// Copyright (C) 2008  Davis E. King (davisking@users.sourceforge.net), and Nils Labugt
// License: Boost Software License   See LICENSE.txt for the full license.
#undef DLIB_WIDGETs_STYLE_ABSTRACT_
#ifdef DLIB_WIDGETs_STYLE_ABSTRACT_

#include "../algs.h"
#include "../gui_core.h"
#include "widgets_abstract.h"
#include "../unicode/unicode_abstract.h"

namespace dlib
{

// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
    // button styles  
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------

    class button_style
    {
        /*!
            WHAT THIS OBJECT REPRESENTS
                This is an abstract class that defines the interface a
                button style object must implement.

                Note that derived classes must be copyable via
                their copy constructors.
        !*/

    public:

        virtual ~button_style() {}

        virtual bool redraw_on_mouse_over (
        ) const { return false; }
        /*!
            ensures
                - if (this style draws buttons differently when a mouse is over them) then
                    - returns true
                - else
                    - returns false
        !*/

        virtual rectangle get_min_size (
            const ustring& name,
            const font& mfont 
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
            ensures
                - returns a rectangle that represents the minimum size of the button
                  given the name and font.
        !*/

        virtual void draw_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& mfont,
            const long lastx,
            const long lasty,
            const ustring& name,
            const bool is_depressed
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
                - c == the canvas to draw on
                - rect, enabled, mfont, lastx, and lasty are the variables
                  defined in the protected section of the drawable class.
                - name == the name of the button to be drawn
                - is_depressed == true if the button is to be drawn in a depressed state
            ensures
                - draws the button on the canvas c at the location given by rect.  
        !*/
    };

// ----------------------------------------------------------------------------------------

    class button_style_default : public button_style
    {
        /*!
            This is the default style for button objects.  It will cause
            a button to appear as the simple MS Windows 2000 button style.
        !*/
    };

// ----------------------------------------------------------------------------------------

    class button_style_toolbar1 : public button_style
    {
        /*!
            This draws a simple toolbar style button that displays its name in the
            middle of itself.  When the mouse moves over it it will light up.
        !*/
    };

// ----------------------------------------------------------------------------------------

    class button_style_toolbar_icon1 : public button_style
    {
        /*!
            This draws a simple toolbar style button that displays an image in the 
            middle of itself.  When the mouse moves over it it will light up.
        !*/
        template <typename image_type>
        button_style_toolbar_icon1 (
            const image_type& img, 
            unsigned long border_size = 6
        );
        /*!
            requires
                - image_type == an implementation of array2d/array2d_kernel_abstract.h
                - pixel_traits<typename image_type::type> is defined
            ensures
                - displays image img in the middle of the button
                - the distance between the edge of the button and the image
                  will be border_size pixels
        !*/
    };

// ----------------------------------------------------------------------------------------

    class button_style_left_arrow : public button_style
    {
        /*!
            This draws a simple button with a left pointing arrow in it 
        !*/
    };

// ----------------------------------------------------------------------------------------

    class button_style_right_arrow : public button_style
    {
        /*!
            This draws a simple button with a right pointing arrow in it 
        !*/
    };

// ----------------------------------------------------------------------------------------

    class button_style_up_arrow : public button_style
    {
        /*!
            This draws a simple button with an up pointing arrow in it 
        !*/
    };

// ----------------------------------------------------------------------------------------

    class button_style_down_arrow : public button_style
    {
        /*!
            This draws a simple button with a down pointing arrow in it 
        !*/
    };

// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
    // toggle button styles  
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------

    class toggle_button_style
    {
        /*!
            WHAT THIS OBJECT REPRESENTS
                This is an abstract class that defines the interface a
                toggle button style object must implement.

                Note that derived classes must be copyable via
                their copy constructors.
        !*/

    public:

        virtual ~toggle_button_style() {}

        virtual bool redraw_on_mouse_over (
        ) const { return false; }
        /*!
            ensures
                - if (this style draws buttons differently when a mouse is over them) then
                    - returns true
                - else
                    - returns false
        !*/

        virtual rectangle get_min_size (
            const ustring& name,
            const font& mfont 
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
            ensures
                - returns a rectangle that represents the minimum size of the button
                  given the name and font.
        !*/

        virtual void draw_toggle_button (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const font& mfont,
            const long lastx,
            const long lasty,
            const ustring& name,
            const bool is_depressed,
            const bool is_checked 
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
                - c == the canvas to draw on
                - rect, enabled, mfont, lastx, and lasty are the variables
                  defined in the protected section of the drawable class.
                - name == the name of the button to be drawn
                - is_depressed == true if the button is to be drawn in a depressed state
                - is_checked == true if the toggle_button is in the checked state 
            ensures
                - draws the button on the canvas c at the location given by rect.  
        !*/
    };

// ----------------------------------------------------------------------------------------

    class toggle_button_style_default : public toggle_button_style
    {
        /*!
            This is the default style for toggle_button objects.  It will cause
            a button to appear as the simple MS Windows 2000 button style.
        !*/
    };

// ----------------------------------------------------------------------------------------

    class toggle_button_style_check_box : public toggle_button_style
    {
        /*!
            This draws a simple check box style toggle button that displays its 
            name to the right of a check box. 
        !*/
    };

// ----------------------------------------------------------------------------------------

    class toggle_button_style_radio_button : public toggle_button_style
    {
        /*!
            This draws a simple radio button style toggle button that displays its 
            name to the right of a circular radio button. 
        !*/
    };

// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
    // scroll_bar styles  
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------

    class scroll_bar_style
    {
        /*!
            WHAT THIS OBJECT REPRESENTS
                This is an abstract class that defines the interface a
                scroll_bar style object must implement.

                Note that derived classes must be copyable via
                their copy constructors.

                There are three parts of a scroll bar, the slider, the background,
                and the two buttons on its ends.  The "slider" is the thing that you
                drag around on the scroll bar and the "background" is the part
                in between the slider and the buttons on the ends.
        !*/

    public:

        virtual ~scroll_bar_style() {}

        virtual bool redraw_on_mouse_over_slider (
        ) const { return false; }
        /*!
            ensures
                - if (this style draws a scroll_bar's slider differently when a mouse is over it
                  or it is being dragged) then
                    - returns true
                - else
                    - returns false
        !*/

        virtual long get_width (
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
            ensures
                - returns the width in pixels of the scroll bar
        !*/

        virtual long get_slider_length (
            long total_length,
            long max_pos
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
                - total_length == the total length in pixels of the scroll bar
                - max_pos == the value of scroll_bar::max_slider_pos() for this
                  scroll bar
            ensures
                - returns the length in pixels of the scroll bar's slider
        !*/

        virtual long get_button_length (
            long total_length,
            long max_pos
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
                - total_length == the total length in pixels of the scroll bar
                - max_pos == the value of scroll_bar::max_slider_pos() for this
                  scroll bar
            ensures
                - returns the length in pixels of each of the scroll bar's
                  buttons
        !*/

        virtual void draw_scroll_bar_background (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const long lastx,
            const long lasty,
            const bool is_depressed
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
                - c == the canvas to draw on
                - rect, enabled, lastx, and lasty are the variables
                  defined in the protected section of the drawable class.
                - is_depressed == true if the background area of the scroll_bar is to 
                  be drawn in a depressed state (because the user is clicking on it)
            ensures
                - draws the background part of the scroll_bar on the canvas c at the 
                  location given by rect.  
        !*/

        virtual void draw_scroll_bar_slider (
            const canvas& c,
            const rectangle& rect,
            const bool enabled,
            const long lastx,
            const long lasty,
            const bool is_being_dragged
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
                - c == the canvas to draw on
                - rect, enabled, lastx, and lasty are the variables
                  defined in the protected section of the drawable class
                - is_being_dragged == true if the user is dragging the slider
            ensures
                - draws the slider part of the scroll_bar on the canvas c at the 
                  location given by rect.  
        !*/

        button_style_type get_up_button_style (
        ) const;
        /*!
            ensures
                - returns the type of button_style to use for a button on the
                  top side of a vertical scroll bar.
        !*/

        button_style_type get_down_button_style (
        ) const;
        /*!
            ensures
                - returns the type of button_style to use for a button on the
                  bottom side of a vertical scroll bar.
        !*/

        button_style_type get_left_button_style (
        ) const;
        /*!
            ensures
                - returns the type of button_style to use for a button on the
                  left side of a horizontal scroll bar.
        !*/

        button_style_type get_right_button_style (
        ) const;
        /*!
            ensures
                - returns the type of button_style to use for a button on the
                  right side of a horizontal scroll bar.
        !*/
    };

// ----------------------------------------------------------------------------------------

    class scroll_bar_style_default : public scroll_bar_style
    {
        /*!
            This is the default style for scroll_bar objects.  It will cause
            a scroll_bar to appear as the simple MS Windows 2000 scroll_bar style.
        !*/
    };

// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
    // scrollable_region (and zoomable_region) styles  
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------

    class scrollable_region_style
    {
        /*!
            WHAT THIS OBJECT REPRESENTS
                This is an abstract class that defines the interface a
                scrollable_region and zoomable_region style object must implement.

                Note that derived classes must be copyable via
                their copy constructors.
        !*/
    public:

        virtual ~scrollable_region_style() {}

        virtual long get_border_size (
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
            ensures
                - returns the size of the border region in pixels 
        !*/

        virtual void draw_scrollable_region_border (
            const canvas& c,
            const rectangle& rect,
            const bool enabled
        ) const = 0;
        /*!
            requires
                - the mutex drawable::m is locked
                - c == the canvas to draw on
                - rect and enabled are the variables defined in the protected section 
                  of the drawable class.
            ensures
                - draws the border part of a scrollable_region on the canvas c at the 
                  location given by rect.  
        !*/

        scroll_bar_style_type get_horizontal_scroll_bar_style (
        ) const;
        /*!
            ensures
                - returns the style of scroll_bar to use for the 
                  horizontal scroll_bar in this widget.
        !*/

        scroll_bar_style_type get_vertical_scroll_bar_style (
        ) const;
        /*!
            ensures
                - returns the style of scroll_bar to use for the 
                  vertical scroll_bar in this widget.
        !*/
    };

// ----------------------------------------------------------------------------------------

    class scrollable_region_style_default : public scrollable_region_style
    {
    public:
        /*!
            This is the default style for scrollable_region and zoomable_region objects.  
        !*/
    };

// ----------------------------------------------------------------------------------------

}

#endif // DLIB_WIDGETs_STYLE_ABSTRACT_



