the editbox with active(zr_true) or inactive(zr_false)
 */
-zr_int zr_spinner(struct zr_context*, zr_int min, zr_int value,
-                                zr_int max, zr_int step, zr_state *active);
+zr_int zr_spinner(struct zr_context*, zr_int min, zr_int value, zr_int max,
+                    zr_int step, zr_state *active);
 /*  this function creates a integer spinner widget
     Input:
     - min value that will not be underflown
@@ -3546,9 +3532,8 @@ zr_int zr_spinner(struct zr_context*, zr_int min, zr_int value,
     zr_combo_close          -- closes the previously opened combo box
     zr_combo_end            -- ends the combo box build up process
 */
-void zr_combo_begin(struct zr_context *parent,
-                        struct zr_context *combo, const char *selected,
-                        zr_state *active);
+void zr_combo_begin(struct zr_context *parent, struct zr_context *combo,
+                    const char *selected, zr_state *active);
 /*  this function begins the combobox build up process
     Input:
     - parent window layout the combo box will be placed into
@@ -3586,7 +3571,7 @@ zr_bool zr_combo_item_symbol(struct zr_context *menu, enum zr_symbol symbol,
 */
 void zr_combo_close(struct zr_context *combo);
 /*  this function closes a opened combobox */
-zr_state zr_combo_end(struct zr_context *parent, struct zr_context *combo);
+void zr_combo_end(struct zr_context *parent, struct zr_context *combo, zr_state*);
 /*  this function ends the combobox build up process */
 /* --------------------------------------------------------------
  *                          GRAPH
@@ -3763,7 +3748,7 @@ enum zr_tree_node_operation zr_tree_leaf_icon(struct zr_tree*,
     Output:
     - operation identifier what should be done with this node
 */
-struct zr_vec2 zr_tree_end(struct zr_context*, struct zr_tree*);
+void zr_tree_end(struct zr_context*, struct zr_tree*, struct zr_vec2 *scrollbar);
 /*  this function ends a the tree building process */
 /* --------------------------------------------------------------
  *                          POPUP
@@ -3816,8 +3801,8 @@ zr_flags zr_popup_begin(struct zr_context *parent, struct zr_context *popup,
 */
 void zr_popup_close(struct zr_context *popup);
 /*  this functions closes a previously opened popup */
-struct zr_vec2 zr_popup_end(struct zr_context *parent,
-                            struct zr_context *popup);
+void zr_popup_end(struct zr_context *parent, struct zr_context *popup,
+                struct zr_vec2 *scrollbar);
 /*  this function finishes the previously started popup layout
     Output:
     - The from user input updated popup scrollbar pixel offset
@@ -3887,7 +3872,7 @@ void zr_contextual_close(struct zr_context *popup);
      Output:
     - update state of the context menu
 */
-zr_state zr_contextual_end(struct zr_context *parent, struct zr_context *popup);
+void zr_contextual_end(struct zr_context *parent, struct zr_context *popup, zr_state*);
 /*  this functions closes a previously opened context menu */
 /*----------------------------------------------------------------
  *                          MENU
@@ -3936,7 +3921,7 @@ zr_bool zr_menu_item_icon(struct zr_context *menu, struct zr_image,
     - `zr_true` if has been clicked `zr_false` otherwise
 */
 zr_bool zr_menu_item_symbol(struct zr_context *menu, enum zr_symbol symbol,
-                                    const char*, enum zr_text_align align);
+                            const char*, enum zr_text_align align);
 /*  this function execute menu text symbol item
     Input:
     - symbol to draw into the menu item
@@ -4009,7 +3994,7 @@ void zr_group_begin(struct zr_context*, struct zr_context *tab,
     Output:
     - group layout to fill with widgets
 */
-struct zr_vec2 zr_group_end(struct zr_context*, struct zr_context*);
+void zr_group_end(struct zr_context*, struct zr_context*, struct zr_vec2 *scrollbar);
 /*  this function finishes the previously started group layout
     Output:
     - The from user input updated group scrollbar pixel offset
@@ -4044,7 +4029,7 @@ zr_size zr_shelf_begin(struct zr_context*, struct zr_context*,
     - group layout to fill with widgets
     - the from user input updated current shelf tab index
 */
-struct zr_vec2 zr_shelf_end(struct zr_context*, struct zr_context*);
+void zr_shelf_end(struct zr_context *p, struct zr_context *s, struct zr_vec2 *scrollbar);
 /*  this function finishes the previously started shelf layout
     Input:
     - previously started group layout