diff --git a/button.cpp b/button.cpp
index 17e6362..56c3874 100644
--- a/button.cpp
+++ b/button.cpp
@@ -5,6 +5,23 @@ Button::Button(SDL_Renderer* r)
 {
 }
 
+int Button::border_width() const
+{
+    return _border_width;
+}
+
+void Button::border_width(int w)
+{
+    _border_width = w;
+    _update_widget_area();
+}
+
+int Button::height() const
+{
+    return _caption.height() * _caption_height_multiplicator
+        + 2 * _border_width;
+}
+
 void Button::render()
 {
     Widget::render();
@@ -67,36 +84,41 @@ void Button::render()
     SDL_RenderSetViewport(_renderer, &old_vp);
 }
 
+const std::string& Button::text() const
+{
+    return _caption.text();
+}
+
 void Button::text(std::string txt)
 {
     _caption.text(txt);
+    _update_widget_area();
     _update_caption_area();
 }
 
 void Button::font(TTF_Font* f)
 {
     _caption.font(f);
+    _update_widget_area();
     _update_caption_area();
 }
 
 void Button::viewport(SDL_Rect vp)
 {
     Widget::viewport(vp);
-    _widget_area.y = center(
-            _viewport.h,
-            _caption.rendered_text_size().h * _caption_height_multiplicator
-            ) - _border_width;
     _update_caption_area();
 }
 
+int Button::width() const
+{
+    return _caption.width() * _caption_height_multiplicator
+        + 2 * _border_width;
+}
+
 void Button::_update_caption_area()
 {
     SDL_Rect txt_size = _caption.rendered_text_size();
 
-    _widget_area.w = txt_size.w + 2 * _border_width;
-    _widget_area.h = _caption.rendered_text_size().h * _caption_height_multiplicator
-        + 2 * _border_width;
-
     _caption_area = {
         center(_viewport.w, txt_size.w),
         center(_viewport.h, txt_size.h),
@@ -110,3 +132,19 @@ void Button::_update_caption_area()
             _caption_area.h
             });
 }
+
+void Button::_update_widget_area()
+{
+    int h = _caption.rendered_text_size().h * _caption_height_multiplicator
+        + 2 * _border_width;
+
+    _widget_area = {
+        0,
+        center(
+            _viewport.h,
+            _caption.rendered_text_size().h * _caption_height_multiplicator
+            ) - _border_width,
+        _viewport.w,
+        h
+    };
+}
diff --git a/button.hpp b/button.hpp
index 5357323..0350d70 100644
--- a/button.hpp
+++ b/button.hpp
@@ -10,22 +10,28 @@
 class Button : public Widget
 {
 protected:
-    static const int _border_width = 3;
+    int _border_width = 3;
     Caption _caption;
     SDL_Rect _caption_area;
-    static constexpr const float _caption_height_multiplicator = 1.2;
-    static constexpr const SDL_Color _color_background = {150, 150, 150, SDL_ALPHA_OPAQUE};
-    static constexpr const SDL_Color _color_background_hover = {175, 175, 175, SDL_ALPHA_OPAQUE};
-    static constexpr const SDL_Color _color_foreground = {0, 0, 0, SDL_ALPHA_OPAQUE};
+    float _caption_height_multiplicator = 1.2;
+    SDL_Color _color_background = {150, 150, 150, SDL_ALPHA_OPAQUE};
+    SDL_Color _color_background_hover = {175, 175, 175, SDL_ALPHA_OPAQUE};
+    SDL_Color _color_foreground = {0, 0, 0, SDL_ALPHA_OPAQUE};
 
     void _update_caption_area();
+    void _update_widget_area();
 
 public:
     Button(SDL_Renderer*);
-    void render();
-    void text(std::string);
+    int border_width() const;
+    void border_width(int);
     void font(TTF_Font*);
+    int height() const;
+    void render();
+    const std::string& text() const;
+    void text(std::string);
     void viewport(SDL_Rect);
+    int width() const;
 };
 
 #endif
diff --git a/examples/button_example.cpp b/examples/button_example.cpp
new file mode 100644
index 0000000..3086227
--- /dev/null
+++ b/examples/button_example.cpp
@@ -0,0 +1,85 @@
+#include <iostream>
+
+#include "button.hpp"
+#include "horizontal_layout.hpp"
+#include "vertical_layout.hpp"
+
+int main()
+{
+    int width = 640;
+    int height = 480;
+
+    TTF_Init();
+    TTF_Font* font = TTF_OpenFont("fonts/FiraMono-Bold.ttf", 20);
+
+    SDL_Init(SDL_INIT_VIDEO);
+    SDL_Window* win = SDL_CreateWindow(
+            "Widget test",
+            SDL_WINDOWPOS_UNDEFINED,
+            SDL_WINDOWPOS_UNDEFINED,
+            width,
+            height,
+            SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE
+            );
+    SDL_Renderer* rend = SDL_CreateRenderer(win, -1, SDL_RENDERER_ACCELERATED);
+    SDL_SetRenderDrawBlendMode(rend, SDL_BLENDMODE_BLEND);
+
+    SDL_Rect layout_vp = {0, 0, width, height};
+    auto layout = new Horizontal_Layout(rend);
+    for (int i = 0; i < 3; i++)
+    {
+        auto column = new Vertical_Layout(rend);
+        for (int j = 0; j < 3; j++)
+        {
+            auto widget = new Button(rend);
+            widget->text("hello");
+            widget->click_handler = [i, j](const SDL_MouseButtonEvent&) {
+                std::cerr << "click@" << j << ":" << i << std::endl;
+            };
+            widget->font(font);
+            column->add_widget(widget);
+            std::cerr << " " << i << "@" << widget;
+        }
+        layout->add_widget(column);
+    }
+    layout->viewport(layout_vp);
+    bool quit = false;
+    while (!quit)
+    {
+        SDL_Event ev;
+        while (SDL_PollEvent(&ev) != 0)
+        {
+            switch (ev.type)
+            {
+                case SDL_QUIT:
+                    quit = true;
+                    break;
+                case SDL_WINDOWEVENT:
+                    if (ev.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+                    {
+                        SDL_GetRendererOutputSize(rend, &width, &height);
+                        layout_vp.w = width;
+                        layout_vp.h = height;
+                        std::cerr << "== WINDOW RESIZED == " << width << "x" << height << std::endl;
+                        layout->viewport(layout_vp);
+                    }
+                    break;
+            }
+            layout->handle_event(ev);
+        }
+
+        SDL_SetRenderDrawColor(rend, 75, 75, 75, SDL_ALPHA_OPAQUE);
+        SDL_RenderClear(rend);
+
+        layout->render();
+        SDL_RenderPresent(rend);
+    }
+
+    delete layout;
+    SDL_DestroyRenderer(rend);
+    SDL_DestroyWindow(win);
+    SDL_Quit();
+    TTF_CloseFont(font);
+    TTF_Quit();
+    return 0;
+}
diff --git a/widget_test.cpp b/examples/input_example.cpp
similarity index 93%
rename from widget_test.cpp
rename to examples/input_example.cpp
index 29a6b50..2b1b0a7 100644
--- a/widget_test.cpp
+++ b/examples/input_example.cpp
@@ -1,6 +1,5 @@
 #include <iostream>
 
-#include "button.hpp"
 #include "horizontal_layout.hpp"
 #include "numeric_input.hpp"
 #include "vertical_layout.hpp"
@@ -33,7 +32,9 @@ int main()
         for (int j = 0; j < 3; j++)
         {
             auto widget = new Numeric_Input<float>(rend);
+            widget->button_step = 0.5;
             widget->font(font);
+            widget->value_range(-2.5, 2.5);
             column->add_widget(widget);
             std::cerr << " " << i << "@" << widget;
         }
@@ -61,9 +62,6 @@ int main()
                         layout->viewport(layout_vp);
                     }
                     break;
-                case SDL_MOUSEBUTTONUP:
-                    //_handle_click({ev.button.x, ev.button.y});
-                    break;
             }
             layout->handle_event(ev);
         }
diff --git a/horizontal_layout.cpp b/horizontal_layout.cpp
index 1555184..f351b13 100644
--- a/horizontal_layout.cpp
+++ b/horizontal_layout.cpp
@@ -19,8 +19,8 @@ void Horizontal_Layout::_update_layout()
             (int)(widget_size - _interspace),
             _viewport.h
         };
-        _widgets.at(i)->viewport(widget_vp);
-        std::cerr << "h-layout:widget:" << i << " " << widget_vp.x << ","
+        std::cerr << "h-layout@" << this << ":widget:" << i << " " << widget_vp.x << ","
             << widget_vp.y << "," << widget_vp.w << "," << widget_vp.h << std::endl;
+        _widgets.at(i)->viewport(widget_vp);
     }
 }
diff --git a/input.hpp b/input.hpp
index a73b6c0..2e7590c 100644
--- a/input.hpp
+++ b/input.hpp
@@ -1,6 +1,8 @@
 #ifndef INPUT_HPP
 #define INPUT_HPP
 
+#include <exception>
+#include <iomanip>
 #include <sstream>
 #include <string>
 #include <type_traits>
@@ -48,7 +50,7 @@ protected:
             {
                 case SDLK_BACKSPACE:
                 {
-                    std::string txt = _input_text.text();
+                    std::string txt = input_text();
                     if (txt.length() > 0)
                     {
                         txt.pop_back();
@@ -111,6 +113,7 @@ protected:
 public:
     SDL_Color border_color {160, 160, 160, SDL_ALPHA_OPAQUE};
     SDL_Color background_color {200, 200, 200, SDL_ALPHA_OPAQUE};
+    int float_precision {2};
     SDL_Color focused_background_color {255, 255, 255, SDL_ALPHA_OPAQUE};
 
     virtual const std::string& input_text() const
@@ -135,6 +138,11 @@ public:
         _update_drawing_areas();
     }
 
+    virtual T process_value(T x) const
+    {
+        return x;
+    }
+
     virtual void render()
     {
         Widget::render();
@@ -191,27 +199,34 @@ public:
         _render_value();
     }
 
-    static T value_from_string(std::string s)
+    T value_from_string(std::string s)
     {
-        T value;
+        T v;
 
         if constexpr(std::is_arithmetic_v<T>)
         {
             s = s.length() > 0 ? s : "0";
-            if constexpr(std::is_floating_point_v<T>)
-                value = (T)std::stold(s);
-            else if constexpr(std::is_integral_v<T>)
-                value = (T)std::stoll(s);
+            try
+            {
+                if constexpr(std::is_floating_point_v<T>)
+                    v = (T)std::stold(s);
+                else if constexpr(std::is_integral_v<T>)
+                    v = (T)std::stoll(s);
+            }
+            catch(std::exception&)
+            {
+                v = value();
+            }
         }
         else if constexpr(std::is_same_v<T, std::string> || std::convertible_to<std::string, T>)
-            value = s;
+            v = s;
         else
-            static_assert(sizeof(T) && false, "string cannot be converted to value type T.");
+            static_assert(sizeof(T) && false, "string cannot be converted to v type T.");
 
-        return value;
+        return process_value(v);
     }
 
-    static std::string value_to_string(T value)
+    std::string value_to_string(T value)
     {
         std::string s;
 
@@ -219,17 +234,17 @@ public:
             s = value;
         else if constexpr(CanToString<T>)
         {
-            s = std::to_string(value);
-            for (char& last = s.back();
-                      (last == '0' || last == '.') && s.length() > 1;
-                       last = s.back())
-                s.pop_back();
+            std::stringstream ss;
+            ss << std::fixed
+                << std::setprecision(float_precision)
+                << value;
+            s = std::move(ss).str();
         }
         else if constexpr(Printable<T>)
         {
             std::stringstream ss;
             ss << value;
-            return std::move(ss).str();
+            s = std::move(ss).str();
         }
         else
             static_assert(sizeof(T) && false, "_value cannot be converted to string.");
diff --git a/meson.build b/meson.build
index e6cd51b..6e072d5 100644
--- a/meson.build
+++ b/meson.build
@@ -2,16 +2,25 @@ project('sdl2_basic_widgets', 'cpp',
   version : '0.1',
   default_options : ['warning_level=3', 'cpp_std=c++20'])
 
-executable('sdl2_basic_widgets',
-	   'horizontal_layout.cpp',
-	   'layout.cpp',
+lib = static_library('sdl2_basic_widgets',
+           'horizontal_layout.cpp',
+           'layout.cpp',
            'button.cpp',
            'caption.cpp',
            'vertical_layout.cpp',
            'widget.cpp',
-           'widget_test.cpp',
            dependencies : [
               dependency('sdl2'),
               dependency('SDL2_ttf')
               ],
            install : true)
+
+executable('button_demo',
+    'examples/button_example.cpp',
+    link_with : lib,
+    install : false)
+
+executable('input_demo',
+    'examples/input_example.cpp',
+    link_with : lib,
+    install : false)
diff --git a/numeric_input.hpp b/numeric_input.hpp
index d60ed48..5758ead 100644
--- a/numeric_input.hpp
+++ b/numeric_input.hpp
@@ -1,6 +1,8 @@
 #ifndef NUMERIC_INPUT_HPP
 #define NUMERIC_INPUT_HPP
 
+#include <limits>
+#include <regex>
 #include <type_traits>
 
 #include "button.hpp"
@@ -18,6 +20,10 @@ private:
     SDL_Rect _increment_button_area;
     Button _decrement_button;
     SDL_Rect _decrement_button_area;
+    std::pair<T, T> _value_range {
+        std::numeric_limits<T>::lowest(),
+        std::numeric_limits<T>::max()
+    };
 
     void handle_event(const SDL_Event& ev)
     {
@@ -28,37 +34,44 @@ private:
 
     void _update_drawing_areas()
     {
-        int widest_button = _increment_button.width() > _decrement_button.width() ?
-            _increment_button.width() : _decrement_button.width();
-        int heighest_button = _increment_button.height() > _decrement_button.height() ?
-            _increment_button.height() : _decrement_button.height();
-        int field_width = Widget::_viewport.w - 2 * 1.25 * widest_button;
-        int field_height = heighest_button;
+        const int widest_button =
+            _increment_button.width() > _decrement_button.width()
+            ? _increment_button.width()
+            : _decrement_button.width();
+        const int heighest_button =
+            _increment_button.height() > _decrement_button.height()
+            ? _increment_button.height()
+            : _decrement_button.height();
+        const int button_area_width = 2 * widest_button;
+        const int spacing = Widget::center(button_area_width, widest_button);
+        const int field_width = Widget::_viewport.w - 2 * button_area_width;
+        const int field_height = heighest_button;
         Input<T>::_input_field_area = {
-            (int)(1.25 * widest_button),
+            (int)button_area_width,
             Widget::center(Widget::_viewport.h, field_height),
             field_width,
             field_height
         };
 
         _increment_button_area = {
-            Widget::center(1.25 * widest_button, _increment_button.width()),
+            spacing,
             Widget::center(Widget::_viewport.h, _increment_button.height()),
             _increment_button.width(),
             _increment_button.height()
         };
 
         _decrement_button_area = {
-            Widget::_viewport.w - (Widget::center(1.25 * widest_button, _decrement_button.width()) + _decrement_button.width()),
+            Widget::_viewport.w - spacing - _decrement_button.width(),
             Widget::center(Widget::_viewport.h, _decrement_button.height()),
             _decrement_button.width(),
             _decrement_button.height()
         };
 
         Widget::_widget_area = {
-            Widget::_viewport.x + Widget::center(1.25 * widest_button, widest_button),
-            Widget::_viewport.y + Widget::center(Widget::_viewport.h, heighest_button),
-            (int)(1.25 * widest_button / 2) + Widget::_viewport.w - widest_button - Widget::_viewport.x,
+            button_area_width,
+            Widget::center(Widget::_viewport.h, heighest_button),
+            Widget::_viewport.w
+                - 2 * button_area_width,
             heighest_button
         };
 
@@ -75,13 +88,21 @@ public:
     {
         _increment_button.text("+");
         _increment_button.click_handler = [this](const SDL_MouseButtonEvent&) {
-            this->value(this->value() + button_step);
-            this->input_text(this->value_to_string(this->value()));
+            T new_value = this->value() + button_step;
+            if (_value_range.second - this->value() < button_step)
+                new_value = _value_range.second;
+
+            this->value(new_value);
+            this->input_text(this->value_to_string(new_value));
         };
         _decrement_button.text("-");
         _decrement_button.click_handler = [this](const SDL_MouseButtonEvent&) {
-            this->value(this->value() - button_step);
-            this->input_text(this->value_to_string(this->value()));
+            T new_value = this->value() - button_step;
+            if (this->value() - _value_range.first < button_step)
+                new_value = _value_range.first;
+
+            this->value(new_value);
+            this->input_text(this->value_to_string(new_value));
         };
     }
 
@@ -99,11 +120,33 @@ public:
         if (input.at(0) >= '0' && input.at(0) <= '9')
             valid = true;
         if constexpr(std::is_floating_point_v<T>)
-            if (input.at(0) == '.')
+            if (input.at(0) == '.'
+                    && Input<T>::input_text().find('.') == std::string::npos)
                 valid = true;
+        if constexpr(std::is_signed_v<T>)
+        {
+            std::string displayed_value = Input<T>::input_text();
+            if (input.at(0) == '-'
+                    && !std::regex_search(
+                        displayed_value,
+                        std::regex("[^\\s]")
+                        ))
+                valid = true;
+        }
         return valid;
     }
 
+    T process_value(T x) const
+    {
+        T value = x;
+        if (x < _value_range.first)
+            value = _value_range.first;
+        else if (x > _value_range.second)
+            value = _value_range.second;
+
+        return value;
+    }
+
     void render()
     {
         Input<T>::render();
@@ -111,6 +154,19 @@ public:
         _decrement_button.render();
     }
 
+    std::pair<T, T> value_range() const
+    {
+        return _value_range;
+    }
+
+    void value_range(T min, T max)
+    {
+
+        if (min > max)
+            throw std::invalid_argument("min cannot be greater than max");
+        _value_range = {min, max};
+    }
+
     void viewport(SDL_Rect vp)
     {
         Input<T>::viewport(vp);
diff --git a/vertical_layout.cpp b/vertical_layout.cpp
index 7d32c11..1fdb485 100644
--- a/vertical_layout.cpp
+++ b/vertical_layout.cpp
@@ -19,8 +19,8 @@ void Vertical_Layout::_update_layout()
                 _viewport.w,
                 (int)(widget_size - _interspace),
         };
-        _widgets.at(i)->viewport(widget_vp);
-        std::cerr << "v-layout:widget:" << i << " " << widget_vp.x << ","
+        std::cerr << "v-layout@" << this << ":widget:" << i << " " << widget_vp.x << ","
             << widget_vp.y << "," << widget_vp.w << "," << widget_vp.h << std::endl;
+        _widgets.at(i)->viewport(widget_vp);
     }
 }